WW1 Austro-Hungarian Armor WW1 US Prototypes

Roy / Lzarnopyski Infantry Fort

USA/Austro-Hungarian Empire (1919)
Infantry Fort – None Built

World War One was, by 1918, the largest and most costly war in terms of lives in the history of mankind. Starting in 1914, the war finally ended officially in June 1919, with the signing of the Treaty of Versailles, although, with the signing of the Armistice in November 1918, all active combat between the Allies and Central Powers ended. The United States had been late to the war, only joining on the side of the Allies in April 1917. For the period of the war which remained, the US built its own derived version of the Renault FT, changed to suit imperial units, and later, the heavy tank Mk. VIII, which was the product of a joint British / American development.

In the meantime, various inventions and designs were being submitted to the US Government and Army or just espoused in the media. These presented military vehicles of varying degrees of practicality and reality. Probably the last such vehicle to be submitted during the active phase of WW1 was filed with the US Patent office just 2 days prior to the Armistice of 11th November – this was the Infantry Fort of George Roy.

The Men

George Roy described himself as a subject of the Austrian Emperor and submitted the patent in his own name, as the inventor, along with a second man, Piotr Lzarnopyski. Roy assigned half the value of the design to Lzarnopyski, presumably because Lzarnopyski helped pay the required filing fees, as his name appears nowhere else on the patent application or drawing. Both men were identified as residing in Chicago, Illinois, and no nationality was given for Lzarnopyski, although the name is likely Polish in origin. Sadly, neither man appears to have applied for other patents before or subsequent to this one, so very little additional information can be gained on who they were or how they came to the design submitted in their names.

The Design

The intent behind the design was to provide a mobile tracked platform from which soldiers could deliver firepower upon the enemy, as well as be elevated and protected by armor when being transported.

The overall shape is one of a large flattened triangle, with the reverse angle of the triangle formed into a series of steps up which soldiers were to climb from a small projecting platform at the rear. Three steps would bring a soldier to the top fighting platform of the vehicle, from where he could fire from behind cover.


The triangular body of the vehicle was dominated by the large angled front glacis, which curved very slightly across its width, providing a well-shaped surface to deflect enemy bullets. In the recess of the curve of the glacis was a small curved firing step or platform on the front. At the top of the vehicle, where the glacis met the roof, the roof itself was just the flattened peak of the triangle, forming the top of a wall from behind which men could shoot.

The plan view of Roy’s design is dominated by the features on the left of the small platform and large curved front glacis. Note the use of two small anchors on the right right of the image.
Source: US Patent US1299620 amended by the author.

Behind this was a series of short steps down to a platform at the tail. Within the triangle, formed by the glacis and these steps, was the body of the vehicle, with a single rectangular door on each side. The tracks were arranged in a triangular pattern, with the top flattened. This matched the shape of the body of the vehicle. The track itself appears from the patent to have used pronounced square section timber spuds attached to the links and was pulled around via a sprocket, which was the rearmost of the two wheels at the top flattened part of the track. This drive sprocket was rotated by a simple chain drive from the engine, which was mounted onto a floor frame inside the body of the vehicle. Eight toothed road wheels were arranged evenly spaced on the bottom, against the ground portion of the track, spreading the load of the vehicle on the ground. No return rollers, jockey wheels, guide beams, or similar supports are shown to support the track either on the way up from the front or on the way back down at the back.

The track itself is full width, i.e. there is only this single track rather than one on each side. Power to drive the track does not get delivered via a sprocket on the left or right but via one arranged towards the center of the width of the track.

The flattened triangular arrangement of tracks taken from US Patent US1299620, with the vehicle parts edited out to highlight the track and engine. Source: US Patent US1299620 amended by the author.


The front of the vehicle was formed from one enormous and continuous glacis, from just above ground level all the way to the top of the tank, forming a door-stop shape. This angled plate would serve to deflect incoming enemy bullets and, whilst there is no armor thickness mentioned – the protection was only ever mentioned to serve against bullets. Thus, a thickness of not more than 8 mm might have been needed to provide the sort of bullet deflection Roy was intending. The steps were meant to be made from bullet-resistant armor plates, as this would allow men or stores to be carried inside the vehicle in safety.

Seen from the front the enemy can only see the enormous glacis plate and the bottom of the full-width track.
Source: US Patent US1299620 amended by the author.

The entire body surrounded the tracks at the front, covering them from enemy fire and likewise at the rear. The sides of the vehicle were protected as well, as this armored covering extended down to the same level as the glacis at the front.

Side view of the vehicle, with the sides shown completely enclosing the sides. The only feature that is drawn is the side door.
Source: US Patent US1299620 amended by the author.


Roy envisaged the vehicle in use as effectively a mobile armored wall, rather than a fort, despite the name he applied to it. With no sides or rear protection for the men using this as a firing platform, all of the firepower and armor was directed only to its front. Seen from any other direction, it would only serve to provide a series of easy and well elevated human targets for an opposing force to pick off.

Seen from the rear, all there is to Roy’s design is the steps and a full-width hinged door below the top step. A small space inside could store additional ammunition.
Source: US Patent US1299620 amended by the author.

The vehicle was clearly intended to either operate in the attack as a platform, or forming some defensive line with other vehicles, as it could be anchored to the ground by means of a simple anchor operated from the small platform at the rear.

The very simple ground anchor for the vehicle. Two of these were drawn with one on each side of the rear platform.
Source: US Patent US1299620 amended by the author.
The British Pedrail tracked shield of 1915. A poor idea that never saw service and yet was still better than Roy’s design in almost every regard, as it was a smaller, cheaper, and simpler machine providing more cover for soldiers behind it. Source: UK National Archives.


No form of propulsion was mentioned, other than the single comment describing the vehicle, where Roy stated it was to have a “motor driven track”. Driven from a single, high-mounted sprocket roughly central in the width of the single track, it is unclear how or even if the machine could be steered.

The engine is located slightly off-center, to the right side of the vehicle.
Source: US Patent 1,299,620 amended by the author.


Roy provided no information at all about any potential crew for the vehicle and, as it was not armed, presumably just a single person would be required to drive it. There is no indication as to where a driver might go, as there are no vision slits or windows provided from which someone inside could see out.


On the topic of practicality, there really was none. The design provided zero protection for the men using it as a firestep from either the sides, rear, or above. Any crew would certainly have struggled to control such a vehicle with no clear idea as to how to steer the machine. It seems Roy intended it to be able to go only forwards.

For a period earlier in the war, this kind of naive tracked shield, for want of a better term, might have been forgivable, but the design was submitted in 1918 – more than 2 years after the first tanks had seen combat and long after images were to be found easily in newspapers around the world. There is simply nothing at all offered by this design that was not or could not be delivered better by a tank or something even simpler. Even the tracked Pedrail Shield of 1915 surpassed this idea, as it was simpler and provided better protection. Unsurprisingly, offering nothing at all to anyone, this design never progressed past the patent office.

Roy / Lzarnopyski Infantry Fort. Illustration by Pavel Alexe.

Roy/Lzarnopyski Infantry Fort specifications

Crew 1? (driver)
Propulsion engine of unknown type
Armament none
Armor bulletproof
For information about abbreviations check the Lexical Index


US Patent 1,299,620 Infantry Fort, filed 9th November 1918, granted 8th April 1919.

WW1 US Prototypes

Ford 3-man Light Tank

USA (1918)
Light Tank – 1 Built

The USA was a mess in WW1. War had broken out in Europe between the major world powers, killing hundreds of thousands and spreading to a front from the North Sea to Switzerland, also covering Northern Italy, the Balkans, Africa, and beyond. Yet, in the 3 years of war before the United States joined in, it had done little to prepare and certainly had not taken heed from the unleashing of tanks by the British in 1916 that a new epoch of warfare had begun. Thus, when it did finally enter the war in April 1917 on the side of the Entente, it did so with no tanks at all. In fact, no US-built tanks would ever see service in WW1, and the only tanks they used would be ones provided by the British and French. US development work was slow and even something as seemingly simple as just license building the Renault FT proved expensive and difficult to accomplish.

The Ford Motor Company had become involved too. Producer of the Model T, the world’s most common motor vehicle of the era, their production lines were well suited to mass production of vehicles for war and they tried their hand at their own tiny tank in the form of the 3-ton ‘Special Tractor’, which became known as the M.1918. This tank became available prior to the American-built version of the French FT, known as the M.1917. Whilst this US-built FT was still languishing unfinished in development purgatory, the Ford Company revealed one more attempt at a tank, this time a slightly bigger version of the FT for 3 men as a light tank, the unimaginatively named Ford 3-man Light Tank.

Design Philosophy

The vehicle itself was more than a little odd. It is not entirely clear why Ford chose to try and redesign the FT to enlarge it just a little, nor who was even asking for it. It is known that the US Army was disappointed with the tiny and mostly useless Ford 3-ton tank. Armed with just a single machine gun, that 3-ton vehicle had armor vulnerable to even small arms fire and lacked a turret. It was objectively worse than the French Renault FT by almost every measure and the most notable was the lack of firepower.

Side view of the Ford 3-ton tank, providing a clear view of the sprung double roller suspension unit and tail skids used to help cross a trench.
Source: US National Archives Reference 165WW-313-A-13

Even if the 3-ton had been fitted with a 37 mm gun in place of the machine gun, it lacked a turret to make the best use of that firepower, whereas the Renault FT could at least deliver fire all around. That French vehicle came in two types, a machine gun version and a light cannon version with a 37 mm gun. The M.1917 was to follow the same layout, so it makes a little logic that the Army might want both a cannon and a machine gun in one package. Trying to achieve this modest goal came at a price and the resultant design was a bigger, rather crude-looking FT-style vehicle trying to embody the good FT bits with the new requirement.

The French Renault FT light tank. Armed with either a single machine gun or 37 mm cannon, the tank was characterized by the large front wheel raised off the ground, a horizontal beam with the road wheels, and a low rear idler with the track’s return run carried in a curve across the top. At the rear is a large skid to assist in crossing a gap.
American M.1917 tank – the American version of the French FT. This example is at the Canadian War Museum. Source: JustSomePics via Wiki


The general arrangement of the Ford 3-man Light Tank was to follow roughly the same lines as the Renault FT. The driver sat at the front, with a turret located above and behind him and, behind that, the engine. On each side was a track unit consisting of a large raised front idler, a series of road wheels under a protective cover, and a smaller rear drive sprocket. The center of the body was square, with vertical sides and a flat top on which was mounted a multi-sided frusto-conical turret consisting of 7 or 8 sections riveted or bolted together and surmounted by a large domed roof. At the rear of the tank, the engine bay had vertical sides and angled top plates over the engine, just like the M.1917, with a spine running lengthwise down the top of this section. At the rear was a large curved skid acting as a tail to help the tank cross ditches.

Front ¾ view of the Ford 3-man tank from a contemporary publication where the original background was edited out.
Source: Pinterest


As the name suggested, the tank was to have a crew of three. The Renault FT, M.1917, and Ford 3-ton all had two crewmen, with one of the crew having to do two tasks, as either commander/gunner or driver/commander. Clearly, it would be preferable and more efficient to divide tasks so the driver could concentrate on driving and the commander on command, which makes the design of the 3-man Light Tank all the more inexplicable. Here, the crew arrangement had a driver, located in the front left of the hull, in a small rectangular section jutting out of the body. Next to him was a small section which can be seen in photographs, with a circular port on the front. That was for mounting a machine gun in a ball mount and also featured a small vision slit in the side for the gunner.

The turret, however, with a large circular opening for the gun mounting, would be occupied by the commander, who would have to not only command but also control the primary armament as well. It has been suggested in some books that the primary armament was to be a cannon and a machine gun but, with only the commander in the turret, he would not be able to operate two guns at the same time. The alternative to all this was that the gunner was not in the hull but was, in fact, in the turret all along, to control the gun from there. This would leave the hull gun to the control of the driver. Whichever way it worked, one crew member was still going to have to do more than one job, unless the gunner was just to hop back and forth between hull and turret armament, in which case, of course, the hull gun was pointless and the gunner could just use the turret machine gun.

The most likely arrangement for the crew in the vehicle was simply that, gunner and driver in the hull and the commander performing the same functions as he would in the cannon-armed FT. This was certainly a major redesign and reworking of the FT idea just to cram in a third man and a limited traverse machine gun. Adding weight to this idea of crew positioning is that both the rectangular driver’s piece and the projecting section next to it for the ball-mounted machine gun could be raised to allow greater ventilation and vision when on a road march. Presumably, the large rounded top of the turret could also open or was provided with a hatch but, without photographs of this area, this cannot be established. Surviving photographs of the wooden mock-up also show a large rectangular forward-opening hatch on the glacis plate, presumably intended to serve as the access for the hull crew.


The goal all along was to increase the firepower over that of the Renault FT/M.1917. Due to their small size, those tanks could only carry either a machine gun or a short-barrelled 37 mm cannon.

The machine gun selected would possibly have been the 0.30 caliber Marlin M.1917 machine gun, although this had already been discontinued even on the tiny Ford 3-ton in favor of the 0.30 caliber Browning, or the Browning. Nonetheless, the Marlin was fitted to some M.1917 light tanks, so it is possible that this gun was to be the front ball mount.

0.30 caliber Marlin machine gun fitted into a mount identical to that used on the Ford 3-ton, prepared here for fitting to the US version of the French Renault FT, the M.1917. Note the aluminum cooling fins on the barrel and bag to catch the spare brass.
Source: Hunnicutt

The Renault FT and M.1917 also had the option of fitting the short-barrelled 37 mm. This single-shot Puteaux SA 18 cannon on the FT could be loaded and fired quickly and easily despite the small fighting space thanks to the small and light ammunition. These 37 mm x 94 rimmed rounds were a 500 gram Armor Piercing High Explosive round (Mle. 1892) traveling at 388 m/s, and a plain 560 gram High Explosive (Mle. 1916) round traveling at 365 m/s. This provided the tank with the ability to support the infantry by taking out enemy machine guns, as well as limited anti-armor capability, which would be useful for breaching small earthworks or gunshields, etcetera.

Interior view of a 37 mm gun, as postulated for the Ford 3-man. shown here in the housing used in the US version of the French Renault FT, the M.1917. Note how compact this gun is.
Source: Hunnicutt

If this gun was the one being planned for the Ford 3-man or if it was a larger gun, like a 6-pounder, is unclear. Certainly, the larger turret would have allowed for a larger gun breech inside, and the later M.1921 Medium Tank A used a very similar style turret face opening for a gun, which may be an indication for what the final gun mount would have looked like. The M.19211 Medium A used the model 1920 6 pounder tank gun, which was accepted for service in January 1920. Thus, in mid to late 1919, when this Ford 3-man Light Tank was being prepared, this gun would not have been ready for use.

Gimbal mount for the 6 pounder (57 mm) gun on the M.1921 Medium Tank A. Noteworthy is that, even in 1921, there still was no cannon and machine-gun mounting in use, supporting the premise that the Ford 3-man would only have a cannon in the turret.
Source: Pinterest
Inside view of the Model 1920 6 pounder (57 mm) tank gun, as used on the M.1921 Medium Tank A. Source: US National Archives

Armor and Dimensions

The Renault FT was a 6.5 tonnes, 5 m long, 1.74 m wide, 2.14 m tall light tank. With 16 mm thick armor on the well-angled front and vertical sides, along with 22 mm thick armor on the turret, the tank was well protected against anti-tank rifle fire at point-blank on all but the sides straight on. Despite this, the FT is not considered a particularly well-armored tank, even though this is the same sort of thickness as utilized on the British heavy tanks of the period. The thickness of the armor was really dictated by the need to protect against German anti-tank rifle fire, concentrated machine-gun fire, or the ‘reversed’ German rifle bullet.

Front view of the wooden mock-up of the Ford 3-man light tank, showing the distinctly Renault FT-shaped turret and the twin front position for the crew.
Side view of the wooden mock-up of the Ford 3-man light tank, showing the distinctly Renault FT-shaped turret (substantially shorter than that of the vehicle when actually built) and the twin front position for the crew.

Considering that the Ford 3-man Light Tank was meant to be an improvement over the Renault FT, it is surprising therefore that the armor was between 0.37” (9.4 mm) to 0.6” (15.24 mm) thick at its thickest, regardless of whether it was on the well-angled front or vertical sides. What this means is that the Ford 3-man, in a tank the same length and a little wider, taller and heavier, had armor thinner than even the thinnest part of the front or sides of the Renault FT. If the armor on the FT had been made that way to protect against German anti-tank rifle fire, then clearly the armor of the Ford 3-man was inadequate.


The general suspension principle for the Ford 3-man was similar to the French Renault FT with the large raised front idler and rear sprocket. This was not the only feature copied from an earlier design. The common axle used by the front idlers, exposed outside the front of the tank, was a legacy of the Ford 3-ton.

Of the few photographs of the vehicle, one taken in the Ford plant of the unfinished vehicle shows the track run sagging down at the top, seemingly supported by simply what appears to be a raised section on the mud cover rather than rollers. The later side view of the tank taken outside shows the track raised and taut, held up by a pair of small return rollers instead.

The wooden mock-up also differs somewhat from the vehicle that was actually completed in that the pair of return rollers were not fixed rigidly to the hull, but were actually intended to be on an inverted spring leaf suspension unit in the same style as used on the Ford 3-ton tank.

One of the rare photos of the Ford 3-man, shown here in an Official Ordnance Corps image probably taken at the Ford factory. This also shows the Ford 3-ton in the background.
Source: Pinterest

Also visible in the outdoor photo is the cover over the road wheels, which is similar to that used on the Ford 3-ton, in that the wheels underneath are not rigidly fastened to this cover but instead appear to be in four pairs of wheels, with two pairs likely connected to either end of a leaf spring suspension unit under the cover. The Ford 3-ton had already switched to just this type of sprung bogie system under a side mud cover, so it is likely that this system was retained for this tank as well. An odd feature on the top of this mud cover is an ‘M’-shaped ridge of steel, the purpose of which is not known, but could be speculated as an attempt to either prevent the accumulation of mud or to help prevent wire or other debris from being drawn along the top of the mud cover into the sprocket.

Side view of the Ford 3-man Light Tank, showing the Renault FT heritage and the new, bigger rear end for the exhaust. Note how much taller the finished turret is than the original wooden mock-up with the Renault FT turret.
Source: Crismon

The tracks were at least something new to the design, or at least partially new. The tracks from the Renault FT and M.1917 were, like those of the Ford 3-ton, relatively simple flat plates with a raised spud on one edge to gain traction on soft ground. The Ford 3-man’s tracks were a little different, featuring what appears to be a spud pressed into the track plate, which also featured a small hole into which the tooth of the track sprocket would fit. The track links still used the same system of a plate riveted to a shoe underneath, into which the teeth of the sprocket could mesh. The addition of this hole would allow the teeth to be larger and improve the purchase of the track during motion. Seemingly unconnected and a case of convergent evolution on the subject of tank tracks, the Italian version of the Renault FT, which was also in progress at this time, known as the Fiat 3000, had a very similar style.

Fiat 3000 – the Italian improved Renault FT, showing the similarity in the track links on this tank to the Ford 3-man, despite seemingly no connection between the designs or designers.
Source: Pinterest


The Ford 3-ton had used a pair of Ford Model T petrol engines, with one engine powering each track, creating a task for the driver, who had to constantly adjust and balance the engines to keep the vehicle straight. This new vehicle would adopt the more powerful Hudson 6 cylinder petrol engine delivering 60 hp.

This engine was connected to a pair of modified Ford transmissions and then, by gearing, to a drive shaft to the drive sprockets.

Whereas the Ford 3-ton required one engine for each side with its own gearbox and could operate them singly to provide a turning moment, this vehicle was an improvement. The gearing system could operate either just a single transmission or both together to produce a 3 speed system with 2 forward gears and a single reverse gear.

A new ventilation and engine cooling system was also installed and the spine on the rear of the engine deck clearly still shows the influence of the Renault FT for the air intake. Cooling for the engine was provided by means of a water-filled radiator and fan, with the air for cooling and combustion drawn in through that spine and the exhaust all vented out of a large grille behind it.

Rear ¾ view of the Ford 3-man light tank, showing the extended engine bay and the distinctive double skid tail, as used on the Ford 3-ton.
Another view of the Ford 3-man light tank, showing a small vision slit next to the front right crew position. The lineage from the Renault FT is undeniable.

Production Outcome

The vehicle was still unfinished when the fighting part of WW1 ended and, yet, even while it was in development, the US Army Ordnance Department were seemingly so impressed with this rather crude vehicle that they still ordered 1,000 of them. With an order for 15,000 Ford 3-ton tanks and 1,000 of these, the war was potentially very lucrative for the Ford Company. With the end of the war and just 15 Ford 3-tons and this partially finished 3-man, however, any such ideas of a financial tank-building windfall was over for Ford. The vehicle was, at some point, tested to some degree by the Ordnance Department in 1919 and was found wanting. Just like the Ford 3-ton, this tank was too rear heavy and the design was not adopted. It is believed that the tank was later scrapped.


The Ford 3-man light tank is an oddity. A ton of effort and redesign work for little benefit. Redesigning the successful Renault FT just so it could include a third man and then to squander that opportunity by placing him in the front to operate just a single machine gun when he would really be more usefully employed in a bigger turret with the firepower concentrated there. With the Renault FT in mass production and being copied in the form of the American M.1917, what role could this vehicle actually perform? Larger, heavier and barely better armed, and yet with less armor, the vehicle stands out as a classic example of trying to improve on a design which was already close to perfection, and an effort which did not achieve success but instead failed utterly. The vehicle was simply worse in every way to the Renault FT with the sole benefit of another machine gun, a large price to pay for a completely new tank and presumably the reason why this vehicle managed just a simple example before being abandoned.

The Ford 3-man Light Tank in its complete form. Illustration by Andrei ‘Octo10’ Kirushkin, funded by our Patreon campaign.


Aberdeen Proving Ground Series: Tank Data 1. WE Inc., USA
Alexander, J. (2015). Briefly Famous. Self Published, USA
Crismon, F. (1992). US Military Tracked Vehicles. Crestline Press, USA
Ford Model
Hunnicutt, R. (1995). Stuart – A History of the American Light Tank Vol.1. Presidio Press, USA
Jarret, G., & Icks, R. (1971). Portrait of Power. Normount Publishing, USA
Jones, R., Rarey, G., & Icks, R. (1969). The fighting Tanks 1916-1933. WE Inc., USA
Mroz, A. (2009). American Military Vehicles of WW1. McFarland and Co. Inc., USA

Ford 3-man light tank specifications

Dimensions 16’ (4.88 m) long excluding tail
6 ½’ (1.98 m) wide
7’ 9” (2.36 m) high
Total weight, battle ready 7.5 tons
Crew 3
Propulsion Hudson 6-cylinder petrol producing 60 hp
Armor 0.37” (9.4 mm) to 0.60” (15.24 mm)
For information about abbreviations check the Lexical Index
WW1 US Prototypes

Tracklayer Best 75

USA (1916)
Mock-up Training Tank – 1 Built

America was not involved in the bloody slaughter on the first years of war on the Western Front not arriving until the summer of 1917. Political pressure in the United States had very much sought to avoid becoming embroiled in the war which most Americans met on a daily basis in newspaper headlines. The US military was also fairly ill-prepared for a major European land war. When, in September 1916, a new mechanical weapon of war known as the ‘tank’ was unleashed by the British in France, it could only have served to reinforce a view of being grossly ill-prepared for a modern war.

When the first images of tanks appeared in November 1916, they were a sensation in the newspapers and newsreels of the day, capturing the public imagination. There was, of course, a serious problem in America – they did not have any. Not only did they not have any, they also did not understand the technology which was at work or have an understanding of the conditions in which a machine would have to operate. The one thing which was easy to understand was the fact of this machine being tracked and there were several American tracked vehicle manufacturers at the time.

The result was several rather hastily conceived vehicles playing ‘tank’ built around these tracked tractor chassis’ used in films, for military training, or for parades. One of the first, a rather crude box-shaped vehicle, came from C. L. Best in California in 1917 and was quickly replaced with a much sleeker vehicle with a large fully rotating turret. Rather than give the tank a direct name of its own, it simply inherited the name of the tractor on which it operated, the Tracklayer Best 75.

The Tractor

The C. L. Best Tracklayer 75 weighed in at a whopping 28,000 pounds (14 US tons / 12.7 tonnes), making it 1,500 lbs. (680 kg) heavier than the larger and more powerful 120 hp Holt tractor and 5,000 lbs. (2,268 kg) heavier than its primary competitor, the Holt 75 (23,000 lbs / 10,432 kg). Shaped in the manner of a tricycle with a single tyreless wheel at the front for steering, with a pair of track units at the back for propulsion and an engine located near the front, towards that steering wheel, the layout was common across a number of tractors of the era. It should be noted that the company founder, Clarence Leo Best, owned a patent for elements of this arrangement since 1914. Holt also owned a series of patents and accused each other of stealing their ideas. A string of litigation and acrimonious lawsuits between them followed.

The Best tractor had started life in 1912 as the C. L. Best 70 hp. Tracklayer but became the ‘75’ in 1913. Powered by a giant 4 cylinder (independently cast cylinders) ‘valve-in-head’ engine with a bore of 7 ¾” (197 mm) and stroke of 9” (229 mm) producing 40 drawbar hp at 450 rpm. The Best 75 was capable of 1.5 mph (2.4 km/h) in first gear and 2.375 mph (3.8 km/h) in second gear along with 1.625 mph (2.6 km/h) in reverse. The fluid load was 6 Imperial gallons (27.3 liters) of petrol mixed with 66 Imperial gallons (300 liters) of paraffin, 7 Imperial gallons (31.8 liters) of oil, and used 27 Imperial gallons (122.7 liters) of water for cooling.

Up until 1916, these tractors were built at the company’s plant at Elmhurst California, until manufacturing shifted to San Leandro, also in California. Production ceased in 1919 and, by the time of the merger in the early 1920s with Holt, some 734 C. L. Best Tracklayer 70 and 75 tractors had been made.

C.L. Best Tracklayer 75. Source: Haddock

In the months following the unleashing of the tank in September 1916 and even after the first photographs of it appeared in November that year, numerous imitations were created. Some were simple wooden boxes or frames covered with canvas for use as training aids or for promotional purposes. After all, what better way could there be to promote sales for tracked vehicles than a ‘tank’? The company C. L. Best managed to put together a quick ‘tank’ using one of their tractors. It was made with a large boxy-shaped body surmounted by a large fixed conning tower. The vehicle, displaying the name ‘Best 75 Tracklayer’ had worked surprisingly well for the company, appearing in some military exercises with the California National Guard, crushing down barbed wire entanglements. However, it was shockingly crude in appearance. Despite the success of the machine in the first months of 1917 or rather because of that success, C. L. Best replaced that crude body with a much sleeker and curvier body with a fully rotating turret. That second version would manage even more publicity for the tractor company, but also be used as a recruiting tool by the Army.

The original Best 75 Tracklayer ‘tank’.
Source: Crismon

The new body of the vehicle, now sporting the reorganized words to switch from ‘Best 75 Tracklayer’ to ‘Tracklayer Best 75’ on the side, was ready by April 1917. It once more took part in mock battles with the California National Guard and Coast Artillery Corps on sand dunes by a beach under the watchful eyes of onlookers.

“The monster plowed its way through all obstacles, clambering easily through dense underbrush, crashing through barbed wire entanglements and crushing wooden houses with all the startling efficiency of the British type that bewildered the Germans in France”
The Day Book, 25th April 1917

The Day Book of 25th April 1917 reported the vehicle under the skin of this leviathan as a 14-ton ‘Caterpillar’, which would make it a Holt-made vehicle, even though the vehicle was clearly sporting the name Tracklayer C.L.B. 75 on the lower parts of both sides at the front and on each side in big letters. That is because despite the vehicle looking like the more famous Holt 75 tracked tractor, it was the rival C. L. Best tracked tractor instead underneath. The weight, quoted as 14 tons, was exactly the weight of the unarmored C. L. Best Tracklayer 75, a ton heavier than the Holt 75, which no doubt added to the confusion over-identification.


The design was rather elegant in its simplicity. Looking like a giant shoe, the body was semi-circular in cross-section, with the central axis of the semicircle running longitudinally down the line of the vehicle, giving it the form of a half-cylinder. The bottom edges of this half-cylinder were attached to small outriggers from the chassis of the tractor and came to a point at the front. There, a large curved attachment was fitted, notionally for cutting wire, and bearing an uncanny resemblance to the wire cutter fitted to the Holt 75 mock-up used in the film Patria. Each half of this curved nose part of the tank was made from 4 large sections, each fastened with ‘rivets’. This is more likely to have been sheet metal over a wooden frame imitating such fixings. Small ripples and creases visible on the vehicle in some photos would indicate the shell to be made from just thin sheet metal as well. In each of these front side sections was a small semi-circular piece projecting out and pointing forwards. Each of the main sides of the vehicle was made from 9 pieces, with the first and third sections from the front also having a loophole for observation. On top of the vehicle, directly above the tracked section, was a circular turret with 8 circular openings and 12 small ovaloid ones below them. Two of the circular openings mounted the ‘guns’ at opposite ends of the turret, facing away from each other. The turret roof was a simple cone covering the whole of the top of the turret. The rear of the vehicle was angled down sharply to the frame of the tractor at the back. Two notable features which can also be seen projecting from the roofline are exhausts for the engine. Sitting in front of the turret, these would serve to produce smoke directly in front of the turret and obscured any view of the ground for the men inside.

Armor and Armament

Given that the vehicle was misidentified as Caterpillar rather than reading the actual name on the side, the claim of armor cladding made from “a lighter weight model of the armor plate used in real war” appears simple exaggeration for the reader’s benefit. The vehicle was, in fact, completely unarmored. For the size of the vehicle, any armor of value would have added several tonnes to the weight and seriously affected the albeit already low speed. Given that

The Day Book reported it weighed 14 tons and Motor Age magazine reported it at 15 tons, and that its unarmed weight was already 14 tons, clearly no protection was carried.

The same is true of the armament. The Day Book (1917) also claimed that it was fitted with a pair of “rapid fire one-pound guns … mounted in the conning tower which revolved to sweep the entire field”. Different photographs on different dates and locations confirm that this ‘conning tower’ did indeed turn, but the armament consisted of just wooden props. This is confirmed in the same article on the vehicle from The Day Book, where it says 3 men were needed in the turret to operate “the ‘one pounders’ ” – the quotation marks added to the description indicated that they were known to be fake but were to imitate real guns. The vehicle, therefore, was unarmed.

Low-quality photographs of the April 1917 exercise in which the vehicle took part, smashing a wooden house (top) and then joining in an ‘attack’ (bottom).
Source: The Day Book 25th April 1917
A clearer version of the second image from above, as seen in Bache 1917. For whatever reason, the infantry is leading the ‘attack’, with the ‘tank’ behind them on the other side of the wire. Source: Bache.


Just like the Holt 75 and other vehicles based on this type of tracked tractor, visibility was a serious problem. Even unarmored, the driver would have difficulty seeing ahead to the left due to the position of the engine blocking his view, as he was positioned approximately halfway back along the length of the track units, on the left-hand side. Confusingly, there is a cut-away drawing of the vehicle showing the driver in the turret, courtesy of Popular Science Magazine July 1917. No other crew positions are visible in that drawing, but it also curiously labels the two small features on the front, either side of the nose of the vehicle, as air intake louvers. The radiator for the tractor was indeed directly next to these areas, but it certainly would not need these two tiny louvers for air. The whole underneath of the vehicle was completely open and unarmored anyway, meaning as much air as could be needed could be drawn up from underneath. This meant that those upper features were useless for cooling air. If, of course, they were needed for air, then the logical positioning would be to turn them to face backward, so as not to direct bullets that struck them into the vehicle. In the account of the design given in ‘The Day Book’ of 25th April 1917, although it did claim the vehicle to be armored when it was not, it did give a listing for the crew. There, there is an explanation for the two features on the vehicle’s front, as it says the driver had to be assisted by a pair of lookouts at the front. With no other features from which to observe, this would mean one man stood on alongside the radiator at the front, looking out of the ‘vent’ hole and providing guidance to the driver sitting in the rear and operating more as a steersman than a true driver.

Cutaway view of the Tracklayer Best 75 showing the driver in the turret. Source: Popular Science Magazine July 1917

This would mean 3 men were required to drive the vehicle and another 3 would be sat inside the turret to operate the guns. These latter 3 persons may or may not have been able to set off small blank charges to simulate fire but, as this was done on the first version, it is likely that the second one too could ‘fire’ in this manner as well.

Tracklayer Best 75 crushing a wooden house during maneuvers in California.
Source: Zaloga
Looking more like TikTok from Return to Oz than an actual fighting machine, the Tracklayer Best 75 is still an imposing sight during this mock battle. Source: Pinterest

Image of the Tracklayer Best 75 from Literary Digest, 21st April 1917, and a wider but shorter view of the same image from Bache 1917.

Final Use

The use of this vehicle during exercises seems to have been relatively short-lived, as there was only so much such a slow vehicle could offer in the way of ‘combat’ training for the men.

However, it did not immediately disappear and was seen leading parades into at least May 1917 in California. There, displaying posters, it was used to help recruit young men and women for the war effort, as the United States had entered the war at the start of April. Its appearance in April exercises and then parades provided some reassurance to both the men being sent to fight and presumably their families, that the USA was not going to go to war without its own tanks. They would be wrong on that account, and it was not until September 1918, just two months before the war ended, that the US finally got tanks of its own into combat – notably not ones of American design. The Tracklayer Best 75 served no part in that development or process, it received no orders and presumably was quickly returned to tractor duties, with its tank-disguise removed when it was no longer needed.

Two views of the C. L. Best Tracklayer 75 from newspapers at the time. It is the same syndicated photo, but the quality varies and the background has been erased for their publication. Sources: Butte Daily Post 22/5/17 (left) and The West Virginian 4/6/17 (right)

Promotional card featuring the Tracklayer Best 75. Source: Wisconsin Historical Society
Traklayer “Best” 75 mock-up. Illustrated by Yuvnashva, funded by our Patreon campaign


Bache, R. (1917). Our Forts on Wheels. Modern Mechanix Magazine, June 1917.
Bache, R. (1917). Our Forts on Wheels. Illustrated World, June 1917.
British Pathe Video. ‘American Tanks in Action (1917).
Butte Daily Post 22nd May 1917. Big ‘Tank’ inspires youths with patriotism ambles down street through surprised traffic’
Crismon, F. (1992). US Military Tracked Vehicles. Crestline Publishing, USA
Haddock, K. (2001). Classic Caterpillar Crawlers. MBI Publishing, USA
LeGros. (1918). Traction on Bad Roads. Reprinted 2021 FWD Publishing, USA
The Day Book. (25th April 1917). Yankee Tank in Action Amazes.
The West Virginian, 4th June 1917. Big ‘tank’ inspires youths with patriotism.
US Patent US1084062 Autotractor filed 23rd June 1912, granted 13the January 1914
Wisconsin Historical Society
Young, J., Buddy, J. (1989). Endless Tracks in the Woods. Crestline Publishing, USA

WW1 US Prototypes

C. L. Best Tractor Tank (‘Best Tracklayer 75’)

USA (1916)
Mock-up Training Tank – 1 Built

In the weeks and months following the tank being unleashed on the battlefields of France by the British in September 1916, the tanks generated enormous amounts of public interest and fascination. It was not until November 1916 that photographs were available from which the public could finally understand that some of the descriptions and artistic renderings which had been circulated were wrong.

Even then, the technology of what went into the tank was secret. However, the dominant feature was not the armor or the guns, but the tracks. The USA had no tanks at the time, but it had tracked vehicle makers and, with sales of Holt tractors during the war and persistent commentary of Holt being the machines of which British tanks were based, the publicity for Holt was enormous. Holt was a maker of tractors for agricultural, commercial, and military use. A competitor of Holt was the C. L. Best company in California. They also had a heavy tractor with tracks, just like Holt, and were eager to promote themselves. A new war with armies suddenly wanting tracked vehicles was a potentially very lucrative win and, not wishing to be left out either on the credit as inspiring the British tank or for any forthcoming sales, C. L. Best produced their own ‘tank’. Based on their tractor, this vehicle was one of the first ‘tank-shaped’ objects ever made in the United States. Whilst it was not armored, it is historically important for that reason. The vehicle was not a success but it also has possibly the oldest surviving footage of a US ‘tank’ to its accomplishments as well.

The Tractor

The C. L. Best Tracklayer 75 weighed in at a whopping 28,000 pounds (14 US tons / 12.7 tonnes), making it 1,500 lbs. (680 kg) heavier than the larger and more powerful 120 hp Holt tractor and 5,000 lbs. (2,268 kg) heavier than its primary competitor, the Holt 75 (23,000 lbs / 10,432 kg). Shaped in the manner of a tricycle with a single tyreless wheel at the front for steering, a pair of track units at the back for propulsion, and an engine located near the front towards that steering wheel, the layout was common across a number of tractors of the era. It should be noted that the company founder, Clarence Leo Best, owned a patent for elements of this arrangement since 1914, but Holt also owned a series of patents and accused each other of stealing their ideas. A string of litigation and acrimonious lawsuits between them followed.

The Best tractor had started life in 1912 as the C. L. Best 70 hp. Tracklayer, but became the ‘75’ in 1913. Powered by a giant 4 cylinder (independently cast cylinders) ‘valve-in-head’ engine with a bore of 7 ¾” (197 mm) and stroke of 9” (229 mm), it produced 40 drawbar hp at 450 rpm. The Best 75 was capable of 1.5 mph (2.4 km/h) in first gear and 2.375 mph (3.8 km/h) in second gear, along with 1.625 mph (2.6 km/h) in reverse. The fluid-load was 6 Imperial gallons (27.3 liters) of petrol mixed with 66 Imperial gallons ( 300 liters) of paraffin, 7 Imperial gallons (31.8 liters) of oil, and used 27 Imperial gallons (122.7 liters) of water for cooling.

Up until 1916, these tractors were built at the company’s plant at Elmhurst, California, until manufacturing shifted to San Leandro, also in California. Production ceased in 1919 and, by the time of the merger with Holt in the early 1920s, some 734 C. L. Best Tracklayer 70 and 75 tractors had been made.

C.L. Best Tracklayer 75. Source: Haddock

In the months following the unleashing of the tank in September 1916 and even after the first photographs of it appeared in November that year, numerous imitations were created. Some were simple wooden boxes or frames covered with canvas for use as training aids or for promotional purposes. After all, what better way could there be to promote sales for tracked vehicles than a ‘tank’? The company C. L. Best managed to put together a quick ‘tank’ using one of their tractors. It was made with a large boxy-shaped body surmounted by a large fixed conning tower at about the level of the driving station, which would indicate the men basically sat on the canopy over the tractor, within its wooden walls.

The original ‘Best’ 75 Tracklayer ‘tank’. Source: Crismon


The design was what might be expected from a tractor turned into a ‘tank’ at very short notice. There was no way to turn a vehicle like the Best 75 into a tank to match the images of British tanks which had been released in November 1916. With literally no other tanks from which to take design cues, the result was not much more than a giant box.

Almost childlike in its simplicity, the sides of the body tapered slightly to the roofline and curved out from about halfway up the body to go down over the tops of the tracks. The front had a pronounced step, transitioning from the tapered upper sides towards the front. In this step was a small circular loophole. The front of the vehicle was big and flat, with a large rectangular flat front angled slightly backward, with a large ‘gun’ sticking out. Around the bottom half of the vehicle, across the front, was a simple rounded front extending beyond the front steering wheel.
The roof over the engine section of the tractor was completely flat, with just the two exhausts from the engine sticking out. Behind these was a raised fixed cabin. This had a pair of large rectangular openings in the front and another on each side. In the back of the cab was a circular opening in which another ‘gun’ was located. The rear of the hull sloped down from the roof to a large bulge, the purpose of which is unknown, and thence to the back of the machine.

The location of the cabin was unfortunate, as it was directly behind the exhausts. Any smoke coming from them would not only obscure the view ahead, but also allow fumes inside, to the detriment of the occupants.

The Best Tracklayer 75 in a still from the footage of it during maneuvers. The hooked device on the front is clear, as is the very angular and crude body. Source: Pinterest

Armor and Armament

There is no documentary evidence known discussing the materials used in making the vehicle, but it is a reasonable assumption to suggest a wooden frame and either wood or sheet metal on the outside. The next vehicle from C. L. Best, which followed this one, certainly was not armored (the Tracklayer Best 75) and was made from a simple framework with sheet metal over it. Quick, cheap, light, and simple to arrange, this body would give the appearance of armor with none of the weight. The vehicle was already 14 tons in weight and any armor to cover the vehicle of these enlarged dimensions would add substantially to that.

The ‘Tracklayer Best 75’ which followed the ‘Best Tracklayer 75’ received a good deal of attention in the media at the time and took part in some military exercises in California. Here, it can be seen crushing a wooden house during maneuvers. Source: Zaloga

One thing which is clear from the vehicle, however, is the ‘guns’. They were clearly not just simple wooden or metal tubes or mock-ups, but could also pretend to ‘fire’. A simple black powder charge or something similar would function as a blank to simulate it firing. This can be seen in remarkable footage from British Pathe of the vehicle during exercise in early 1917. However, despite this mock gunfire ability, the vehicle was unarmed.

Video ‘American Tanks in Action’ (1917) by British Pathe shows the vehicle during mock battles and firing ‘blanks’.


No written record of how many men it took to crew the vehicle is known, but the vehicle which followed it did have a discussion of crewing. The Day Book of 25th April 1917 revealed that as well as the single driver, presumably sitting in the normal position above the tracks towards the rear on the right-hand side, a pair of ‘lookouts’ were also used. The pair of loopholes on the front of the vehicle could serve as a lookout for the driver, for whom there would be no view of the road ahead. In order to operate the ‘guns’, even during a mock battle, probably another 3 men would have been needed as well.

Best Tracklayer 75 crushing through a wall, providing a good view of the hooked wire cutter on the front. Source: Landships forum

Use and End

The vehicle did not see much use for exercises. It was clearly a very crude rendition of a ‘tank’ for the purposes of training and disappeared around March 1917. When it reappeared, it had a different form, rounded and rather sleek, with a single fully rotating turret. The vehicle had dubious value as a training tool, being so big, so slow, and so different from real tanks. It went no further than its mock-up and survives today as only a short length of film and a few photographs.

The first type of C. L. Best Tracklayer 75 tank seen crossing a barbed-wire entanglement during a mock battle in California.
Source: NARA Ref: 165-WW-313-B-9
The first type of C. L. Best Tracklayer 75 tank seen crossing a barbed-wire entanglement during a mock battle in California.
Source: NARA Ref: 165-WW0313-B-8
The Best 75 Tracklayer was little more than a tractor covered in wood. It did, nonetheless, see use as a training mockup. Illustration by Yuvnashva Sharma, funded by our Patreon campaign.


Bache, R. (1917). Our Forts on Wheels. Modern Mechanix Magazine, June 1917.
Bache, R. (1917). Our Forts on Wheels. Illustrated World, June 1917.
British Pathe Video. ‘American Tanks in Action (1917).
Butte Daily Post 22nd May 1917. Big ‘Tank’ inspires youths with patriotism ambles down street through surprised traffic’
Crismon, F. (1992). US Military Tracked Vehicles. Crestline Publishing, USA
Haddock, K. (2001). Classic Caterpillar Crawlers. MBI Publishing, USA
LeGros. (1918). Traction on Bad Roads. Reprinted 2021 FWD Publishing, USA
The Day Book. (25th April 1917). Yankee Tank in Action Amazes.
The West Virginian, 4th June 1917. Big ‘tank’ inspires youths with patriotism.
Young, J., Buddy, J. (1989). Endless Tracks in the Woods. Crestline Publishing, USA

WW1 US Prototypes

Holt Caterpillar G-9

USA (1916-1917)
Mock-up – 1 Built

Tanks first came to the public consciousness with the British unleashing them at Flers-Courcelette on 15th September 1916. It was some time before pictures of them started to appear in the media and, in the meantime, various artistic renderings of this new weapon of war came out as well. Being tracked and with a complicated development, many claimants put themselves forwards as being the inventors or, at least, the inspiration for the design. The most obvious of these was the American firm of Holt with their ‘Caterpillar’ vehicle. Indeed, the name Caterpillar is now synonymous with tanks and other tracked vehicles in general, but they were not the vehicle on which the British based their tanks in WW1, despite numerous books and television programs repeating this again and again over the decades. There were, in fact, numerous tracked armored and unarmored Caterpillar vehicles used in WW1, and one which received widespread attention was the G-9. If the attention it garnered from the media of the time was impressive, then its ignominious fate did not. Since WW1, it has largely vanished into obscurity. Even the movie ‘Patria’ in which it featured has disappeared from the public consciousness. The Caterpillar G-9 was one of the first American ‘tanks’, a rather poor vehicle built at a time of little or no knowledge of armored vehicle development, but undoubtedly an important one in the history of US vehicle development.

The ‘Tank’

The body of the vehicle was rather crude. Consisting of a slab-sided superstructure that taped slightly towards the roofline, with multiple loopholes or vision slots in the side. At the front, the shape of the body followed the shape of the tractor underneath, curving around the circular mount for the leading wheel and then angling upwards to a large rectangular hatch on the front. At the rear, the slab sides, as well as taping towards the roof, also taped in slightly at the back and there was another large rectangular hatch. Poking out from the rear hatch was a tube for a fake gun and presumably the same from the front hatch. However, with the tractor radiator directly behind it, the option for even a movie extra to stand there and play make-belief is doubtful. 

In the film and in some of the photos of it being observed by the US troops, it can clearly be seen to have a pair of turrets, one right at the front of the cab, directly over where the engine was, and a second directly over the rear. Some photos, however, only show a single turret in that second position, with the front one missing.

Given that the structure, other than the tractor underneath, was made of just wood, it is easy to assume that the front turret either fell off, became damaged, or was otherwise removed from the vehicle shortly after filming. Popular Science June 1917 reported that examination by the US military took place straight after filming had finished and this front turret was in a terrible position. Not only would the turret be directly over the engine and all its heat and noise, but it would also obscure any field of observation or fire from the rear turret. On top of that was the small matter of the exhaust. Images of the G-9 with just a single turret show clearly the exhaust from the vehicle exiting the roof right where turret 1 had been, implying that turret 1 simply sat over the exhaust for the film, something likely to have caused exhaust fumes to come back into the vehicle. 

Scene from the final battle in Patria with the ‘tank’ advancing.
Source: American Falls Press 28th September 1917

The height of the vehicle seems to be a function of the tractor underneath having a large canopy over the top. Building a framework for the ‘armor’ on top of this canopy would also allow someone sitting on top of it to operate the rear turret, making it move for the camera. If this was a real attempt at a design, then this extra height was utterly unnecessary and would only serve to make it a bigger target and more top-heavy. Underneath the turret/turrets and the ‘armor’ was a standard Holt 75 tracked tractor.


The Holt 75 tractor normally weighed 10,432 kg (23,000 lbs.), but was reported as being a ‘13 ton’ (US short tons) at the time of its crash in 1917. Thirteen US short tons is 11,793 kg, meaning an added weight from the ‘tank’ body and turret of just 1,360 kg. This confirms that the body was not truly armored. Were the vehicle to actually carry real and effective armor, such as something not less than 8 mm thick, it would have added substantial mass to the tractor, in the region of 10 – 20 tonnes. This meant that the 75 hp engine would not have been very effective. The maximum loading capacity of the tractor was just 21,350 lbs. (9,684 kg), so it is doubtful that, without a substantial change in the design of the G-9, any worthwhile armor could be carried on the vehicle.

The Holt ‘Caterpillar’

The Holt tractors, sold under the name ‘Caterpillar’, were effective and reliable tracked tractors. Indeed, the Holt design had been, to a degree, one of the reasons behind the impetus behind some of the British push for tracked vehicles in 1915 by men like Robert Macfie. It had some shortcomings too, such as poor speed and an underpowered engine. Even without any armor added, the machine was slow. Cladding several tonnes of extra weight would raise the center of gravity, making it unstable and even slower or utterly immobile, as well as making it hard for the driver to see where he was going.

As a farm vehicle or tractor for hauling guns, these were less problematic but not ignorable. The driver, sitting at the back on the right-hand side, had to try and see forwards over all these obstructions. Even when the vehicle was open and unarmored, his view was obscured by the engine to his front left. With armor, he stood no chance of seeing out of a small slot in the front. Instead, he would have to be guided by at least one other man, probably sat or stood right next to the noisy and hot engine. At least two men were therefore needed to control a vehicle with terrible visibility and, with the problems of communication between them caused by the engine, this was not a recipe for success. 

Holt had been successful even before the ‘tank’ appeared, having sold the US Army 63 of its Model 60 tractors with a 60 hp engine. The Model 75, however, was an order of magnitude more successful than the Model 60, staying in production until 1924 at the plant at Peoria, Illinois. Some 442 Holt Model 75s were even manufactured by Messrs. Ruston and Hornsby Ltd. in Lincoln, England. Combined, 4,620 Model 75s were made, of which more than 2,000 entered military service. 


In 1916, at the time of the Patria movie, the Holt 75s available would have been US-built examples using the Holt M-7 7 ½” (190 mm) bore, 8 inch (203 mm) stroke ‘valve-in-head’ engine delivering 75 hp, originally known as the Holt 60-75 (A-NVS), if they were made since production began in the Stockton plant in 1913. Some 16 Peoria-built tractors made between 1914 and 1915 used the Holt M-5 ‘Ellhead valve layout’ (T-6 series) engine. Due to problems, this was quickly changed to the Holt 75 (T-8 series) engine being fitted at the Stockton plant in California. Given that the film was also shot in California, it is most probable that the Holt used was a Stockton-made one rather than a Peoria-made example. 

The engine was considered perfectly adequate for its normal duties and remained the standard engine until 1921 when it was improved with a new radiator. The T-8 series Holt-75 engine was a 4 cylinder water-cooled unit that ran on paraffin with a capacity of 22.9 liters (1,400 cubic inches), delivering 75 hp at 550 rpm. This power was carried to the drive sprockets moving the tracks via a multiple disc clutch made from 5 plates made from bronze and cast iron, along with a simple reversing gearbox. The gearbox provided for 2 forward and a single reverse gear. Forward speed was limited to 2.13 mph (3.4 km/h) in 1st gear, 3.5 mph (5.6 km/h) in second (top) gear, and 2.13 mph (3.4 km/h) in reverse. The fuel tank held 53.5 Imperial gallons (243.2 liters) which, along with 5 Imperial Gallons (22.7 liters) of oil, and 67 Imperial gallons (304.6 liters) of water, provided the fluids required for the engine to operate.

The Holt tractor itself used cast iron wheels running on heat-treated axles on Hyatt roller bearings. The track itself was connected by case hardened steel pins linking pressed steel plates 24” wide (607 mm), although 30” (762 mm) wide tracks could be fitted. All of the links had pressed corrugations 1.5” (38 mm) deep acting as spuds for traction in soft ground. The load was carried on four double-coil helical springs springing the track along its 80” (2.03 m) ground contact length.

The steering was managed via a single wheel at the front, controlled via a long steering control shaft from the steering wheel and driver’s position. This was located roughly in line with the center of the track units. The steering wheel controlled a non-reversible worm and wheel gear.

Side elevation of the Holt 75 hp tractor. Source: LeGros


An article in Popular Science June 1917 makes it clear that both the body and guns were made of wood, but also that there was a wire cutter built for the front of the vehicle. The G-9, therefore, was completely unarmed, although it is possible that pyrotechnics, like blanks, could be used to simulate gunfire.

The Movie

With the tanks of Britain and, later, France seeing combat and appearing in the press, it is no shock that, when William Randolph Hearst made a war movie in 1916, he would need a ‘tank’ of his own. Hearst was a very wealthy man and a media tycoon owning numerous newspapers and an animation studio called ‘International Film Service’ (I.F.S.). In 1916, filming of the first episodes began at Wharton Studios in Ithaca, New York, on a movie for I.F.S., all funded by Hearst and very much pushing a political agenda of military preparedness.

To an audience of 1917, the script had lashing of patriotism of dedicated Americans organizing for collective defense against a foreign foe, which culminated in a pitched battle in which, obviously, the ‘good’ side would prevail. In the modern world, it is impossible to see the film without cringing at the blatant jingoism as well as the overt racism of the movie, with stereotyped Japanese villains. However, what is unacceptable now was simply grist for the mill of the overall desire of many for the US to enter the war. It is perhaps odd then that the Japanese were the ‘enemy’, given that, in 1916, Japan was aligned with British interests and actively opposed German ones having already fought the Germans over Tsingtao in 1914. Nonetheless, the rather cartoonish plot involved a secret Japanese cabal of spies in league with nefarious Mexican interests gathering arms and gold in preparation for war in the US. This is perhaps the only time such an alliance has ever been contemplated on film. The Mexican angle was the more reasonable topic of the time, given the invasion of the US in March 1916 by Pancho Villa. Villa’s raid had sacked the city of Columbus, New Mexico, sparking a punitive retaliatory expedition by the Americans.

The shooting of the first episodes of the film took place on the site of Greystone Manor, which is now part of Cornell University. It starred Irene Castle (as Patria Channing) in her screen debut, along with established actors Milton Sills (as Captain Donald Parr), and Warner Oland (as Baron Huroki), an actor most famous later for his portrayal of Fu Man Chu and Charlie Chan. 

Patria was a massive work made in no less than 15 separate episodes, costing a phenomenal US$85,000 (over US$2 million in 2021 values). The first 10 episodes were directed by Theodore and Leopold (Ted and Leo) Wharton, but the film was a little too jingoistic even for the day, particularly in its anti-Japanese portrayal.

After the first 10 episodes had been shot, allegedly, President Woodrow Wilson intervened with an appeal to the wealthy Mr. Hearst, requesting that the anti-Japanese sentiment be toned down. The result was that the leading villain, Baron Huroki, was changed from a Japanese character to that of ‘Manuel Morales’. However, the motion picture press coverage of the film at the time makes no mention of such an intervention and Huroki is both clearly villainous, Japanese, and referred to as Baron Huroki. Interplayed with this fiendish Japanese fifth columnist (although the term was not even coined at the time) plot was a criminal Mexican connection on the southern US border playing on the problems there at the time. 

The wafer-thin plot of Hurki was contrasting with the glowing, alluring, and wealthy Elaine ‘Patria’ Channing (‘Patria’ means homeland in Latin, i.e. Elaine as the personification of the noble country defiled) working with handsome and dashing Secret Service agent Captain Parr. Together, these two would try to thwart the insidious threat to national security from the invaders and insurrectionists in the form of Huroki, the Japanese, and the Mexican soldiers. 

Advertising Poster for the serial-movie Patria. Irene Castle is billed as ‘Mrs. Vernon Castle’ (her husband, Vernon Castle, was a pilot with the Royal Flying Corps on the Western Front at the time). The man next to her is Milton Sills. Source: IMDB

The final 5 episodes were to culminate in stopping the invading Mexicans at the border. The filming for these episodes was moved from New York to the West Coast and were shot in Los Angeles by director Jacques Jaccard. No doubt, California offered a better landscape to match ‘Mexico’ or the Southern USA than New York did. 

The film was published for release on 1st January 1917 and premiered on 6th January. It did not receive general release until 14th January 1917 in the USA. By the time of the final episodes being released, the political situation was changing. This culminated in the US declaring war on 6th April 1917, making it an ally with one of the main villains of the film, rendering many of the sentiments of Patria immediately and woefully redundant.

Sadly, the original serial episodes have suffered from the ravages of time and only the first 10 episodes are known to survive. They were pieced back together in 2012 by Serial Squadron. Only limited stills of episodes 11-15 are known to survive and, unfortunately, it is in these final episodes in which the ‘tank’ appears. 
Patria movie (10 episodes)
Source: Serial Squadron

Although these final scenes are missing from the film, there are both clues and a few photographs of what the ‘tank’ was that appeared. In fact, the correspondent for Moving Picture World reported that there was not a single ‘tank’ but ‘tanks’ in the final battle.

“…we have used every known appliance of modern warfare, including tanks, dirigibles, machine guns, gas bombs”. Source: Moving Picture World 24th March 1917

No footage or stills of the climactic battle are currently known to survive, although one syndicated photograph was thankfully printed in several newspapers at the time. In the photo, a twin-turreted ‘tank’ can be seen ahead of a line of US troops, heading towards what appears to be men either standing or running and with a cloud of smoke or ‘gas’ rolling across the battlefield.

Scene from the final battle in Patria with the ‘tank’ advancing. Note that it has two turrets. Source: American Falls Press 28th September 1917

Further to the single image was a long explanation of the action in the scene, which, in the days of silent movies like this one, was fairly common. An audience could read up on the action before watching it and thus be fully informed as to nuances not easy to convey in the occasional slide of words during the film.

Two excerpts from the account of the ‘battle’. Source: American Falls Press 28th September 1917

Here, in this account, it very clearly states once more that ‘tanks’, plural rather than ‘tank’ singular, were used. It even goes so far as to describe them vividly as “monstrous armadailloes [sic: armadillos]”. More than just two vehicles are actually mentioned, as the final charge is supported by “a fleet of ‘tanks’ – armored caterpillar tractors carrying machine gun crews”, yet this pluralization may simply be colorful reporting rather than strictly and literally correct. 

This account of at least two vehicles is somewhat contradicted by that of Lescarboura (1919), who provides actual numbers of the extras and vehicles involved in the scene. He described the use of more than 2,700 men, including 1,200 of the California National Guard, 325 horses, multiple field guns, 25 aircraft, and just “one armored tractor or ‘tank’”. His account of just a single vehicle is backed up by the fact that there is no photo of more than one vehicle at the same time and, more importantly, by a review in Current Opinion which has the same still as before but printed more clearly. From this, it is also clear that there is just a single vehicle involved. A serious explanation of the episode’s key plot points was provided by the magazine Dramatic Mirror of the Stage and Motion Pictures, which also made clear it was just a single-vehicle.

Better quality and wider framed shot of the assault scene from Patria. Source: Current Opinion Volume 63, 1917


Episode 15 ‘For the Flag’

Baron Huroki plans a night attack on Patria’s line of intrenchments, in which he hopes to surprise her troops. The Japanese advance is driven back, but an attack of liquid fire enabled them to creep up upon the trenches. In desperation, the American troops play their trump cards and send out their huge Caterpillar tank, which ploughs through the enemy’s ranks and scatters them over the border.

Amid the enthusiastic plaudits of the soldiers, Patria seeks out Donald Parr, who had been wounded in the battle, and this thrilling story of romance of war ends blissfully in love’s young dream

Dramatic Mirror of the Stage and Motion Pictures, Volume 77, Part 1 dated 28th April 1917

The Famous Photos

There is a trio of slightly more famous or well-known images of this vehicle that appeared in the media at the time, outside of the stills from the battle scene. The shooting of Patria had finished before January, as the episodes were rolled out into cinemas and the film-prop ‘tank’ which had been made was still around afterward. In April 1917, images of the tractor appeared in various newspapers and magazines as a ‘tank’ being evaluated by US officers for potential use.

More curious than those April photos was not that the images would be repeated even into September that year or that they even appeared as rather fanciful art, but that the vehicle appears to have predated all of those and the movie. 

The first outline of the vehicle appears in the November 1916 issue of Popular Mechanics magazine, although it is important to note that the image is not a photograph but an artist’s impression of a tank. This is an important distinction as, although tanks were used on 15th September and news of their success captured the public’s imagination – images did not appear until 23rd October 1916. In this intervening gap, various fanciful depictions appeared and the November edition of Popular Mechanics is no different. Obviously, November is after October, but the November edition would go out in October and prior to the 23rd. Thus it missed the reveal of the real tank and was out of date almost immediately. Nonetheless, this was likely one of the first proper conceptions of what a tank actually looked like, which many Americans may have seen.

The British ‘tank’ in action according to Popular Mechanics November 1916. Note the twin turrets. Source: Popular Mechanics 1916

It is obviously not possible for the artist to have copied the vehicle from the film, as filming had not yet begun, yet the two vehicles are virtually identical, meaning they are assuredly connected. If one can imagine a wealthy man like Hearst trying to fund a great ‘patriotic’ movie at exactly the same time and not having access to an actual image of a tank but needing one in his film, it is not hard to imagine a situation where the film copied the design from this depiction. In the Popular Mechanics’ depiction, there is a clear explanatory note stating that their artist has rendered the drawing based on reliable data and on photographs of the Holt tractors which were already known to be in British use and purchased for the war. If a soldier at the time described a metal machine clad in armor and with two turrets, this drawing would indeed be a fair conclusion based on the common assumption of the turrets being mounted on the top of the tank rather than on the side as, in fact, they were on those first British machines. In the still image from the film, the vehicle can be seen still using a pair of turrets, as it is in the promotional images published in April 1917 and afterward.

Front view of the vehicle with the front wheel off the ground with a pair of soldiers and a civilian in the foreground looking on. Note that this image, like others, was issued by I.F.S. rather than an independent photographer. The top of the rear turret is also visible at the back, as is the ‘wire cutter’ on the front, which appears as nothing more than a large slightly curved blade. Source: Literary Digest New York 7th April 1917
Front cover of the periodical Le Miroir (English: The Mirror) from 29th April 1917 with the caption announcing the vehicle as a ‘tank’ of the US Army. Note that this is a wider framed and uncropped view of the same image as appeared in Literary Digest earlier that month. Source: French National Library

In those April images, one thing is very clear –  namely that the vehicle had a pair of turrets. Other images of the vehicle, purported to be taken during evaluation by the US Army, are also known and these feature just a single turret at the back. This change has led to speculation that there were, in fact, two different vehicles and that this is backed up by some of those film reports of multiple tanks in the final scene of Patria. However, not all of the film reviewers agreed that more than one tank was seen. It was, after all, just a prop for a single scene and those tractors were expensive. 

This particular image, cropped from a slightly wider framed one, has appeared captioned as both being evaluated by the US Army at Sandy Hook, New Jersey (by Icks in 1975, quoting Wilson) and by contemporary sources as taking place in Los Angeles. Source: Clark.
Wider left-framed version of the same photograph which appeared in Literary Review. Source: Alexander.
The following shot showing the rear of the vehicle as it climbs a steep slope under the watchful eyes of soldiers. The vehicle can be seen leaning dangerously over to the right on this side grade. Also visible sticking out of the front is the exhaust stack for the motor, under where the lead turret used to be. Source: NARA Photo Ref: 165-WW-313-A-59.

Whatever interest the US military may have had in this beast is unclear. By the time they were allegedly looking at it, in the spring of 1917, the British tanks were already seen in the press and, unlike this ungainly machine, were fully tracked. Despite the structure being made out of wood and sheet metal (with wooden pegs inserted to imitate rivets) to simulate armor, the vehicle was still top-heavy and this helped to bring it to grief sometime in March 1917, at least a month or so before photos of it being ‘evaluated’ were shown. When the vehicle rolled over down a bank, it was utterly wrecked and thus it would have been unable to be evaluated, leaving just two possibilities. The first, that there was a second vehicle all along, or second, that the photographs were released after the crash.

Published in June 1917, this image shows the collapsed body of the G-9 tractor fallen onto its right-hand side. Note the entire side section with the word ‘CATERPILLAR’ on it has come off and is lying to the front right of the picture.
Seen in the March 1917 edition of Illustrated World, the G-9 is toppled over onto its right-hand side off the road. Source: Motor Age.

Motor Age magazine, reporting on the crash in March 1917, also used the single-turret image and was clear that the photos were both taken in Los Angeles. With the different publishing dates distinct from the dates on which events happened, the reporting of multiple ‘tanks’ during filming, and the removal of one of the mocked-up turrets, it is not hard to see why it can be confusing as to whether there were two vehicles. Clearly, having crashed no later than March 1917, it could not be trialed in April or June, but the publishing dates are misleading, as they are not necessarily reporting events happening at that time, but events that had happened. I.F.S. owning the images is the first clue that option 2 is more likely the answer, as they could release the images to help promote the vehicle and, by default, their own film.


The design was somewhat awful. Impractically large, the tractor itself was solid and reliable and had been seen as helping to inspire some of the British tank development, but it was still not a tank by any interpretation of the word. The vehicle was simply a movie prop for Patria and not much more. The film has largely vanished from the collective consciousness and no full reel of it even exists anymore. 

It might, however, be worth remembering the movie a little more. Not for its racism and xenophobia, but because it is likely to be the first ever representation of a tank recorded on film in the United States. In the post-unveiling of the tank by the British in the previous September, the world had come to see this new weapon of war as making a sea-change in the dynamics of land combat. America had clearly been languishing without. America would produce other imitations of foreign designs, eventually putting into production its own version of the French Renault FT. The G-9 design was clearly never a seriously considered tracked vehicle concept and, with the accident destroying the vehicle, it was quickly forgotten. In the century since, however, the appearance of soldiers next to it has led many to believe and claim that this was a real project considered for the US Army. Holt and Caterpillar did not suffer from this. Holt took over the firm of C.L. Best, a rival tractor firm, some years after the war, and together, the brand of Caterpillar went ahead to become a world-renowned brand in all manner of heavy plant equipment, surviving to this day.

Author’s Note: The author would like to thank the Wharton Studio Museum, New York, and Serial HQ for their help in preparing this article.

Side illustration of the Caterpillar G-9 mock-up tank that starred in the Patria movie. Illustrated by Yuvnashva Sharma, funded by our Patreon campaign.

Specifications Holt Caterpillar G-9

Crew: 2+ (driver x 2)
Armor: None
Armament: None
Engine: Holt M-8 series paraffin engine delivering 75 hp
Speed: <3.5 mph (5.6 km/h)


Alexander, J. (2015). Briefly Famous, The 1917 Caterpillar G-9 Tank and other American Tanks 1916-1918. Privately Published.
AllMovie Database. Patria (1917). 
Automobile Topics (1917). Volume 45
Bache, R. (1917). Our Forts on Wheels. Modern Mechanix Magazine, June 1917.
Bache, R. (1917). Our Forts on Wheels. Illustrated World, June 1917.
Crismon, F. (1992). US Military Tracked Vehicles. Crestline Publishing, USA
Duncan-Clark, S. (1919). History’s Greatest War: A Pictorial Narrative. E.T. Townsend Publishing, USA
Haddock, K. (2001). Classic Caterpillar Crawlers. MBI Publishing, USA
Icks, R. (1975). Steam Power for Tanks. AFV-G2 Magazine Vol.5 No.4
Icks, R., Jones, R., & Rarey, G. (1969). The Fighting Tanks since 1916. WE Publishing, USA
IMDB. Patria (1917). 
LeGros. (1918). Traction on Bad Roads. Reprinted 2021 FWD Publishing, USA
Lescarboura, A. (1919). Behind the Motion Picture Screen. Scientific American Publishing Company, New York, USA
Motor Age Magazine 29th March 1917
Moving Picture World (10th March 1917). (Scenes in Patria Episodes explained)
Moving Picture World (24th March 1917). Battle Scenes in Closing Patria Episodes.
Omaha Daily Bee, 27th March 1917. ‘First tank to be built in the United States.
The Day Book. (25th April 1917). Yankee Tank in Action Amazes.
The People’s War Book and Pictorial Atlas of the World. (1920). R.C. Barnum Co. Cleveland, F.B. Dickerson Co. Detroit, Better Farming Association of Cleveland, USA and Imperial Publishing Co., Canada
Wharton Studio Museum, Filmography 1913 – 1919 
Young, J., Buddy, J. (1989). Endless Tracks in the Woods. Crestline Publishing, USA

WW1 US Prototypes

Holt’s ‘America First’ Tank

USA (1916)
Mock-up – 1 Built?

Tanks first appeared on the battlefields of Europe on 15th September 1916 at Flers Courcelette, during a British attack on German trenches. Whilst their use was by no means decisive, they showed that not only did the concept of a tracked armored vehicle work but that they had significant tactical potential. The success at that battle, no matter how small or temporary, was received with glee by a war-weary population in the UK and garnered substantial media attention domestically and abroad. Keen to capitalize on the lack of official photos of the tank at a time when what these weapons even looked like was not known, the firm of Holt, which was known to be supplying tracked vehicles to the British, took action. Even though the US was not yet in the war, Holt was keen to take credit for ‘tanks’ even if his vehicles had little to do with their actual development. The result was that, within just a couple of weeks of their first use, Holt had prepared one of their 75 hp tractors with a ‘tank’ body. The vehicle was used through October 1916 in parades in Peoria, Illinois and, at some point, was painted with the slogan ‘America First’.

‘America First’ the name

It is perhaps odd that the name of this vehicle, at a time of a worldwide war in which the United States was not even involved, would be ‘America First’, a campaign slogan for non-interventionism and isolationism. Whether the motives of promoting this slogan on the vehicle were to try and promote isolationism or to promote the vehicle as the first in the world is unclear. It was certainly a slogan known and used politically at the time and would later gain more prominence. However, in 1916, in this context, the phrase might be considered as one or both of those variants. An image of the vehicle from 16th October 1916 shows no such slogan on the side but, by the end of the month, the slogan had appeared.


The design of the vehicle was relatively simple, consisting of 4 parts making up a large slug-shaped body. The first part was the nose of the vehicle, which curved sharply down from the top of the roof to a rounded point at the front. It was made from 12 large curved pieces, in the center of which was a large opening through which a ‘cannon’ poked through. The gun was presumably a fake one, as the weight of a real gun had no obvious means of support, as well as the fact that it would sit directly over the radiator and engine, making serving the gun as difficult, awkward, and impractical as could be imagined. Alongside this ‘cannon’, in the front, were a pair of narrower tubes sticking out of the nose to simulate some kind of guns or flame projectors. No vision slots or holes were provided in the front for the driver.

The center section of the vehicle was effectively a large rounded boiler made from 5 curved pieces running circumferentially around the vehicle to encapsulate the tractor underneath. Each of those curved pieces was made from a single piece running up to the level just above the ‘guns’ on the front, at which point it was joined to another section. Assuming that the top section went all the way around the top of the vehicle to the same height on the opposite side, it would mean that the ‘boiler’ body was made from a total of 15 pieces. On both sides, pierced through each of the pieces making up the side apart from the very first one, were simple circular holes. No covering for the holes appears to have been provided and they had the appearance of a loophole from which soldiers would be able to fire or provide observations. The holes were right at the top corner of the pieces, slightly above the level of the guns.

Side view of the Holt vehicle from the side, clearly showing the tractor underneath and the enormous and impractical overhang at the rear. This image was repeated in multiple newspapers of the day, garnering a lot of good publicity for Holt, titled as a ‘Land Battleship’.
Source: Corsicana Daily Sun, Texas November 1916 (image has been digitally cleaned)

The third section was the rear. Once more, this had two narrow ‘tubes’ sticking out of the back, roughly in line with the two smaller ones on the front and once more presumably to simulate weapons. The shape of the rear was roughly the same as the nose as well, as it curved sharply down from the roofline down to the rear and covered the back of the tractor. Unusually, a side view of the vehicle showed that the rearmost section entirely projected past the rear of the tractor underneath, making the vehicle about a third longer than it needed to have been. Two other features identifiable on the rear are the US flag flown near to the top. Below this, a small tube was sticking out of the rear. This is presumed to be an extension for the engine exhaust to carry it backward. Although this normally went vertically, there does not appear to be anything sticking out of the front of the roof of the body, above where the engine went.

The final section of the vehicle was the turret. Made from a simple low cylinder with either a flat roof or just open, at least two more ‘guns’ are seen poking out. It is unclear if the turret was purely decorative or if someone could work in that space, as this would need some form of platform made underneath.


The minimum number of people needed to operate the vehicle was two. At least one person had to sit in the tractor under that body to control the steering and propulsion. With no windows to look out of and being sat just behind the midline, inside the hull, he would have no way of seeing outside. Thus, a second person would be needed, located either in the front or in the turret, to act as a guide to direct it in motion. This second person may also have acted as the commander. This was an awful arrangement for controlling a vehicle and alone should have precluded ideas of it being useful in combat as a successful weapon.

Assuming the other ‘weapons’ were operational, then more than 2 men would be inside. Three weapons pointed forwards each would require at least one man and the same at the back for those other two. The small turret could house perhaps two men at most and there is no indication of whether a few more could be housed inside to fire out of the circular loopholes in the side. Even ignoring those loopholes, that would be at least 9 men (2 drivers, 7 gunners). Despite the large crew complement, there is no indication as to how they could get in or out of the vehicle, as no hatches are shown. This leaves the only obvious means of access being to dip under the outer edge of the body and to climb in from ground level. This was perhaps acceptable for a display machine operating in parades, but was both utterly impractical and potentially deadly if there was ever an idea that this vehicle might serve as a template for a combat-viable vehicle. After all, if, operating on slightly soft ground, the vehicle caught fire, none of the men would be able to get out.

Image of the Holt 75-based vehicle which appeared in the press mid-October 1916. Note the lack of ‘America First’ on the side.
Source: Harper’s Weekly


The Holt tractors, sold under the name ‘Caterpillar’, were effective and reliable tracked tractors, but they were relatively slow and heavy. They were, after all, designed for hard work, ploughing fields, etcetera. There, power and pulling were more important than speed or comfort. Unarmored, the Holt 75 tractor normally weighed 10,432 kg (23,000 lbs.). With a 75 hp engine, this meant a power to weight ratio of just 7.2 hp/tonne. Any armor or armament on top of the vehicle’s base weight would only decrease performance further, as well as altering the center of gravity, making it less stable. To have armor of any value, such as for stopping bullets, such a vehicle would need at least 6 to 8 mm of steel. Covering such a large body in that shape would add several tonnes to the weight. Assuming the weight of any armor, crew, armament, ammunition, etcetera added to the Holt 75 to make it into a ‘tank’ could be kept to perhaps not more than 10 tonnes, then it would mean a vehicle of over 20 tonnes propelled by just the same 75 hp engine, with a power to weight ratio of 3.75 hp/tonne. Effectively, in order to carry enough armor to be useful, this vehicle would become stuck on anything other than an ideal hard surface, at which point it may as well have just been an armored car, the type of which were already in existence. The design, as presented, could never be a viable tank in that sense – it was a display vehicle only, and the ‘armor’ likely just sheet metal fastened over a wooden frame to keep weight down. The bigger problem for the design was the armor at the rear. Any vertical slope or step to climb would raise the front of the vehicle, pivoting over the track area, where the longitudinal center of gravity was, making it tip back. The projection would then dig into the ground and immobilize the vehicle, therefore seriously limiting the amount of climb possible.


In 1916, at the time the America First vehicle was being prepared, there were two plants owned by Holt producing the 75 Model. One was at Stockton in California, and the other at Peoria, in Illinois. Given that the parades taking place with the vehicle were in Peoria, it is virtually certain that the Holt 75 used was a Peoria-built example.

The tractor was powered by the Holt M-7 7 ½” (190 mm) bore, 8 inch (203 mm) stroke ‘valve-in-head’ engine delivering 75 hp. It had been in production since 1913, originally under the name Holt 60-75 (A-NVS), followed by the slightly improved Holt M-8 series engine. This was the standard engine and virtually unchanged until the end of production of the tractor in 1924.

This engine was a 4 cylinder water-cooled unit that ran on paraffin, with a capacity of 22.9 liters (1,400 cubic inches), delivering 75 hp at 550 rpm. This power was carried to the drive sprockets moving the tracks via a multiple disc clutch made from 5 plates made from bronze and cast iron, along with a simple reversing gearbox. The gearbox provided for 2 forward and a single reverse gear. Forward speed was limited to 2.13 mph (3.4 km/h) in first gear, 3.5 mph (5.6 km/h) in second (top) gear, and 2.13 mph (3.4 km/h) in reverse. The fuel tank held 53.5 Imperial gallons (243.2 liters) which, along with 5 Imperial Gallons (22.7 liters) of oil, and 67 Imperial gallons (304.6 liters) of water, provided the fluids required for the engine to operate.

The Holt tractor itself used cast iron wheels running on heat-treated axles on Hyatt roller bearings. The track was connected by case hardened steel pins linking pressed steel plates 24” wide (607 mm), although 30” (762 mm) wide tracks could be fitted. All of the links had pressed corrugations, 1.5” (38 mm) deep, acting as spuds for traction in soft ground. The load was carried on four double-coil helical springs springing the track along its 80” (2.03 m) ground contact length.

The steering was managed via a single wheel at the front, controlled via a long steering control shaft from the steering wheel and driver’s position. This was located roughly in line with the center of the track units. The steering wheel controlled a non-reversible worm and wheel gear.

Side elevation of the Holt 75 hp tractor.
Source: LeGros

In Action

A somewhat fanciful depiction of the America First tank in action appeared at the end of October 1916, a few days before any pictures of an actual tank were available. The artist made it seem like this giant slug of a vehicle was a viable weapon.

A close look at the image, however, provides some additional information on the structure. If it is correct in its representation of the vehicle, then the top of the hull was formed without a seam or joint along the top, meaning 5 large curved pieces made up the whole upper structure. Less believable are the three (or possibly four) large guns poking out of that small cylindrical turret leaving zero room inside for any crew, loading, or even a breach for the guns.

The fanciful depiction of the Holt design in action crossing an enemy trench scattering the defender with three guns crammed into the tiny turret Source: Image edited from the Ogden Standard 21st October 1916

More interestingly, perhaps, than the fanciful depictions of these weapons in use, is that the front wheel of the tractor can clearly be seen to be suspended in thin air over the trench. This was not an error of art and was either good luck from the artist or an actual representation of something the tractor was often pictured doing – driving with the front wheel off the ground. This is because, despite the engine being towards the front of the vehicle, most of the weight was at the back, over the tracks. The result was that, when ascending or descending a slope or when crossing an obstacle, the front wheel was often seen off the ground. This looked very dramatic for images showing the capability of the vehicle, but was a serious problem if the vehicle needed to turn. That small wheel was the method of steering the vehicle and, when it was not in contact with the ground, this was a problem.
Front page of French periodical Le Miroir in April 1917, showing the same ‘wheel off the ground trait’ from the Holt tractor. Note that this vehicle is also based on the 75 hp Holt Caterpillar but was only a movie prop and not a serious tank design.
Source: Le Miroir


The first use of tanks was on 15th September 1916 and the first photos in print did not appear in the USA or anywhere else until the middle of October. This left a gap of around a month in which various drawings and pictures of tanks were published in the press based on descriptions, which were often rather laughably inaccurate. In this gap came the vehicle from Holt, which was not a serious design for use off-road and was clearly put together as quickly as possible to show off the contribution of Holt to the war. By the time photos became available in the US press, at the end of October (although not in the British press until November), showing what real tanks looked like, such a vehicle from Holt probably looked a little ridiculous, sharing no design features at all with the real thing. By November 1916, the vehicle appears to have disappeared from the parade scene, likely stripped of its body and simply reused as a tractor.

The giant bulk of the vehicle is obvious from this image, as are the tubes poking out of the front. The unusual squiggle on the front is not part of the design, but a left-over part of a newspaper headline printed over the photo when it was published. Obvious in this image is the total lack of hatches for the ‘crew’ to enter.
Source: Image edited from the Ogden Standard 21st October 1916 (image has been digitally cleaned)
Post-WW1, General Swinton (right) was one of the two men credited as the actual inventors of the tank (along with Sir William Tritton) and is seen here shaking hands with Benjamin Holt next to a Holt Caterpillar in Peoria, Illinois, August 1918. The caption was carefully and still not technically correctly worded, saying “General Swinton made his first public acknowledgment of the fact that he derived the traction principle for the tank from a Holt Caterpillar”. Such public recognition and attention for Holt only served to continue the misconception that British tanks were based on the Holt traction system, which they were not, unlike French tanks like the CA1 and St. Chamond, or the German A7V, which were actually based on Holts.
Source: NARA Re: 165-WW-425-869
The Holt ”America First” Tank. Illustrated by Yuvnashva Sharma.
Original Press Photo of the vehicle
Source: Western News Union


Alexander, J. (2015). Briefly Famous, The 1917 Caterpillar G-9 Tank and other American Tanks 1916-1918. Privately Published.

Corsicana Daily Sun, Texas 4th November 1916

Le Miroir, 29th April 1917

LeGros. (1918). Traction on Bad Roads. Reprinted 2021 FWD Publishing, USA

Harper’s Weekly 16th October 1916

The Ogden Standard, 21st October 1916, To the rescue in a land cruiser.

Young, J., Buddy, J. (1989). Endless Tracks in the Woods. Crestline Publishing, USA

Specifications (Holt America First)

Crew 2+ (Driver)
Propulsion Holt M-8 series paraffin engine delivering 75 hp
Speed (road) <3.5 mph (5.6 km/h)
Armor Nono
WW1 British Prototypes WW1 US Prototypes

Automatic Land Cruiser – ‘Alligator’

USA/United Kingdom (1915)
Tank – None Built

The USA was a latecomer to WW1. By the time they started sending men and machines to Europe to fight the Central Powers (Germany and Austria-Hungary), it was June 1917. By that time, millions of men had already been killed and the war on the Western Front had become a war of attrition in trenches in a shell-blasted landscape.

Prior to this date, however, parts of America had not been idle. Indeed, the first British work on tanks had used the American Bullock Creeping Grip track system, which formed the basis first of Colonel Crompton’s work and was eventually fitted to the vehicle commonly known as Little Willie – the world’s first tank.

What is less known is that the Bullock system was also planned for use by another retired British officer – this time in America, albeit at a time when the British were dropping the Bullock tracks in favor of their own system developed by Sir William Tritton and William Foster and Co. Ltd.

The British man concerned here is Alexander McNab and he was based in the heart of America’s arsenal – Hartford, Connecticut. A ship engineer by profession, he proposed a well shaped and well armed ‘tank’ which became known as the ‘Alligator’ – the most viable tank design to come from America in the whole war.


The first use of tanks in WW1 was by the British at the Battle of Flers-Courcelette on 15th September 1916 as part of the Battle of the Somme, and there was a quick reaction to the employment of this new mechanical weapon of war in the press around the world. Various newspapers, magazines, and artists, whether officially or even humorously, tried to envisage what these machines looked like based only on written reports, leading to some rather outlandish ideas of what a ‘tank’ looked like. However, it was not until November that year, when the first official photographs were passed by the censor and published in newspapers, that the public finally got to see these machines.

In this dark period between knowledge of their use and the first photos lay, amongst others, a serious article in Scientific American published on 7th October 1916. Serious because, unlike the majority of newspaper speculation which seemed (especially in America) to claim that the Holt tractor was the basis of the British tanks (it was not), Scientific American instead considered them to be based on the Bullock system. They were not based on that either, but they could not have known this at the time and given that the first tank, known as Little Willie’ or the Lincoln No.1 Machine, was indeed fitted with Bullock Creeping Grip tracks when it was first made, meant that this is a very forgivable error.

A Mk.I Female tank is seen in multi-colored camouflage and using a pair of wheels at the back. Of note are the wire nets over the top, intended to stop grenades from landing on the roof, and the leather helmet worn by the man standing out of the top. Although this was the first official photo of a tank, the first images of tanks did not reach the public until November that year.
Source: Imperial War Museum Q2488

Scientific American, in their article, presented what was to be a common image of the Alligator tank which they described as “a military tractor for use against the trenches”. They claimed that the vehicle had been designed as a response from the British to an unnamed “Western firm” and named the vehicle as an ‘Armadillo’. Given the rounded top of the Alligator and the lines of bolts holding it together, the name Armadillo is, despite it being the product of the magazine, perhaps a better name than the name provided by the designers.

When the article is referring to a “Western Firm”, it is unclear if it is referring to the Bullock Company’s work for the British in 1915 supplying lengthened versions of their Creeping Grip or something else. Certainly, it is possible that the Bullock work was being referenced, although it is notable that the company was actually based in Chicago, Illinois, in the east of the country.

Scientific American went on to state that the design for this vehicle was submitted to the British Naval Munitions Board in London some months prior to the actions by tanks that September. The armored tractor shown in Scientific American, named as ‘Armadillo’ in the artist’s rendering, was not the product of some artist’s febrile or absinthe-induced imagination like so many others, but one based on these Bullock Creeping Grip plans.

The Alligator, as imagined by the artists at Scientific American and based on the published drawings. Here it is shown patriotically and dutifully crushing ‘the Hun’ in their trenches. Of note is that the tank is shown with Maxim-type machine guns in the front in error. The lengthened Bullock Creeping Grip tracks are evident.
Source: Scientific American.
Plan and side view of the Alligator, as published in Scientific American. Note the high position of the driver in the center.
Source: Scientific American.

The Men

In understanding the origins of the Alligator, those behind it need to be considered. There are, in fact, two men involved in the story of the Alligator. The first and most important was Alexander McNab. The second was an American called Norman Leeds.

McNab was originally from Scotland and according to him, had served 12 years in the Royal Navy, finishing with the rank of Lt. Commander. As early as July 1913, he was demonstrating his skill as a marine engineer, with a patent application for an automatic circulator for a steam boiler, followed by another patent related to steam boilers in 1914, and a third in 1915.

From those patents and US census data, followed by his military census record of 1917 as well as various local newspapers, it is possible to determine that he was a British citizen born in 1876, meaning that he was 38 years old at the outbreak of the war.

In 1917, he had given his original occupation in the USA as an inventor and that he was, by that time, a marine engineer and was running the McNab Company (and McNab Indicator Company) which made nautical and engineering appliances, including his ‘iceberg detector’, amongst others.

He would eventually move around Bridgeport as his fortunes increased through the First World War, with addresses changing from Post Office Arcade (1915), where the McNab Indicator Company held large offices on the 1st floor (2nd floor in America), to Fairfield Avenue (1916), and Brooklawn Park (1917). By the time of his last patent in 1931, he was still in Bridgeport but was residing on Main Street.

The elegant Post Office Arcade in Bridgeport, Connecticut. The building survives to this day.
Source: Bridgeport Library

The second man was Norman Leeds. Leeds was the managing director of the Automatic Machine Company (A.M.C.) in Bridgeport, Connecticut. Born on 15th November 1871 in Manhattan, New York, Leeds was an American citizen also residing in Bridgeport (on Boston Avenue). Unlike McNab, however, prior to 1917, he had no prior military experience disclosed on his US military census card. He had, however, a prior career with Western Electric Company amongst others, until 1908 when he and a few others took a controlling interest in the Automatic Machine Company. Leeds was also the President of the Board of Construction and Supply in 1914 and both he and McNab were donors to various charitable causes in the area, in particular when war broke out.

Norman Leeds pictured in 1922.
Source: The Bridgeport Times

Together, these two men worked to seek potentially lucrative engineering work for the new war in Europe. This is no surprise, as that area was producing vast quantities of arms at the time. The nearby town of Hartford, for example, was where John Browning invented his automatic pistol machine gun and automatic rifle in 1917 and the location was home to the Colt Armoury, which made more than ½ million guns during the war.

Both men were skilled and knowledgeable in the boat industry, with A.M.C. producing, amongst other things, boat engines ranging from a single-cylinder motor producing just 6 hp all the way up to a 6-cylinder 150 hp unit as their common motorboat engines. By at least 1913, they were also offering engines up to 250 hp.

In July 1912, Leeds was already in the news, traveling around Europe in order to promote and sell his marine engines. Business was obviously good enough to sustain the enterprise through to the start of the First World War in 1914.

Advertisement for Automatic Machine Co. marine engines. Source: Motor Boating March 1911

The Design

Using the lengthened ‘Alligator’ type tracks from the Bullock Creeping Grip tractor, the vehicle was to be some 23’ 6” long (7.16 m) long, 10’ (3.05 m) wide, and 11’ (3.35 m) high. The front of the vehicle was noticeably pointed, with an upturned portion at the bottom and then meeting at a point to the two sides forming a piked-nose. Directly above this double-glacis was a fighting section consisting of a semicircular shape with three guns pointing forward and to the sides. The sides of the hull were vertical and the roof curved, creating an arched roof over the large interior. The rear of the machine was rounded off with a pair of guns pointing backward. On each side of the machine was a small sponson projecting outwards, fitted with yet another gun. Surmounting the whole lot was a low cylindrical structure for the driver and commander to see out of.

The fuel tank was designed to sit directly above the water tank and directly in front of the driver’s position which, rather like the later German A7V, was atop the vehicle. The driver was, therefore, sat directly above the gearbox and controlled the direction of the vehicle with a simple steering wheel. This position would provide an unobstructed view of the terrain ahead, but also created a huge blindspot at least the length of the vehicle directly in front of it. This would mean that the vehicle was dangerous to maneuver against obstacles close by and, should the front elevate to cross an obstacle slightly, the driver would see nothing but the sky above, making control of the machine difficult.

Crew-wise, there are no details at all, other than an obvious driver’s position atop the machine. Assuming two men in the elevated driver position (a commander and a driver), and at least one man per gun, this would mean a crew of not less than 9 men.

Development and Timeline of the Alligator

It was apparent to Leeds and McNab that the war engulfing Europe brought with it certain commercial opportunities. It is also clear that reports of this new war and the shocking numbers of casualties were something their respective engineering skills might be able to redress. The result was Leeds’ idea for a fully tracked and armored fighting machine to break the deadlock. His initial design work on this vehicle idea was completed on 9th July 1915.

Shortly thereafter, he consulted with McNab and some changes were made to the design, with this second version ready on 14th July, making this a sort of Anglo-American project. No drawings are known of the first Alligator design to which a comparison with the modifications done in conjunction with McNab could be made. It is not clear, therefore, how extensive or visible, if at all, any of the changes were.

The Alligator, as it appeared in Scientific American in October 1916. Despite the lack of public knowledge of what British tanks actually looked like, the vehicle, as shown, is very competent. Full length tacks, a clear cupola to command and steer from and well positioned armanet on the front and sides. Note the distinctive swirl-pattern of the Bullock Creeping Grip wheels at the front and rear of the track. Source: Scientific American.

There was no point in having a design for this weapon of war and having no means of selling it, so, Leeds tasked McNab with taking it to the relevant British and French authorities. This is at least part of why Leeds brought McNab into the project in the first place, although this is perhaps unfair to McNabs’ skills. They were both in the same industry, both qualified and skilled men and McNab had the advantage of being British, ex-Royal Navy and therefore more likely to be taken seriously by the British establishment, as well as able to leverage whatever contacts or knowledge he would have as to where to go with the concept.

McNab left New York on 17th July, arriving in Liverpool on 27th July 1915. Upon arrival, he went to see Colonel Holden, then head of the British Army’s Army Service Corps (ASC). McNab left Holden with a copy of the plans for the vehicle, even though he was unable to assist McNab. It seems that rather than digging further into the military establishment in Britain, McNab chose to get straight over to France instead.

He had only been in Britain until 15th August, meaning a stay of just 19 days. Two days after his arrival in Paris, McNab tried to elicit interest from the French military authorities in the vehicle in a presentation at the War Office in Paris. McNab was left with the impression that the French were interested in the idea of the vehicle and especially in placing an order for engines from the firm. Nonetheless, he left on the 20th, after just 3 days, and returned to London. On 23rd August, McNab met with General Moir (Comptroller of Munitions Inventions) who, according to McNab, was so interested that he sent McNab to get the plans back from Holden to show him. Why that course of events was necessary was utterly unclear as, apparently, on his sales trip, McNab must have only brought two copies of his plans with him – something of an oversight for a sales trip.

Following the conversation over the plans with Moir, an appointment was made for him to attend the Naval Armoured Car Division at Pall Mall and once more reported that the officers he spoke to were very interested. He thereafter returned to the USA.

The first trip had clearly pricked some interest and it spurred a second trip, which took place in September that year. By the 8th of that month, McNab, visiting London with his wife, even managed to witness the aerial bombing of London by a Zeppelin from their balcony at the Metropole Hotel. Traveling to France on this second trip, McNab was able to speak with Monsieur Corcas, the Secretary to Albert Thomas – the French Minister for War. M. Thomas was later to be a thorn in the side of the nascent French tank program, which was working on a 2-man tank from Renault (the Char Renault FT), as Thomas had wanted a bigger machine.

McNab was back in Bridgeport by the 24th, meaning that this second trip – like the first, was an all too brief affair. Seemingly, no more was heard of the matter and, with the failure to obtain either engine orders separately or together with their vehicle design, both men went back to their normal business but still seeking to profit from the war. The same month McNab returned from his second visit to Britain, he was acting as a promoter for the New England and Pacific Steamship Company – a company he founded in 1915 to ship goods from Bridgeport and New London to the Pacific Coast via the Panama Canal. He advocated strongly for this war as a “golden opportunity” for the US shipping industry to produce as much new merchant shipping as possible, both for commercial benefit and replace the losses of Allied shipping by German submarines.

Even though their efforts had been unproductive, both men were still successful in other respects. In February 1916, McNab was giving his title as ‘Vice-President of Marine Specialties Ltd.’ and had made yet another trip back to France, where he had engaged with the French military authorities over his becoming an advisor to their engineering corps. The advisor stint perhaps was a little bit of an overstatement by McNab, as he was back in the USA in March 1916 with his wife who had accompanied him to France suggesting a little more of a business trip combined with sightseeing than a formal appointment as a technical advisor.

When in September 1916 Leeds and McNab got to hear about the use of tracked armored machines on the Somme, it is therefore forgivable and understandable why these men might believe that their machine was the basis of the British work. They could not, and would not have known of the top-secret work which had already taken place a year beforehand to develop a machine better than theirs. British work had, in fact, started in February 1915 – several months before their own efforts.

Certainly, McNab remained closely involved in both his Bridgeport community as well as providing talks locally on the war. In March 1917, he was providing local talks on the war in the Bridgeport area, claiming to have been to France to study the war, although, given that even the Landship Committee (the body tasked with designing and buildings Britain’s first tanks) was denied access to the front line, his reconnaissance would likely have been fruitless. The idea that he would be directly visiting the front is also undercut by the fact he had brought his wife on the trip and was mainly reported to be in Paris.

In September 1916, following the announcement of the British use of this new weapon, there was obviously a lot of attention paid to the machines and, in response to this event, Leeds was claiming that it was he who had invented the tanks as used by the British. He pressed the fact that it was he, not McNab, who pushed for their ‘tank’ design and that he had commissioned McNab to go to Europe in 1915. The phrasing of his claim is significant because when it states “….McNab… to go to England and France and try to enlist the interests of the Allies in the invention, but that since then the English have adapted the idea by using an English engine”. In other words, whether or not the idea was to promote the whole design or just the engine within it, as the Director of a business supplying marine engines, his concern was with engine production contracts.

It could be taken from that statement that his primary goal was only to sell engines, but then why go to the effort of designing or promoting the vehicle around them? This claim is also the origin of the ‘Alligator’ perhaps being explained as to why the name is applied to the vehicle as Leeds states that his design was more to do with that type of tracked vehicle than the Holt caterpillar.

In November 1916, just two weeks before the first photos of British tanks were published, Leeds provided the most thorough account of the theory, purpose, and design of the Alligator vehicle.

In that article, Leeds described that it was he who, upon realizing that combat on the Western Front had ground to a halt, had conceived of a vehicle based on this Alligator-type tractor chassis, long enough to cross trenches and that the tracks would not be bothered by enemy barbed wire. Clad in armor and fitted with weapons, the machine would break the deadlock and bring victory for the Allies – at least in theory. With the knowledge of the vehicle in use in September 1916, but unaware of what the machine was that the British were using or when they had started their secret design work (before his own), his claim to the invention is understandable if incorrect.


No armor thickness is specified in the writing available from Leeds or McNab. However, the protection was going to be substantial, as Leeds was wanting armor capable of protection from enemy 3” (76 mm) guns. However, when it came to convincing the British or the French over the design, Leeds and McNab were quite happy for the end-user to determine the final armor protection.

Although the protection level is not specified, it is reasonable to assume that, at an absolute minimum, protection from bullets would have to be provided, meaning at least 8 – 12 mm of plating. The available images of the Alligator show that the body is riveted together throughout. With the heavily angled front, the Alligator design would actually provide some sharp angles to incoming fire to help deflect shells and bullets and the same was true for plunging fire on the roof. Overall, this rather crude machine was well designed in terms of a shape for ballistic performance in comparison to its contemporary British designs.

Construction and Deployment

Leeds proposed at least 1,000 such machines would be required – certainly a very healthy contract if he had to provide the engines. For use, he imagined them operating as a naval screen, protecting the soldiers who followed from enemy fire both with their armor and also by attracting the enemy fire to them.


The artists for Scientific American clearly drew Maxim-type machine guns in the vehicle. Belt fed, these guns were definitely not the same as the ones shown in the plans of the Alligator, and neither Leeds nor McNab mention exactly what weapons they were proposing. The drawings are unclear, but there are some options as to what the guns may be.

A close-up view of the front of the Alligator from Scientific American clearly shows Maxim-type machine guns fitted. Note the vision slits to the right of the machine guns.
Source: Scientific American
Digitally cropped from the drawings shown in Scientific American the armament for the Alligator clearly sits atop a skewed conical mounting and is more than a mere machine gun. What appears to be a small hand crank is visible in the right-hand image and the outline of what may be a magazine sat on the top left-hand side at the back. Source: Scientific American as modified by the author.

The first option is the Driggs-Schroeder 1-pounder gun. Like all Driggs-Schroeder guns, this used a rifled barrel where the twist progressively increased towards the muzzle. The 1-pounder guns all had a caliber of 1.445 inches (36.7 mm).

The gun had started life in 1889, with a request from the US Navy for a 1 pounder gun that could outperform existing designs and still be under 100 pounds (45.4 kg) in weight. The result was the Driggs-Schroeder 1-pounder Mark I, with a 40-caliber bore and firing shell at a muzzle velocity of between 1,313 and 1,800 feet per second (400 to 549 m/s, respectively).

A second design followed shortly thereafter, known as the Mark II, with a 50-caliber barrel and a muzzle velocity of 1,884 fps (574 m/s). It used the same shell with 140 grams of black powder as the propellant, as used in the Mark I gun.

A final version of the 1-pounder was developed specifically for light vessels, such as yachts, and used a shorter bore (33 calibers) and a lighter charge than the preceding guns. Made in one piece as forging, the light 1-pounder was 12 lbs. (5.44 kg) lighter than the Mark I, weighing in at 88 lbs (39.9 kg).

The total shell weight, including case and propellant, was 1.53 lbs. (0.69 kg), with the actual projectile weighing 1.06 lb. to 1.10 lb. (0.48 to 0.50 kg) including a 0.03 lb. (13.6 gram) burster charge in the armor-piercing shell. With no burster charge or fuse, the armor-piercing shell weighed 0.94 lb. (0.43 kg). This shot was capable of perforating up to 1 ¼ inch (32 mm) of steel at point-blank range and up to ¾” (19 mm) at 1,000 yards (914 m). These shells were developed for naval combat but were more than sufficient to deal with the tanks of WW1.

1 pounder Driggs-Schroeder gun on standard conical recoil mount. The small size of the gun is readily apparent.
Source: American Ordnance Company

A lower weight of gun was obviously a good thing to help keep the weight of a vehicle down, as was the reduced charge. This would result in reduced recoil forces, meaning any mounting could be smaller and lighter as well. Considering that the low-power 1 pounder was designed on a simple conical mount and bolted to the wooden deck of a yacht, this was an excellent choice of gun for a tank design in terms of dealing with enemy bunkers or penetrating the shield of a field gun, or even enemy armor.

Unfortunately, the small size of the gun came with a serious handicap – a small shell. For the Driggs-Schroeder guns, steel shells with a base fuse and small explosive filling (Armor Piercing High Explosive – APHE or ‘Semi-Armor Piercing’ – SAP) and common (High Explosive – HE) shells were available for all calibers. The small size of the 1-pounder HE shell, however, would mean a very weak performance for a round which would be needed in the anti-infantry role or to smash an enemy position.

1-pounder steel shot fired from the Driggs-Schroeder gun and photographed after having penetrated a 1 inch (25 mm) thick iron plate (right), the shell on the left is a 3-pounder Driggs-Schroeder after passing through a 3 inch (76 mm) thick iron plate. Note that neither shell has burst from the small explosive filler so was presumably fired unfused to demonstrate the robust steel body of the round. The contrast in size between the two shows the diminutive size of the shot from the gun selected for the Alligator.
Source: American Ordnance Company
1-pounder standard shell (left) compared to the 1-pounder low-power cartridge (right). Both fire the same 92 mm long shell but from different sized cases.
Image composited by the author.
Source of the original: American Ordnance Company
Steel armor-piercing shell (left) showing the base fuse and small high explosive bursting charge compared to the common shell (right) with the larger charge. Image composited by the author.
Source of original image: American Ordnance Company

The drawing is, however, different from the Driggs-Schroder guns in some important regards. Firstly, the barrel of the Driggs-Schroder gun appears to be thinner than that shown and, if the item on top is a magazine or feed-trough, then the breech-fed DS guns are not the ones drawn.

Another option is the Hotchkiss 37 mm revolving gun, another common, albeit somewhat ancient naval weapon (it first came out in 1871). This one, unlike the Driggs-Schroder guns, had both a vertical magazine on top and a cranking handle. With five 37 mm barrels, each 20 calibers long, the weapon was a means of delivering serious firepower both at sea and on land.

Hotchkiss 37 mm revolving cannon.
Source: Koerner

Described as a cannon, the Hotchkiss revolving gun is basically a large compound machine gun with 5 barrels rotated by a cranking handle which also fed rounds from a vertical hopper or magazine on the top, firing them in turn as the barrels rotate. Each trough can hold up to ten rounds and, fed by another operator, the firing soldier operating the gun can fire between 60 and 80 rounds per minute. If he has to feed the trough on his own the rate of fire is still substantial, at around 40 rounders per minute.

For naval use, the gun weighed 200 kg, although the light version for field use was 225 kg, as well as having a ‘powerful’ version weighing 475 kg. The light versions of this gun were able to deliver their Common 37 mm shells out to 4,473 m.

Ammunition for the 37 mm gun included Steel shot, Common shells, and Canister shells, all using a metal cartridge case. The Common (High Explosive) Shell was made from cast iron and was hollow, with this cavity holding an explosive charge. Other calibers of this gun included 40 mm, 47 mm, and 53 mm caliber versions.

The Steel Shot was pointed and used no explosive bursting charge, relying on its mass, velocity, and shape to penetrate light armor and ship’s decks.

Left to right shells are Common, Steel, and Canister. The shell on the far right is a common shell, showing how large the complete round is with its case. Source: Composite image created by author from Koerner.

Even the Hotchkiss cannon is not a perfect match for the drawing. The feed-trough for the ammunition is not quite right and, of course, these are not multiple barrels shown. So perhaps the guns drawn in the Alligator are neither of these options. Given, however, that both Leeds and McNab were marine engineers and had expertise in shipping, it is no surprise they might select a gun like the Driggs-Schroeder or Hotchkiss. At the end of the day, however, they were also perfectly happy for the end-client to select and install their own armament to suit their needs.

Exactly what the guns were aside, the plans clearly show three of these guns in the front of the tank forming an arc across the front and able to provide fire across nearly 180 degrees of fire. Less clear are the side and rear guns, although these two appear to be the same designs, with one in a small sponson on each side, in a manner very similar to how British tanks did actually use them and then two more covering the rear. This meant a grand total of 7 guns although, in reality, rear-facing weapons would be of little use and the absence of a machine gun would render the machine more vulnerable to enemy infantry swarming the tank.

For the purpose of comparison, if the Alligator was fitted with the Driggs-Schroder guns and a modest ammunition supply of just 50 rounds per gun, this would mean a total load of about 520 kg. If it was the light Naval Hotchkiss 37 mm for the same assumption, it would be 2,263 kg – more than 4 times the weight.


Perhaps the defining element of the Alligator is not the shape, the guns, or even the attempts to sell it, but the selection of engine and track. The track, as already discussed, was an extended form of the Bullock Creeping Grip but the engine was not from Bullock.

The engine – the primary purpose of the entire project, was located just slightly aft of the center down the length of the tank and centrally along the longitudinal axis. It is clearly shown in ‘The Iron Age’ of September 1916 to be a 4 cylinder petrol motor from the Automatic Motor Company delivering 100 hp. The transmission lay in front of the engine and was itself preceded in the vehicle by a large water tank.

The ‘Alligator’ type tracks from the Bullock Creeping Grip tractor were to be 16’ (4.88 m) between the centers of the main wheels at each end and this length allowed the Alligator to cross a gap up to 8’ (2.44 m) wide.

For the Alligator, the Bullock suspension was stretched forming 6 distinct sets of bogies, each containing a trio of road wheels supported by a horizontal bar between them. Right In the middle of the length of the suspension is a single wheel on its own, meaning a total of 19 road wheels. This single central wheel was connected to the bogies fore and aft by a single horizontal bar running along all 7 wheels. Also visible in the cross-section view are 7 return rollers on the top of the track run, keeping the track tight.

Close up of the suspension system on the Alligator.
Source: Scientific American
Bullock Commercial Tractor with 150 hp engine and short tracks. Source: Le Gros
The lengthened Bullock Creeping Grip tracks ordered by Colonel Crompton and fitted to the Juggernaut / No.1 Lincoln Machine.
Source: UK National Archives

The track too was an issue. Colonel Crompton, whose work led to Little Willie, was certainly in favor of the Bullock track on the rather sensibly pragmatic basis that it was the only one available at the time that worked reasonably well. Nonetheless, there is no mention from Leeds or McNab of any idea of changing the actual track on the Bullock suspension so it can be reasonably assumed that the Alligator’s tracks would be little more than an extended version of those fitted to the Juggernaut/No. 1 Lincoln Machine.

The selection of the Automatic Machine Company 100 hp 4-cylinder petrol engine would certainly have been an improvement over the standard engines available from Bullock, of which the largest was the 75 hp 4 cylinder with a 5” bore and 6.5” stroke (127 mm bore / 165 mm stroke) as used on the Creeping Grip ‘Giant’.

Automatic Motor Company 4 cylinder engine as installed in a motorboat.
Source: Motor Boat, December 1920

However, assuming for a moment a similar level of performance from the Alligator as could be achieved at best from the Bullock Creeping Grip ‘Giant’, this would mean a top speed of 1.06, 2.4, and 3.4 miles per hour (1.7, 3.9, and 5.5 km/h) in 1st, 2nd, and 3rd gear and just 1.77 mph in reverse. Whilst the 100 hp engine from A.M.C. was larger, so too would be the weight of the vehicle and soft ground smashed by shellfire littered with the detritus of war and barbed wire would only serve to slow the vehicle even more. Certainly, the speed would be slow.

The End

In the end, the design of the Alligator came to nothing. The British, for their part, had already decided well before McNab’s first trip in 1915 on the direction of their own studies. Regardless of any advantages or disadvantages the Alligator had, the work did not appear to influence British designs in at least so far as the tracks and body shape. The one piece which could be argued was derived might be those side sponsons that were to become the dominant and most recognizable of features of British tanks of WW1. These too, however, may also be explained by the British designers – men like Sir Eustace D’Eyncourt who was himself a naval architect and simply took inspiration from naval weapon mounts as well.

Whatever claim to the invention of the tank in whole or part by Leeds and McNab they do not seem to have engaged with the Royal Commission on the invention of tanks after the war to press their case. Perhaps it is not too surprising either – there was a wealth of inventors both genuine and fraudulent after September 1916 claiming to be the inventor or inspiration for the tank. They were also successful businessmen and had moved on from their foray into tanks.

The design, however, was actually rather well organized, providing substantial firepower directly to the front as well as coverage over the side. In some regards, the design even had a better fighting arrangement for the crew than was on the later British Mk.I, as the engine was further back and control could be by a single driver rather than a driver and gearsmen having to work together.

The biggest flaw in the idea was the tracks. Whilst the lengthened Bullock system was a good system, it simply was not as good as the Tritton system the British were eventually to adopt and the track layout was just too simple. No Alligator tanks were ever built.

McNab passed away on 6th March 1941 and his former colleague, Norman Leeds followed him three later, dying on 29th October 1944.

What-if view of the Alligator Automatic Land Cruiser in green camouflage. Illustration by Pavel Carpaticus Alexe, funded by our Patreon campaign.


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Bridgeport Evening Farmer, 20th September 1915: ‘See airmen fight over city roofs’
New Britain Herald, 20th September 1915. ‘London damaged by Zeppelin raid’
The Farmer, 24th September 1915: Connecticut shipyard owners have unusual opportunity to restore once famed business’
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The Farmer, 3rd August 1916: ‘M’Nabs indicator is advertised in wireless waves’
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‘Alligator’ specifications

Crew est. 9 (Commander, Driver, 7 gunners)
Propulsion A.M.C. 100 hp petrol
Armament up to end-user but shown with 7 guns of an unknown type
Armor up to end-user but desired protection from 3” (76.2 mm) enemy guns
For information about abbreviations check the Lexical Index
WW1 US Prototypes

Miller, DeWitt, Robinson SPG

USA (1916)
SPG – None Built

World War One brought about numerous technical innovations to break the stalemate of static warfare which had rapidly become the defining characteristic of the war. Then, as now, it was artillery that was the key to defeating enemy defenses. The need to move large caliber guns to the front was fundamental to any army trying to achieve a breakthrough. Although the USA was not at war in 1916, this was a conflict watched keenly around the world as the fighting developed and was widely reported. Stanley Glonin̈ger Miller from St. Paul, Minnesota, a manufacturer by trade, Dorcy Olen DeWitt, also from St. Paul, who worked for the Crex Carpet Company as a machinist, and Myron Wilber Robinson, from New York City and also a manufacturer, submitted a patent application on 21st February 1916, ostensibly as an ‘Improvement in Belt-rail tractors’ for military purposes. What they actually designed was one of the world’s first tracked self-propelled guns.

The information for the design is held squarely within patent applications filed in the UK, Canada, and United States by those three men. These three men knew each other, as they all worked at the Crex Carpet Company. DeWitt was a machinist and employee, Miller was a Vice President, and Robinson was the President of the firm.

The firm itself bears some scrutiny, as it took harvested and dried wiregrass and wove it into twine and later into wicker products. The company had previously been the American Grass Twine Company which, in 1903, was rebranded as ‘Crex’, taken from the Latin name for the grass used, Carex Stricta. Woven into mats and carpets and wicker products, Crex was a profitable market-leading company for a short time and was even listed on the New York Stock Exchange in 1908.

Large factory floor space was needed to turn this dried tough grass into a workable material and machine looms would run, turning it into matting and carpet and eventually into wicker. By the time of the outbreak of the World War, the wicker industry from grass was waning. It was being replaced with wicker made from paper which had been invented in 1904 and, being cheaper to produce and easier to work with, rapidly ate away at Crex to the point where, in 1917, the firm had all but ceased to exist. Wicker was gone from its products and its decline only ended in 1935, when it finally went bankrupt.

This is relevant to the design from Miller et al. as, at the time it was drawn up, these men, who knew a thing or two about machinery and engineering processes, were looking for a new and profitable enterprise to which they could turn their energies.

Quite what inspired the design they came up with is not clear. It could well be a function of seeing tracked harvesting machines at work collecting their raw grass product. After all, this was the inspiration for Robert Macfie to look at Holt tractors in the UK in 1915 using his sugar plantation experiences.

With a war raging in Europe, it cannot have been made in isolation and, yet, the time of application for the patent is somewhat remarkable. January and February 1916, just months after the British had ordered a Top Secret new weapon into production – the tank. There was absolutely no way in which these men could possibly have known of that development so this was an advance made in isolation, a case of convergent evolution where the same solution comes about as a result of the same pressures.

The patents in question were filed in the UK on 18th February 1916, but the Canadian filing for it was even earlier, on 20th January 1916. All this was at a time when the United States was not even engaged in World War One, but in which these men could not have been unaware of one of the key problems encountered – how to get large artillery guns and other material to the front.


Traveling on what they called a ‘belt-rail’, which would be recognized today as a caterpillar-type track, the machine was to be able to traverse irregularities and undulations of the ground, soft or broken, and small obstacles to get where it needed to go. One of the key features in doing so was to keep the center of gravity for the vehicle as low as possible to reduce the chance of it overturning.


The vehicle was divided into two sections. The first took the form of the mobile tractor frame mounted on tracks and which was fitted with the engine and gearing. The second part of the vehicle was a structural framework that pivoted to the tractor frame. This part was fitted with guiding wheels that controlled the steering of the entire vehicle.

The primary frame was rectangular in shape and made from two longitudinal steel beams. Slung perpendicular between those two beams was a series of bracing beams to which the tractor units were connected.

Above the track units was a low slung platform on which the load of the vehicle sat.

Plan view of the vehicle showing three narrow track units supported by five supporting beams. The steering wheel can be seen at the front right of the track section and the large framework for the four drum-style wheels in front of that. Note that the image has been cleaned digitally to improve clarity. Source: UK Patent GB102849
Side view of the tractor showing the engine at the extreme rear, the very low-slung track units, and the four-wheel steering system at the front. Note that the image has been cleaned digitally to improve clarity. Source: UK Patent GB102849


In the patent drawings, three sets of tracks are used, but the description is clear that any number of track units could be fitted to a framework in this way. Power to those tracks was delivered via a very simple worm gear from the output shaft. This worm gear drove a large tooth gear that powered the tracks. The power for that worm gear came from an internal combustion-type engine.

Side view of the engine. It is clear that it projects over the rear of the tractor on a metal framework. The gearing from the engine and the engine is all exposed, but it is hard to imagine it would not be enclosed by some sort of cover had the vehicle even been constructed, as it would soon have fouled with dirt. Note that the image has been cleaned digitally to improve clarity. Source: UK Patent GB102849

The tracks were formed from interconnected metal links with a V-shaped grouser and were considered sufficiently different from existing tracks to warrant another patent application, submitted on the same day like that for the tractor. UK patent GB104135 for the tracks shows these interconnected thin one-piece links connected together by steel pins and using a built-in track guide in the center to hold the hold to the wheels preventing lateral movement. This is notable as, in 1916, the form of track being used was a simpler plate attached to a shoe, with the shoes being connected together and dragged around the vehicle by the drive sprocket. Early tanks, such as the British Mark I or French FT, used this shoe method. Those tanks also had separate plates which were fitted close together but did not intermesh. The design from Miller et al. wanted the edges of each link to intermesh with the preceding and following links. For a design in February 1916, seven months before tanks were even first used and entered the public imagination, this was an advanced system of track for a vehicle. It is worth noting that, although the British patent for this link was filed in February, the US patent for the tracks was filed on 10th January 1916.

The 1916 track links show a deep V shape for obtaining traction in the ground and an interconnecting link shape connected by steel pins. In the center of each link is a pronounced guide horn for keeping the track from sliding sideways on the wheels. Note that the image has been cleaned digitally to improve clarity. Source: UK Patent GB102849
From the patent for the tracks submitted at the same time as the tractor, more details of the design are clear, showing how the wheels ride on the inside of the links. This seems obvious in a 21st-century world, but in 1916, this was not the normal means by which tracks operated. Note that the image has been cleaned digitally to improve clarity. Source: UK Patent GB104135

Vertical movement of the front of the vehicle was controlled by hydraulic cylinders which served to prevent lateral movement but permit vertical movement whilst ensuring that the wheels stayed pressed onto the ground.

The similarity of this idea to the British use of wheels on the back of the Mark I tank in 1916 is very striking here. The Mark I used a system of springs to push the wheels down for the dual purpose of steering and to help raise the nose of the tank to climb obstacles. There is no mention of obstacle climbing assistance for the Miller et al. design, but the use of a system to keep the steering wheels pressed into the ground is very much the same.

On the Mark I tank, these were found to be superfluous and really a bit of a hangover from the original ideas of 1915, slaving tractors back to back, and were quickly abandoned. It is not necessarily the same situation with the Miller et al. design, as the wheels are at the front, substantially wider, and also more numerous. However, should Miller et al. have selected a second steerable track unit to be mounted in place of those wheels or a mechanism to vary drive to the tracks to provide the steering, this would have been a better steering solution for the vehicle.


No armament is specifically mentioned in the patent for the vehicle, other than to say there was sufficient space for “a gun”. The drawing, however, clearly shows a large-caliber mortar or howitzer on a mounting which appears to be shown capable of rotating on its base. Mounting a gun in this manner would have been a significant advantage for an Army of the age as, in 1916, there were no heavy guns mounted on tracked self-propelled carriages. Heavy guns, instead, had to be hauled around on old-fashioned wheeled limbers by horses, or trucks. This was a slow process which meant they were hard to move and slow to get into position on broken ground. They would then have to be set up in place to fire and could only fire from that position. If the gun had to be moved even a relatively short distance, it would have to be limbered back up, moved, dismounted, and set up all over again. This situation was even worse for large-caliber guns, which often had to be shipped in multiple pieces due to the size and weight of the elements of the gun and carriage.

With a self-propelled chassis, this was not the case and several armies, notably the Italians, placed field guns on heavy trucks to create a mobile artillery force. Whilst that system could indeed move guns around fairly quickly, what they could not do was move very well off-road and the maximum load carried was just 5 tonnes or so – limited by the strength of the truck frame and tires.

By using tracks in this design, Miller et al. would be able not only to move around on or off-road more easily but also carry a far larger (and heavier gun) if they wished to. A gun such as the British Ordnance BL 9.2” howitzer of the era weighed over 5 tonnes just for the gun alone, without including ammunition. A platform like this would have been able to mount such a gun and ammunition and the men to crew it and move it around. It might not have been fast but it would be a far quicker alternative method of moving the gun used to that point.

Seen as a whole vehicle carrying a hypothetical heavy gun of some description, the lack of wheels on the gun mount and elevation would indicate that it was envisaged that such a platform could be used to fire from Note that the image has been cleaned digitally to improve clarity. Source: UK Patent GB102849

Even if a gun was not being carried, this platform system would have been adequate for men, supplies, ammunition to be carried relatively simply, although it must be borne in mind that there is no armor and no protection from the elements for the men or load being carried.


The design from Miller, DeWitt, and Robinson was never built, it received no orders and the hopes of these men to profit from this design turned to nothing. When they submitted their design, Great Britain had already been at war since 1914 and, in 1917, the USA also joined in. Spring 1916, when they submitted this design, coincided with the British work on their new war invention, the tank, using a quite different system of track.

It would be 1917 before the British got their own tracked gun carrier, the Gun Carrier Mk. I. With a maximum payload of 7 tonnes, the Gun Carrier Mk. I allowed for heavy guns to be moved across broken ground with the added advantage of being able to load and unload field guns via a ramp at the front. No such ramp was provided for by Miller et al.’s design but it is nonetheless an advanced design and the tracks, in particular, were substantially more advanced as a design than those used on British tanks, although making them resilient enough for use is a different thing to designing them.

British Gun Carrier Mk.I. of 1917. Source: Wiki

Little can be found of the three men responsible for the vehicle, Dorcy Olen DeWitt, Myron Wilbur Robinson, and Stanley Glonin̈ger Miller. The US Census of 1910 and 1920 provides few details, but DeWitt is known to have been born on 23rd May 1880 and died on 15th June 1964. Myron Robinson, the President of the Crex Company and likely the team lead for this design, is more obscure. It is known that he was born on 11th August 1881 and was from New York but little more than that. The Crex Carpet Company went bankrupt in 1935 with just US$24.90 in the bank. The third man, Stanley Glonin̈ger Miller, is yet more obscure and all that can be confirmed about him at this time is that, in 1917, he held an associate membership of the American Society of Mechanical Engineers. The men were amateurs in that they were not military men or tracked vehicle experts, but they clearly knew about engineering and designed one of the first tracked self-propelled guns.

The vehicle would assuredly have been slow, the steering system inadequate, and the gearing system somewhat over-simplistic, but there is no denying the advanced design of the tracks and the theories being considered in mounting the gun.

The Miller, De Witt, Robinson SPG with the front wheels lowered down. This would have been one of the first SPGs in the world. Illustration by Yuvnashva Sharma, funded by our Patreon campaign.

Thank you to for supporting us in writing this article. Check out their free tank games on their website.


UK Patent GB102849 Improvement in Belt-rail Tractors. Filed 21st February 1916, granted 4th January 1917
UK Patent GB104135 Improvements in Beltrail Tractor Tracks, Filed 21st February 1916, granted 21st February 1917
Canadian Patent CA195323 Tractor. Filed 20th January 1916, granted 21rd December 1919
US Patent US1249166. Caterpillar Tractor Track. Filed 10th January 1916, granted 4th December 1917
Holmes, F. (Ed.). (1924). Who’s Who in New York City and State. Who’s Who Publications Inc. New York City, USA
The American Society of Mechanical Engineers Yearbook 1919. New York, USA.
Nelson, P. (2006). Crex: Created Out of Nothing. Ramsey County Historical Society Magazine Vol. 40 No. 4, Minnesota
United States Census 1910. Beloit Ward 3, Wisconsin Sheet A11

WW1 US Prototypes

Wagner’s War Tank

USA (1918)
Tank – None Built

The last name Wagner is more usually associated with classical music than armored vehicles, but Frederick Wagner of Detroit, USA may have had more than the compositions of his last-name sake on his mind when, in 1918, he submitted a patent application for a deceptively simply named ‘War Tank’.

The Man

Frederick W. Wagner of Detroit, Michigan may well have been one of the tens of thousands of immigrants to that part of Michigan who arrived in the years preceding the First World War from Germany and Poland. Sadly, the name is common enough both there and in Detroit at the time that it is not possible from available records to find more biographical information on him. What is clear, however, is that from a review of his design that his ideas were not as outlandish, impractical, or separate from mechanical possibility as many of those which had gone before or since. Indeed, it could be theorised that Wagner had either some experience in the vehicle field or at a minimum had done some research on armored vehicles when working on his own design. With both tracks and wheels, Wagner’s War Tank is not even one of those peculiarly limited number of wheel-cum-track machines which became popular during the period between the end of WW1 and start of WW2.


The donor vehicle for Wagner’s design, if it could be called that, appears to be based around a large agricultural or industrial tractor of some sort, with a pair of large wheels at one end and a pair of small wheels at the other. Usually, this arrangement is done so that the large wheels, which bear the majority of the load, are the driven wheels and the smaller wheels are steered. Also usually, these are arranged so that the large wheels are at the back and the small wheels at the front, a layout still on many tractors to this day.

Wagner’s War Tank
Digitally cleaned plan view of Wagner’s War Tank facing to the right with the large wheels at the front. Source: US Patent US1292170.

Wagner, however, had swapped this around. Not only are the small wheels at the back but also the large wheels which are at the front are the wheels used for steering. At first glance, this seems illogical, as larger wheels are harder to steer but the logic is actually clear as Wagner‘s vehicle would benefit when it comes to climbing over a parapet or across a trench where these large wheels are less prone to becoming stuck. One point of note on the wheels is that they were to be fitted with solid rubber tyres according to the text but are shown with agricultural-style ribbed steel treads around the circumference. A pronounced rib on the inner ring of the wheels is described as “detachable flanges”. The purpose of these ribs or flanges is so that, when not operating on road (on the rubber tyres), or off road in soft mud (on the tracks and steel treads), it could be conveyed on a railway either by itself or by being towed. In total, the vehicle was to be around 30 feet (9.14 m) long and 15 feet (4.57 m) high with a maximum width of 10 feet (3.05 m).

Wagner’s War Tank facing to the right
Digitally cleaned side view of Wagner’s War Tank facing to the right with the large wheels at the front. Source: US Patent US1292170.


Automotive power for Wagner’s design is somewhat lacking. He clearly states that the engine is to be a somewhat inadequate 50 hp, although he does not state if this was to be petrol, diesel, or kerosene. Power would be delivered by a simple connection of shafts which then drove chains connected to the rear wheels at both sides and the rearmost wheel of the four-wheel track unit slung underneath the hull. No means are provided by which to raise or lower the track units on each side, as they would only be in use when the vehicle sank into soft mud. Even so, as the large front wheels remain undriven, the entire effort of propulsion through the mud would be left to these small track units and small driven wheels. With such little horsepower available, it seems likely that Wagner’s War Tank would simply become hopelessly stuck very quickly once it sank into the ground. With the track units fixed, the vehicle is really an Armored Car with some track assistance rather than a ‘tank’ in the true sense of the world.


Multiple armaments are mounted on Wagner’s design, with two sponsons projecting from each side, a limited traverse gun mounted in the front and a fully rotatable turret on the roof. Mounted in all of these positions are what Wagner described only as “rapid fire guns” and then drawn as small cannons. The sponson guns are undoubtedly the weakest part of his design, as both of them can only face forwards or to about 90 degrees to the side. Whilst this means a lot of potential forward-facing firepower it also seriously limits the effectiveness of the machine. Perhaps this is why a small loophole is also provided in the side wall below the turret through which another rapidly firing weapon could be fired. Even so, that would only allow fire directly to the side and not forwards. The gun at the front would likewise be very limited to doing anything other than firing across a limited forward arc. To assist in firing, a searchlight was to be provided at some point on the vehicle (not shown) so it could operate at night.

It is the turret which is perhaps the most useful part of the design and something which, in 1918, was not even present on many tanks. With the ability to deliver firepower or allow for easy observation in all directions, the turret would logically be placed at the top or at least the front section of the vehicle. Here, however, in probably the single largest flaw in Wagner’s design, the turret is not only placed in the back half but also cannot fire to about 90 degrees of the front due to the built-up superstructure at the front half to accommodate two sponsons and the forward-facing gun. This limits the potential of the turret to just around 270 degrees of traverse and, with the rest of the guns positioned as they are, that at no point could Wagner’s design ever bring all of its guns to bear on a single target or even in a single direction whether fore, aft, or to the side.


No specific number of crew are mentioned by Wagner in his application and obviously at least one man is needed just to drive the machine, whether it is a ‘tank’ or a truck. With two guns in the sponsons projecting from each side, a turret and the forward-facing gun, men will obviously be needed to operate those weapons too. Even with just one man per gun, that is at least another 6 men for a crew of likely not less than 7 in total.

The driver would still be sat alone in the front, sandwiched between those two large front wheels, although his head height from the drawings would be above the top of the wheels so they would not obstruct his vision to the side.


The armored body of Wagner’s War Tank offers no finery or finesse in terms of shape, as it consists of not much more than a large rudimentary box. Wagner had, however, done this with the goal of having the body as simple as possible, so that it could be removed easily. With no armor, the machine would be left as a heavy utility vehicle for hauling guns or carrying men and stores. Here, once more the switch from the usual location of the small wheels at the front to at the back has an advantage for Wagner – it simply permits a larger load to be carried when not in use as a tank. In terms of protection, Wagner is clear that the vehicle would have armor plating (presumably steel) ¾ inch (19 mm) thick, certainly thick enough to protect against all of the standard small arms of the era.

Wagner’s War Tank facing to the right
Digitally cleaned cut-away side view of Wagner’s War Tank facing to the right with the large wheels at the front. Source: US Patent US1292170


Wagner’s ‘War Tank’ is certainly an interesting design coming in the final months of WW1 in Western Europe. The designer has clearly spent some time considering the relative merits of tracks and wheels and more so, the merits of large versus small wheels for traction. The wheeled part of his scheme, switching from the convention of small front to larger rear wheels provided the design with flexibility as a load carrier as for crossing obstacles. Likewise, the ability to use rubber tyres would provide a smooth ride of the road or then with the steel treaded wheels to gain traction off-road, and to provide for a means of movement by rail was a notable plus too. The tracks however, are simply superfluous. Slung underneath, they add a lot of weight and complication without any benefit up to the point of being bogged down, whereupon the low engine power seemingly would leave the vehicle stranded.

Whilst the adoption of a turret was a good idea for this vehicle, the multiple other weapons and the poor positioning seriously limits both the effectiveness of the turret and other weapons.

Overall, Wagner’s War Tank, whilst having some interesting technical merits and ideas, was a failure. No vehicles were made and, by the time the patent was granted, the war was effectively over anyway.

What Wagner’s ‘War Tank’ would have looked like. Illustration by Pavel ‘Carpaticus’ Alexe, funded by our Patreon campaign


Dimensions (L x W x H) 30ft x 10ft x 15ft
(9.14 m x 3.05 m x 4.57 m)
Crew 1 + at least 6
Propulsion 50 hp liquid fuel
Armament Rapid firing guns x 6
Armor 3/4 in (19 mm)
Total production None built


US Patent US1292170 War Tank, filed 17 July 1918, granted 21 January 1919

WW1 Italian Prototypes WW1 US Prototypes

Longobardi’s Combination Vehicle

USA/Kingdom of Italy (1918)
Prototype – None built

In the centuries of the patent system, a veritable pantheon of good and bad ideas have come and gone and, in the wake of World War One, this tradition continued with some truly awful ideas. One of these ideas was quite rightly consigned to the dustbin of history. The idea of a wonder weapon capable of fighting both on the seas as a warship, in the air as a combat aircraft, and on land as a tank. This is Mister Longobardi’s improbable armored car-plane-submarine-warship of 1918.

The Man

Felix Longobardi is anything but a household name, but there are clues to this man from his patent application in the United States on 12th June 1918. Mr. Longobardi provided a city residency as Chicago, Illinois and was clear that he was a subject of the King of Italy i.e. had not yet adopted US citizenship.

Felix Longobardi arrived at Ellis Island, New York on the SS Patria from Naples, Italy on 23rd September 1915 (the ship left Naples on the 8th) with his brother Domenico (and his brother’s wife), a baker by profession. As Felix was an “additional person” on that record to his 53 year old elder brother, it is fair to assume that Felix was born after Domenico although no actual date of birth or age is listed for him.

Ellis Island immigration register
Felix Longobardi’s name in the Ellis Island immigration register 23/9/15.

Felix is only recorded as submitting a single patent in the US – this one for the combination vehicle, although it should be noted that a ‘Felice Longobardi’ with an address in Chicago did submit a patent application in 1929 for a pneumatic vehicle wheel and used the same firm of attorneys to do so, namely Messers. Glenn and Noble. Whether this patent applicant is the same person as ‘Felice’ rather than ‘Felix’ cannot be determined.

To add to the unknowns about the designer, Felix is not listed on the 1920 or 1930 US census nor in the rolls of the US Expeditionary Force War dead from 1917-1919. What happened to him is unclear. He may have changed his name, returned to Italy, or been one of the numerous casualties of the flu which swept across the US at the end of the decade.

The Vehicle

The outline of the shape of the vehicle is very distinctive and, as can be imagined for a vehicle capable of operating in 4 domains, is impractical in all of them although it is really the break-down of trying to make a vehicle suitable to travel in each medium which requires some analysis.


As a land-based vehicle, the Longobardi Combination Vehicle is utterly hopeless. Four small wheels lie astride the central third of the vehicle along its length. None of the wheels appear to be fitted with any kind of suspension and the patent explains they are on common axles and can be steered somehow. The ground clearance for the vehicle is woefully inadequate for anything other than the smoothest possible road with the three propellers underneath in each third of the length reducing this even further. This terrible clearance is compounded by enormous overhangs at both the front and rear, meaning that the bow and stern of this vehicle would be guaranteed to strike the ground on even the most rudimentary upwards or downwards slope. Add to this the exceedingly narrow track width (the distance between the centre-line of the tyres of wheels on a common axle) and this ungainly machine is seriously overbalanced laterally. Should it attempt to negotiate even a modest side slope it would likely topple over.

The idea that this vehicle could be used as a land-based weapon of war is frankly therefore laughable and creates probably one of, if not the worst designs for an armored car imaginable.


When this design was submitted in 1918, the basics of flight had been known for many years and armies had already deployed aircraft in combat. As a result, there is little excuse for such an inadequately designed machine as an aircraft. Firstly, there is the problem of the wings. Two relatively short rectangular wings protrude from the front third of the machine, each of which is barely wider than the hull of the machine itself.

Longobardi’s Combination Vehicle
Digitally cleaned front views of Longobardi’s Combination Vehicle with wings out (left) and stowed (right). The extremely narrow track width is apparent. Source: US Patent US1286679

The main wings were to be supported by cables and were also hinged at the body. When not in use, these wings could be raised and stowed in the vertical position, ensuring that this already enormous vehicle was even more visible when used on land.

Propulsion in the air was the same as in the sea – propellers – lots of propellers. In fact, two large propellers at the front provide pull in the air and in the water. Likewise, the three propellers underneath were to provide uplift in the water and (according to Longobardi) in the air as well. Thus, these horizontal propellers could provide vertical trim and additional lift.

Control of the horizontal and vertical attitude of the craft was to be provided by means of the small tail rudder working in combination with a small set of wings at the back when operating in the air or water.

ongobardi’s Combination Vehicle
Digitally cleaned plan-view of Longobardi’s Combination Vehicle shown facing to the right. At the front a pair of propellers were to provide propulsion. Of note is the very small wing surface on the rectangular wings at the front. A small rudder is positioned at the back. Source: US Patent US128667
Longobardi’s Combination Vehicle shown facing to the left
Digitally cleaned side view of Longobardi’s Combination Vehicle shown facing to the left. Source: US Patent US1286679


All of the propulsion for the vehicle via wheels and propellers (save for the rearmost propeller) was provided by a pair of large batteries in the bottom central portion of the hull. No means appears to have been provided by which these batteries could be charged up in the manner of an electric or hybrid-drive system, so once the vehicle set off, it would continually be reducing the available charge in the batteries. Unlike a conventional liquid or even solid-fuel vehicle, no combustion takes place, which means that the Longobardi’s vehicle is the same weight when the batteries are half or fully discharged as they are when full. With a conventional vehicle, as it consumes fuel it gets progressively lighter, which assists in extending the range. No such advantage exists here with a purely battery-driven system.

Two motors are provided inside the vehicle, one in the front third which could drive propellers as well as a cable drum for winching in-or letting out the cable which controlled the position of the wings, and a second motor at the very rear which drove the primary propeller at the back.

No sizes or motor capacities were described in the patent. Nor is there any detail as to the power source for these motors. No estimates as to the weight of the batteries is provided or the available storage.

The primary advantage of electing this electric-drive system is that it obviates the need to burn fuel so the vehicle does not need an exhaust or funnel to vent out gases. This is an advantage for a vehicle planned for potentially going underwater, as it allows for the hull to be kept watertight more easily. The large funnel-shaped object on the vehicle is not, in fact, a funnel, but is the conning tower for observation and access, although when in use on land or flying, observations were to be carried out from the small compartment in the front roof of the vehicle marked as ‘38’ on Longobardi’s cut-away drawing.

 Longobardi’s Combination Vehicle shown facing to the right
Digitally cleaned cut-away side view of Longobardi’s Combination Vehicle shown facing to the right. Source: US Patent US1286679


No weapon of delivering war to your enemies is much use without some form of offensive firepower and Longobardi’s vehicle is no different. Clearly shown on the drawings in the patent as a trio of cannons. Looking at the foremost of these weapons, it is also clear that it is intended for firing out of a split rectangular hatch in the side of the hull and, as the left view of the vehicle also shows, such a door strongly suggests a fourth gun as a single gun to fire out of both sides would be extremely limited in what it could fire at, as it would be set back too far from both of those side hatches.
The rearmost of the guns are both shown pointing upwards through hatches in the roof of the vehicle and were intended for protection against aircraft. No details of what type of guns these may be is explained by Longobardi but the most notable part of his plan for armament is the lack of forward-facing weaponry.

Although the hull is air-tight, there is no mention of any thickness of it or what material it would be made from. If steel, even lightweight and all welded steel is considered it would have to be thin to keep that weight down but also strong enough to withstand the pressure of being submerged even a small distance under the water. It could only be concluded that no meaningful protection to even bullets could be provided for this vehicle.


The only mention of crew was the single operator/driver of the machine. Considering the potential for 3 to 4 guns, however, this would mean a crew complement of at least 5 to be of any possible use.


Considering the year of the design was 1918, Longobardi certainly took inventiveness to a new level. In his design, he was picturing an electrically powered vehicle capable of independent flight as well as what would have been one of the largest wheeled vehicles on the roads of the day. The design is frankly a poor one. Far too boat-like and almost certainly incapable of any form of flight short of driving off a cliff. Ungainly and hopeless on the road, the vehicle was an enormous target as a ground-based vehicle, too big and too heavy for any realistic flight and added nothing to the issue of sea power that a conventional and far smaller, less technically complex ship could already accomplish. The whole machine is far too big to be able to have any kind of meaningful protection. There is, after all, a good reason why there are no flying submarines and despite Longobardi’s intentions to try and create an all-encompassing vehicle capable of operating anywhere, what he created instead was a design for a vehicle incapable of operating anywhere in any way better than vehicles, ships, and planes which already existed.

Longobardi’s Combination Vehicle in all of its glory, showing its wings, wheels and propellers to move on all sorts of terrain. Or, more physically accurate, sink, fall and break down on all terrains. An illustration by Yuvnashva Sharma, funded by our Patreon campaign.


Crew at least 5
Propulsion Electric batteries and motors
Speed little or none
Armament 3 – 4 guns
Armor little or none
Total production None built


US Patent US1286679 ‘Combination Vehicle’, filed 12th June 1918, granted 3rd December 1918.
US Patent US1796952 ‘Vehicle Wheel’, filed 15th June 1929, granted 17th March 1931.
New York Passenger Arrival Lists (Ellis Island) 1892-1924. Page 99, Line 9. US National Archives.