Category: WW1 Italian Prototypes

Kingdom of Italy (1917)
Monocycle Tank – None Built

If someone is to consider the means of propulsion for an armored fighting vehicle, there are the common options: tracks or wheels, the less common options: track and wheels, air-cushion, and there are the rare options: legs, or rails. Probably the least likely method ever considered would be a monocycle, literally a vehicle built around a single wheel. This is precisely what Carlo Pomilio proposed in 1917 – a giant single-wheeled landship to crush its enemies and the obstacles before it.

Carlo Pomilio filed a patent for what he described as a ‘Monocycle Vehicle’ on 8th August 1918 in the United States. Pomilio, living in Rome, presented the vehicle as breaking new ground in the arena of military vehicles, being able to carry passengers or other materials in places where there were no roads. He had already filed this design with the authorities in Rome on 13th December 1918 as “Veicolo monociclo per trasporti protetti e per scopi offensivi” (English: “Monocycle vehicle for protected transport and offensive purposes”)

Layout

From the front, the layout looked like a barrel of beer on its side, with a swollen section in the middle which formed the ground contact area as the ‘keg’-shaped machine rolled. The shape, however, was misleading, as this was not a single keg or barrel and this is clear in looking at the side and plan views, where it can be seen that the large wheel was internal within a lozenge-shaped body which projected behind this wheel on all sides.

Symmetrical fore/aft and left/right, the body was dominated by a large sponson mounted weapon projecting out from the side centrally on the vehicle at the deepest and tallest part of the body. As the body went forwards or backwards from that point, it became progressively lower, and narrower, with the nose and tail angled up away from the ground. A barrel-shaped caster at both ends prevented the nose or tail from digging into the ground. At the tapering sidewalls of the vehicle front and rear, a vertical door formed a pair of doors on each side (4 doors total) and weapons placed in the nose and tail too alongside this barrel-shaped caster. In order to maintain weight distribution on the design, the engine lay dead centre on the vehicle, within the rotating part of the wheel.

One significant advantage of the layout from Pomilio, notwithstanding the practicality of how it would work in real life, was the fighting space. Because the wheel moved within the frame of the vehicle, which balanced itself around its central axis, the fighting platform could extend all around the vehicle. Likewise, the use of multiple doors would make it easy for crews to get in or out and, regardless of which was it was facing, at least two of the doors would be facing away from the enemy, allowing the crew to exit under cover from the body of the machine.

Crew

There is no specified crew within Pomilio’s design, but the layout, as envisaged when in use for combat, gives a good idea of how many men would be required. With one man per machine gun in the nose and tail and at least one man for the side guns, this would mean no less than 4 gunners. There are a pair of periscopes fitted within the hull, although it is not clear exactly where they were to go. The periscopes are only shown in a cut-away view down the longitudinal axis of the vehicle, suggesting that they were alongside the engine, but this would be a terrible location for a commander and driver – presumably the only two crew of consequence who would have need of such a device. There is sufficient width in the nose and tail of the machine for these periscopes to actually be in the forward or rearward or both ends of the machine, although that itself would cause complications.

If the periscopes were only in the front, then there would be no means of observation to the rear given the fact that the body got higher from the front, reaching its maximum height in the centre. Likewise, if there were periscopes at both the front and back, then either the machine would need two drivers, one of which sat mostly idle in the back and a commander hustling from the front to back to control or two commanders – something which would likely not improve decision making within the machine. Therefore, based on the shape of the machine in the side drawing and on the single-cutaway, it can only be surmised that, despite the problems of placing the commander and driver in the centre, that this is in fact the only logical place they could go within the machine. With one on each side of the engine, careful cooperation would be needed to control and command the machine, as each man could at best only see one half of the side of the vehicle, with a large blindspot blocking much of their view of the other side. All this would lead to the conclusion that a crew of not less than 6 and more likely 8 men would be needed to operate this machine.

The Propulsion System

Propulsion for the vehicle was formed from two parts; the wheel and the engine. The wheel itself was the only means of traction for the machine, taking the form in plan view of a pair of capital letter ‘D’s back to back. The face of the wheel in contact with the ground was formed in three sections, with the central section being flat to the ground and then the flanking sections slightly angled away from it.

Arranged around the outer rim of the tyre and transverse to the direction of rotation were a series of 16 triangular ‘teeth’ which would ‘bite’ into the ground to provide traction for the wheel. Driven from inside by the centrally positioned engine, the gearing for the drive was located below the level of the 6-cylinder engine and below the centre of the wheel, ensuring a low centre of gravity for the drive system. The engine crank is actually shown completely ungeared and connected at both ends to drive sprockets connected to tooth gearing inside the wheel, which was hollow. It is unclear how exhaust gases from the engine were to be vented, as those tubes showing the drawings are not exhaust pipes but periscopes for observation.

It is important to note that, technically, the wheel was not driven by the engine. Instead, forward, or for that matter, reverse movement was actually a function of the engine moving as a weight within the wheel and the mass of the machine moving in the same direction to retain the engine at the centre of gravity. This system relies upon a heavy mass at the centre of the vehicle but was also likely to result in an awkward rocking motion as it rolled forward rather akin to the motion of a rolling barrel with water sloshing inside causing it to roll.

Not only could the mass of the machine lead to a sloshing motion, but a rolling barrel also has a tendency to wobble laterally due to the unevenness of the ground causing the centre of gravity (here as the engine) not to be directly over the central third of the wheel. The result would be a horrible side to side wobbling where the guns on the side would be moving up and down during forward or reverse motion, making the occupants the equivalent of sailors on a rough sea.

https://www.youtube.com/watch?v=p3UtZrDf5Dg
Footage of these barrels rolling gives a good impression of this unpleasant wobbling motion during rolling.
Source: British Movietone

This side-to-side wobbling motion could be countered to an extent by the steering means of the vehicle. This steering consisted of another heavy mass, this time one moving side to side by either hand or motive power. By bringing this mass to the right within the wheel, it would cause the machine to lean to the right and roll to the right. Likewise, moving the mass to the left would cause the machine to roll forwards and left. If the machine was moving across ground which sloped away to the right down a bank or so, the weight would have to be moved over to the left in order to hold the vehicle on a straight course, but it also meant that steering would be slow, and furthermore that steering could only take place during forward or reverse motion – a complex procedure.

Come In Numbers 14

When Pomilio filed his patent in Italy in 1917, he included an unusually shaped object on a pole within the centre of the machine and around which the wheel would rotate. This was marked at number 14 on his attached drawing.

By the time he filed his claim in the USA the next year, this piece of the drawing was omitted and was not mentioned. It is utterly unclear as to why this may be the case, as the design is otherwise identical. Unfortunately, the patent application filed in Italy is still in the patent office there on paper and cannot currently be accessed to verify what this unusual part was. Whatever it was, by 1918, Pomilio clearly felt it was unnecessary and dispensed with it. It is an amusing little change that, within his US patent filing, he changed number 16 from whatever this feature was to simply adding another direction arrow onto his wheel drawing.

Armor and Armament

There is no mention of protection for Pomilio’s vehicle, but armor is implicit within the concept of a vehicle for military purposes and within his claim for ‘protected transport’ which would make it a type of armored personnel carrier too. In 1917 and 1918, the majority of tanks and armored cars were carrying armor in the 8 to 12 mm thickness range, with some parts a little thicker. This thickness of armor was sufficient to be bulletproof but vulnerable to artillery. There is no indication within Pomilio’s design as to whether he was trying to make a vehicle proof against artillery and so much armor would add a lot of weight which would have served only to make the vehicle even harder to control.
Pomilio was hedging his bets with the vehicle design, making sure it could be used both in peacetime for carrying stores and in wartime with the allowance for weaponry. Specifically, he provided for machine guns in the nose and tail and large weapons in the sponson on the side. This arrangement of firepower was very much along the lines of the British tanks of the era, with Male tanks having 6 pdr. guns in sponsons which projected out from the sides of the body. Pomilio’s layout also provided for good coverage of firepower around the vehicle, leaving blindspots just in the corners, where neither the end or side weapons could reach.

Conclusion

Pomilio was clearly thinking about the needs for a tank in terms of how to disperse firepower all around the vehicle whilst, at the same time, considering how to keep the vehicle balanced. The drive system itself was simple, avoiding a gearbox and complex steering systems, yet also far too complicated to be able to balance during motion in terms of sideways wobble or forwards and backwards rocking. Not only that, but the impossibility for the vehicle to turn on the spot would be a major hindrance in combat, as the vehicle would be unable to protect itself up close by maneuvering to turn its guns on an enemy.

Perhaps the greatest flaw, however, was the one thing which Pomilio did describe in terms of a benefit. He foresaw the ability of the machine to exert its weight on a small footprint as an advantage, as it could crush enemy positions, obstacles and barbed wire. Assuming it could move and get to the enemy, then indeed, this would assist the machine, although driving over obstacles like a trench seems like a terrible idea considering the single point of contact on the ground from the machine would likely lead to rapid toppling. This single point of contact was not, as Pomilio considered, an advantage. Instead, it was an enormous problem as the wheel simply concentrated too much weight in one place, ensuring it would get stuck in soft ground or inside a shell crater, where driving out would effectively be tracking the contour of the crater, whereas a multi-contact-point vehicle or tracked design would straddle portions of the hole.

In the case of a deep water-filled gap, even a relatively narrow one, this wheel ran the significant risk of simply becoming stranded. His application in Italy, submitted in December 1917, was already after the Fiat 2000 project was underway and other nations, like France, had a much smaller and simpler tank in the shape of the Renault FT in production. There was literally no reason for Italy to adopt this style of machine as a military vehicle and, in terms of carrying passengers or a load, there was nothing that this design offered over a simple truck. By the time his patent was granted on 12th April 1921 in the USA, there was little appetite or market for new tanks and the idea was quickly forgotten.

Specifications Pomilio’s Monocycle Tank

Crew: est. 6 – 8? Commander, driver, gunners x 4 (or 6)
Engine:6 cylinder
Armor: bulletproof
Armament: 2 x machine guns, 2 x larger guns in the sides

Sources

US Patent US1374761, Monocycle Vehicle, field 8th August 1918, granted 12th April 1921
Pignato, N., Cappellano, P. (2002 ). Gli Autoveicoli dei Esercito Italiano. Uffico Storico, Rome, Italy.

Kingdom of Italy (1919)
Armored Car – Concept Only

Patents are odd things. Some of them are clearly insane flights of fancy devoid of common sense or actual use, and some are solid renditions of actual designs which get built. A third type is where the inventor has an idea which seems good on paper, but would not be usable in the real world. The Calisi trench crossing armored car is one of those ideas.

Side views of Calisi’s War Car showing the rails in the raised and lowered positions. Source: Patent: US1307238

The Inventor and the Design

Adriano Calisi was an Italian citizen living in Waterbury, Connecticut, when he submitted a patent application on the 18th January 1919. He came up with the idea of combining the road speed of an armored car with the off-road abilities of a tracked vehicle. The concept was fairly simple on paper. A wheeled armored car (he called them War Cars) carrying a pair of rails ahead of it on supporting ‘arms’.

Use

With the rails secured in place, the War Car is free to drive around unhindered by them during normal operation. Upon meeting an obstacle, such as a ditch or trench, though, the crew would lower (by means of chains), these rails to cover the gap. The chains used to move the rails go inside the vehicle and connect to a winch linked to the engine inside the vehicle. The vehicle then crosses the gap over the rails with the rails still attached by chains which spool out as the vehicle moves forwards.

Calisi’s design from above showing the steps of using and then recovering the rails. Source: Patent: US1307238

Illustration of the Calisi Armored Car by William ‘Rhictor’ Byrd, funded by our Patreon Campaign.

The Clever Bit

So, the vehicle has crossed the trench and needs to recover those rails safely. This is done simply and elegantly by winding back in the chains. The chains are affixed to two points on the supporting struts on the rails and those struts are hinged in the middle. When the chains are pulled back, the hinge gives and the supporting struts fold up to now be narrower than the distance between the front wheels. Pulled all the way back to the front they are then lifted and resecured into position ready to be used the next time.

The Drawback

The problems with the idea are obvious. Firstly, those rails projecting from the front would themselves be subject to damage and loss as they are very vulnerable to the effects of rough terrain or enemy fire. The idea of stopping to recover the rail afterwards means you have to stop on the enemy side of the obstacle just to recover this bridge – this means the next vehicle would have to do the same and so on. All this potentially while under enemy fire too. It is not just a bad idea, but probably a fatal one on the battlefield.

Cross section of Calisi’s design showing location of engine and winch for winding chains in and out. Source: Patent: US1307238

Why

Given that this is just one more odd patent for something never built, why is it important? It is one of the first patents relating to armored cars from anywhere, and is at the end of WW1 still showing a relative naivety about modern warfare. Also, this is an early – maybe the first – wheeled military bridging vehicle idea for military purposes and regardless of the merit as a workable idea, the Calisi design stands out as an example of the thinking around the problems of crossing obstacles for wheeled vehicles.

Links & Resources

US Patent 1307238 filed 18th January 1919, and accepted 17th June 1919

Kingdom of Italy (1916)
Tank – Concept Only

The entry of the Kingdom of Italy into the First World War in 1915 spurred a lot of technical innovation and, like their British and French allies, the Italians too were faced with the same issues of crossing broken ground and trenches swept by machine gun fire, issues which were costing thousands of lives.
The obvious answer was some kind of armored vehicle able to cross the difficult terrain, protect the crew from machine gun fire and, at the same time, deliver fire to the enemy. Like many early ‘tank’ projects, the modern ideas of tank shape and layout had not been fully considered, leading to a period of genuine innovation, with ideas ranging from giant balls, to walking machines, wheeled tanks, and of course, track laying machines.

Design

The outline for the Testuggine Corazzata (Italian: ‘Armored Tortoise’) began in 1916 after a study by engineers from the firm of Ansaldo led by engineer and industrialist Gino Turrinelli. He was an expert in electrical transmission and suspension from Milan, who had previously founded in 1899 the Societa Italiana Vetture Elettriche Turrinelli and Co. (SIVE), dedicated to building electric cars. Turrinelli concluded that any machine to cross heavily shelled ground criss-crossed with obstacles and trenches must have a uniformly distributed load and that four tractive elements would have to be used operating independently of each other, each with its own electric drive motor. This arrangement, it was felt, would provide stability and allow the vehicle to cross obstacles up to 60cm high without unduly tilting the machine, which would have reduced the effectiveness of the weapons and caused excess strain on the mechanical parts of the machine.

Turrinelli electric carriage, 1902. Source: Belloni
The plans for the vehicle illustrate it crossing various obstacles. These show that, without the ingenious system for the track units, just crossing a 50cm high step would pitch the nose of the machine 2.75 metres into the air. This would render it vulnerable to enemy fire without being able to bring any of its weapons into use.

Diagrammatic representation of the obstacle crossing ability of the Testuggine Corazzata. The dashed line represents the position of the vehicle if it were not using the special system of suspension designed and clearly shows a far more stable platform. Source: Pignato
The plans show that the large 200hp 24 cylinder engine was to be mounted transversely in the middle of the machine. At the end of the engine was the large electrical generator which then provided power to 4 electrical motors, each of which would drive one set of tracks. These motors were mounted transversely between each pair of tracks down the centre line of the vehicle and delivered the power via two large chains to the main drive wheels.
The tracks were laid out in a 2 x 2 configuration with each set having two large wheels, one at each end, and two smaller rollers in a stacked arrangement in the centre. Supporting brackets across the track units provided rigidity and each set was attached to one end of a large hinged arm. In arranging the units in this way, each unit could not only be driven independently but could move up and down independently too, rotating not only on the pin at the end of the arm, but around the centre. In front and behind each track unit was the final element in the mechanics for crossing bumpy ground, a large roller which would prevent the machine from bellying out over an obstacle or getting trapped nose first in a ditch or trench.
On top of these track units, within the machine, was a floor which provided the fighting platform for troops along the sides. A central circular turret on top of the Testuggine provided a good lookout point and was presumably intended as the post for the commander of the machine. Two other turrets were built in. There was a position at one end of the machine presumably for the driver who would be provided with a small look out from which to see where he was going, with control provided by means of steering levers which would brake the track units for steering. Due to the choice of an electrical transmission, it is probable that this position was to be duplicated at the other end of the vehicle. This would have allowed the vehicle to quickly get out of a sticky situation, especially since the front driver had no way of seeing backward otherwise.

Blueprints of the Testuggine Corazzata 1916. Source: Pignato

Testuggine Corazzate Ansaldo Turrinelli modelled by Mr. C. Ryan, funded through our Patreon Campaign!

Scale

It is hard to understand the size of the machine from the plans, but it was very large indeed. 8 metres long and 4.15 metres wide, the Testuggine was huge and at 4.65m, was taller than any other tank at the time. For comparison, the very large Fiat 2000 was ‘only’ 7.4 x 3.1 x 3.8 m respectively. Armor was also not going to be light. Whereas the Fiat 2000 had up to 20mm of good quality steel armor, this design was meant to sport more than double the protection. Some 50mm of steel armor plate was envisaged which, combined with its rounded shape, would have made it almost impervious to enemy fire.
The weight of the machine is not known, but taking into account it was larger and had more than double the armour of the 40 tonne Fiat 2000, leads to a probable weight for the Testuggine in the region of 80 tonnes. This would have given it a power to weight ratio of about 2.5 hp/tonne, which meant it was not only called a Tortoise, but would move at about the same speed. This large weight would have also given it a large ground pressure and hampered it in the difficult terrain it was meant to handle.

Armament

The armament was meant to be just as impressive as the armor. This large machine was to carry no less than 10 machine guns, 4 mounted into fixed loopholes on each side fastened by brackets to the inner wall of the armor, and one more machine gun in each of the turrets, fore and aft. If the 10 machine guns were not sufficient to subdue the enemy, there were also 12 small flamethrowers to be mounted as well. The location of these is less clear, although the plans show them mounted below the level of the machine guns, suggesting 4 flamethrowing points on each side of the machine, with two more probably at the front and rear. Their low position suggests that they were intended for defensive purposes to keep the enemy infantry away, but also for clearing trenches and enemy bunkers.

Crew

No crew numbers are provided by the design, but the size and armament provides some insight. With 10 machine gun positions, a commander and at least a driver, though possibly two, the Testuggine would likely have had a crew of no less than 12 men.

Conclusion

This machine was never built, perhaps because it was simply too huge making it too hard to transport. There were limited funds available for tank construction but the actual machine was within the ability of Ansaldo to have been constructed although the actual military value of such a machine would have to be questioned to. At the time it would have been by far the largest tank ever made. Quite what effect it would have had on the Italian battlefields of the Piave cannot be known, though whether it would have worked or just failed, no one would forget seeing such a behemoth and it would have come as quite a shock to their enemies and allies alike. Certainly, by current standards, the design appears somewhat ridiculous overall, but the special suspension system was ingenious, especially considering the state of tank technology in use at the time by France and Great Britain. No orders were made for the Testuggine, and consequently, it was not adopted by the Regio Esercito (Royal Army) and the idea was forgotten. Nonetheless, this would not be the last design by Ansaldo or by Gino Turrinelli, nor the last idea for a powerful war machine from Italy during WW1.

Specifications
Dimensions	8m long x 4.15m wide x 4.65m high
Weight	est. 80 tonnes
Propulsion	200hp motor with electrical transmission
Speed	est. 2-4km/h
Crew	est. 12+
Armament	10 x machine guns, 12 flamethrowers
Armour	50mm all round

Links, Resources & Further Reading

Gli autoveicoli da combattimento dell’Esercito Italiano, Nicola Pignato & Filippo Cappellano
The Engineering Index, 1922
News.apmi.it
La Carrozza nella Storia della Locomozione, Luigi Belloni
L’Ansaldo e l’industria bellica, Andrea Curami

Kingdom of Italy (1917)
Assault Vehicle – 2 Prototypes Built

The need for armor to breach enemy defenses and to move guns across heavily broken, shell damaged ground had become apparent to many in WW1 and there were many suggestions to overcome these problems. Italy had entered the war in 1915 and was soon faced with many of the same problems Britain and France were having to deal with in making a machine to cross the battlefield. One Italian engineer came up with a very unusual solution to those problems. His name was Luigi Gussalli.
Born in Bologna on the 18th December 1885, Luigi Gussalli was a man with an aptitude for mechanical engineering; building miniature vehicles in his spare time, such as toy airplanes and steam-powered cars. He was also a dreamer and experimented with rockets whilst at the same time devouring science fiction novels. After school, he studied physics in Pavia. As a young man, in 1911, he showed himself to be a pioneer in vehicles, having patented an unusual animal powered wheeled vehicle. That vehicle design did not find any use, but the outbreak of WW1 for Italy in 1915 led him to join the Regio Esercito (Royal Army), originally as a driver, but soon became an engineer for the Testing Commission.

Captain Luigi Gussalli. Source: Bresciacity.it
By 1916, Gussalli, a Captain of Artillery in the Regio Esercito (Royal Army) was not convinced about the use of tracked vehicles. At the time, these had a lot of problems with the resilience of the track. Instead, he turned his attention to the development of an assault vehicle using ski-like-skids (runners) instead of wheels or tracks.
With limited means at his disposal, a model of the vehicle was made in Novara, Italy. The design was not put into production, but did garner the interest of the Fonderie dell’Erra and Officine Airoldi di Novara which patented a larger 2 seater walking machine. Working with Gussali in 1917, this machine followed the same principles, and although Gussalli’s original machine does not survive, the design of the larger vehicle does.

Gussalli machine from 1917 patent showing the large central tower and oval drive wheels

The larger machine

This new, larger machine consisted of a large central tower structure with a circular turret. Motion was provided by two pairs of large skids moved by means of geared oval shaped wheels on each side driven by the motor. As the wheels turned, their oval shape causes the leg to raise and then lower again producing the walking motion. Experiments were done with this design concept and it showed great promise, with a prototype beginning construction in 1917. It could cross trenches and ditches with ease as well as climb small walls. Everything expected of a tracked tank. The problem was speed. It was just far too slow, even when compared to the slow machines of the era.
Although many officers and engineers came to see the vehicle and were impressed, the military were not interested in the machine, and development of the prototype languished into 1918 and the project ended. No trace is known to remain of the prototype or Gussalli’s original design, but General Montu provides the last word on the design itself in ‘Storia dell’ Artiglieria’ describing it as ‘undoubtedly original’.
No engine or armament is specified for the Gussalli design, but a small petrol engine would be expected along with likely a machine-gun as the main armament. Protection would be light and, in keeping with armored cars of the era, an estimate of 8mm to be bulletproof is likely.

Post War

After WW1, Gussalli, then living at Via Montesuello, Brescia, dedicated himself to his science fiction writings and studies of astronautics as well as patents, and in 1929, submitted another patent for a much smaller and simpler walking machine titled ‘Improvement in Vehicles for Undulating Ground’.

Gussalli patent for vehicle for crossing undulating ground, 1929

Construction

The body of this single-seater vehicle consisted of a boat-shaped superstructure, akin to a sledge, in which the driver sat behind a large pedal-driven wheel. The body is attached via cranked arms to two pairs of runners which act as feet providing a walking motion for the vehicle.

Movement

Movement for this Gussalli design is effectively the same as his other walking machines, intended specifically for crossing “natural ground, such as ploughed, sandy, stony, marshy or submerged land, obstructed by fallen tree trunks, furrowed by trenches, drains, cracks and the like and also over the snow and ice of ice belts”. The ‘walking’ motion was effected through two or more long runners formed from bent steel tubing driven mechanically and supported by wheels to the body of the machine.
The mechanism was designed to be simple to improve the efficiency of the machine. Steering was simply done by braking the movement of one runner allowing the other to continue moving and the vehicle could turn within its own length.
A second small motor was to be fitted to provide additional power when traversing particularly rough ground as it would accelerate the runners which were moving during their ‘walking’ cycle.

Remembrance

Luigi Gussalli might not have found success in his ‘tank’ design of 1917 or some of his other ideas and he is mainly remembered not in military matters, but as a visionary of space flight. He published ‘Jet Propulsion for Astronautics’ in 1941 followed by several other books on the subject of space travel, including the use of multi-stage rockets or the creation of ‘gravity’ through rotation. Gussalli died in the Italian town of Salò in 1950. His correspondence with Robert Goddard and Hermann Oberth (leading proponents of rocket technology for space flight) ensure he is remembered as a visionary in astronautics and even had an asteroid named after him in 1995, ‘32944 Gussalli’.

Links, Resources & Further Reading

Gli autoveicoli da combattimento dell’Esercito Italiano, Nicola Pignato & Filippo Cappellano
UK Patent GB 346022 filed 21st December 1929
Reichspatentamt Patentschrift 549021 Patented 29th June 1930
French Patent 437247 filed 6th December 1911
Minor Planet Center.net

The Carro d’assalto ‘Gussalli’, showing it’s peculiar movabled skids. Illustration by Yuvnashva Sharma, . It has been sponsored by Stephen Reah through our Patreon page

Kingdom of Italy (1915-1917)
Armored Car – 1 Prototype Built

Amongst the many ideas for cutting barbed wire in the First World War, there is one vehicle which stands out for its unusual appearance. Unlike some merely sketched out by a bored engineer at a meeting in Whitehall, Berlin, Paris, or Rome, this vehicle was actually built and tested.

1925 promotional image of the Pavesi Autocarro Tagliafil. The 1915 date is incorrect, however. Photo: Ceva and Curami

Ingg. Pavessi & Tolotti

The designer of this unusual machine was Ugo Pavesi (17/7/1886 – 13/7/1935), a well-respected engineer from Novara, a city just west of Milan in Italy’s industrial North. After finishing his engineering degree in 1909, he worked for a while for Giovanni Enrico’s engineering firm. He then partnered with Giulio Tolotti (also an engineer) to form their own company called La Motoaratrice (Brevetti Ingg. Pavesi & Tolotti) between 1910 and 1912 with an office in Rome but with the workshops in Milan. Ugo Pavesi was the main designer and Managing Director and Giulio Tolotti was the Technical Director.

The future prospects for the firm were to blossom with the outbreak of WW1 and the sudden need from the Army for all types of vehicles for a variety of purposes. La Motoaratrice was therefore in a perfect position of having a design for a tractor suited for hauling material over badly broken ground at just the right time. An initial Army order asked for 150 truck tractors followed within the first year for another 350 machines. In total, during the war, the firm received orders for 1000 of their tractors and 5000 trailers.

Details of the P.T. Pad Wheel compared to the original spade wheel. Photo: Chilton’s Automotive Industries, 1917

The Wheels

The wheels were very unusual and were a design from Pavesi-Tolotti known as the ‘P.T. Spade Wheel’. Each wheel was fitted with 12 large flat plates acting as the spades. They had first been shown off in 1911 at the World’s Fair in Turin and had been the spur to create the firm to capitalize on the interest in this design. In 1912, when production had begun at their factory, the intention had been to market the wheels primarily for agricultural purposes in South America. The individual plates actually could be

“operated from an eccentric on the axle through an intermediary of strong links, in such a way that the spades would enter the ground almost vertically, remain vertical for sometimes and then be drawn out in practically the same direction. In this way the spades gave a very powerful grip without any great loss of power due to scraping of the soil. By turning the eccentric through an angle of 90 deg., by means of suitable levers, the spades were kept within the outer diameter of the wheel, thus permitting of driving the machine over hard roads”

This spade wheel would find use in other designs, but the wheels for the Pavesi Autocarro Tagliafili would, in fact, not end up using these excellent wheels, but a follow-on design called the Pad wheel. Far simpler than the complex spade wheel, the pad wheels did not rely on the motion of an eccentric to turn a spade into the ground, but instead, were held to the wheel by means of tension springs securing traction on the ground through the friction of the plates in contact with the ground rather than spades penetrating it. Some of the tractors produced for the Italian Army used double wheels at first to increase the ground contact area, but these were replaced by 1916 by means of simply widening the pad wheels as used on the Pavesi Autocarro Tagliafili. The double wheels had a diameter of 95cm with 25cm wide pads. This type of wheel is sometimes referred to as a ‘track-laying-wheel.’

First prototype of the Pavesi Autocarro Tagliafili. Note the single turret and 4 wheels. Photo: Pignato

The Machine

The original Army tractors without any armor weighed in at nearly 5 tonnes and were fitted with 4 cylinder petrol engines producing 50hp at 800rpm. Despite the small size of the engine, the tractors could haul up to five 20 tonne wagons hitched together up to a total weight of 100 tons at up to 3 miles per hour. This hauling ability made them an ideal basis for work on an armored vehicle.

Rear view of the first prototype showing the absence of a rear firing machine-gun and that the single turret is open-topped and open-backed. The path of the vehicle can be seen having ploughed successfully through the wire obstacle. Photo: Pignato

The design and construction of the prototype are known to have started by at least early 1916 using the body of a Pavesi-Tolotti Tipo A tractor. The Pavesi-Tolotti tractor powered its special rear wheels from a front mounted engine. The wheels at the front of the tractor were smooth rimmed. However, on the Pavesi Autocarro Tagliafili, the larger wheels with the special pads were on the front with the smooth wheels at the rear. The arrangement of the machine therefore appears to simply be a reversal of the standard tractor. The prototype has just the four wheels and with the engine at the back, explaining the low rear half of the machine. The front wheels were covered with some plating, removing the view of the spokes, although it is not clear if this was armor or something else like timber simply to stop them clogging-up with mud or to prevent the ends of cut wire from snagging in them. Over the ‘front’ of the machine was a large boxy cab with a flat face and sloping front plate above it, in which a single rectangular viewing hatch was located on the right hand side for the driver. A small circular port was provided in the side of the cabin on both sides.

Another test against wire was successful having cut a wide path through it. The path is now caused by those horizontal beams on an X frame.

On either side of the front were two tall wire cutting serrated vertical bars which stuck out from each side. As the vehicle would drive forwards into a wire entanglement, these serrated vertical sections would separate the wire against the cutting surfaces. Rather than simply relying on the forward motion of the vehicle to cut the wire, there was a driven horizontal shaft coming out of the side of the cab which connected to the middle of each vertical bar. Rotation of that shaft driven from the engine caused the two sets of vertical teeth in the cutting column to move up and down opposite to each other producing a cutting motion.

Under the front of the cab and protruding out to each side to the same extent as the serrated vertical cutting columns was a small horizontal bar fixed securely to the cabin. The exact purpose of this bar is unclear, but it may just have been to remove smaller obstacles the vehicle would pass over.

The only weapon mounted on the prototype was a single Fiat model 1914 6.5mm water-cooled machine-gun mounted behind a gun shield within an open-topped and open-backed cylindrical turret. The cylinder for it covered the full height of the vehicle. Construction of the machine, having started by at least early 1916, was not quick. The testing for the Commission set up by the Army to evaluate the design was delayed from 10th July 1916 to the 9th of 9th November that same year.

Tests on the prototype with it driving through wire obstacles were delayed by mechanical problems with the machine, postponing further testing from the 9th November to the 13th. This second round of tests was much more successful, but the Army was concerned that the vehicle was unsuitable for crossing anything but flat ground, was too slow, and had inadequate protection.

Recommendations for improvement were to boost the speed and protection, reduce entangling of the front wheels from broken wire and improve traction.

Modified prototype with an additional set of wheels and modified wire cutter. Photo: Pignato

The Pavesi Autocarro Tagliafili – Illustrated by Bernard “Escodrion” Baker

Modifications

As the existing machine was based on the existing Tipo A tractor, very little could be done to improve the power of the vehicle, but modifications were carried out at Belluno, in the Italian Veneto region, from May 1917. A second set of wheels was added to the front which would improve traction cross country, as well as improve performance on soft ground. To prevent snagging and entangling by wire, a new cover was designed to go over both wheels with an additional serrated section between them to catch any wire before it could get wrapped around the axle of the wheel or in the pad mechanism. Likewise, at the rear, the pair of smooth rimmed wheels which were previously open spoken were also covered over.

Modified prototype during road trials prior to completion. Photo: Pignato

The inadequate protection complaint was resolved by moving the small turret further forward to the very top front corner of the machine and adding a second one on the other side, giving the vehicle its’ unique side by side turret appearance. Both turrets were now completely enclosed. To achieve this, large curved portions had to be cut out of the front sloping armor plate. The armor itself was steel, only 3.5 to 4mm thick, riveted to a steel frame. The new sides of the cabin also gained two long horizontal vision slits in each side in addition to the previously existing small porthole. These slits would provide additional vision for the occupants, although they were only chest hight with respect to the driver, suggesting that they were cut into the sides to facilitate looking down at the terrain and obstacles being crossed. A final addition to the vision was the inclusion of a further rectangular hatch in the rear of the cab directly behind the driver.

The rear of the machine was modified too, with an additional Fiat model 1914 6.5mm water-cooled machine-gun added to the back panel flanked by two horizontal vision slits.

A final modification was to the wire cutters. Photographic records show that on the early machine, both sets of these moving teeth were triangular, but on this improved modified version that one set of teeth were rectangular to assist in grabbing and cutting with wire.

Rebuilt prototype showing the new double wheeled arrangement and double turret arrangement during road trials 1917. Photo: Pignato

Modified prototype during off-road testing 1917. The rectangular section in the middle of the armour is an extension to the body, moving the cab forwards to cover the new pair of wheels. Photo: Pignato

Replacing the single Fiat model 1914 6.5mm machine-gun in a single turret was a response to the advice of the Army commission. Both turrets mounted a pair of Fiat machine-guns, giving the vehicle a total of five machine-guns. With both turrets fully traversable, the vehicle could bring at least 2 weapons to bear at any point around it, with up to 4 weapons firing across almost the whole frontal arc (save for where one turret gets in the way of the other).

Automotive

The machine was essentially an armored tractor driven backwards by the engine at the back. This meant that it was actually steered by the rear wheels and without any changes to the steering mechanism, the driver seated in the front right would have his steering controls reversed when driving forwards. A left turn on the wheel would actually turn the vehicle to the right, which might be very confusing under fire. It is not clear how the controls were arranged as the driver would normally also have to be facing backwards, but the viewport on the front indicates that the position for the driver, rather sensibly, was moved to be forward facing. Perhaps the confusion was not so bad, as the speed, at just 10km/h unladen for the tractor with no load, and just 6km/h with the armored body fitted, was slow anyway.

The engine was too weak for the task of assaulting the enemy with just 50hp at 800 rpm from the 4 cylinder petrol engine, leaving this large machine in enemy sights for too long and would have rendered it extremely vulnerable. Combined with the very thin armor, the military value of the machine was very low and thus, the Army rejected it.

The end

The Army had rejected the first prototype of the Pavesi Autocarro Tagliafili for being too slow and too poorly protected. The armament and armor had both been improved as had the off-road ability with extra wheels, but the inherent lack of engine power of the tractor it was based on remained and the need for the vehicle simply disappeared. Not because of the end of the War, but because other vehicles were now becoming available to the Italian Army for the same purpose. The Fiat 2000 heavy tank was being developed and was much better protected and armed as well as being more manoeuvrable. Small tanks, such as the Renault FT, were also beginning to show a lot of promise, carrying more armor in a much smaller tracked package, rendering the whole concept of the Pavesi Autocarro Tagliafili was obsolete. The one prototype vehicle was broken up for scrap. The First World War had been good for business for La Motoaratrice, but this was not one of their commercial successes.

Postwar, Giulio Tolotti left the firm and it was renamed and reformed from La Motoaratrice to La Motomeccanica (Brevetti Ing. Pavesi). Ugo Pavesi would also leave the firm he had helped found in 1925, handing it over to Ezio Mazzagio. The firm changed names again in 1932 to Motomeccanica, but the firm continued to survive. Ugo Pavesi, however, did not, dying suddenly on 13th July 1935.

Specifications
Crew	Est. 5
Propulsion	4 cylinder petrol producing 50hp at 800 rpm
Speed (road)	6 km/h
Armament	5 machine-guns
Armor	3.5mm to 4mm thick steel
Total production	1 Prototype in two stages
For information about abbreviations check the Lexical Index

Resources and Links

Gli Autoveicoli da Combattimento Dell’Esercito Italiano, Nicola Pignato
Machines of Pavesi, Claudio Pergher
trattoridepocapiacentini.it
La meccanizzazione dell’Esercito Italiano, Ceva and Curami
La Motomeccanica, Angelo Alpe
Chilton’s Automotive Industries Vol.37, July 1917
Motor Age Vol.32, November 1917
Oil field Engineering, Vol.18, December 1916
The Gas Engine, Vol.18, January 1916