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WW2 British Prototypes

TOG 300G

United Kingdom (1939)
Heavy tank – None built

The precipitous plunge into a new major European land war against Germany in 1939 found the British utterly unprepared for the type of intense combat fought a generation earlier on much of the same ground in Northern France and Belgium. As Britain and France raced desperately to design and deliver a new series of heavy tanks able to break the inevitable German defensive lines to beat them on this old battlefield, the mud of Flanders loomed large in British military thought.

The French Army and the British Expeditionary Force (B.E.F.) had tanks and a lot of modern equipment of a bewildering variety and utility, from the diminutive unarmed UE tracked resupply vehicle and obsolete WW1 Renault FT light tanks, to the giant Char B1 Heavy Tank for the French, and the ‘Universal Carrier’ and Mk.IV Light tank to the A.11 and A.12 Matildas of the British. These forces were meant, as succeeded by their parents’ generation, to blunt and stall the German advance through the Low Countries (Belgium and Holland). After that, the Allies would bring over new forces and push the Germans back. A fine plan maybe in the first months, September and October 1939, with the obvious problem that the Germans did not want to play that game and instead when in May 1940 the attack came, it was launched with greater speed and focus of intensity than the British and French could cope with.

Picturing a need in the first months of the war for a new and improved heavy tank for special purposes, there was no suitable vehicle at all, as the heaviest tank available was the A.12 Matilda. A new tank was to be rapidly considered and one of the first of these came from a team led by Sir Albert Stern – a team of men largely responsible for most of the British tanks of WW1. Stern was the chairman of the Special Vehicle Development committee – more commonly known by its adopted nickname; The Old Gang (TOG) and this was to be the first TOG tank of WW2, although it never left the drawing board.

The Theory

It has to be acknowledged that, in these first few months, the requirements for a new ‘Special’ or heavy tank were fluid. Despite the issuance at the end of September 1939 by the General Staff of a set of improbable and perhaps impossibly optimistic requirements for a tank, the team led by Stern took liberties with their task. It is clear from reading the letters of the time that, right from the start, the TOG team favored only a turreted tank. Adding heavy armor and a high front track to help climb an enemy parapet or wall, the vehicle design resembled almost a hybrid between the existing A.12 Matilda and a rival vehicle of sorts being built to a different set of demands, known as the A.20.

TOG 300G redrawn from blueprints. Source: Author

When the specifications for this new tank were finally revealed at the end of September 1939, the demands were extreme. The vehicle would have to be able to cross a 16’ (4.9 m) wide trench without the use of a bridge or fascine, be heavily armored, and capable of climbing a 7’ (2.1 m) high obstacle. The 300G was simply unable to cross such a huge gap. In an effort perhaps to assuage the General Staff and have them come around to a more conventional turreted option, the vehicle was even redrawn in a longer form capable of crossing a gap 10 to 12’ (3.0 to 3.7 m) wide. Although the goal was to produce this new special tank at just 32 tons (32.5 tonnes), this longer option would obviously mean more weight, perhaps around 40 tons (40.6 tonnes), and a reduced performance (assuming the same power plant was to be used).

Based on the drawing for the outline of the tank, it would measure around 20’ to 25’ (6.10 to 7.62 m) long for the ‘compact’ and ‘lengthened’ options respectively. The width is easier to gauge, as it is shown in a railway tunnel. Railway tunnels were the size-limiter for width. The 300G vehicle completely filled the tunnel allowable width, indicating a vehicle some 10’ (3.05 m) wide.

Automotive

It is difficult to consider the automotive elements of 300G because the design simply never got that far. The requirements of TOG were to produce a diesel-engined vehicle and eventually that led to the adoption of the excellent Paxman-Ricardo series of diesel engines for the TOG 1 and TOG 2. In the early days of that part of the work of TOG, the lack of a suitable diesel motor prompted a look at various alternatives, including the use of petrol boat engines to provide sufficient power.

The designers involved in work on the S.V.D.C. project also considered alternatives to the ‘normal’ kind of mechanical transmissions, eventually considering alternatives including hydraulic and electric types. However, just like the engine, this was after the 300G idea had been replaced with work on a Mk.VIII-shaped machine for the General Staff. As a result, the engine and transmission choices or options for a TOG tank built to the outline of 300G remain unknown.

Surviving side outline of 300G in both compact and long’ forms crossing an 8’ (2.44 m) gap. The vertical obstacle shown is not given a size but is around 4’ (1.22 m) high. Source: Tanks of TOG by the author via UK National Archives.

Crew

Other than a single figure on the original drawing of a somewhat awkward-looking driver, no crew is shown, so it is hard to know how many crew were planned. The ‘special’ tank discussion originated with an idea for a tank with a crew of up to 7. Examining the design, it can be assumed this would be at least 5 or maybe 6 crew members, consisting probably of a driver in the front left of the hull, a hull gunner on the front right to operate the primary armament and BESA, and three more men, commander, gunner, and loader in the turret, just as they were on the A.12.

British A.12 Matilda. Source: Wikimedia Commons

Comparison between A.12 Matilda and TOG 300G Design

A.12 Matilda TOG 300G
Weight (ton / tonne) 25 tons (25.4 tonnes) 32 tons (32.5 tonnes) to est. 40 tons (40.6 tonnes)
Length (ft / m) 18’ 5” (5.61 m) 20’ to 25’ (6.10 to 7.62 m)
Width (ft / m) 8’ 6” (2.59 m) 10’ (3.05 m)
Height (ft / m) 8’ 3” (2.51 m) est. 8’ 9” (2.75 m)
Trench ~8’ (2.44 m) ~8’ (2.44 m) to
10 – 12’ (3.05 – 3.66 m)
Hull Armament None 7.92 mm BESA plus HV gun
Turret Armament 2 pdr. / 7.92 mm BESA 2 pdr. / 7.92 mm BESA
Hull Armor 3” (76 mm) basis 3 – 4” (76 – 102 mm)
Turret Armor 3” (76 mm) basis 3” (76 mm) basis

Armament

While the tank resembled an A.12, it certainly was not one. This tank was going to have to be able to take out heavily-fortified enemy positions and, as such, a variety of guns was being considered to find whichever was best suited to the task. Amongst these were the 2” (as used on the A.12), a 3” howitzer, a 3.7” howitzer, the Naval 6 pounder, and the French 75 mm gun. These last two were certainly too large in an A.12-style turret. Both the 3” and 3.7” options were abandoned quickly due to them being low-velocity weapons. No design studies are known to have been carried out for this turret. The solution would, therefore, be to mount the ‘big’ gun in the hull, much in the manner of the French Char B, and use the otherwise perfectly adequate 2 pounder in the turret on top. The requirements for a front-mounted Besa machine gun in the driver’s plate and another in the turret were to complete the complement of weapons.

Armor

Although a thickness of armor is actually shown on the blueprint, this was not a ‘to-scale’ drawing, just an illustrative one. The armor is shown, quite rightly, as being focussed on the front with a thick and slightly angled glacis, a cut-back lower front and a vertical and slightly thicker driver’s plate. No armor is shown on the turret, which is assumed to be identical to that of the A.12, which makes it cast armor 3” (76 mm) thick all around.

If 76 mm is to be assumed as the basis, this would give the 300G a 3” thick glacis and a driver’s plate perhaps as thick as 4” (102 mm). It is certainly not possible to consider the armor to be 60 mm or so, as the ‘rival’ A.20 design was already known to be woefully under-protected with armor of that thickness, unable to keep out German 37 and 47 mm anti-tank guns even at generous combat ranges. The other reason to discount the idea that the armor was less than around 3” is that the armor designer on the TOG team was Kenneth Symes. Symes was an expert in armor protection and a strong proponent of face-hardened armor plates made in flat slabs. The slabs meant ease of production not available to castings, which needed machining, but also the ability to produce a uniform hardening on the surface. Against uncapped anti-tank shot, this face-hardened armor provided improved protection over the ‘softer’ homogenous or cast armor plate. The side armor, being vertical, would have to at least match the nearly vertical turret sides, so once more 3” (76 mm) is the most reasonable estimate for this.

If the relationships between thicknesses on the only surviving drawing (drawing 477G) are reliable, then the rear armor was about half the thickness of the front, probably around 1.5” (38 mm) thick.

A lengthened version of ‘TOG 300G’ shown crossing an 8’ (2.4 m) gap. Source: Author

Death of the Project

The death knell for what would basically have been a heavier Matilda-type tank came almost as soon as the idea was born. The General Staff were insistent that they wanted an all-round track machine with heavy unditching gear on top, which meant no turret. Lengthening the 300G would not suffice and the attention of The Old Gang would be diverted into producing a tank they very much did not want to make to meet the exacting criteria issued by the General Staff in September 1939 as ‘RMB-17’.

Conclusion

The opportunity of TOG 300G, however, was small. The Army did not need a bigger, heavier, and wider Matilda-type tank even with the benefit of a little more armor, a little more obstacle-crossing capability, and the benefit of a large front-mounted gun. They wanted something much larger, inevitably much heavier, better protected, and even more capable of crossing obstacles. That was the direction TOG was to take, against their better judgment, and it is perhaps with some irony that the 300G-style option was eventually the one adopted after years of messing around, as the A.22 Churchill. That tank was to start life as much the same layout, a small cast turret with a 2 pounder gun and a 3” howitzer in the front and got off to a rough start with serious design flaws, reliability issues, mobility problems, and inadequate armor and firepower. A similar fate might have been expected from 300G but, given that the A.22 went on to be a very successful design by the end of the war, after years of upgrades to every feature, it is hard not to project that the 300G had the same sort of potential.

Concept art of the shorter variant of the TOG 300G taken from the drawings. The hull’s similarity to that of the later Churchill is striking, while the turret is very similar to that of the Matilda 2. Illustration by Yuvnashva Sharma, funded by our Patreon campaign.

Sources

Hills, A. (2017). The Tanks of TOG. FWD Publishing, USA

TOG 300G Specifications

Dimensions (L/w/h) 6.10 to 7.62 x 3.05 x est. 2.24 (short version), 2.75 m (longer version)
20’ to 25” x 10’ x 8’ (short version), 8’ 9” (longer version)
Total weight, battle ready 32 tons (32.5 tonnes) (compact) – longer version ~40 tons (40.6 tonnes)
Crew 5 – 6
Propulsion Diesel
Range (road) 50 miles
Trench Crossing 8’ (7.3 m) to est. 10 – 12’ (3.0 -3.7 m) wide
Step Up to 7’ (2.1 m) high
Armament Naval 6 pounder or French 75 mm in the front hull
7.92 mm Besa machine gun.
2 pounder and 7.92 mm BESA MG in the turret.
Armor Turret: 3” (76 mm)
Glacis: est. 3” (76 mm)
Driver’s plate: est. 4” (102 mm)
Sides: est. 3” (76 mm)
Rear: est. 1.5” (38 mm)

5 replies on “TOG 300G”

I see that another major failure of this tank was it lack of heavier firepower than Matilda 2. This tank offers not much more than its a lot lighter and cheaper variant. Designers had failed to distinguish their heavy tank sufficiently from up coming designs and thus they had created a tank which was obsolete on arrival. TOG 300 would had benefited immensely of having bigger turret design to house potentially bigger guns (6 pounder). That alone would be a major selling point of this tank over its competition. Protection levels could also be increased slightly. All of this would result in a tank which is slightly heavier, but still practical and useful for British army.

This article however leaves me little confused. First of all, in schematic and picture there is no indication of hull mounted gun. Even concept art leaves hull mounted armament out.

In statistics sheet there is just vague HV gun mention. Practice at that time was usually putting anti tank gun in turret and infantry support gun in hull. Having HV gun in hull and HV gun seem to be unrealistic as standard practice was to mix infantry support weapons with tank destroying weapons. In this case, we have 2 pounder which is quite pointless if you have bigger, better gun at destroying tanks in tank’s hull. I highly doubt that those unspecified guns were high velocity and comparison sheet could be improved by adding information about secondary hull armament from final sheet.

” It is certainly not possible to consider the armor to be 60 mm or so, as the ‘rival’ A.20 design was already known to be woefully under-protected with armor of that thickness, unable to keep out German 37 and 47 mm anti-tank guns even at generous combat ranges.”

I’m confused by this statement. Pak 36 penetration was 36 mm at 100 meters and 29 mm at 500 meters. I do not know any 47 mm anti tank guns, but closest equivalent – Pak 38 (50 mm) had 100 mm penetration at 100 meters, 79 mm penetration at 500 meters and 60 mm penetration at 1000 meters.

The only anti tank gun which could threaten British and French tanks at that time wasn’t even produced. Nor said gun had entered into mass service at that time. 60 mm of armor at that time was more than enough, German tanks had far less armor than that and no common weapon in German armament could penetrate 60 mm of armor. This is why Germans had called their anti tank guns during invasion of France as an army door knockers.

The only tank which came even close to being able to penetrate 60 mm of armor was the latest anti tank variant Pz.3 F. It also was a recent up gun effort and came in low numbers during invasion of France. Even its 5 cm Kwk 38 cannon could manage 58 mm of armor penetration at 100 meters! In other words, penetration of 60 mm all around armor during invasion of France was not practical. It is theoretically feasible, especially if Germans use tungsten APCR ammunition, but it requires ammunition which might not be even available and use of most recent German anti tank guns (pak 36 could only manage 64 mm of penetration with APCR at 100 meters).

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