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TOG I / TOG II

The era of the 1920s and 1930s in the history of tank building was marked by the appearance of the most incredible armored monsters, which are difficult to call tanks. The concept of using armored vehicles was based on the experience of the Great War - since there was simply no other experience, and the rare use of tanks in the colonies was limited to intimidating the natives with unprecedented iron cars. So, the division of tanks into classes was archaic, especially in light of the rapidly developing military science and technological breakthroughs - infantry, cavalry and assault tanks. The first type, as the name implies, was obliged to support infantry (hence slowness, so that the tank would not suddenly overtake the attacking infantrymen), cavalry (they are also cruising), lighter machines played the role of cavalry - rapid breakthroughs to the rear and flank round.

In July 1939, a meeting was held at the British Ministry of War where the requirements for new heavy tanks for the upcoming conflict in Europe were discussed. Leslie Burgin, the newly appointed Minister of Supply, met with Sir Albert Stern, the secretary of the Land Ship Committee and a key figure in the development of the tank during the Great War, to discuss what sort of tanks might be needed in the increasingly likely war with Germany. On 05 September 1939, a few days after the German attack on Poland, Sir Albert was asked to form a committee to carry out the same task.

In September 1939, the development of the first new tank design of World War 2 began. The General Staff drew up specifications for a new heavy infantry tank, the A20. This was intended to fulfil a Great War style infantry support role, able to cross the wide trenches that were expected between the Maginot and Siegfried Lines.

Stern believed that the war in the west would require the breakthrough of heavily fortified defensive lines. This view was not unique to Stern, being shared by the General Staff, which issued a requirement for a shelled area tank. British tank development and production in World War II, a tale marred by by unclear direction from both the War Office (responsible for figuring out what kinds of tanks were needed) and the Ministry of Supply (responsible for producing tanks).

Stern managed to gather a distinguished group of colleagues. Among them were Walter Wilson (engineer, gear-box expert and joint inventor of the tank), Sir William Tritton (Joint inventor of the tank and chairman of Fosters of Lincoln, the company that built the first British tanks), Sir Harry Ricardo (an important engine designer during both Wars), Ernest Swinton (Army Officer and joint inventor of the tank) and Eustace Tennyson D'eyecourt (Director of Naval Construction for the Royal Navy 1912-1924). In October 1939 the committee was officially named the Special Vehicle Development Committee of the Ministry of Supply, but for obvious reasons it became known as 'The Old Gang', and their two designs as the TOG I and TOG II.

The specification called for a maximum speed of between 5mph over heavily shelled terrain and 9mph everywhere else. It had to be able to cross 16 foot wide trenches and climb 7 foot high obstacles. The new tank had to be able to resist hits from 37mm and 47mm anti-tank rounds, it had to have a crew of 8 and be armed with a field gun in the front hull, a 2 pounder and 7.62mm BESA mg in each side sponson, 2 further BESA mgs to give all round fire and 4 2-inch smoke mortars.

This initial specification resembled a cross between the Mk VIII International from 1918 and the eventual A22 Churchill. The design was refined and 2 different tanks were the result. The first was the 80 ton TOG Super Heavy Tank, which proved to be unworkable, the second was the 41 ton A22 Churchill.

Developed for trench warfare, initially, armament was to be placed in the front part of the hull and side sponsons. However, later it was decided not to add the sponsons and instead mount a turret. TOG II was a much more original design. It has two remarkable features, apart from its great size and weight. Firstly there is no gearbox or mechanical transmission. The huge Paxman-Ricardo V12 diesel drove two generators which power two electric motors which drive the tracks. The steering wheel was connected to a potentiometer that varied the voltage to the track motors.

This system was chosen by the TOG team to avoid the issue of mechanical gearboxes that were prevalent in all Great War tanks. The excessive toll on both the gearboxes and the crew manning the system leading to a multitude of unnecessary breakdowns. The first trial of TOG 1 took place on 27th September 1940, followed shortly after by the first official demonstration on 6th October. During trials, which continued until June 1941, a recurring problem was overheating of the electric drive motors. In early tests the electric transmission proved to be a failure. The motors were put under too much strain, and burned out during the tests. These lasted until June 1941, and then stopped while a new hydraulic transmission was developed. With the new system the tank became the TOG IA. This system, which wasn't ready until May 1943, was also a failure, as there was too much time lag within the hydraulics. A basic problem was that the TOG was three times longer than wide, making it very difficult to steer. Alterations were still being made as late as spring 1944. TOG 1 was subsequently transported to Chobham after which nothing more was heard of it.

The order for TOG 2 was placed on 6th May 1940. The most obvious difference from TOG 1 was in the layout of the tracks. The tracks themselves, after passing around the sprocket and idler, drop down below floor level in a tunnel to create more space in the engine and crew compartments - an idea which is virtually unique to this tank. Thanks to the novel tunnel track design, TOG offered the best option for a well armored tank with a 17 pounder or 28 pounder gun (the 3.7 inch AA Mark I gun, the counterpart to the German 88) into service during the war. Tunnel tracks permitted a large turret ring, needed to mount the large guns required to defeat German tanks. British railway loading gauge, the most restrictive in Europe, made it very difficult to provide a large enough diameter turret ring. This explains why British tanks were under-gunned, a problem only remedied by Centurion, which arrived too late for the war, (and which disregarded the railway loading gauge limitation). The only British built tank to mount the 17 pounder to see combat, the Challenger, had an overloaded suspension, so it had thin armor.

Diesel-electric drive was retained for this second prototype, notwithstanding the problems of overheating electric drive motors encountered with TOG 1 and the consequent conversion to a hydraulic drive system. There appears to be no record of TOG 2 having any similar problems. Unlike TOG 1, it had two separate generators, set side by side, driven by the TP through a gearbox. TOG II ran for the first time on 16 March 1941. By 1943, when the TOG II was completed and ready for trials, it was already obsolete. The vehicle never entered service. TOG 2 has survived and is now on display in the Tank Museum at Bovington.

Modifications of TOG II * R and TOG III went to the design, but they were never built. The main result seems to have been to keep a bunch of crusty old Great War tank designers out of everyone else's hair. Stern and the Old Gang wound up being marginalized (perhaps not least because Winston Churchill didnt like Stern). Usually tank historians portray this as a good thing, dismissing the TOG designs as fit only to refight the trench battles of the Great War.

TOG-ITOG-II
Production 11
Manufacturer William Foster & Co.William Foster & Co.
Tracks/WheelsFull TrackedFull Tracked
Weight (Overall)63.5 tons 80 tons
Length (Overall) with Gun Forward33 ft 2 in (10.11 m)10.13m
Width (Overall) 10 ft 2 in (3.10 m)3.12m
Height (Overall)9 ft 10 in (3.00 m) 3.05m
EnginePaxman Ricardo 12TP
water-cooled Diesel engine
delivering 600 hp (447.5 kW)
Paxman Ricardo 12 cylinder
Power (Engine Output) 600bhp
Suspension Torsion spring
Transmission
  • TOG-I : electric transmission
  • TOG-IA : hydraulic
  • Diesel electric
    Type (Fuel)DieselDiesel
    Volume (Fuel) liters
    Radius (Range)50 miles
    Maximum (Speed - Road)8.7 mph (14 km/h) 8.5mph
    Maximum (Armour Thickness) 2.4 in (62 mm) 76.2mm
    Armament - Main Weapon Type 75-mm (2.95-in) field howitzer 17 Pounder Gun
    Armament - Secondary Weapon Type
  • 2 x 2-pdr (40-mm) guns
  • 4 x 7.92-mm (0.312-in) Besa machine guns
  • 1 x Machine Guns (Besa)
    Number (Projectile)
    Number (Crew)six (commander, gunner, loader, driver and two machine gunners)
    + sponsons, each manned by two gunners
    6

    TOG I Tank TOG I Tank

    TOG II Tank TOG II Tank TOG II Tank TOG II Tank TOG II Tank TOG II Tank TOG II Tank TOG II Tank

    TOG

    TOG



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    Page last modified: 10-12-2018 18:40:00 ZULU