M4 SHERMAN MEDIUM TANK
'THE MINE CLEARING TANK'

The Americans go also for the flail

The pilot of the T3 without the chains on the rotor

The T 3 was flail concept of the British Scorpion. The first tests in the United States were on the M4A4. The flail rotor was driven with a separate engine on the right of the tank. The chains of the T3 swept in a spiral pattern. At the front of the tank a shield was placed to protect it from debris and rocks. Thirty T3’s were produced by the Pressed Steel Car Company and shipped to North Africa in May 1943. A total of 41 T3’s were produced by Pressed Steel Car Comp. During the outbreak from Anzio towards Rome, the T3’s drove at the front. But the vehicles were often broken down because of the exploding mines. Soon afterwards the T3’s were pulled back from the front.

A T3E1 without the flank-engine and without the chains

With the T3E1 the separate engine on the right was deleted. Instead the M4’s own engine was used to rotate de rotor. The weight of the was reduced with a half, to 2540 kilos. The speed of the rotor went from 75 rpm (T3) to 178 rpm with the T3E1. Testing brought to light that, just as with the British Crab I, only on a smooth surface the flail worked at its best. Crews did not liked the T3 and T3E1 because of the rocks and dust the flail produced during operations.

A small test contraption of the Rotoflail

Some testing was done with a larger diameter rotor, the so called Rotoflail. It was a big step forwards, but the war was almost over and further testing was stopped.

The final flail-version for an M4, in this case an M4A3 (HVSS) 76mm

The last version with a flail-system was built for the M4A3’s who were put into action in the Korean War in the fifties of the last century. These rotor were powered once again by a separate engine on the right.

In the 2nd World War in the field, often some homemade solutions were built by handy mechanics, such as the one by the ‘Seabees’ for the US. Marine Corps.

An M4A2 of the US. Marine Corps with an
improvised flail constructed by the 'Seabees' (1944)

America continues the experiments

The previous models were based on the flail or roller system. But there were other experiments to look for an alternative. An example is the T5. The principle was simple. A Bulldozer blade with a special angle pushed under a mine and drove it to the side of the road. Previous versions, the T4 and the T4E1, with a diagonal blade in a flat angle were no success and were not further developed. The V-shaped blade of the T5 had also a curved edge on top of the blade to prevented mines from toppling over the blade and fall in the running path of the tank. After some adjustments the final version was named the T5E1. Another model, the T6, with the same principal, was tested and developed to the T6E1 and T6E2 before testing was stopped. The solutions of both the version, T5E1 and the T6E2 were combined to become the T5E2. Fine tuning let to the T5E3. At Plante-Choate 100 T5E3’s were produced from March till May 1945. It was the only type of mine clearing tank shipped to the frontline in the Pacific Ocean.

Een T5E3

Lt-Col. A.R. Williams designed a very ingenious system for mine detonation. At the front of the tank 18 mini pile-drivers were installed. It was connected to the front wheel. When activated the ‘ram’ hammered out of the cylinder. When a mine detonated, the ram jolted back into the cylinder that had a heavy spring as a brake, just as a shock absorber.

A T8 with three ‘pile-drivers’

It was designated as the T8, but had as nickname Johnny Walker. The first test were done with three ‘pile-drivers’ at the front of an M4A4. The test were not a great success, and an another test was done with six drivers. This T8 was somewhat better, but working in rough ground was a problem. During testing the hammers were damaged and the testing was stopped.

The T8 test vehicle with six ‘hammers’

The roller system once again re-surfaced. The next idea was the use of a giant roller, used for ground flattening. The T9 had a big cylinder that was covered with 5 inch spikes. A push-frame had a extensible axel what made it a difficult to operate. The weight of the whole contraption was 84.000 pounds.

This test with a T9 ended sucked solid into the mud.

It’s successor, the mine exploder T9E1, had a smaller cylinder with smaller spikes. The wall of the cylinder was made thinner. This reduced the weight to 64.000 pounds. The extensible axel, to slide the roller outwards, was 236 inches in the short position, and 314 inches in the outstretched position. Because it’s contraption was almost as heavy as the M4 that pushed the thing, it was during operations very hard to maneuver with it, so further development was stopped.

The last version of the T9E1 with lighter installation.

The Big Foot M4 Sherman T10

Maybe the most eccentric and futuristic idea to clear mines, was the T10. It was developed out of the Tricycle constructed by the NDRC. The idea was to built small engines into the giant 96 inches front wheels (so it could drive without the internal engine of the tank). Between the traction wheels were six heavy discs loosely placed around the axel so it good follow the rough ground easy. It had a long frame at the rear with a wheel (were it’s nickname came from; Tricycle). Test were done at Aberdeen with wheels without the engines and the discs in the middle. It worked well, but it was not further developed.

The T10 looked a lot of the Big Foot monstertrucks that are used in shows today

The Tricycle dropped the idea to place engines inside the wheels, and used the traction of the internal engine. Fisher was given de order to produce a pilot with the designation T10. The standard bogies with tracks were removed from an M4A2. The underside was thickened with 25mm steel. The side of the tank was adapted to give room for the enormous 96 inch wheels. The wheel at the rear was 72 inches in diameter.

The M4A2 T10 stood high on her wheels

The M4A2 stood 55 half inches above the ground. The width of the path was 153 inches (the front wheels had a width of 36-half inch each). The 116.400 pounds heavy tank could reach a speed of 3 km/h when it was clearing mines (on a clear road it could drive 10 km/h). In June, 1944 the T10 was tested, but it was evident that the weight was the drawback in action.

During the war a lot of ideas and testing was done to clear mines, even mortars were used to detonate mines. Or, a sort of conveyor belt was used with an explosive at the end that would detonate just above the ground, so it would trigger mines hidden in the ground. This Pancake, as it was called, was a flop. Another idea was the so called demolition snake M2, a long tube of 400 feet long, filled with 3200 pounds of explosives (a total weight of 12.500 pounds). The tank pushed it into a minefield. After detonation there was a path of 320 feet in length and 16 to 20 feet wide ’cleansed’. The M3 had instead of a steel tube, an aluminum tube. This brought the weight down with 3500 pounds (in comparison to the M2). But all these ideas let to nothing.

The T15 in January, 1945 at Chrysler.
(Notice the heavy rubber ‘stoppers’ above the wheels
to ‘break’ the shock of an explosion)

The last mine clearing Sherman I mention here is the T15 and the T15E1. It was developed out of the T14, an almost indestructible Sherman tank. The underside was strengthened and the suspension with the tracks were made very strong, so it could drive shockproof into a minefield. But the tank was far to heavy in muddy terrain. Instead of a heavy indestructible tank, it was better to use a lighter one that could deal with a ‘punch’. Chrysel developed the first mine resistant vehicle T15. The underside was made thicker and the bogies and suspension were covered in armor plating. The turret was deleted and a 25mm thick armored plate covered the hole. In this plate an oval hatch and a cupola for the commander was placed. This T15 had a weight of 72.7000 pounds (just 2.7000 pounds more than the standard M4 tank).

The T15E1 with the stud-tracks

The next development of the T15 was the T51E1. It looked exact as it’s predecessor, but had heavier tracks with studs on the track. In the cover plate (where the turret used to be) two hatches were placed, one cupola for the commander, and a two-split hatch with a .50 machinegun (the same hatches as on the M4A1 76mm, but in mirror). During testing at Aberdeen both, the T15 and T15E1 had their transmissions damaged when it struck a single T6E1 anti-tank mine. The tracks on both models could sustain the explosions of mines, but the T15E1 was a bit better that the T15 (which had parts damaged of the suspension.

Plannes were made to built pilots of the T15E2 and the T15E3. Bud both projects were at an early stage canceled.

At the end it was concluded that the flail was the best, even when it was not the perfect solution. The most clumsy was the T1E3 with her enormous wheel on the front. The ugliest had to be the T9 (and also difficult to work with). The most attractive one in my view, was the T10. It’s a pity not one example of the Big Foot was preserved.

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