Far East Modernizations

"To the Chief of the GBTU TU

RE: #1142232

January 24th, 1944

Repair factory #105 developed blueprints and processes to rearm the T-37 and T-38 tanks to use the ShVAK gun. The mass of the tank increases by 100 kg as a result of rearmament. After being rearmed, the prototype was tested by firing on the move and by swimming. Trials show satisfactory results. Repair factory #105 is performing the rearmament. As of January 1st, 97 T-37/38 tanks have been rearmed with the ShVAK gun.
Repair factories #77 and #105 are installing applique armour on BT-7 tanks. As of December 1st, 1943, 113 tanks have received applique armour.

The armour is of homogeneous type, 363-495 on the Brinell scale, indentation is 2.7-3.2 in diameter.
As a rule, BT-7 and T-26 armour is used for applique plates. Occasionally armour of captured PzIII and PzIV tanks was used.
Applique armour is attached by welding and (in the case of the driver's hatch) rivets.
The following parts received applique armour:

Nose of the tank: vertical plates are covered in one layer 13-15 mm thick.
Front of the tank: plates are covered in two layers, total thickness of both is 28-30 mm.
Driver's hatch: covered in two layers, total thickness of both is 28-30 mm.
Turret: covered in two layers, total thickness of both is 25-30 mm.
Rear plate: covered in one layer 13-15 mm thick.

The tank with applique armour can climb a 25 degree slope. At a tilt of more than 20 degrees it becomes difficult to rotate the turret all the way around.
The tank's components and mechanisms perform satisfactorily.
Use of the tank by our forces shows that the tank can pass over swampy terrain.

Assistant to the Commander of the Motorized and Armoured Forces of the Far Eastern Front, Engineer-Colonel Rogachev"

Chief of the UK ORT Motorized and Armoured Forces of the Far Eastern Front"