[date cut off] July, 1941
I report that trained dogs carrying an anti-tank pouch filled with high explosives can be considered a viable method of combat with enemy tanks.
Trials of this anti-tank method were conducted by the Communications Directorate and Engineering and Armoured Directorate in 1939-1940. The results of the trials proved that this method is effective.
On the BTU KA proving grounds at the Kubinka station, an MS-1 tank moving at second gear was destroyed by a dog carrying an AT pouch, which caused the following damage: torn track, torn out tank side, torn off and destroyed drive wheel, damage to the upper front plate and lower hull, tank turret torn off. During all other trials with dummy pouches, dogs dove under a moving tank without fail.
The Central Dog Training School of the Communications Directorate has staff that can train these dogs, as well as staff that can use them. 3000 AT pouches were produced at Gromov factory #2 (Solnechnogorsk) in 1939-1940.
Principle of operation:
A dog that is trained to dive under a tank is equipped with a special AT pouch filled with explosives. The pouch is equipped with a lever. When the dog dives under the tank, the lever pulls out the safety pin, the striker hits the detonator, and the explosives go off underneath the tank.
Materials on trials with conclusions, blueprints, and AT pouch and detonator samples, as well as a production run of 3000 units, are available at the Communications Directorate of the Red Army.
Attached: a diagram.
Senior Engineer of the 2nd department, Military Engineer 2nd grade, Gulik."
CAMD RF 38-11355-141
And here's the diagram: