Wreckers.

This is coolbert:

"That preponderance of tanks found on the battlefield in the aftermath of Brody [1941] not destroyed by enemy weapons fire. Mechanical breakdown the primary reason for tanks being abandoned and out of action!"

See previous blog entry the Battle of Brody. Largest armor battle in history in terms of tanks involved.

Soviet armor during the Second World War the breakdown on the battlefield quite common. 

MORE TANKS OUT OF ACTION FROM MECHANICAL FAILURE THAN AS A RESULT OF ENEMY WEAPONS FIRE.

Slightly more than one year later [1942] Soviet tanks out-of-action from "mechanical breakdown" continuing and the subject of a much feared Stalin Order. An edict directly from the BOSS himself.

"Our armored forces and their units frequently suffer greater losses through mechanical breakdowns than they do in battle. For example, at Stalingrad Front in six days twelve of our tank brigades lost 326 [82 %] out of their 400 tanks. Of those, about 260 [80 %] owed to mechanical problems. Many of the tanks were abandoned on the battlefield. Similar instances can be observed on other fronts."

"Since such a high incidence of mechanical defects is implausible, the Supreme Headquarters sees in it covert sabotage and wrecking by certain elements in the tank crews who try to exploit small mechanical troubles to avoid battle." - - Stalin Order, August 1942.

Wreckers those individuals in a deliberate and malicious manner doing damage to sabotage a machine or process vital to the war effort.

Being deemed a wrecker the punishment swift and severe. Execution on-the-spot or duty in a penal battalion for which the Red Army during the period of WW2 famous/infamous.

coolbert.