Tank Warfare on the Eastern Front, 1941-1942: Schwerpunkt

Aside from inferior mobility in deep snow, the German tanks were badly affected by the penetrating cold in Russia. Although both German and Soviet tanks had means to divert warm air from the engine exhaust to the interior of the crew compartment, this only sufficed when the engine was running. When fuel was in short supply, as in October–December 1941, they could not run their engines continuously. Lacking petrol-fired personnel heaters in their tanks (which could operate with the engines off), panzer crews retreated into nearby houses or peasant izbas, leaving their tanks out overnight in deep freeze. Consequently, the water inside the tank’s batteries froze, cracking the cases, which then required immediate replacement – but batteries were in short supply. Even if the batteries didn’t rupture, the charge they could hold dropped off rapidly below freezing. Rubber coatings on power cables could also crack at temperatures below –29°C (– 20°F). Petrol and diesel fuels were also affected by severe cold, which could have ice crystals form in fuel lines. Below –32°C (–25°F), the hydraulic fluid in the main gun’s recoil system would freeze, resulting in the main gun being thrown out of battery if fired. The lubricant in machine-guns froze at –37°C (–35°F), making the weapons unusable until cleaned. Ammunition became difficult to work with after being frozen and the main gun breech could become very ‘sticky’ after a frost, resulting in rounds getting stuck in the breach.¹⁷ Even when the unit received more fuel, starting an engine that had been idle for several days in sub-zero temperatures proved very difficult for the Germans and they resorted to extreme measures, such as building a wood fire under the tank. Once heated, the frost turned to condensation inside equipment. In contrast, the Soviet T-34 had internal compressed air bottles for cold weather starting and the T-34 had been extensively tested in winter conditions. As a result, German panzer units became very vulnerable if attacked by Soviet armour early in the day, when many panzers could not start; if the German unit was forced to withdraw, non-starting tanks were abandoned.

Even when the Germans could start their tanks, they found that the cold weather seriously degraded critical systems. Radios were particularly vulnerable to freezing and condensation, as well as the gunner’s primary optical sight. The optics tended to trap frost inside the lenses, which prevented effective aiming. Tank maintenance became very difficult in temperatures below –29°C (–20°F), with exposed skin adhering to metal surfaces and even standard oil lubricants and tank grease becoming too thick to properly use. Without lubrication, tanks quickly lost the ability to move without damaging the running gear. Tasks like changing a torsion bar or drive sprocket were all but impossible without shelters in sub-zero weather. While the Red Army could shuttle its damaged tanks back to nearby Moscow for repair in proper facilities, the Wehrmacht was at a distinct disadvantage, far from its industrial base in Germany and lacking forward repair bases.

Indeed, the Russian winter reduced much of Hitler’s panzer armies to frozen scrap metal in a matter of a few weeks – proving to be the most effective Soviet anti-tank weapon of 1941. This is not to say that the Russian winter defeated Hitler’s panzer armies, but that it neutralized an already spent and defeated force. Nor were German tank crews prepared for winter weather in either material or psychological terms. Most crewmen wore their black panzer uniforms throughout the winter of 1941–42, since the bulk of the available winter uniforms went to the infantry and artillery, not the panzer troops. German panzer crewmen had not been led to expect a winter campaign and when the heavy snow and deep cold began, many seemed to lapse into the idea that they would be sent home to get new tanks. Some surplus crews were sent home, but the majority were pressed into service as infantry or anti-partisan troops, for which they were ill-suited. In contrast, most Soviet tank crews were well supplied with warm winter clothing. While Soviet tankers were too thinly spread to achieve decisive results in the winter of 1941–42, they did learn a great deal during the period when their opposite numbers were laid low.

Fateful Decisions and Armoured Renewal, April–May 1942