How are tanks built

Directives for machine maintenance under winter conditions (1942)

Everyday image, a Panzerkampfwagen III has to be shoveled out of the snow

The Directives for machine maintenance under winter conditions (1942) of August 27, 1942 contain instructions, tips and rules for the technical personnel of the Wehrmacht in dealing with machines and weapons technology in the winter war, which were created under the impact of the catastrophic conditions in the war winter 1941/42. In parallel to the directives for the maintenance of winter military forces, which in their appearance still seemed very improvised, the directive for the maintenance of winter machinery is a binding service instruction under the name: Motor vehicles in winter - instructions for maintenance and operation, Service instruction number: D 635/5 published. The publisher was the High Command of the Army, in particular the Heereswaffenamt, Office Group for Development and Testing.[1]

Ensuring operational readiness and combat readiness [edit]

Symbol of the Russian road conditions; Motor vehicles in the ditch

With the onset of stronger cold, especially in Russia and among the troops on the Eastern Front, increased conditions for motor vehicle operation after the apprenticeship year from the disaster winter 1941/42. This affected both simple motorcycle drivers, as well as the readiness to drive and the supply brigades up to the heavy armored fighting vehicle units. The Wehrmacht leadership recognized that, without special preventive measures, entire engines and radiators could be destroyed by freezing the coolant and that the previously common lubricants solidified at low temperatures in the east and every movement of the vehicle opposed such high resistance that the engine started or the vehicle started was sometimes impossible. Snow and ice made the journeys extremely difficult and often turned them into downright ascendants. Entire supply trains and supply columns were left behind on their way to the fronts, making it difficult to stabilize the front. In order to ensure the combat readiness and combat readiness of the combatants, as well as the rear troops, it was necessary, indeed of vital importance for the war effort, that the motor vehicles (regardless of whether they were tanks, trucks or passenger cars) were to be kept in perfect condition. This also applied to the maintenance of weapons.[2] In order to ensure this and to cope with the winter difficulties (and their consequences), the duties of the unit leaders have been rigorously increased. He alone was responsible for the careful training of the soldiers deployed in the motor vehicle service with regard to the measures listed in this regulation.[3] To this end, he was entitled to assign an on-call service before the onset of the cold season, which was supposed to prevent frost damage, especially in the event of low temperature drops, and to guarantee that the vehicles were ready for use as quickly as possible.[4]

The service instructions in detail [edit]

Operating materials [edit]

Map of the Heereswaffenamt with the expected low temperatures in Europe
Table for reading off the mixing ratio with antifreeze
Conversion sheet for measuring the mixing ratios at different temperatures

Antifreeze [edit]

When it was cold, the first place in the Wehrmacht's vehicles was the cooling water in the radiator. This should be prevented by adding antifreeze to the cooling water. The Heereswaffenamt had found out through numerous tests that at that time only two agents were suitable as antifreeze. On the one hand:

There were also other antifreeze, first and foremost, of course, Russian prey antifreeze. The use of such antifreeze was forbidden, however, and was only allowed to take place after it was approved by the Army Weapons Office. The Heereswaffenamt is also experimenting with diesel fuel as an antifreeze. The tests showed, however, that diesel fuel was only conditionally suitable as an antifreeze. However, it was used as a so-called admixture in the lubrication and oiling of machines. It should be added to the cooling water of all motor vehicles in front at the onset of the cold season, as only the addition of the above-mentioned antifreeze protected the engine against freezing. For this purpose, both the radiator and the engine had to be completely drained of the previous cooling water and flushed several times with fresh water. When adding antifreeze to the cooling water, the Wehrmacht made a distinction between the following mixing ratios:

  • With built-in cooling water heater: Especially in the case of the Eastern Army, the cooling systems of the motor vehicles were already integrated into the cooling water heaters at the factory in order to be able to meet the harsh conditions. The mixing ratio was here for all Combat vehicles 60 (Glysantin) to 40 (water). At very low temperatures and if the glysantine content was too low, however, the water thickened in such a way that the heat circulation of the cooling water heater was hindered or could fail completely. On the other hand, however, a higher proportion of Glysantin was also unnecessary, since it did not improve the resistance to cold.
  • Without built-in cooling water heater: Motor vehicles in which the cooling water heater was not installed permanently or from the factory were found especially in the rear army areas and on the western and southern fronts. Here the mixing ratio was only 50 (Glysantin) to 50 (water).

If the available quantities of Glysantin were not sufficient to supply all vehicles of a division or unit with it, the Glysantin was allocated according to a list of priorities. First and foremost were those vehicles that were ready for action continuously had to be guaranteed (e.g. battle tanks, self-propelled guns, etc.). The glysantine level had to be checked weekly after filling with the so-called glysantine spindle. Missing amounts of liquid then only had to be supplemented with water. In the case of parked motor vehicles that had not been treated with Glysantin, the cooling water had to be drained off while it was still warm.

For units of the Wehrmacht that Not were used in the east, the mixing ratio was based on a climatic map of Europe and the associated ratio scale (see graphics on the left). This map was visible in the headquarters of every company. If the radiators and engines of these vehicles had been flushed through, antifreeze could be added according to this table. The mixture distillate was then finally poured back into the motor vehicle engines. It was important to ensure that the cooling systems were not completely filled so that the liquid would not overflow when the motor heated up. However, the undiluted Glysantin (in barrels) arriving at the Eastern Front already became viscous at −15 degrees, so that the barrels, once they arrived at the troops, had to be warmed up in order to use the contents. The Wehrmacht leadership, especially the Heereswaffenamt, also experimented with ethanol as an antifreeze, but came to the conclusion that it could only be used to a limited extent as an antifreeze. The reason for this was that, in contrast to Glysantin, ethanol simply evaporated at an operating temperature of +70 degrees and, as a result, the cold resistance of the radiator and the engine fell sharply again. However, it was allowed to use it temporarily on the eastern front, since Glysantin was not available to the extent that the army command had hoped for. In the reserve army, however, ethanol was widespread and the standard antifreeze in general.[5] What all antifreeze had in common was that after the cold season the glysantine-containing liquid had to be drained off again and stored in suitable containers for reuse. Liquids containing ethanol, on the other hand, did not need to be drained off, since by their nature they would gradually evaporate anyway.

Winter fuels

Front usePetrolDiesel fuels
Eastern FrontCold-resistant down to -40 degreesCold-resistant down to -40 degrees
Outside the Eastern FrontCold-resistant down to -25 degreesCold-resistant down to -20 degrees

For the winter of 1942/43, after the experiences of the winter of 1941/42, the Army Weapons Office created new types of special fuels, all of which showed increased resistance to cold. The petrol for the eastern front, which is cold-resistant to −40 degrees, was brought to the front in yellow barrels for better visual differentiation. Tank cars and containers for diesel fuel down to −40 degrees were marked with a large white. Fuels with insufficient resistance to cold for the eastern front were allowed to move to the east when the troops were moved Not get picked up! The existing fuel had to be drained beforehand and stored at the current base. The motor vehicles were then refilled with the same fuel for the Eastern Front. In the case of longer rail transports, the vehicles had to be allowed to warm up for about five minutes after unloading so that the lines, filters, fuel pumps and carburettors were flooded with the new fuel. This procedure was also necessary because all too often arriving vehicles and armored vehicles were sent directly from the loading point to the front.

It is worth mentioning that in addition to these petrol and diesel fuels for the Eastern Front there was also another special form of fuel, the Special fuel T, which stood for the tropics and was intended for use in North Africa. Light petrol was used as the starting fuel in the eastern regiongasoline. It was highly flammable and was able to generate an ignitable fuel-air mixture despite the low temperatures. Since it was easily flammable, it had to be handled with particular care and caution. It was to be protected from direct sunlight and kept away from open flames. The fuel was then filled and transferred in the following way:

  1. Before the fuel was poured into the transport containers, they had to be allowed to drain upside down so that all residues were removed.
  2. Snow and ice had to be removed from the feed openings.
  3. Pumps, taps etc. were to be freed from snow and ice in the same way and kept dry.
  4. When it rained or snowed, the openings had to be covered.
  5. Emptied containers were to be closed tightly immediately.
  6. Full barrels were to be stored in a cold place in order to freeze out the inevitable water at the bottom.
  7. For this reason, immersion pipes and pumps could not be led to the bottom of the barrels.

Special fuel lines exposed to the airstream had to be insulated with particular care. This was mostly done with wool or fiber residues. Lines and connections that were already frozen had to be unscrewed and blown through with the air pump or thawed.

Motor oil [edit]

Just like the specially developed winter fuels, special engine oils were also developed for the East, with the designation Wehrmacht winter oil (winter) were brought to the issue. In contrast to the standard engine oil of the Wehrmacht (Wehrmacht engine oil), a lower viscosity and an improved low-temperature behavior. It was better than that too Motor oil of the Wehrmacht Pz, which was specially designed for use in armored vehicles. In the absence of alternatives, the three oils mentioned could also be mixed with one another, which gave the vehicle drivers a certain degree of flexibility. The on-site commander had to ensure that the Wehrmacht engine oils (winter) were poured in when the cold set in (below 0 degrees). If the Wehrmacht engine oil was not available (winter), the Wehrmacht Pz engine oil was to be used. Motor vehicles that were pushed in for the east in winter, had to be filled with the engine oil of the Wehrmacht (winter), whereby the oil could continue to be used even when the warmer seasons came. However, in order to prevent the higher oil consumption, it was against that as soon as possible in these cases Wehrmacht engine oil to exchange again. Drained engine oils were also to be caught and collected at the appropriate storage points. As with the type of fuel, with engine oil, there was that Special engine oil T, for use in the tropics (North Africa).

Gear oil [edit]

As with fuel and engine oil, there were also gear oils specially developed for use in the East. This has become known under the name Wehrmacht gear oil (winter). In contrast to the standard gear oil of the Wehrmacht, this oil had improved lubricating and cold behavior. With it, change gears, steering gears, axle drives and steering systems could run smoothly even at low temperatures. If the Wehrmacht's gear oil was not available (winter), it could in front At the start of the frost period, diesel fuel can also be used as a makeshift. The mixing ratio in this case was 4 (gear oil) to 1 (diesel fuel). The gear oil of the Wehrmacht (winter) was, if available, always to be filled in undiluted and also to be refilled undiluted if it was lost. It also did not need to be specially lowered if the motor vehicle was moved to the west. Nothing is known about a gear oil especially for the tropics (special gear oil T).[6]

Grease [edit]

In very cold weather, the standard Wehrmacht grease solidified in such a way that the lubrication points could no longer be adequately lubricated and it was virtually impossible to press it into the lubrication point. Melt water entered the now incompletely filled lubrication chamber, which subsequently solidified to ice and could thus lead to severe damage to the joints. A special one Lubricating grease (winter) was tested by the Army Weapons Office, but never went into series production due to the increased complexity in production. It was therefore recommended that from the winter of 1942/43 onwards, with the beginning of the frost period, all grease lubrication points, except for the wheel hub bearings, should be lubricated with a mixture of the previous Wehrmacht grease and engine oil (winter). The mixing ratio was:

  • up to −20 degrees: 2 parts grease to 1 part engine oil
  • below −20 degrees: 1 part grease to 1 part engine oil

Shock absorber oil [edit]

The shock absorber oil also became more viscous with increasing cold. It could partially freeze even at temperatures of −40 degrees. But even viscous oil caused the shock absorbers to fail in their primary buffer effect. This influenced both the now spongy and jerky driving behavior of the motor vehicles in such a way that driving safely and arriving without sufficient freedom from shock absorbers on the unpaved roads of Russia became a matter of luck. Especially when the motor vehicle was loaded with explosives or used as a troop transport. For this reason, before the onset of frost, the shock absorber oil was carefully removed with an oil syringe that had to be carried in the vehicle, mixed with a proportion of 1/4 diesel fuel and then carefully poured in again. To avoid damage, it was advisable to drive slowly for the first few kilometers until the shock absorbers had warmed up sufficiently with the mixed oil.[7]

Other oil changes

In addition to the engine, transmission and shock absorber oil mentioned, there were other machine parts on a motor vehicle in which oil played a decisive role in the mode of operation. For example the oil of the central lubrication and the oil filter. Therefore, before the onset of the frost period, all other machine parts in which oil played a central role were diluted with diesel fuel. For central lubrication in a ratio of 3 (engine oil) to 1 (diesel fuel) and the oil bath air filter in a ratio of 3: 1.

Preparing and maintaining

The second important point in the maintenance and operation of motor vehicles in winter was the point Preparation and maintenance. He mainly dealt with the winter equipment of the motor vehicle in general, the braking performance in winter conditions and the most important central point of all, the heating effect for the motor vehicle driver. For this purpose, before the onset of the frost period, the usual winter equipment for the individual vehicles was issued, which consisted of the following parts:

  • Anti-skid chains with emergency links and locks,
  • Anti-skid agent for full chain vehicles,
  • Snow grab for full-track vehicles,
  • Blocks, billets and straw carpets,
  • Motor blankets (self-woven straw mats)
  • Radiator hoods,
  • Frost protection hoods,
  • Tow bars,
  • Tow ropes,
  • Shovel or spade,
  • Hatchets or axes and
  • Sand or grit for spreading.

The parts that were already part of the equipment in the summer, such as the tow rope, had to be checked, repaired and, if necessary, supplemented. Folding radiator walls were to be made passable. If there were no radiator hoods and hinged radiator panels, makeshift covers had to be made from cardboard, blanket and plywood and attached in front of the radiator.[8]

Preparing electric starters

The starter was another important sticking point for a successful start-up of the vehicle. The Wehrmacht distinguished between several starter types, the majority of which were manufactured by the Bosch company at the time. The most important distinguishing features were:

  • Starter, relubricating and warming up Not was required:
    • Thrust drive starter with foot engagement: Type Bosch CE, CG and CJ
    • Push-button starter: Type Bosch BGC, BJG and BJH
    • Push-button drive starter with push-button operation: Type Bosch EJD
  • Starters that have been relubricated or warmed up:
    • Screw drive starter: Type Bosch AJB and DT
    • Screw drive starter with push button operation: Type Bosch EED, EGD and ECD
  • Starters that do not smell but had to be warmed up:
    • Type Bosch BNF, BNG, BPC and BPD

The starter had to be completely removed for relubrication and with the Special fat (winter) to repaint. This work should only be carried out by experienced specialists in army workshops, as they usually completely dismantled the starter and completely removed the old grease.[9]

Brakes [edit]

Mechanical brakes

Mechanical brakes worked (and still work) through the guidance of traction ropes. At its joints and bearings under the chassis, as with all brakes, splash water and snow mud could freeze them, rendering the brakes unsuitable. Brake shoes that were already on could no longer be released without further ado. Therefore, the overriding principle was that all Bearing points, joints and brake cables had to be re-lubricated on all motor vehicles and that in fact after every long period of use. The mixing ratio was here:

  • up to −20 degrees: 2 (grease) to 1 (engine oil)
  • from −20 degrees: 1 (grease) to 1 (engine oil)

Frozen lumps of ice on the brake parts had to be knocked off with a hammer or the like and no brakes had to be applied when the vehicle was parked. The vehicle was to be secured from rolling away by putting in a gear or by securing it in place.

Oil pressure brakes [edit]

The problem with ice formation on oil pressure brakes was that the transition valves and transfer openings were most affected by ice formation. They therefore had to be kept clean and free of water under all circumstances. In the case of pipes that were bent downwards particularly strongly, they had to be lubricated separately, as brake hoses covered with ice could easily break. When filling with brake fluid, it was important to ensure that no water, snow and ice could get into the filler openings. If brake lines were frozen anyway, the lines had to be carefully defrosted and the brake system vented until no more water or air bubbles were pressed out.

  • Schematic representation of the compressed air braking system

  • Schematic representation of the compressed air braking system part II

  • Filling antifreeze into the trailer brake

  • Filling antifreeze into the tire inflation bottle

  • Filling in antifreeze at the pressure regulator

Air brakes [edit]

The air brakes were also not safe from ice formation. Above all, with this type of condensation water formed in the pipes and valves, which resulted in complete icing. In such a case, the brake no longer had any braking effect. Therefore, before the onset of frost, the previously used brake oil had to be drained and replaced with glysantine or ethanol. In a pinch, methanol did too. However, methanol has been extremely dangerous in practical use because it is highly toxic. The soldier was therefore required to protect his face and especially his eyes when filling with methanol, otherwise there was a risk of blindness from possible splashes.

Suction air brake [edit]

The type of suction air brake was located under the chassis and was therefore extremely susceptible to icing from spray water and snow mud. As a result, the brake could fail or was very difficult to operate. Therefore, the standard oil had to be removed and mixed in a ratio of 3 (engine oil) to 1 (petrol or diesel fuel) and then refilled. The oil change should be repeated after 1000 kilometers of driving at the latest.[10]

Heaters [edit]

The last point in the fitting out and maintenance of motor vehicles concerned the heating for the driver (s). The motorbike drivers were particularly exposed to the cold and the icy wind, for whom the Army Weapons Office found a practicable and dangerous solution. However, the driver in a truck was also exposed to the cold, since the insulation of the vehicle types at that time was not designed for tough use in the east. The main thing that was missing here was the insulation on the driver's doors. A distinction was made between the following types of heating:

Fresh air safety heaters [edit]
There were also heating elements for motorcycle riders
Motorcyclist during a smoking break

Old-style fresh air (exhaust) heaters were no longer allowed to be used for health reasons. There was a replacement, the so-called fresh air safety heater TRIA. If this was not available, such fresh air heaters could also be made makeshift. For this purpose, a funnel with the largest possible inlet opening (about 250 mm diameter) had to be installed close to the fan rotation circle. A pipe with a diameter of at least 70 mm led from this funnel into the interior of the car. Care had to be taken that the pipe was not kinked during installation. However, the bonnet was then not allowed to be completely closed while driving. This stopgap measure was life-threatening, however, as oil evaporation in the engine compartment and leaky exhaust lines could get toxic fumes into the vehicle cabin.

Hot water and steam heating [edit]

According to their operating instructions, hot water and steam heating had to be kept running, as far as this was somehow resolvable and feasible in the cold. If no antifreeze was added to the liquid, the entire heating system had to be drained at the same time as the cooling system. In other words, the entire heating system would not work without antifreeze.

Combat space heaters [edit]

The radiator warm air was used to heat the fighting compartment of a tank. The cooling flow was led into the fighting compartment through a pipe inside. The loader and / or commander was constantly required to keep an eye on the carbon oxide indicator and the carbon oxide test paper, especially when the main battle tank was closed. The background to this procedure was that carbon oxide gases were also carried into the fighting compartment through leaky exhaust pipes and could thus trigger the death of the tank's crew. For heating in winter, there were specially made winter fans that had to be installed in accordance with their operating instructions.

Hand and foot heating on the motorcycle [edit]

In the case of motorcycle heating, part of the combustion gases from the engine was used for heating. For this purpose, the exhaust line of the motorcycle engine was tapped several times immediately after the engine cylinder and the hot gases escaping in this way were fed in pipes or metal hose lines to the radiator on the handlebars, the footrests and the front section of the sidecar. The changes made were life-threatening for the motorcyclist. When pushing the motorcycle with the engine running, he was not allowed to bring his head near the handguards, otherwise there could be a risk of poisoning from the exhaust gases.[11] But that was almost impossible when the bike got stuck in the snow and had to be pushed out by the bike driver. In most cases, this could not be done alone without the help of the engine. Despite these dangers, this type of heating was a welcome, but also hated winter accessory for motorcyclists.

Turret slewing gear, optics and weapons [edit]

Armored vehicles of the Wehrmacht were given special attention in the preventive measures against frost. In particular the armored car. In these, all hinges and joints, here the viewing flaps, shooting flaps, hatch covers and engine flaps, had to be greased regularly so that water and snow mud could not penetrate in the first place. In particular, snow mud had to be removed in good time so that the towers and hatches did not freeze or only had to be moved by force.

  • Freezing of the towers: If snow and snow mud collected in the tower gap, the tower froze. Therefore, snow and snow mud had to be removed from this gap. Towers that were frozen in place were not allowed to be turned by force. In this case, the ice was difficult to thaw and remove with a blowtorch.
Detail of a dust bag
  • Tower slewing gear: Tower slewing gear that was still lubricated with cylinder oil or conventional factory grease could no longer be moved in the very cold. Therefore, these greases had to be removed by hand and replaced with engine oil from the Wehrmacht (winter).
  • Weapons: The locking flaps of the weapons were difficult to operate in very cold weather and in an unheated combat area. The same applied to the return pipe. The old oil and grease had to be removed from the guns and replaced with cold-resistant gun lubricating oil. However, they were only applied very thinly. The muzzle tubes and barrels were to be protected against the ingress of snow and water by muzzle guards, caps or dust bags. After firing, the barrel had to be cleaned and lightly oiled inside during breaks in the fighting. In order to avoid failure, it was advisable to check the operability and the catches as well as the complete emergence of the firing pin tip more often during a longer break in the fire. Before the battle, frost and ice inside the pipe had to be removed with the wiper. The absolute rule was: It was not allowed to shoot from an icy pipe! Muzzle caps that can be pierced through (this refers to the dust protection bags) should not be pierced with an explosive grenade due to gunfire.
  • Bullets, cartridges: Small calibers such as cartridges, cartridge belts and guide straps had to be freed from frost and ice before loading, otherwise it was not possible to attach them firmly to the weapon.
  • Optical devices: stiff driver and rifle scopes could only be operated when they were sufficiently heated. The Wehrmacht leadership also helped themselves here. Optical devices that were marked with a blue circle next to their stamped company name could move down to −40 degrees without heating. Another lesson from the winter war of 1941/42. To protect the optics against fogging and freezing, they were rubbed in with a thin layer of Glasil. Glasil had to be requested from the tank spare parts stores.

After the combat compartment heating was switched on and the engine had run under load for around 30 to 45 minutes, the sluggishness of the turret slewing mechanisms, the weapon locks and optics could be avoided. It was therefore common for combat groups to warm up their armored vehicles about an hour before the start of the battle or attack.[12]

Event preparations after the end of the journey [edit]

Schematic representation of a Finnish hut
Parking of vehicles under a roof
Assembling two cars outdoors

The third point of the service instructions concerned the preparations for the occasion after the end of a journey. The drivers were asked to make preparations as soon as the vehicle was parked so that their vehicle could be started properly again, for example after one night. If the motor vehicle was parked after a journey or a battle, it was primarily necessary to ensure that it did not cool down too much. This measure not only prevented frost damage to the vehicle, but also ensured that it would start up in the event of an emergency. In addition, measures had to be taken to reduce engine resistance during later starting and start-up or, ideally, to switch them off completely. The parking of motor vehicles in the open naturally made the subsequent commissioning particularly difficult. Therefore, all opportunities, including seizures, were to be used to create temporary storage rooms. If such barns and the like were available, the air-permeable areas (cracks in boards, etc.) had to be temporarily sealed with straw and brushwood so that an almost closed space was created. If there was no such shelter, other makeshift structures could be built, for example Finnish garages or wooden crates. The Wehrmacht leadership therefore distinguished the following makeshift structures for motor vehicles:

  • Finnish garage: The Finnish garage consisted of tree trunks, slats and the like. A kind of frame was made with these, which was then to be clad with the materials available on site. Coverings made of cardboard, boards and stones were better than those made of brushwood or twigs, since the former were better at keeping the heat. The half or full garage that was soon built made it possible, if possible, to dug or blow up a heating duct to accommodate a chimney pipe. On the narrow side of the Finnish garage, a furnace was then to be built in a dug pit, which was expediently protected by a small roof. It had to be built so high that there was enough draft for the heating. Clay pipes were to be used for the pipes to be used, as iron pipes were too dangerous because they could ignite fuel residues. Cement pipes, on the other hand, tended to crack or break in the cold. If only the last two types could be used due to the lack of clay pipes, these had to be covered with wet clay. The floor of the garage had to be insulated as best as possible with brushwood or bundles of straw. Finn garages were easy to manufacture yourself with little effort and thus at least allowed the engine of the vehicle in question or even a whole motorcycle with a sidecar to be stored.
  • Tied roofs: Tied roofs could be erected quickly and easily in a similar way to Finnish garages from existing natural materials from the area concerned. They had to be provided with at least three closed side walls, since in the opinion of the Army Weapons Office, open towed roofs had little protection against ice and snow.
  • Earth huts, earth cuts, snow walls: In suitable places earth cuts and earth huts for parking individual vehicles or just for their engines could be created by hand. The cuts in the ground then had to be built over for camouflage. So-called snow walls, which were built from snow bricks around the vehicle, also offered effective protection against the biting cold and snow winds for armored vehicles. If that was not possible, it was enough to cut into a snowdrift. The snow walls had to be built so high that at least the chain cover was covered at the front and sides. The space under the vehicle was stuffed with straw.[13]

In heated and unheated storage rooms [edit]

In the first place, only motor vehicles were to be parked in heated storage facilities always had to be operational or ready for action, or the way they were manufactured, had already started with difficulty. Before entering the storage facility, the vehicle had to be cleared of ice and snow. If there were halls, the motor vehicle had to be driven in so that the radiators were not facing the gate. Vehicles without antifreeze in the radiator were constantly checked by the on-call service so that if the heating failed, the cooling water of these vehicles could be drained off immediately. Parked vehicles had to be warmed up in front of the hall after starting. Firstly, in order not to have to keep the hall gates open forever and thus allow the cold to move in and, secondly, there was a risk of poisoning from escaping exhaust gases when the gates were closed.[14] The same rules also applied to the Finnish garages and storage rooms in the case of cuts in the ground. The vehicles were to be set up under pent roofs with a rear wall so that the radiators were in front of the wall. If there were no walls at all, the cooler had to be positioned in such a way that it did not face the wind. If the tent roofs allowed the motor vehicles to be set up in two rows, the motor vehicles should be placed cooler by cooler. Both engines then had to be covered together with a tarpaulin or blanket.

Outdoors

If it was impossible to avoid setting up the motor vehicle in the open air, it should be in places protected from the wind, for example on walls, bushes, railway embankments and the like. These then had to be brought as close as possible with the cooler to the draft shield. If there was no wind protection at all, as in the open country, the cars with their radiators were to be placed against one another. Boards, brushwood, straw and the like had to be placed under the wheels or crawler tracks to prevent the wheels from freezing to the snow. The handbrake could not be applied as it could freeze too. Likewise, there was no gear to be engaged. The vehicle was secured against rolling away, etc., in that stones or wedges were pushed under its wheels.[15]

Keeping warm [edit]

After parking the vehicle, it was important to maintain the operating heat of the engines and collectors for as long as possible.This was less difficult in heated rooms. The following options were available to keep the vehicles warm in unheated parking spaces or outdoors:

Cover [edit]

The motor vehicle was simply covered with existing tarpaulins, blankets, sacks, etc. But straw or reed mats, which were made by the local troops themselves, could also be used. When covering the motors, care had to be taken that no wind could blow under the motor. The ends of the tarpaulin etc. were then to be weighed down with stones. If the ceilings did not reach the ground, boards and other materials were needed to cover the sub-floor.

Supply of heat
  • a) Catalytic ovens: Due to their design, catalytic ovens developed only small amounts of heat and were therefore only used to a limited extent in smaller, well-covered engines for keeping warm. They were operated with the starting fuel gasoline or alcohol.
  • b) Dalliöfen: Like the catalytic oven, Dalliöfen developed only a small amount of heat and could therefore only be used as a heat source in smaller, well-covered engines.
  • c) Other devices for keeping the engines warm: On other devices, the soldiers at the front had cooling water heaters and hot air blowers available. These had sufficient power to bring the engines at least approximately one night in arctic conditions.
Running the engines

Another means of keeping the engines warm was, of course, to keep the engines on while idling. The disadvantage here was the immense fuel consumption. Therefore, the unit's commander only allowed the engines to run when the force was in combat readiness or when it was imminent.

Thinning the engine oil [edit]

That developed Wehrmacht engine oil (winter) Guaranteed trouble-free cranking and lubrication of the car engines down to outside temperatures of −20 degrees. However, the temperatures in Russia were sometimes as low as −40 degrees and lower. From −20 degrees, therefore, the developed thickened Wehrmacht engine oil (winter) increasingly. When using simple Wehrmacht oil or the Wehrmacht engine oil (Pz), these types of difficulties were more likely to arise. Here already from −10 to −15 degrees. Therefore, the engine oil was simply diluted. The following formula applied:

  • At temperatures of −20 degrees to −30 degrees, 15% petrol was added to the engine oil. This applied to both gasoline and diesel engines.
  • At temperatures from −30 degrees, 25% petrol was added to the engine oil. This dilution formula was also generally required for winter transports by rail!

The added fuel then boiled off again when the engine warmed up. Long-term tests by the Heereswaffenamt did not show any adverse effects on the operational safety of the engines.[16] The first oil dilution was not to be carried out by an inexperienced driver, but required the supervision of the service engineer. To do this, you proceeded as follows:

1. The oil filling and the admixture quantity for the most common engines could be found in an attachment (see picture gallery). If the vehicle in question was not listed, the filling quantity had to be determined manually. To do this, it was important to ensure that the vehicle was standing horizontally and that the engine was filled with oil up to the mark: or on the dipstick.

  • Oil filling quantity of the engines in various vehicle models Part I