Tank Start-Up

Frenchmen at the Saumur workshops brought to well-nigh exhaustion as they attempt to start up the museum’s King Tiger by working the inertia starter:

The same tank start-up procedure undertaken by Enghlishmen shown on #131, the Tiger I at The Tank Museum, Bovington, UK.

NOTE: The German word “Durchdrehanlasser” is not the correct term for English “manual inertia starter”, instead it should say “Schwungkraftanlasser” (while being mindful of the fact that this video was not published by The Tank Museum).

Once started, the pre-selective gearbox throws a slight tantrum when upshifting into 2nd gear … .

Ever so competent Englishmen at The Tank Museum, Bovington, UK, explain the process of operating the manual inertia starter on the Tiger Tank in detail. Not surprisingly, they manage to crank up their Tiger rather much faster than their French colleagues:

Manual inertia starter

The manual inertia starter was a device used to start up the Tiger’s Maybach tank engine specifically in case of a dead battery. This was a likely scenario, especially during winter fighting at the Eastern Front.

The starter mechanism works by accelerating a heavy flywheel (separate from the engine flywheel) to high speed, using a reduction gear driven by a hand crank. Once sufficient rotational speed is achieved by hand-cranking, a clutch is engaged manually to mesh the starter flywheel with the engine flywheel. After clutch engagement, the inertia stored in the rotating starter flywheel carries the entire crankshaft train and engine internals with it. By rotating the crankshaft and moving the pistons up and down, ideally enough downdraft is generated in the carburetors’ cold start circuits to actually start the engine – after the generator has developed sufficient voltage to generate a spark via the ignition coils, by that same rotational speed.

Compared to normal hand-cranking of an engine, operating this type of manual inertia starter poses less of an injury hazard – if you let go of the crank handle during the clutch engagement procedure (!). However, the dead weight to be carried is rather substantial, and the entire mechanism is liable to freeze up in the winter time - when it is needed most.

The T34 tank, by comparison, was a completely different animal. The elegance and ease of the starting process on this diesel-powered tank is just one of the reasons why the T34 was a coveted trophy among German troops. Many of these Soviet main battle tanks were placed into service with Wehrmacht units.

The T34, once running, was remarkably quiet. This video shows a specimen with the larger modern turret, in service with the Polish military until well after the war:

Primed for start-up

T34 start-up ... you hear the oil pump priming first. Starting could be done by electric starter, or in case of dead battery, by compressed air stored in a reservoir while the tank was previously running. No need to disembark the tank for emergency starting in the cold …

Listen to the priming pump from minute 00:20:

Compressed air starter

The T34 used a compressed air starting system to push air into the cylinder at high pressure, and crank the engine over. This type of compressed air starter, using the “Direct Starting” principle, was pioneered by American diesel engine manufacturer Waukesha, and adapted by the Soviets in 1930s - as were many things in the course of the lucrative and lively trade relationship between US and USSR prior to WW2.

Tanks fighting under extreme cold conditions were always liable to encounter trouble starting their engines. This applied regardless of whether they were powered by a diesel or petrol/gasoline engine. As engine oil thickens to a sludge and the batteries are drained, it becomes that much harder to turn over the engine using an electric starter motor.

The T34’s compressed air starter allowed the tank to operate in as low as minus 36 degree (Celsius) temperatures before Moscow in 1941, as German vehicles were unable to function because their oil and lubricants had frozen, causing engines to seize up.

The M4 Sherman has gotten a bad rap over the decades. Despite the far-reaching standardization efforts undertaken as America prepared for war, a hodge-podge of different engines were installed to power this prime mover of a battle wagon for the US Army. This particular specimen, a Sherman M4A1E8 HVSS 76mm restored in Bastogne by the team at the War Heritage Institute, is powered by a Continental R-975-C4 radial engine originally designed for airplanes:

Stalin ordered a Diesel

All of Stalin’s modern tanks had diesel engines. He insisted on this and those tanks produced by America for the Soviet Union under Lend-Lease were made special order for Stalin. As a result, all Lend-Lease Shermans sent to the Soviet Union had diesel engines.

This included the vast quantities of M4 “Emcha” Sherman tanks supplied via Murmansk and Tehran. After the surrender of Nazi Germany, these tanks empowered Stalin to evict the Japanese from Manchuria in the final days of WWII.

Stalin's engineers and military planners – well ahead of “the West” already at that time – had figured out that diesel power is the way to go in a tank.

Despite the cold-starting issues that diesel engines by design will have, they settled on diesel rather than petrol/gasoline power. The compressed air starter used in the T34 greatly alleviated any concerns about starting a tank under freezing conditions, with a dead battery.

Building a tank powered by a petrol/gasoline engine is of course complete lunacy, on all fronts. Nearly all other Sherman tanks, as in fact most other tanks at the time, had petrol/gasoline engines. This included of course the enormous Maybach Tiger tank engine, and the other German tank designs. This mode of propulsion, specifically the type of fuel used, greatly diminishes the survivability of the crew. One is puzzled that this practice was continued well into the 1960’s.

Whiskey in a barrel

The father of General Herbert Norman Schwarzkopf Jr.† was stationed in Tehran to coordinate Lend-Lease supplies to the Soviet Union. Gen. Schwarzkopf’s book is a worthwhile read, as it includes second-hand accounts on the situation on the ground, which he relays from stories his father told him, and letters received by his mother.

One such account details how Lend-Lease M4 “Emcha” Sherman tanks were supplied with whiskey bottles hidden in the gun barrel. This was surely meant well, a kind gesture by Rosy the Riveter and her colleagues, saluting their brothers and sisters in the Soviet Union, as they packed up those tanks in Detroit, to be shipped to the Soviet side of the Eastern Front.

But more than once the Red Army soldiers receiving these tanks did not bother to look inside the breech, or even bother to clean the barrel. The end result was of course the same as if pouring sand down the muzzle. Glass being made from molten sand, this proved a reliable way of destroying the M4’s main weapon.

So to prevent this, General Schwarzkopf’s father had to take care and remove the whiskey bottles already in Persia, prior to loading the Sherman tanks placed in his care onto railway cars at Tehran, destined for the Soviet Union.

The T34 was an advanced Soviet evolution from originally American designs, namely by noteworthy tank engineer Christie. The US Army had no use for his designs. But Soviet generals and designers saw the potential of a fast lighter tank. It seems they put the idea of mobile armored warfare into practice while great strategists like Guderian were still thinking about it (?).

The Christie design was reincarnated by the Soviet war machine as the type BT-5 tank. In this video, one of them is being salvaged from the bottom of the river Neva:

Very impressive, and of historic interest is this T34 – one of many captured by Wehrmacht forces, and fitted with German markings. Here it is being pulled out from the swamps in the year 2000, somewhere in Ukraine: