Tuesday, 2 June 2020

Common Questions: Sherman vs. Tiger

The topic of Sherman vs. Tiger is one of the most consistently popular ones that comes up during the discussion of WWII armoured warfare. Despite the years that have passed, such simple questions as "at what range can a Sherman penetrate the Tiger's armour" can get results ranging from "point blank" to "not at all". Many contemporary sources had much more optimistic evaluations, for instance the Americans estimated this range to be over 1000 yards (914 meters). Results of Soviet testing were much more conservative, ranging from 400 to 625 meters.

As the British were not only avid users of the Sherman tank, but rearmed their Churchill and Cromwell tanks to also take a 75 mm gun with similar ballistics, they naturally produced their own tables (I obtained this example from Harold Biondo). These also show a much more conservative estimate: 700 yards (640 meters), close to the Soviet figure.

British penetration data agrees with this table, the Sherman's 75 mm gun (muzzle velocity of 2050 feet per second) drops below 82 mm of penetration required at around 750 yards (685 meters).

However, theory isn't everything. There were a number of live fire trials of 75 mm guns against Tigers, although the British typically only used 6-pounder and 17-pounder guns in these trials.

The limit between what the Soviets defined as partial and complete penetration is 1810 f/s, which maps to around 800 yards (731 meters), making the British chart a little conservative, but still short of the American number. It's worth mentioning that they would have received vastly different results if they shot at the other side of the same Tiger. German armour plating often varied greatly in quality, even within the same vehicle.

Another trial was conducted against a different Tiger, this time with a constant range, but at varying angles.

At 100 yards the penetration limit is 17.5 degrees, which falls in between the normal and 30 degree line in the British table as expected. Looks like the British estimates were right and a Sherman crew would have a 50% chance of putting a hole clean through the side of a Tiger 50% of the time from about 750-800 yards.

So were the Americans wrong when they were writing their instructions? The answer is still no. Real life is not like a video game where a shot that does not achieve a complete penetration does no damage to the enemy at all. In the British system, the W code represented a shell or shot that passed clean through the place, but R, the code before that, still involved penetration of the armour. Even if the projectile did not enter the target, the Tiger's crew would still be struck by fragments of their own tank. Considering the brittle nature of German armour, seen in the above tests as well as many others, this would have been a good chunk of steel that would still have done significant damage to the crew and internals of the tank. Cracks to the armour would be difficult to repair even if the tank could be recovered.

In short, it was worth popping out and putting a few shots into a Tiger's side to see what would happen. The relative blindness of the Tiger's crew compared to the Sherman meant that the latter had a good chance of retreating before the enemy noticed it if the gamble didn't pan out.

1 comment:

  1. The US and British penetration criterion are very close but,
    the British critical limit is a velocity where at least 20% of the projectile passes through the armor 50% of the time.