I’ve been writing a bit of military history lately on this blog, courtesy of a couple of recent anniversaries – Jutland and D-Day. I thought I’d wrap it up, for now, with a two-parter debunking some of the mythology surrounding the German battleship KM Bismarck, whose sortie into the Atlantic in May 1941 lasted just 210 hours before she was sunk by the battleships of the Home Fleet.

Part of the mythology, I suspect, flows from the fact that Bismarck and her consort, heavy cruiser Prinz Eugen, sank HMS Hood – largest warship in the Royal Navy. As for Bismarck – well, let’s look at the myths:

1. Supposedly, Bismarck was the most powerful battleship in the world. Bismarck was not even the fastest or heaviest-armoured German ship. The preceding Scharnhorst class was faster by a knot (more in service) and had thicker belt armour. Nor did Bismarck have the greatest fire-power by comparison with contemporary British, French and Italian battleships. Bismarck was armed with eight 38 cm SKC/34 (14.96-inch) guns firing Psgr. m. K. L/4,4 projectiles for a broadside of 6,400 kg. Setting aside rates of fire, this was less than the 7,030 kg fired by Britain’s WWI-era battleships with eight 15 inch guns – ten of which were still in service in May 1941 – and less than the 7,212 kg fired by their latest King George V class. It was way less than HMS Rodney, which had nine 16 inch guns firing a broadside of 8,360 kg. Bismarck’s final battle on 27 May 1941, thanks to break-downs in King George V’s guns, was essentially down to a ship-to-ship duel between Rodney and Bismarck between 0920 and 0954 hours. Rodney pulverised the German vessel.

2. Apparently, Bismarck’s armour was special composition and proof to all shells. By the 1930s metallurgy had long since hit the limits possible with the chemistry of steel additives and processing techniques. Naval armour worldwide was based on the process invented by Krupp in 1894, and there was little to choose between variations. Bismarck’s armour was of the types used on German warships since the Deutschland of 1928. Wotan Harte n/A (‘new type’) steel was within a few percent of the quality of equivalent Allied armour. Krupp Cemented n/A face-hardened armour, used for vertical plates, was marginally inferior to US Class B armour. Wotan Starrheit (WSh) was extra-hard but brittle armour used in thin sections to protect the crew of light guns from splinters and bullets.

Bismarck’s 320-mm main belt was vulnerable to British 14-inch shells at ranges below 11,872 metres and to British 16-inch/6 CRH APC shells below 16,400 metres, and an examination of the wreck in 2001 revealed that it was penetrated. Anything that penetrated the main belt was meant to be stopped by the sloped armour deck beyond. In the final battle, two shells got into the propulsion spaces – a complete armour system failure. Examination of the wreck in 1989 revealed that the conning tower, with its 350-mm side armour, was penetrated 25 times. The difficulty the British had was that despite the theoretical vulnerability of her armour, Bismarck was optimised for the ranges of that battle – the British guns were firing horizontally, so many shells ricochetted off the water before hitting, destroying their ability to penetrate.

3. Allegedly, Bismarck was unsinkable and had to be scuttled. The debate reflects bragging rights. The British wanted to say they’d sunk Bismarck – avenging the loss of Hood. The Germans were as eager to claim the British couldn’t. The controversy arose because Bismarck did not succumb to a 90-minute bombardment by two battleships and two heavy cruisers that produced around 300-400 hits. Admiral Sir John Tovey had to abandon the engagement for lack of fuel, calling for any ship with torpedoes to finish off the blazing wreck. Bismarck sank at 1039 hours, a few minutes after being struck by torpedoes from HMS Dorsetshire. The controversy erupted because at 0920 hours, just 33 minutes after the final battle began and 69 minutes before Bismarck sank, two heavy shells penetrated the machinery spaces. This prompted the XO, Hans Oels, to order scuttling charges set and fired – 6 sticks of dynamite in each engine room. However, a study by US naval analysts W. Garzke and R. O. Dulin shows the charges were not fired in every case because of water inflows into the engineering spaces caused by battle damage. Indeed, by 0930 the ship was already wallowing from the amount of water on board, some of it deliberately introduced to counter-flood after battle damage three days earlier in the Denmark Strait.

Ships sink for two reasons; loss of reserve buoyancy (flotation) or loss of reserve stability (rolls over or, less often, sinks by bow or stern). One of the reasons why Bismarck did not lose the latter is because the British bombarded her from both sides – evening out damage to a ship that had unusually high natural stability. Her designed metacentric height of 4.09 metres was the highest of any battleship of the 1930s, meaning she was lively in a seaway but hard to affect with asymmetric flooding. Sinkage was therefore by loss of reserve buoyancy. Analysis of the wreck in 1989, by submersible, showed the hull had not imploded, meaning Bismarck was flooded when it sank. An investigation in 2001 revealed significant underwater damage to the hull sides, including areas of missing plating, consistent with torpedo damage. In other words, the scuttling order contributed to Bismarck’s end, but was not sole cause.

Oels’ order made military sense because it meant the Germans could end a lost battle and save life. By 0930, when the order was given, the ship was wrecked, all heavy guns had been disabled (turret Caesar was knocked out at 0931) and the crew were being slaughtered by the British barrage. Unfortunately, few of those left in the water could be picked up by the British because of a U-boat alert.

In fact, Bismarck was a fairly average battleship, even by European standards. I’ll be exploring the design in the next post. Watch this space.

Meanwhile, check out my book Dreadnoughts Unleashed, a short essay collection with the story of Admiral Sir John Fisher and OMG, fire-control issues at Jutland, more on Bismarck and details on other battleships of the age. Available on Kindle.

Copyright © Matthew Wright 2014