Battle of Denmark Strait

rheinuebungmapsmallIn 1941 Great Britain was relying on convoys to provide much needed resources. During May the German battleship Bismarck accompanied by the battlecruiser Prinz Eugen formed operation Rheinübung.

Led by Admiral Lütjens, this was a sortie to sink as many Atlantic convoys as possible. Regarded by many as the most powerful battleship in the world, the threat of the Bismarck was of grave concern to the British navy.


Breakout into the Atlantic

But in order to harass the convoys, the Bismarck had to break out into the Atlantic from the Baltic where she had been completing sea trials. The Bismarck made the first part of the journey from Gotenhafen (Gdynia) in German occupied Poland to Grimstadfjord just south of Bergen in German occupied Norway.

rheinuebungmap

From here the German ships had several options into the Atlantic:

1. The riskiest option was a dash down the English Channel. The advantage was that the Luftwaffe could provide air cover for the whole journey. But with the home fleet at Scapa Flow in the Orkneys (at the northern end of Scotland) and the whole journey within easy reach of the RAF, this was never regarded as a serious option. It is interesting to note that later in the war, the Scharnhorst and the Gneisenau successfully made the dash up the Channel from Brest to the Baltic, despite some damage from mines, much to the embarrassment of the British.

2. Between Scotland and Iceland were three passages to the Atlantic:

2a. The passage between the Orkney Islands and the Shetland Islands was too risky. This was narrow, only 78km wide, and too close to Scapa Flow and the RAF.

2b. Between the Shetland Islands and the Faeroe Islands was a much wider channel, 280km wide. But still too close to Scapa Flow and the RAF.

2c. Between the Faeroe Islands and Iceland was a more promising route 430km wide. This was the route recommended by the German High Command, but they left the final decision to Admiral Lütjens.

3. Between Iceland and Greenland lay the Denmark Strait. This 280km gap was reduced by pack ice off the Greenland coast to 150km in May 1941. A minefield laid by Britain off the northwest tip of Iceland further reduced this to just 50km.

Admiral Lütjens chose this passageway because it was the furthest from Scapa Flow. This was the area patrolled by the cruisers Norfolk and Suffolk. The two British ships picked up the German ships on radar and shadowed them, but did not engage as ordered. Their job was to call in reinforcements. They did this in the form of the battlecruiser HMS Hood and the battleship HMS Prince of Wales. The latter was still being commissioned and this meant during the coming engagement that 4 out of 10 main guns were unable to fire.

The Opposing Ships

KGM Bismarck

ghqbismarck

Main armament: 4 turrets with 8 x 15” guns, 6 turrets with 12 x 5.9” guns, 8 turrets with 16 x 4.1” guns plus 8 mounts with 16 x 37mm AA guns.

Maximum speed: 30 knots, Length: 251m, Weight: 40.4 tonnes standard.

 

KGM Prinz Eugen

ghqprinzeugen

Hipper class heavy cruiser with 8” main guns

Armament: 4 turrets with 8 x 8” guns, 6 turrets with 12 x 4.1” guns, 6 mounts with 12 x 37mm guns plus 8 x 20mm AA guns.

Maximum speed: 32½ knots, Length: 208m, Weight: 19.4 tonnes standard.

 

HMS Hood

ghqhood

Battle cruiser

Main armament: 4 turrets with 8 x 15” guns, 4 turrets with 8 x 4” guns, 3 mounts with 24 x 2-pdr AA guns.

Maximum speed: 29½ knots, Length: 262m, Weight: 41.3 tonnes standard.

 

HMS Prince of Wales

ghqprinceofwales

King George V class battleship

Main armament: 3 turrets with 10 x 14” guns, 8 turrets with 16 x 5¼” guns, 4 mounts with 32 x 2-pdr AA guns.

Maximum speed: 28 knots, Length: 227m, Weight: 38.4 tonnes standard.

The Engagement

The opposing forces sighted each other just after 5:30am on 24th May. Prior to the battle, the Bismarck had sustained some damage to her forward looking radar from gun blowback when trying to scare off the shadowing cruisers. Because of this, the Prinz Eugen was the leading ship. The profiles of the two German ships were similar at a distance. This caused Admiral Tovey on the Hood to order the British to fire on the leading ship, which he expected to be the Bismarck.

Naval vessels usually have much lighter deck armour than side armour. The design of any ship is a compromise between armour, armament and speed. More armour increases the weight of a ship and so reduces the speed. More or heavier armament requires a bigger ship and stronger support structure, which in turn increases the weight and further reduces the speed.

Lighter deck armour is only a problem for shells fired with a high trajectory. This is known as plunging fire and only occurs at the extreme ranges of the guns. Closer ranges have flatter trajectories which will hit the side armour (if they hit at all).

The British attempted to close the gap quickly to get out of the danger zone of plunging fire; particularly for the Hood which had very light deck armour. The German ships steered to reduce the closure rate as they attempted to identify the British ships and also allow them to bring their rear turrets to bear. The British opened fire first, at a range of 26,000m. The Hood fired on the Prinz Eugen, which it mistook for the Bismarck, but the Prince of Wales correctly identified the ships and fired at the German battleship.

The German ships were quickly on target, with the Prinz Eugen causing the first hits on the Hood. The Bismarck soon found the range, so the Prinz Eugen was ordered to now bring the Prince of Wales under fire. The British ships now turned to allow all their main guns to fire, but so far had caused few hits and minimal damage. The German fire was accurate, causing damage to both enemy ships.

A shell from the fifth Bismarck salvo penetrated the deck of the Hood. It entered the rear magazine. The resultant explosion broke the ship in two. To the surprise of all combatants, the Hood quickly sank leaving only 3 survivors. The Prince of Wales was now the focus of both German ships. With only a few guns left working, the Prince of Wales made heavy smoke and withdrew, but not before causing a hit on the Bismarck just above the waterline. This caused minor flooding and a fuel oil leak. This minor damage soon forced the Bismarck to head to Brest – a course which resulted in her destruction a few days later after a massive hunt.

Wargaming the Battle of Denmark Strait

There are many wargames rules available for World War 2 naval combat. I had recently bought some beautifully detailed 1:2400 ships from GHQ so I decided to try out their rules called ‘WWII Micronauts: The Game’. One of the scenarios in the rules is the Battle of Denmark Strait. This is a great starting scenario because there are just 2 ships per side. We decided to ignore torpedoes and aircraft in this scenario. So it allowed us to learn the basics; such as how movement and gunnery works. As with many naval games, each ship has a sheet on which you mark off damage to different sections.

The game started with the opposing groups at long range. We followed history by leaving the ‘A’ turret (front most) for the Prince of Wales out of action and having the Hood fire its initial few salvoes on the Prinz Eugen rather than the Bismarck. Both sides scored hits in the first four turns, although not every time.

An early hit on the Prinz Eugen caused minor flooding damage, but this was quickly repaired. The Bismarck received some minor damage to hull and some turrets, but not enough to put them out of action. Some engineering damage caused its maximum speed to be reduced to 15 knots on the opening salvo. Despite numerous attempts from the crew this was not able to be repaired during the battle, but did not affect the outcome.

After a few salvoes the Hood had minor hull damage with flooding. The repair party could not stop the flooding and to reduce to only a small amount of flooding damage each turn, the Hood slowed down. The flooding damage was only minor but more serious was the loss of ‘A’ turret. The Prince of Wales was also taking some damage, but nothing significant as yet.

The Prince of Wales slowed to match the Hood and both British ships veered to port to allow all guns to keep firing. The gap between the German ships was opening up due to the slow speed of the Bismarck. On the fifth turn the ships were now close enough to fire their secondary guns as well. The British caused minor damage to the Bismarck and knocked a rear turret out of action on the Prinz Eugen.

The Bismarck missed with its main guns. But the arcing fire from the secondary guns caused a critical hit on the Hood, resulting in a massive explosion of the rear magazine. This caused 70 hull hits on the Hood (it started with 85), leaving it with only 3 hull points. Failing to stop fires and flooding damage was just enough to sink the Hood early in the next turn.

In the following few turns, the Prince of Wales exchanged fire with both German ships. ‘B’ turret was knocked out, 2 fires had been started and it had now lost a quarter of its hull points. In return it had knocked out a further turret on the Prinz Eugen, started a small fire on the Bismarck and partly damaged ‘X’ turret on the Bismarck. The Prinz Eugen limped away as fast as it could, while the Germans turned south to the Atlantic.

The game was amazing in that it closely resembled the historical battle. This was not fudged, although we did follow the historical tactics (who fired on who). But with different dice rolls this could easily have given a different result. The British player was unlucky. Although hitting the Bismarck’s main turrets three times, each was on a different turret so none were knocked out. If the Hood had survived a few more turns the Bismarck may have been running out of guns. A critical hit is not easy to achieve and does not always hit a magazine, so the German player was lucky in this regard. We felt the rules flowed well and are happy to try them again.

References

Map courtesy of Professor Gerald Boerner (www.boerner.net/jboerner/?p=17058)

Pictures of ship models courtesy of GHQ from http://www.ghqmodels.com/store/military-models-wwii-micronauts.html.

I recommend their exceptionally detailed models.