Regarding HMS Hood and the Battle of Denmark Strait By Buzz Beurling
So this post is here.. ...to answer the questions that keep getting posed and to put right some myths. Firstly a bit of background history. I see it time after time people comparing HMS Hood's loss to those of the ships at Jutland. Aside from the fact that all the ships we are talking about exploded THERE IS NO COMPARISON. The armoured cruisers HMS Defence and HMS Warrior were battered at such close range they were annihilated. It's hardly surprising what happened. All three of the Battlecruisers at Jutland were lost to UNSAFE AMMO HANDLING PRACTICES, where stacks of unprotected cordite were piled up just inside the magazine doors, which were then left open throughout combat. Had this not been done ( and this was proven with the Q turret hit to HMS Lion ) NONE OF THE BATTLECRUISERS AT JUTLAND WOULD HAVE BEEN LOST. Also not one was lost to plunging fire or any weakness in their decks. The ships of both fleets were simply too close to each other. Now it would be helpful to explain that all Naval gunfire has a plunging aspect. That is how they work. When we refer to plunging fire we are talking about a shell incoming at such an angle as to be able to pierce the decks of a warship. On the largest ships this would have to be above 20 to 25 degrees descent angle to penetrate. Higher velocity guns fire at a flatter trajectory than lower velocity guns. Now in the case of HMS Hood there was nothing similar to what happened at Jutland. British ammo handling practices had been wholly and completely changed after Jutland and this did NOT happen again. So with the Jutland part out of the way... let's get onto HMS Hood herself. After the Battle of Jutland, HMS Hood's build was stopped. She was totally redesigned with the addition of 5000 tons of extra armour and her keel was re-laid 3 months later on the 1st September 1916. She had with the various additions, in all reality, ceased to be a Battlecruiser. She kept the DESIGNATION as Battlecruiser right up until WW2. The Royal Navy designation for a "Fast Battleship" ( that being a Capital Warship with the speed of a Battlecruiser, but the protection of a full Battleship) was Battlecruiser. (See Note 1 in Appendix 1 on Fast Battleships and Battlecruisers and Note 2 in Appendix 1 on BB and BC Armour differences) To put this into perspective the G3 Battlecruisers, had they been built, would have been the most powerful Warships on the planet. Yet due to their speed they were DESIGNATED Battlecruisers. The same would have applied had the RN built the Iowa class in the 20's. In fact, when HMS Hood was commissioned she was pretty much the most powerful single capital unit on the planet. She was the most heavily armoured and protected warship in the RN until the launch of the Nelson class, with protection in vertical, deck, and underwater, wholly superior to that of the Queen Elizabeth class. There are multiple sources for this, including the DNC and the Admiralty, her designer D’Eyncourt and can be found in books by Maurice Northcott, Raven and Roberts, and Friedman, not to mention any actual study of Hood’s design and specs. Now jump to 1941. HMS Hood was 21 years old and well overdue for a major refit/rebuild. We have a vague idea what this would have entailed ( looking at HMS Renown is a good starter), but the ideas were only vaguely written down and no official plans yet drawn up. HMS Hood was struggling with her engineering plant ( the boilers were past due, but her turbines were still good ) and her fire control was overdue updating. However she was still faster than the KGV's , and had one of the finest and best trained crews in
Page 1 FINAL Regarding HMS Hood and the Battle of Denmark Strait By Buzz Beurling the RN. She was a Battleship and as such, she was expected to be used to engage enemy capital units when needed. The main reason for her not getting this refit earlier ( other than the obvious flying the flag escapades and the start of WW2 ) was simply because she was considered far stronger than any of the older ships, and as such the older ships were prioritized modernizing. Bismarck herself although more modern, was riddled with her own flaws. Her decks were just as vulnerable to plunging fire, her armour was barely superior to Hood's, in fact she had a similar main belt, and she was vulnerable to mission kill due to not adequately protecting her communications equipment ( this is the briefest of summaries ). In no way shape or form was HMS Hood incapable of taking her on. Comments such as "she should never have been there" are frankly ridiculous. She wasn't there on her own. There were 2 county class cruisers and the POW ( See Appendix 1, Note 3 Brief summary of POW readiness and combat performance ). The Germans only ever had a 25% success rating and if you played this out 1000 times it would end badly for the Germans. However luck is a huge part of naval combat and luck was not with HMS Hood that day. I won't go into battle tactics in this post.
Bismarck's 15inch guns fired a lighter shell than the British but at very high velocity. This gave them a very flat flight trajectory. Much flatter than the RN shells. We know this as we have the Germans OWN gunnery manual for details. As such we know what their armour penetrating characteristics were. ( it's also known that the German shells had issues, for whatever reason, in activating their bursting charge ) They had excellent penetration properties for vertical armour, but to be sure of penetrating Hood's decks she had to be out as far as 25k to 32k yards. Bearing in mind that the longest ever confirmed ship on ship hits ( shared by Warspite and Scharnhorst) was 26k yards, HMS Hood wasn't in too bad a position. In fact Hood's own guns had superior deck penetrating characteristics. HMS Hood had a total of 7 inches of protection over 3 decks above her magazines. Slightly less over her engineering spaces. By 24k yards her magazines were pretty much safe and by just under 22K yards there was simply NO PHYSICAL WAY her magazines were going to suffer a plunging hit. HMS Hood was sunk at 16,500yards. At that range the German shells were "plunging" in at 11 degrees down angle. Let that sink in a little. There is simply no way ( unless you want to change the laws of physics ) that the German shells will penetrate ALL 3 of Hood's decks above her magazines AND her magazine crown.
Now... Bismarck's shooting was not good ( an argument for another time ). She had a baring issue. The gunnery officer had abandoned the ladder after 2 salvos and was making adjustments on the fly. The shell of the 5th salvo that hit HMS Hood was going to be a near miss. Unfortunately, HMS Hood had begun her 20 degree turn to port at this time and turned INTO the shell. This turn opened up the length of the ship and she was hit at between 50 degrees and 60 degrees to the horizontal plain ( see Appendix 1 ).
Now to put this in perspective. Battleships are designed for broadside engagements. So even if the shell penetrates, the armour is designed to slow it in the most efficient way. The evidence is clear. When you collate the witness statements AND the time frame of what actually happened, there was only ever one way for the German shell to penetrate to Hood's magazines.
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Now it would be helpful to mention certain aspects of Hood's design that enabled Bismarck's shell to do what it did. Firstly the main armoured deck ( Refer to Figure 1 & see Appendix 2 ) curved down at the edges into the 2inch slope. It was known in the 20's that not only was the 2inch slope inadequate ( it was upgraded to 4inches in Renown for example ) but the horizontal deck didn't go all the way out to the edge of the hull abreast the engineering sections as it did abreast the magazines. Had either of these issues been dealt with (and it was relatively simple) it's highly possible the shell would have been deflected away from the engineering spaces. In fact tests by the Admiralty on Hood’s armour mockups prove this very statement. ( see Apendix 2 )
Also HMS Hood in 1939 and 1940 had her AA armament substantially increased. As such this necessitated an enlarged 4-inch magazine. Unlike say Renown whose rebuild had allowed more space within the citadel to Figure 1 - HMS Hood hull armour plan adequately protect her secondary magazines, there was no space in Hood. Please refer to Figure 1 above for the following analysis They were wrapped round the upper Look at the Deck that curves at the end ‘8’. ( See Appendix 2 for Builders level of X magazine and butted up pics ) against the magazine bulkhead. Also That deck needed additional 3 inch plating extending all the way to the hull. they were extended forward behind a That never happened so a shell coming in through the side, wouldn’t be weakly protected bulkhead to the deflected due to the angled deck plate. engineering spaces. This gave a direct connection whereby a shell detonating This was known about since the early 1920’s. Putting the additional deck around that bulkhead could potentially plate in, would have taken her out of service for longer than the Navy was set off a catastrophic explosion. Which willing to allow. is exactly what happened. Now time is not at issue here. I often hear it said “oh she was taken out with only one shell.” That shell hit could have happened after 5 minutes or 3 hours. Had it been 3 hours, many would lose an excuse to calling HMS Hood a weak ship. Time is simply a non-factor. So the kill shot. As has been explained with HMS Hood turning into the kill-shot, this gave the shell access to the length of the ship. It hit the side of the ship in the vicinity of the main mast in the area of the upper (7 inch ) belt at over 500mps.
In penetrating the plate, it was rotated towards the surface normal of the plate just enough to put it on a path through the weak slope discussed earlier ( without the 3 inch deck protecting it ), and to the bulkhead at the rear end of the engineering space where the enlarged 4-inch magazine ( See Figure 3 )had been extended too.
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Had it hit during the interception or when the ship had completed her turn it would have missed this magazine. It was the turn and the impact angle of 50 to 60 degrees which allowed the deflection of the shell towards the plate normal to target the magazine.
This weak spot was about 30ft x 10ft ( see Appendix 1c). Just hitting it was unreal. The end catastrophic result was wholly unbelievable. A complete fluke in anybody's book. The proof for this table of events is simple. The shell hit itself wasn't the destructive element, merely the catalyst. The ship didn't immediately explode. There was a very slow ( relatively speaking ) conflagration. When the 4-inch magazine went up ( either as a direct hit or splinters from the shell going through the bulkhead), the cordite vented from the path of least resistance. This path was forward up through the engineering vents next to the mainmast. If you look at that very famous drawing by HMS Prince of Wales's Captain Leach, the cordite plume vented high into the air through these vents by the main mast. ( see Figures 2 & 3 ) It was only after this venting that the main magazines exploded. Either by damage to the magazine bulkhead or heat transfer from the 4-inch magazine explosion. This rent the sides of the ship open ( See Figure 4 ) and blew the bottom out of the ship. This is why she stopped almost immediately.
Figure 2 - drawing by Captain Leach (HMS Prince of Whales)
Please refer to Figure 3 for the following analysis
The cordite venting seen between the mast and X turret was escaping via the engine room vents (of which there are two between the mast and rear range finder). So, how does cordite smoke travel into the engine room from X magazine for several seconds before the ship blows up? The simple answer is that it doesn't - This venting is from another smaller explosion which also spreads to the 15 inch X magazine. - Compartment #12 is the 15 inch cordite magazines - Compartment #13 is the 15 inch "powder" handling room, - Compartment #6 is the 4 inch magazine,
Now, if you look at the walls, compartment # 6 has a thick bulkhead or barrier to compartment #12. But a very thin barrier to the spaces which connect it to the engine spaces and vent ( Item # 79 )
So, the reason we get venting next to the main mast is this - and while that was happening, the heat was eating through the wall between 6 and 12... This only takes a few seconds before we get the big boom...
Figure 3 - Technical analysis of the venting
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Figure 4 - The fatal shell and resulting sequence of events (See also Appendix 1)
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Now it is often mentioned that the fire from the ready use ammo on the boat deck is what destroyed Hood. That fire was started by the German cruiser Prinz Eugen. She was firing High Explosive shells as there was zero chance that she could penetrate Hood's armour with AP shells. Let me say that again. ZERO CHANCE. Also it is useful to know she'd changed fire to POW minutes before HMS Hood was sunk. Now the fire on the boat deck may have looked spectacular. There were 4-inch "ready use" and UP projectiles popping off like fireworks. But all the hatches would have been closed. There was NO WAY WHATSOEVER for this to go down four decks to set off the magazines. NO WAY. So let's put that to bed now shall we? I would suggest you find and read Bill Jurens excellent paper on the sinking of Hood. He is the foremost expert on these matters. It is useful to mention that The Admiralty were disappointed and embarrassed at the loss of the Hood. The speed and scale of the explosion was a serious issue for the RN who had spent so long bathing in the glory of Hood's size and power. There would have also been questions asked why a known issue ( which almost certainly sent her to the bottom ) wasn't addressed.
Because of this, HMS Hood was cast as not fit for purpose in the press and inquests into the loss. The Admiralty ( as they did after Jutland ) turned attention from themselves by blaming the ship. Once more "Fisher's Folly" was raised and used as a scapegoat. It perpetuated the view that it was "common knowledge" that HMS Hood was a failed ship who never stood a chance against Bismarck ( newer ship, more powerful etc... ).
This is both untrue and unfair. HMS Hood was in poor health at the time of her loss, this is true ; but she should have been in for her refit years before her loss. This common knowledge has crept into 7 decades of books and research and nobody has dared question the veracity of it. Serious technical reviews of the ship and the battle paint a different story, and highlight the errors of the Admiralty, and the luck of the Germans.
NOTE: See Sources -Next page
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Citations and References
Sources: