Tovey's decision not to attack at the evening of 26th

[Herr Nilsson]

IIRC only one boiler room. OTOH Group West didn't know anything about the loss of an boiler room at all. Officially there was just a minor flooding in boiler room 2. The information about the loss of the boiler room is just from survivor reports.

[RNfanDan]

The term "machinery", in this case, more properly applies to the ship's propulsion gear (turbines, shafts, moving parts, etc.). Boilers are part of the overall machinery scheme, but as long as the engines and auxiliary machinery are functional, they can operate with reduced boiler plant. This is an integral part of any well-designed steam-driven warship's survivability; a ship could suffer the loss of even a fair percentage of its boiler capacity (depending on its requirements and redundancy) and still retain its mobility--albeit at some compromise of speed and/or power.

Dan

[Bill Jurens]

Mr. Dale wrote:

"The torpedo strike in the rudders jammed them at 12 degrees to port."

This is not correct, although it's a common enough misconception, which appears to stem from a comment made by 'the Baron' that after the torpedo hit the rudder indicator stopped at 12 degrees to port. This doesn't mean thats where the rudder(s) were, only that that's where the indicator ended up. If you examine the drawings showing how the rudder was attached to the indicators, it's fairly obvious that the indicator itself would not be giving a reliable value after serious damage had occurred.

I've been fortunate enough to able to examine Bismarck's rudder situation in detail; and even to have entered (via R.O.V., of course) the lower rudder compartment. The starboard rudder has been pushed forward into the starboard screw. Considering the distortions involved, there is no real way the crumpled and twisted remains of this rudder can be said to be at any precise rudder angle at all. The port rudder is gone.

An examination of the break in the port rudder collar suggests that the port rudder snapped off at the same time the torpedo explosion occurred. An explosion near the starboard rudder would catch the structure 'end-on' and therefore transmit relatively small forces to the rudder itself, though certainly enough to translate it fore and aft to a considerable degree. It blast wave would, however have found the port rudder nearly 'flat-on', and -- because the ship was turning at the time, under faily high transverse loads already. It's likely that the port rudder detached at the same time the explosion occurred or shortly thereafter. There are no signs of it in the debris field, which has been searched extensively, which suggests that it was already gone when ship sank.

Bill Jurens

[Vic Dale]

Bismarck's Final Action.jpg (32.08 KiB) Viewed 2215 times

0808 to 0850: general heading 250deg. 0850 until sinking: general heading 330Deg.

During the battle the force nine gale was blowing from the north west at 220deg.

It is easy to see that Bismarck could steer independent of the wind, though very slowly at about 12 knots.

If I am correct in suggesting that Bismarck's heading into the wind during the evening and night of the 26th-27th was due to the need to minimise the impact of the sea on her rudder compartments to facilitate repairs, it seems that by 0808 they had given up and probably did so earlier.

During the attempts to fly off the Arado to save the Fleet War Diary, the ship turned beam to the wind, so there most certainly was some control available to the ship's command.

The heading between 0808 and 0850 may indicate that Lutjens was heading towards U-74, perhaps having picked up her midnight position report. I believe that U-552 had been directed to take the diary, but being low on fuel had had to pass the task on to U-74.

[dunmunro]

At 2200 on the 26th, it might have been worthwhile to try to position KGV between Bismarck and her base, then Tovey would have had insurance in the event that Bismarck managed to repair her damage. Rodney would still be able to join the battle at 0800, in the event that repair was not possible.

It is hard to understand why Tovey settled for 22 knots at 1705 on the 26th. Bismarck was making 28 knots or thereabouts and as he signaled other units of the fleet; he could not catch Bismarck unless she was slowed. Had he become fatalistic about his chances of catching her? Certainly he had decided that KGV would leave the chase at 2400 on the 26th if she was not slowed (see Tovey's report para. 64 - last sentence).

KGV never made more than 22 knots for the whole of the time between 1705 and 2200 - about the time that Tovey learned that Bismarck had been damaged. It sounds very much as though Tovey had given up on Bismarck and was simply marking time whilst other units and even other services took her on. At that time he was probably wondering how he would look in a bowler hat.

We should remind ourselves that he decided to delay the battle until after first light, so as to be sure of clear target identification and so as to have the best light. He will also have been aware of the possibility that KGV might take heavy damage. Bismarck was perfectly capable of putting up a good fight and might even come out on top in a one-on-one slugging match. It begins to sound as though the loss of HMS Hood had heavily impacted Tovey himself. He was well aware that Hood was armoured as well as any of the Queen Elizabeth class battleships, yet she had gone to the bottom in short order and consequently the order had gone out that Repulse, Renown and battleships of the Queen Elizabeth and Royal Sovereign class should not engage Bismarck alone. After Hood was lost, rapid and accurate fire was shifted immediately to PoW.

I get the impression that Tovey thought that KGV would be a poor match for Bismarck, considering her rapid and accurate gunnery against Hood and PoW, reinforced no doubt by known problems with KGVs own guns. Engaging without Rodney in company would be fraught with risks. That is most probably the reason he slowed and maintained a speed which Rodney could match. Bismarck was slipping from his grasp but it appears he was not going to risk battle without Rodney.

Had Tovey chosen to engage alone and been forced to withdraw or been disabled, sunk even, that could have had a disastrous impact on the nation's morale, and raised Germany's morale in inverse proportion. This is a major consideration in time of war, because as Napoleon observed, "The moral is to the physical as three is to one."

Tovey sets out his reasons in his despatch.

It is impossible for a 29 knot ship to catch a 28 knot ship when the latter has a 130nm lead. Even if Bismarck was only making 20 knots, it would have required 14 hours with KGV burning 40 tons/hr of fuel and it would have left KGV with only a few hundreds of fuel remaining while at the same time being inside the striking range of the Luftwaffe.

Tovey was down to 1200 tons around 11am on the 26th. Going to 28 knots would have consumed 36/tons/hr and rapidly exhausted KGV's remaining fuel reserves. Additionally Tovey knew that Ark Royal would be making TB attacks on Bismarck and the mix up with Sheffield showed that friendly fire incidents were all too possible.

It was RN policy to always try and engage with a superiority of force, since the power of two ships versus one is more than twice that of one on one (USN studies suggest that 2 - 1 gives the numerically superior side a 4-1 advantage). Tovey was not in the business of trying to prove the RN or KM's technical superiority, rather he was in the business of destroying the enemy while minimizing his own losses, and he accomplished that mission brilliantly.

[ede144]

Compared to the state of the rudder the machines were fully intact. It would have been sufficient to escape to Brest.

[Vic Dale]

Hi Duncan.

Precisely. KGV could not hope to catch Bismarck.

I think the answer is; given just 1050 tons of fuel remaining in KGV, at 1500 on the 26th, reducing to 800 tons by 2240. Tovey could not hope to catch Bismarck unless she was stopped. Even if she had managed 5 knots, catching her would, have reduced KGV's fuel to such a level, she would not be able to make an oiling port without steaming at the greatly reduced speed of 16 knots and in known U-Boat waters. She would just about reach Londonderry, the nearest safe oiling port. That is without taking into account the possibility of battle damage, including extensive flooding and ruptured fuel tanks. Flooding would greatly increase drag and fuel consumption to maintain speed.

The hope that Bismarck could be stopped by a single TB attack was slender in the extreme, so at 1700 on the 26th, Tovey was probably mentally preparing himself to give up the chase. Taking Rodney in company was simply making a show of having force at sea. The two ships would mark time until it was clear Bismarck had escaped and then they would make for an oiling port.

[paul.mercer]

Gentlemen,
Surely the decision to keep to 22 Knots was so that Rodney could keep up, after all her top speed was only abot 23-24 knots when she was in good condition - which she was not at the time. As for the other class of ships, Renown and Repulse were battlecruisers, even more lightly armoured than Hood, The QE's were also old and slow but Queen Elizabeth, Warspite and Valiant were modernised and Warspite and Valiant were two of the best shooting ships in the RN. This has been discussed before on another thread and the conclusion was that neither one would stand up in a straight fight against Bismarck, but they probably would not disgrace themselves either.

[tommy303]

The QE's were also old and slow but Queen Elizabeth, Warspite and Valiant were modernised and Warspite and Valiant were two of the best shooting ships in the RN.

Be that as it may, QE, Warspite, and Valiant were not available for operations against Bismarck, being in the eastern Mediterranean and engaged in the Battle for Crete.