KGV sorties with POW

[Paul L]

Absolute top speed is only marginally important in operational movement. Its speed at range that is critical.

Bismarck =4500nm @ 28 Kts & 5000nm @ 27kts*
TWINS =3900nm @ 28 Kts* & 4280nm @ 27kts *
PE/Hipper= 1700nm @ 28 Kts
KGV= 2400nm @ 27 Kts
Hood & Renown = 3000 @ 27kts.
Repulse = 2000nm @ 27kts*
Edinburgh =4227nm @ 27kts
Suffolk=4900nm @ 27.5kts
Norfolk = 4000nm @ 28kts
Ark Royal; Indefatigable ;Implacable = 5000nm @ 27kts*
* estimates

The general advantage of the German endurance of course is there replenishment at sea which can effectively double endurance over short distances. This is how the short legged Prince Eugen cruiser with 3900nm @ 19kts or 6 days compared to the mission that lasted 12 days with one refuelling.

Likewise the shorter endurance of the RN Battleships is aggravated by the fact that their groups have to sortie to and from fixed ports; effectively cutting range in half.AT least the RN battle cruisers ; aircraft carriers and cruisers can match the unrefueled range of KM capital ships.

[dunmunro]

This was further indicated by the precise salvo firings at night against VIan's destroyers.

On the other hand, there is also the Baron's statements to the effect that he could see Vian's destroyers clearly through the optics of his night target director as they approached. I'm not saying that Bismarck was incapable of blind fire, just that at that particular time period, the preferred method was to utilize radar for range and optical for bearing. I am sure Dave can give a better assessment.

If Bismarck was capable of radar controlled blind firing, it would have made life very difficult for W-W's cruisers. In the same vein, if Bismarck had increased speed to 30.5 knots, he would probably have been able to out run W-W as well...or at least make it very difficult for them to maintain contact or to regain it if lost.

[alecsandros]

This was further indicated by the precise salvo firings at night against VIan's destroyers.

On the other hand, there is also the Baron's statements to the effect that he could see Vian's destroyers clearly through the optics of his night target director as they approached. I'm not saying that Bismarck was incapable of blind fire, just that at that particular time period, the preferred method was to utilize radar for range and optical for bearing. I am sure Dave can give a better assessment.

... Lack of effective response during the 3rd engsgement with Primce of Wales also shows defficiencies in the blindfire system.
Still, the ship mantained her firing solutions while manoivreing, and fired repeated salvos theough the smoke.
hy would they do that if not using some kind of blind fire technology ? That the firing was imeffective, along with several other problems , could show thst it was a technology still in its infancy...

[tommy303]

... Lack of effective response during the 3rd engsgement with Primce of Wales also shows defficiencies in the blindfire system.
Still, the ship mantained her firing solutions while manoivreing, and fired repeated salvos theough the smoke.
hy would they do that if not using some kind of blind fire technology ? That the firing was imeffective, along with several other problems , could show thst it was a technology still in its infancy...

Salvos through smoke and whilst maneuvering may not always indicate complete radar controlled blind fire. The fire control computer has an element that acts as a predictor, modified for own ship movement, changes in target course and speed, and fall of shot spotting. If your view of the target is obscurred, the computer will continue to give firing solutions based on the last optical bearing and on radar ranges, allowing a few salvos to be fired until the target has come back into sight again.

Dave Saxton would know more about the radar problem than I, but if I recall correctly, the KM radars in use at sea, while giving very accurate ranges, were limited to relatively coarse bearing readings due to the bearing scales then in use. Optical bearings from the director sight were more precise, at least when the target was visible, particularly at medium to long ranges. There were both coarse and fine bearing scales, but even the fine scale did not provide the bearing accuracy for true blind fire radar controlled gunnery in 1941. Later on, after the Bismarck episode, improvements were made to the range and bearing scales.

Bismarck had, therefore limited blind fire capability. As Duncan has pointed out, had she had true, effective blind fire radar systems giving bearing data comparable to the optical systems, then it is doubtful Wake-Walker could have maintained contact coming down the straits without running a very serious risk of being overwhelmed by Bismarck's firepower. As I said before, German naval radars in spring of 1941 were in a state of transition, and it would be some months before a completely workable system for blind fire was developed.

[Dave Saxton]

As newer radars became available and older sets brought up to new standards, this became less of a problem and true blind fire capability was realized, but if I recall, the Bismarck episode came at a time of transition as far as radar goes.

I concur with this. The Bismarck was equipped with the newest equipment that was capable of blind fire, but there were still technical problems to be worked out and there were additional procedural/operational problems to overcome before it could be consistently realized in May 1941.

The technical problems which needed to be worked out did indeed involve problems of bearing accuracy.

[alecsandros]

As newer radars became available and older sets brought up to new standards, this became less of a problem and true blind fire capability was realized, but if I recall, the Bismarck episode came at a time of transition as far as radar goes.

I concur with this. The Bismarck was equipped with the newest equipment that was capable of blind fire, but there were still technical problems to be worked out and there were additional procedural/operational problems to overcome before it could be consistently realized in May 1941.

The technical problems which needed to be worked out did indeed involve problems of bearing accuracy.

Of course,
my point was that, thanks to these early blind-fire systems, the Bismarck was capable of firing with reasonable accuracy even at 30.6kts speed.

I do not understand why this is put into question any more, as Antonio demonstrated years ago that the Bismarck accelerated up to 30.6kts.

[Dave Saxton]

Vibration would have no effect upon radar presentation for range. Even violent pitching and rolling of a ship has little to no effect on most shipboard radar systems range presentation because almost all ship board radars are designed to have wide vertical beams. (Vibration could effect radar signal processing if there were vacuum tubes with loose internal connections, however.)


Vibration could effect the bearing presentation on radars which used a relatively narrow horizontal beam and a PPI or B-scope presentation. This type of presentation combines bearing and range data so a blurring of the image from vibration is possible.

Even with the slightly wider beam of Seetakt; observing the coarse bearing presentation (which was not a B-scope or PPI presentation) could be a problem on German destroyers operating in rough seas. It does not appear to have been a problem on larger German warships.

It was mentioned by the Proving and Testing Command that while the 1943 trials of Scharnhorst's newest radars proved beyond question that the accuracy for both range and bearing was excellent, additional tests needed to be carried out to see if adverse weather conditions could impair bearing accuracy. It is not clear if this potential problem was caused by pitching and rolling or other weather related effects. However, further blind fire trials carried out at night and in snow storms by other warships, as mentioned by Giessler, do not allude to any bearing inaccuracy.

[dunmunro]

Entry in the Kriegsmarine Operations Division War Diary, 27 December 1943:

The main experience gained from the combat is the fact that the enemy is able to take bearings in the darkness at daylight ranges of visibility and that he can fire acurately at daylight ranges...

...Particularly serious is the fact that our own radar equipment does not possess either the great range and reliability or the great accuracy of' the enemy equipment. For this reason the SCHARNHORST had very little chance of using her guns successfully.

[Dave Saxton]

It's an incorrect assumption made too soon after the event without knowing several key facts. Operations did not know the true performance of the British firecontrol radar or that it was no more accurate or had as much range as the Scharnhorst's before it was destroyed. By March it was known from B-dienst intercept transcripts that the Duke of York had been unable to spot the fall of shot using radar.

The technical people took a much more level headed approach than operations as the facts were gradually learned over time. KzS Giessler of the Marine Nachritchen und Ortungsdienst wrote:

It is apparent that the radar on the Scharnhorst was knocked out during the first engagement…It is known that the radar equipment aboard the Scharnhorst had previously been functioning extremely well and been upgraded steadily with the most recent innovations.

As it turned out, however, the Scharnhorst was rendered practically blind during the entire mission.

Giessler eventually came to the realization the Scharnhorst's fate was determined much more by the how the radars were (not) used- instead of by their comparable technical capabilities and limitations. Key was the examination of the German destroyers' KTBs and the revelation that Bey had ordered the German radars to be kept switched off in the Operational Orders. Giessler wrote years later:

It is therefore wrong if today the fate of the Scharnhorst in this battle is given simply as the result of far superior British radar equipment. Obviously it does not follow, especially if Scharnhorst had only switched on its own radar equipment. It would be better to now consider the possibilities had the Scharnhorst been allowed to detect the British forces with sufficient time for the German leadership to take appropriate action.

[Steve Crandell]

What was wrong with Scharhorst's aft radar that it could not be used effectively against DoY during that gunnery engagement?

[Dave Saxton]

What was wrong with Scharhorst's aft radar that it could not be used effectively against DoY during that gunnery engagement?

Who said it wasn't used effectively?

[alecsandros]

What was wrong with Scharhorst's aft radar that it could not be used effectively against DoY during that gunnery engagement?

Hi Steve,
Duke of York was straddled repeatedly by Scharnhorst's aft 3-gun turret. However, there were no hits recorded, only 2 shells that passed through the upper radar antenas. Bad luck, or perhaps Scharnhorst not providing a steady enough platform on the heavy seas ?
Anyway, let's remember that Duke of York was firing her 6 frontal guns against the 3 rear guns, and the Duke obtained 4 or 5 hits against Scharnhorst in 80 minutes of firing. Also, the Duke was a heavier ship (39000 tons vs 32000 tons standard), and I suppose it was somewhat more stable than Scharnhorst on those rough seas...

Repeated 14" hits were scored only later, when range was down to 8km or less, and the Scharnhorst was doing 5kts.

[Steve Crandell]

I may have a mistaken impression of what happened. I thought the DoY opened fire at less than 10km and the battle was short ranged until Scharnhorst eventually managed to open the range to 18km before the engineering casualty caused it to begin to decrease again. Is this wrong?

[alecsandros]

I may have a mistaken impression of what happened. I thought the DoY opened fire at less than 10km and the battle was short ranged until Scharnhorst eventually managed to open the range to 18km before the engineering casualty caused it to begin to decrease again. Is this wrong?

No, it's right...
but Scharnhorst required 80 minutes to open the range from 11km to ~ 19km or so (distance when Duke of York ceased fire). in that interval, Scharhorst suffered 4 or 5 x 14" hits.

[Steve Crandell]

I may have a mistaken impression of what happened. I thought the DoY opened fire at less than 10km and the battle was short ranged until Scharnhorst eventually managed to open the range to 18km before the engineering casualty caused it to begin to decrease again. Is this wrong?

No, it's right...
but Scharnhorst required 80 minutes to open the range from 11km to ~ 19km or so (distance when Duke of York ceased fire). in that interval, Scharhorst suffered 4 or 5 x 14" hits.

One would think that with her flat shooting, fast firing 11" guns and nine of them firing initially, she would have achieved multiple hits during that time. Certainly more than DoY. Also, at that range she can penetrate DoY's armor. Why not keep all nine guns bearing and see if she can actually defeat her? A close range fight like that seems to me to be the optimum situation for Scharnhorst. She can keep the cruisers astern and turn away from DoY, still keeping the forward guns bearing. An 11" hit on one or more of DoY's turrets or FC could turn the whole fight around. It just doesn't make sense to me, because in theory she had a chance to take DoY out of the fight, where running away gives all the chances to the British.