Was the battleship Bismarck really the best of its time?

[fsimon]

PoW's DCT optics did not suffer spray issues during her engagements with Bismarck nor any loss of 14in output due to water ingress. She did suffer a loss of Radar however. Bismarck had Anton turret RFs removed due to spray issues, IIRC.

Concerning the spray and water in the turret I am referring to this: http://www.naval-history.net/xGM-Chrono ... 0Wales.htm
At 0549 hours course was altered to 300 degrees. At this time the PRINCE OF WALES took station on HOOD's starboard quarter, four cables distant (810 yards), bearing 135 degrees. The HOOD and PRINCE OF WALES were now approaching the enemy ships bow on.

(The KGV class had a lack of freeboard forward; this was due to the design requirement for A turret to fire ahead at minimum elevation. By turning on to course 300 degrees the HOOD and the PRINCE OF WALES were driving directly into the wind; this caused spray to wet the lenses of the forward rangefinders and allow water to enter A turret through the gun ports, soaking the gun crew. The water shipped then ran down the ammunition hoist into the shell room wetting the interlock and hoist mechanisms and affecting the efficiency of the handling room personnel, all of which affected the performance of A turret.

The bow-on approach also negated the gunnery advantage of the HOOD and PRINCE OF WALES as neither ships after turrets could engage the enemy vessels)

Best regards
Frank

[dunmunro]

PoW's DCT optics did not suffer spray issues during her engagements with Bismarck nor any loss of 14in output due to water ingress. She did suffer a loss of Radar however. Bismarck had Anton turret RFs removed due to spray issues, IIRC.

Concerning the spray and water in the turret I am referring to this: http://www.naval-history.net/xGM-Chrono ... 0Wales.htm
At 0549 hours course was altered to 300 degrees. At this time the PRINCE OF WALES took station on HOOD's starboard quarter, four cables distant (810 yards), bearing 135 degrees. The HOOD and PRINCE OF WALES were now approaching the enemy ships bow on.

(The KGV class had a lack of freeboard forward; this was due to the design requirement for A turret to fire ahead at minimum elevation. By turning on to course 300 degrees the HOOD and the PRINCE OF WALES were driving directly into the wind; this caused spray to wet the lenses of the forward rangefinders and allow water to enter A turret through the gun ports, soaking the gun crew. The water shipped then ran down the ammunition hoist into the shell room wetting the interlock and hoist mechanisms and affecting the efficiency of the handling room personnel, all of which affected the performance of A turret.

The bow-on approach also negated the gunnery advantage of the HOOD and PRINCE OF WALES as neither ships after turrets could engage the enemy vessels)

Best regards
Frank

There's no need to refer to secondary sources when we have PoW's Gunnery Aspects Report (GAR):

http://www.hmshood.org.uk/reference/off ... 09guns.htm

According to the GAR there were no issues with spray for the DCTs and even A and B turret RFs were able to range prior to the turn away at salvo 18. The problems with optical ranging appear to have been due to poor atmospheric conditions due to the mirage conditions present.

The water ingress issues were actually quite minor and didn't effect 14in output; The cause of each round that failed to be loaded was identified in the GAR and water was not identified as a factor in the loss of output. The lack of suitable drains appeared to have been largely corrected as DoY didn't report any issues with loss of output due to water ingress into A turret despite the much worse conditions that she encountered. These issues were certainly nothing like the issues that hampered Scharnhorst and Gneisenau during their action with Renown.

[fsimon]

Thank you dunmunro for pointing me to PoW's Gunnery Aspects Report (GAR).

The report says:
"3. The rangefinders failed to develop a satisfactory range plot before opening fire; the fore D.C.T. 15-ft rangefinder was the only rangefinder which had a reasonable chance; the closing rate was very high and "A" and "B" rangefinders were able to see the enemy's superstructure for a short time only before "table turning." Conditions for ranging on the enemy's masts were not easy. As a result it required two down ladders to find the target."

The report also says:
"Throughout the engagement the conditions in "A" shell handling room were very bad; water was pouring down from the upper part of the mounting. Only one drain is fitted and became choked; with the result that water accumulated and washed from side to side as the ship rolled. The streams above and floods below drenched the machinery and caused discomfort to the personnel. More drains should be fitted in the shell handling room and consideration given to a system of water catchment combined with improved drainage in the upper parts of the revolving structure. Every effort is being made to improve the pressure systems and further attempts will be made as soon as opportunity occurs to improve the mantlet weathering, but a certain amount of leaking is inevitable."

best regards
Frank

[dunmunro]

Thank you dunmunro for pointing me to PoW's Gunnery Aspects Report (GAR).

The report says:
"3. The rangefinders failed to develop a satisfactory range plot before opening fire; the fore D.C.T. 15-ft rangefinder was the only rangefinder which had a reasonable chance; the closing rate was very high and "A" and "B" rangefinders were able to see the enemy's superstructure for a short time only before "table turning." Conditions for ranging on the enemy's masts were not easy. As a result it required two down ladders to find the target."

The report also says:
"Throughout the engagement the conditions in "A" shell handling room were very bad; water was pouring down from the upper part of the mounting. Only one drain is fitted and became choked; with the result that water accumulated and washed from side to side as the ship rolled. The streams above and floods below drenched the machinery and caused discomfort to the personnel. More drains should be fitted in the shell handling room and consideration given to a system of water catchment combined with improved drainage in the upper parts of the revolving structure. Every effort is being made to improve the pressure systems and further attempts will be made as soon as opportunity occurs to improve the mantlet weathering, but a certain amount of leaking is inevitable."

best regards
Frank

As I stated the atmospheric conditions for ranging were poor, and this not due to spray, or it would have been noted. During her 2nd engagement PoW's
15ft RFs were able to range to ~33k yds because the seeing conditions were better.

Here's an example of Renown reporting spray issues due to very high speed and severe seastate:

Rangefinder. All rangefinders including the D.C.T. were washed out by sea and spray before opening fire. No rangefinder ranges were obtained during the course of the firing. “A”, “B”, and “Y” rangefinders were continually submerged, and D.C.T. was covered with spray as fast as the rangefinder windows could be cleaned and dried by men stationed to this.
After this action, the rangefinders were dessicated and cleaned, but as only one motor dessicator is provided for the 15 inch armament it was two or three days before all the rangefinders were in action again. It is recommended that at least two motor dessicators should be provided for the 15 inch Rangefinder

https://www.naval-history.net/xDKWD-HF1940BCS1.htm

Water ingress did not cause a loss of 14in output. This was PoW's first sortie, after a very abbreviated work up, and it was inevitable that these relatively minor issues would be uncovered. You'll note from the above that Renown had similar water ingress issues, and again, no loss of 15in output occurred. The RN had long experience with seawater ingress because all RN battleships (except Vanguard 1944) were built to same design spec that allowed for 0deg elevation when firing directly ahead. Consequently turret FC and shell handling equipment were designed to operate when wet.

[hans zurbriggen]

Hello Mr. Nilsson, thanks for all information.

You write: "Because Bismarck's fuel consumption rate is different from Tirpitz'...", but I don't see yet why a different fuel consumption rate might affect max overload power (and max speed). It might affect max range only.

Assuming Bismarck could have achieved same overload power than Tirpitz (163,000+), she should have reached at least same speed and the Baron confirms she did 'in one occasion' in November (a pity there is no reference when exactly and with which displacement, as well as for the 30.6 kn referenced in BS-Richelieu comparison).

hans

[Herr Nilsson]

Hello Mr. Nilsson, thanks for all information.

You write: "Because Bismarck's fuel consumption rate is different from Tirpitz'...", but I don't see yet why a different fuel consumption rate might affect max overload power (and max speed). It might affect max range only.

Assuming Bismarck could have achieved same overload power than Tirpitz (163,000+), she should have reached at least same speed and the Baron confirms she did 'in one occasion' in November (a pity there is no reference when exactly and with which displacement, as well as for the 30.6 kn referenced in BS-Richelieu comparison).

hans

Assuming Bismarck could achieve 163,000 WPS she would have reached the same speed as Tirpitz, that's right, but I doubt this was possible.

Bismarck's machinery was more efficent than Tirpitz' in large parts of their fuel consumption curves, but it was getting rapidly more inefficent at very high WPS. So she reaches a possible limit of the burners much earlier.

[Herr Nilsson]

2.1.5. Rate of fire

A video recorded from cruiser Prinz Eugen during the Denmark-straight battle shows a sequence of Bismarck firing for effect at high rate (Wirkungsschießen). The rear turrets fire at 24, then 29 and then 32-sec.-intervals (at the correct tape speed). 24 sec. equals a rate of fire of 2.5 rounds per minute. The average is 28.3 sec. This equals an average rate of 2.1 while firing at PoW. However, normally Bismarck would fire one eight-gun full salvo (at Denmark Straight two) to warm up the guns and spot for line of fall and thereafter four-gun half salvos in four hectometer ladders to find the range. Three half salvos fired for different ranges (under, on, over) could be in the air at the same time to speed up the ranging process. Once the range was found, fire for effect would be ordered at high rate and typically also in half salvos. Half salvos would normally be ordered to the forward and aft turrets alternating, with the next half salvo ordered while the first salvo was still in the air. Due to the short flight times, the high precision and low dispersion and the continuously computed firing solution, Bismarck was often able to straddle very quickly compared to other battleships and thus was able to go over to fire for effect at high rate very quickly.
No other battleship main gun achieved a comparable high rate of fire (except Scharnhorst’s).
The nominal rate of fire of the modern American 16” guns was 2 rpm. The highest rate of fire that USS Washington achieved while firing at Kirishima under optimal and very urgent conditions was 1.73 rpm. Washington herself was not being engaged, but utmost urgency lay at hand since the almost defenseless South Dakota was lying under fire from Kirishima. Engagement range was very short (8.2km), Kirishima was lit up and the crew of Washington was well experienced.
The same maximum rate can be deduced for South Dakota and Iowa.
Bismarck: 8*2.5 = 20 rpm
8*2.1 = 16.8 rpm
Washington: 9*1.73 = 15.57 rpm

The Denmark Straits footage frame rate is to high. Bismarck's rate of fire was physically restricted to 2.3 (26 sec).

[hans zurbriggen]

Hello Mr. Nilsson,

thanks, do you have any information about 'possible limit' of burners actually reached during Bismarck's or Tirpitz's trials ?
As said, a less efficient fuel consumption at high powers would have affected range, not necessarily speed.

During trials, Gneisenau reached only 30.7 kn @ around 154,000 shp, while Scharnhorst achieved 32 kn @ 166,500 shp.
However both ships were able of 32 kn, as recorded on Gneisenau War Diary during HMS Glorious chase (developing therefore same max power).

IMHO, Bismarck had just never tried to achieve her max power (possibly to avoid problems, when her mission looked to be imminent) during her 'official' speed trial. This was quite common practice, e.g. in R.M. where Littorio's never tested their overload power (around 20%) during their trials.

The account of 30.6 kn from Bismarck-Richelieu comparison and of 30.8 kn from the Baron make me confident that both ships were good for around 31 kn in case of emergency.

hans

[fsimon]

Thank you Herr Nilsson for the information about the restricted rate of fire. Can you explain how the rate was restricted?
Best regards
Frank

[Bill Jurens]

I would certainly share Herr Nilsson's skepticism about the speed of the film being presented. Internet sources do not pay much attention to this sort of thing as so long as the speed seems 'about right', we accept it as plausible. This represents a particular problem where one has, in effect, no gauge, e.g. the speed of people walking, to determine if speeds are even roughly correct or not. One can, however, speed up or slow down even normal events by 10% or so without any noticeable difference to the viewer. There is a lot of jiggery-pokery done, on a routine basis, to 'convert' the old frame rates of film exposures to those used on video. These are (now) so cleverly-done that the ordinary observer can't detect them at all. The bottom line is that attempting to time German salvos from computer generated 'films' is -- except in the very broadest terms -- essentially futile. One needs to look at the original film, and even then, because frame rates in the camera were often not identical to the advertised frame rates, considerable caution is often required.

The idea the Bismarck's rate of fire might have been artificially constrained is not surprising to me at all. The U.S. Navy imposed similar restrictions on rates of fire due to safety concerns during the loading process(es). Ships were actually penalized if they fired too fast. So just because they 'could' fire at some given rate in very high speed testing, did not mean that this was actually practiced in service...

Bill Jurens

[Herr Nilsson]

Hello Mr. Nilsson,

thanks, do you have any information about 'possible limit' of burners actually reached during Bismarck's or Tirpitz's trials ?
As said, a less efficient fuel consumption at high powers would have affected range, not necessarily speed.

During trials, Gneisenau reached only 30.7 kn @ around 154,000 shp, while Scharnhorst achieved 32 kn @ 166,500 shp.
However both ships were able of 32 kn, as recorded on Gneisenau War Diary during HMS Glorious chase (developing therefore same max power).

IMHO, Bismarck had just never tried to achieve her max power (possibly to avoid problems, when her mission looked to be imminent) during her 'official' speed trial. This was quite common practice, e.g. in R.M. where Littorio's never tested their overload power (around 20%) during their trials.

The account of 30.6 kn from Bismarck-Richelieu comparison and of 30.8 kn from the Baron make me confident that both ships were good for around 31 kn in case of emergency.

hans

Hans,

everything is possible, but as long as it isn't officially documented (at best in several different sources) it's anecdotal.

I agree that official sources can be problematical. I mean there is even an official source that claims Tirpitz was able to sail at 31.7 kn. But under what conditions? I own one original source that states Gneisenau could produce ~165.000 WPS at about 75% payload at 65m water depth. The same source contains one data point with ~171.000 WPS at 200 m!
The speed trials are standardized. The Germans tested at about 75% payload at 65m water depth at Neukrug. That defines the conditions to make ships comparable. It's absolutely possible that they could be faster under other conditions, but I personally tend to use the trial data, because they are comprehensible.

[Herr Nilsson]

Thank you Herr Nilsson for the information about the restricted rate of fire. Can you explain how the rate was restricted?
Best regards
Frank

The rate of fire depends on the interplay of several work flows. The bottlenecks are: the shell hoist cage, the cartridge ring car and the shell ring car. They had a period of exactly 26 s. The workflow of the gun platform was just 24.75 s, but just for loading postion. In a 26 second cycle Bismarck was able to elevate the barrels up to 4°. That means in reality the rate of fire was even "worse" than 26 seconds.

[hans zurbriggen]

Hello Mr. Nilsson,
thanks again for all these info.

You are right that, comparing ships under same conditions, we must stay at 30.1 and 30.8 kn for BS and TP, as well as 30.7 and 32 kn for GU and SH.

However, as we know GU and SH were equivalent under operative payloads and able to run 32 kn (possibly GU was even able 32+ with 171,000 shp), my point is that very likely BS was able to reach around 31 kn (as reported independently by the Baron and by the BS-Richelieu comparison).

What I find really interesting is the top speed officially reported for Tirpitz at 31.7 kn (I had never heard about that): impressive result for such a large, 3 shafts ship. Is your source reporting the date when this speed was recorded ?
Can you please share the name of the document ?

hans

[Herr Nilsson]

In regard of the Denmark Straits footage frame rate:

It's very unusal to stick out the tongue like Jasper?? does.
The footage was filmed on 35mm with an Arriflex 35. The standard frame rate was 24 fps, but Lagemann's camera already had the adjusting knob for 18-30 fps.

My DVD-version apparently has a frame rate of 25 fps (PAL-TV). Assuming that the original frame rate in the later part of the film was 18 fps, I slowed down the DVD to ~70%. At that frame rate Jasper doesn't dart his tongue like a snake anymore and Brinkmann's cigar smoke respectively the rate of fire are getting more realistic.

[Herr Nilsson]

What I find really interesting is the top speed officially reported for Tirpitz at 31.7 kn (I had never heard about that): impressive result for such a large, 3 shafts ship. Is your source reporting the date when this speed was recorded ?
Can you please share the name of the document ?

Unfortunately not.
"Vergleich Fahrbereiche u. stündl. Verbräuche Tirpitz u. Hood" (Comparison of cruising range and fuel consumption per hour Tirpitz and Hood)