Bismarck range

Discussions about the history of the ship, technical details, etc.

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marcelo_malara
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Re: Bismarck range

Post by marcelo_malara »

I want to share this numbers from Hood to illustrate the value of length (260 m, beam 30 m), from Northcott´s Hood.

41600 t 20.37 kt 29080 hp
41850 t 25.24 kt 58020 hp
42100 t 27.77 kt 89010 hp
42150 t 29.71 kt 116150 hp
42200 t 32.07 kt 151280 hp

Compare this with:

Warpite (lenght 196 m)
24 kt 75000 hp

North Carolina class (222 m)
28 kt 121000 hp

South Dakota class (207 m)
27.5 kt 130000 hp
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hans zurbriggen
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Re: Bismarck range

Post by hans zurbriggen »

Hello Mr.TTT,
undoubtedly Vittorio Veneto and Richelieu trials (1940) were done at light displacement. However, I doubt Tirpitz was still able of 31 knots in 1944 (apart from damages, her hull had been never in dry dock since years). Has anyone the data from any Tirpitz 1944 speed trial (done after x-craft attack and repairs) ?

Richelieu was surely heavier in 1943 while Littorios never tested their (considerable) extra-power reserve in a measured trial. I fear it is very difficult to compare such inconsistent data among them.

hans
TTTT
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Re: Bismarck range

Post by TTTT »

Agree. Late war US BBs were generally 1 to 1,5 knots slower than their "original" speed - Tirpitz was probably the same - if (s)he had stayed fit.
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Re: Bismarck range

Post by dunmunro »

hans zurbriggen wrote: Sun Sep 05, 2021 7:03 am Hello Mr.TTT,
undoubtedly Vittorio Veneto and Richelieu trials (1940) were done at light displacement. However, I doubt Tirpitz was still able of 31 knots in 1944 (apart from damages, her hull had been never in dry dock since years). Has anyone the data from any Tirpitz 1944 speed trial (done after x-craft attack and repairs) ?

Richelieu was surely heavier in 1943 while Littorios never tested their (considerable) extra-power reserve in a measured trial. I fear it is very difficult to compare such inconsistent data among them.

hans
Scharnhorst gives us a some idea of how much speed Tirpitz would have lost:
On 25 November 1943 Scharnhorst carried out a two-hour full-power trial achieving 29.6 knots (54.8 km/h; 34.1 mph) and it was noted that her draught had increased by over 0.5 metres (1.6 ft) from her 1940 trials where she had attained 31.14 knots (57.67 km/h; 35.84 mph)
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Re: Bismarck range

Post by TTTT »

Interesting, so by the time of her death, Scharnhorst (and Tirpitz) was barely a 30 knot ship. OTH, DOY was probably slower than KGV had been in 1941, too. Perhaps 27 knots? And if Bismarck had survived (s)he would have been able to do just 29 knots? Even the Iowa class seem to have been able to do "just" 31,5 knots by the end of the war.
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Re: Bismarck range

Post by dunmunro »

TTTT wrote: Sun Sep 05, 2021 12:49 pm Interesting, so by the time of her death, Scharnhorst (and Tirpitz) was barely a 30 knot ship. OTH, DOY was probably slower than KGV had been in 1941, too. Perhaps 27 knots? And if Bismarck had survived (s)he would have been able to do just 29 knots? Even the Iowa class seem to have been able to do "just" 31,5 knots by the end of the war.
KGV ran trials in 1940 at ~41.6K tons and made ~28.8 knots at ~110K SHP, DoY ran trials at ~42.5K tons and 28.6 knots at ~110K @ ~230 RPM. However the KGV class had another ~20% power in reserve, as PoW achieved 134K SHP prior to engaging Bismarck and she recorded 239 RPM in her log at 29 knots. This would equate to a trials speed of ~29.8 knots. DoY's full load displacement in Dec 1943 was about 2K tons more than her trials displacement, probably equating to a .3 - .5 knot speed loss, but she would have burned nearly that much fuel prior to the engagement. However, she may have had a dirty bottom as well, depending on when she was last drydocked.
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hans zurbriggen
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Re: Bismarck range

Post by hans zurbriggen »

Hello Mr. TTT,
apparently Bismarck did not use the full extra-power reserve in trials (Tirpitz did), because her boilers/machinery were equivalent to her sister's one. I think Bismarck could have achieved the same speed as Tirpitz (with just slightly less range due to less fuel bunkers capacity).
Tirpitz was not much heavier by 1944 than the 53,200 tons of her 1941 trials, possibly only 1,000 tons more maximum but less in normal load conditions. For her displacement, this extra weight was almost negligible in terms of loss of speed. Scharnhorst was quite heavier than during her trials (but I don't have exact figures: just using the additional draught (thanks to Mr.Dunmunro), she should have been almost 3,000 (55.1 tons/cm x 50 cm) tons heavier (for her total displacement, these are not negligible).
Main problem for Tirpitz was not the displacement: it was the distance from Germany, the fact that she went into dry dock for the very last time in november 1941 (after that, her hull was never cleaned anymore) and that her machinery could have not been possibly correctly maintained in Norway.

hans
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Herr Nilsson
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Re: Bismarck range

Post by Herr Nilsson »

marcelo_malara wrote: Fri Sep 03, 2021 9:39 pm We have already discussed this before. Bismarck´s machinery was not efficient, her consumption was 325 grams/hp/hour, whereas for example Massachusetts´ was 305.
325 grams/hp/hour was just a contractually guaranteed maximum fuel consumption for 265 rpm at 3x46,000 SHP. In case of rpm and SHP didn't correlate in reality the guaranteed maximum fuel consuption had to be recalculate with the help of a special table.
TTTT wrote: Sat Sep 04, 2021 10:00 pm
Max fuel capacity:
Bismarck: 8,294 tons (this site) (7,400 Wikipedia)
Actually cubic metres!
8294.3 cubic metres according Krux and 8337.8 cubic metres according "Schlachtschiff "Bismarck" Bunker-, Tank- und Zellenplan"

...however, that figures include additional bunkers for special purposes. Without these bunkers it's 7700 cubic metres according Krux and 7705.6 cubic metres according "Schlachtschiff "Bismarck" Bunker-, Tank- und Zellenplan". AFAIK all German range calculations are based upon 7700 cubic metres.


Fun fact:
Tirpitz according to
  • B.d.S.: 7500 cubic metres
  • O.K.M.: 7700 cubic metres
  • Fleet command:
    • a) 7388 cubic metres
    • b) for special tasks 7717 cubic metres
  • Krux: 7717 cubic metres
Regards

Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)
TTTT
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Re: Bismarck range

Post by TTTT »

I see - so that explains the difference between this site and Wikipedia? Wikipedia operates with "tons" : "The two ships had different fuel stores; Bismarck was designed to carry 3,200 tons of fuel oil, but could store up to 6,400 tons of fuel in a normal configuration; with extra fuel bunkers, the fuel carried could be increased up to 7,400 tons. Tirpitz was designed to carry 3,000 tons of fuel, and with additional bunkers, was able to store up to 7,780 tons."
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marcelo_malara
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Re: Bismarck range

Post by marcelo_malara »

Herr Nilsson wrote: Tue Sep 07, 2021 5:19 pm
325 grams/hp/hour was just a contractually guaranteed maximum fuel consumption for 265 rpm at 3x46,000 SHP. In case of rpm and SHP didn't correlate in reality the guaranteed maximum fuel consuption had to be recalculate with the help of a special table.

Hi! Do you have actual consumption numbers for Bismarck?

Regardfs
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Re: Bismarck range

Post by TTTT »

Hans, according to this site and Wikipedia their engines were different:

"Bismarck was equipped with Blohm & Voss turbines, while Tirpitz used Brown, Boveri, and Co. engines."

"Both ships were rated for a top speed of 30 knots (56 km/h; 35 mph); Bismarck just exceeded this speed on sea trials, reaching 30.01 knots (55.58 km/h; 34.53 mph), while Tirpitz made 30.8 knots (57.0 km/h; 35.4 mph) on trials. This difference was largely the result of a significant increase in horsepower for Tirpitz, which reached 163,023 PS (160,793 shp; 119,903 kW), compared to 148,116 for Bismarck."

The HP numbers are slightly different on this site. 163,026 hp (maximum obtained) vs. 150,170.

But you are saying that Bismarck was not going "full out"?
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hans zurbriggen
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Re: Bismarck range

Post by hans zurbriggen »

Hello Mr. TTT,
power actually achieved at official speed trials (the ones you mention) are different between BS and TP, but design was 138,000 hp for 29 knots for both and (large) extra-power reserve should have been the same for both.
Boilers too were manufactured by different companies (Blohm & Voss for BS, part Kriegsmarinewerft Wilhelmshaven and part Deschimag for TP). Turbines were different, but their specifications were the same and there is no reason (at least, I'm not aware of any reason) why Tirpitz should have been faster (she was even slightly heavier than Bismarck). The propulsion plant was designed to perform the same on both ships (only difference was the cruising turbine present on Tirpitz, that has no influence on top speed).
Coming to BS, as per KGV's and Littorio's, it was not always considered appropriate to perform speed trials exploiting the full extra-power. Official documents mention 30,6 knots for BS (comparison between Richelieu and BS) while the Baron mentions a speed of 30,8 knots achieved by his ship (possibly in other trials when extra-power was exploited).

Same was for Scharnhorsts, when at speed trials SH achieved 166,500 hp for 32 knots and GU "only" 153,900 hp for 30.7 knots. However during HMS Glorious chase, GU actually achieved 32 knots (as per her war diary). Thus the two ships have to be considered equivalent in terms of top speed.

We don't know how many knots Bismarck actually achieved on May 24 morning, having lost her log, but just considering the range closure rate versus PoW, I feel she was well over 30 knots (my personal opinion).

hans
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Re: Bismarck range

Post by TTTT »

Interesting, thanks!
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Re: Bismarck range

Post by dunmunro »

hans zurbriggen wrote: Wed Sep 08, 2021 7:15 am Hello Mr. TTT,
power actually achieved at official speed trials (the ones you mention) are different between BS and TP, but design was 138,000 hp for 29 knots for both and (large) extra-power reserve should have been the same for both.
Boilers too were manufactured by different companies (Blohm & Voss for BS, part Kriegsmarinewerft Wilhelmshaven and part Deschimag for TP). Turbines were different, but their specifications were the same and there is no reason (at least, I'm not aware of any reason) why Tirpitz should have been faster (she was even slightly heavier than Bismarck). The propulsion plant was designed to perform the same on both ships (only difference was the cruising turbine present on Tirpitz, that has no influence on top speed).
Coming to BS, as per KGV's and Littorio's, it was not always considered appropriate to perform speed trials exploiting the full extra-power. Official documents mention 30,6 knots for BS (comparison between Richelieu and BS) while the Baron mentions a speed of 30,8 knots achieved by his ship (possibly in other trials when extra-power was exploited).

Same was for Scharnhorsts, when at speed trials SH achieved 166,500 hp for 32 knots and GU "only" 153,900 hp for 30.7 knots. However during HMS Glorious chase, GU actually achieved 32 knots (as per her war diary). Thus the two ships have to be considered equivalent in terms of top speed.

We don't know how many knots Bismarck actually achieved on May 24 morning, having lost her log, but just considering the range closure rate versus PoW, I feel she was well over 30 knots (my personal opinion).

hans
Speed is a function of power at a given displacement (with a clean bottom). Here's Scharnhorst's power curve at ~39k tonnes (possibly tons) and this seems to match the 1940 trials. By 1943 her full load displacement was well over 40K tonnes.

http://www.sfu.ca/~dmunro/Scharnhorst_speed.jpg

Note that full speed = ~31 knots at 160k shp at 39k tonnes as per the 1940 trial.
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Re: Bismarck range

Post by bigjimslade »

One piece that is missing in this discussion is that the Iowa-class battleships were designed to carry fuel for themselves AND THEIR ESCORTS (and the earlier battleships adopted this).

Fuel Capacity / Fuel Consumption = Range

—gives a theoretical measurement, not an actual operational measurement.

In operational terms, the large fuel capacity of the Iowas meant they could go longer without refueling.
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