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Re: Fuel consumption Bismarck

Posted: Thu Jan 12, 2012 7:56 pm
by dunmunro
Whitely, German Capital Ships of WW2, p49, gives the following ranges for Bismarck:

8600nm @ 15kts

8150nm @ 21kts

5200nm @ 27 kts

3750nm @ 30kts

and a usable capacity of 7400 tonnes of fuel.

Fuel used per 1000 tons of displacement per 100nm:

Bismarck; 1.7m3 @ 15kt, 1.8m3 @ 21kt, 2.9m3 @ 27 kts, 3.9m3 @ 30 kts.

Scharnhorst / Gneisenau @ 27 kts; 3.4m3 / 4.0m3

Whitely states that these are OKM figures.

Re: Fuel consumption Bismarck

Posted: Sat Jan 14, 2012 8:17 pm
by delcyros
What are the specific fuel consumption figures of the classes of ships under discussion?

For BISMARCK I don´t know them but the data proposed so far look convincing.

Nor do I know the specific required SHP to attain any given speed but the data from HerrNielsson from the other thread allow these interpolations between a limited set of three datapoints:

Speed data BISMARCK, accurding to MMF model based on
three aviable datapoints communicated by Herr Nielsson out of EKK Erkundungskommando
Kriegsschiffneubauten, Table:
"Schlachtschiff "Tirpitz". Ergebnisse der Meilen-
und Brennstoffmeßfahrten (3 Wellenfahrten)

Displacement: 68% to 75% load.
Displacement without load: 43220 t (metr.)
1% load = 83.6 t (metr.).

actual displacement for trials:
48,905 t (metr.) to 49,490 t (metr.)

002000SHP = 07.2kts (primary data, trial)
010000SHP = 13.5kts (interpolation)
020000SHP = 17.0kts (interpolation)
030000SHP = 19.3kts (interpolation)
040000SHP = 21.1kts (interpolation)
050000SHP = 22.5kts (interpolation)
060000SHP = 23.7kts (interpolation)
070000SHP = 24.8kts (interpolation)
080000SHP = 25.7kts (interpolation)
090000SHP = 26.5kts (interpolation)
100000SHP = 27.2kts (interpolation)
110000SHP = 27.9kts (interpolation)
117000SHP = 28.3kts (primary data, trial)
120000SHP = 28.5kts (interpolation)
125000SHP = 28.8kts (interpolation, design power 1)
134000SHP = 29.3kts (interpolation, design power 2)
140000SHP = 29.7kts (interpolation)
150000SHP = 30.1kts (interpolation)
150170SHP = 30.1kts (primary data, trial)
155000SHP = 30.4kts (interpolation)
156000SHP = -------- (trial curve BISMARCK ends, no measured trial datapoint)
---------SHP = 30.6kts (primary data, without details from
Anlage K/K III A Nr. 231/41 g.Kdos from March, 13th 1941)
160000SHP = 30.63kts (extrapolation, max. overload 1)
168000SHP = 30.99kts (extrapolation, max. overload 2)
Reference TIRPITZ, displacement unknown:
163026SHP = 30.80kts (primary data, trial)
Reference SCHARNHORST, displacement unknown:
160050SHP = 31.65kts (primary data, trial)

The same MMF model was quite effective in determining a good fit speed curve of USS IOWA and USS NEW JERSEY as of 1944 and post war with
comparably low margins of error in the discussion evolving with Mr. A.St. Toby. A word of warning should be issued not to misunderstand these figures as real data, these represent best guess interpolations based on aviable set of data with to few datapoints for my taste. Precision may be misleading.

What are the host requirements for BISMARCK- and KGV-class? I mean, what non-propulsion related consumptions are necessary to create a high degree of combat readiness or cruise readiness and what are the corresponding SHP/t/h fuel consumption figures for these ships? I have seen so many different data, that I don´t know what is based on serious, comparative data and what based on singular event data.

some comparative data

Posted: Sat Jan 14, 2012 10:44 pm
by dunmunro
Speed Model predictions
41000 / 45000 tonnes
(MSHP or MT)

26kt; 71,015 (72,000) / 72,990 (74,000)

30kt; 119,345 (121,000) / 133,155(135,000)

31kt; 138,085 (140,000) / 151,695(153,800) 0.50


22.71kt @ 42,786tons (43,473) 45,489shp (46, 120)

26.35kt @ 41,182tons ( 41,843) 81,963shp (83,100)

30.38kt @ 41,244tons (41 ,906) 135,284shp (137,160)

30.31kt @ 41,392 (42,056) 132,798shp (134,640)

32.6kt @ 43500


Re: Fuel consumption Bismarck

Posted: Sun Jan 15, 2012 3:46 pm
by delcyros
Thanks Duncan. With these and Data taken from Dumas, th MMF model predicts for RICHELIEU are surprising:

five aviable datapoints communicated by Duncan and
taken from Dumas and three more model datapoints.

actual displacement for trials:
41,843 t (metr.) to 43,473 t (metr.)

010000SHP = 14.5kts (extrapolation)
020000SHP = 17.8kts (extrapolation)
030000SHP = 20.1kts (extrapolation)
040000SHP = 21.8kts (extrapolation)
045489SHP = 22.7kts (primary data, trial)
050000SHP = 23.2kts (interpolation)
060000SHP = 24.4kts (interpolation)
070000SHP = 25.5kts (interpolation)
080000SHP = 26.5kts (interpolation)
081963SHP = 26.4kts (primary data, trial)
090000SHP = 27.3kts (interpolation)
100000SHP = 28.1kts (interpolation)
110000SHP = 28.9kts (interpolation)
120000SHP = 29.6kts (interpolation)
123000SHP = 30.0kts (primary data, trial)
130000SHP = 30.2kts (interpolation)
132789SHP = 30.3kts (primary data, trial)
140000SHP = 30.8kts (interpolation)
150000SHP = 31.4kts (interpolation, design power)
155000SHP = 32.0kts (primary data, trial)
160000SHP = 31.9kts (interpolation)
170000SHP = 32.5kts (interpolation)
179000SHP = 32.7kts (primary data, forced power trial)
180000SHP = 32.9kts (extrapolation, max. output 1)
190000SHP = 33.4kts (extrapolation, max. output 2)
model data:
actual displacement for model tests:
41,000 ts

071015SHP = 26.0kts (primary data, model)
119345SHP = 30.0kts (primary data, model)
138085SHP = 31.0kts (primary data, model)

That would strongly indicate that RICHELIEU was the fastest battleship ever buildt.

Re: Fuel consumption Bismarck

Posted: Mon Jan 16, 2012 5:54 pm
by delcyros
addendum to data from above:

The reported Displacement of RICHELIEU suggests that the trials were conducted at unusually light displacement, figuring roughly ~50% load for the 43,500t displacement figures and close to 25% load for the ~41,800 t displacement figures. The model tests for ~45,000t are roughly 75% fuel load.
Full displacement was 47,548t, max. fuel buncerage is reported with 6,796t fuel oil.

MMF model in graphic displac (figures above stem from it):


That beeing said, it´s nevertheless an extremely fast battleship, faster than what IOWA was able to attain.

Re: Fuel consumption Bismarck

Posted: Mon Jan 16, 2012 11:47 pm
by dunmunro
delcyros wrote:

That beeing said, it´s nevertheless an extremely fast battleship, faster than what IOWA was able to attain.
Thanks, that's quite interesting. What displacements are modelled for both ships?

Re: Fuel consumption Bismarck

Posted: Tue Jan 17, 2012 9:09 am
by delcyros
From the data above.

RICHELIEU: ~41,800 to 43,500t (~25% to less than 50% load)
BISMARCK: ~48,900 to 49,500t (68 to 75% load)

So it´s a bit of an disadvantage for the latter but even using the right load on RICHELIEU, the vessel should be able to attain 32.5kts forced at 120% rated power, which is a good 2 kts faster than what BISMARCK could manage on 120%.

Does anybody happen to have data for the Littorio´s?

Re: Fuel consumption Bismarck

Posted: Tue Jan 17, 2012 9:23 am
by delcyros

These are the MMF models for IOWA (from her trial in 1985 with modern and smoother underwaterpaint) and USS NEW JERSEY as of 1943. The problem is that any predictions past ca. 2400000SHP are increasingly overstating performance that´s because cavitation set´s (60000SHP per shaft was the maximum possible with period technology anything past that increasingly bumps up with more and more cavitation, starting at the tips of the props and growing), which is unaccounted for in the model.

USS IOWA was a bit faster at est. 31.9 kts at 212000SHP in 1985 for the reasons outlined above. USS NEW JERSEY would have been unable in 1943 to attain 31.0 kts at 56,000 t displacement with 212000 SHP an couldn´t be expected to exceed 31.8kts despite forcing the engines. The max. speed these vessels could attain lies right in between 31.0 and 32.0 kts, but closer to the latter.

Re: Fuel consumption Bismarck

Posted: Wed Jan 18, 2012 8:14 am
by dunmunro
Axis Battleships has the results of full power trials for V.V. and Littorio:

VV; 31.428 knots with 132775 shp at 41473 tons @ 238 rpm
Littorio: 31.292 knots with 137652 shp at 41123 tons @ 239 rpm

Max overload power is stated to be ~140,000 shp.

Re: Fuel consumption Bismarck

Posted: Wed Jan 18, 2012 9:00 am
by alecsandros
I do not share your points.
For the comparison to have any meaning, the ships must have the same % load.

25% load for Richelieu and 75% for Bismarck is outrageous!

Vittorio Venetto reached 45500-46.000t during the war, so the load figure given above is very small. Richelieu after refit was more at ~ 47000 tons.

I remember some data from Iowa @51.000tons reaching 34-35kts. I'll try looking into it.

Re: Fuel consumption Bismarck

Posted: Wed Jan 18, 2012 10:47 am
by alecsandros
A research onto Iowa's speed (estimated at 33kts by the study at 56.000t) ... eships.pdf


"Now, the Navy also estimated that every 1,000 tons less in displacement would give an additional 0.25 knots of speed. If I can "cheat" by saying that I've offloaded every last piece of unnecessary gear to reduce my displacement - after all, who needs those silly Harpoons, anyway? This is a big-gun battleship, not a DDG - then I can reduce those numbers a bit. The above mentioned reference sources have a good deal of equipment weight data which I have used for these estimates. Semi-reasonable offloads (my definition, I'm not going to cut away the foremast just yet) could reduce the displacement down to 48,900 tons (see the Appendix below for details). This is 5,000 tons less than Trial Displacement, which would imply a maximum speed of 33.75 knots @ 212KSHP. My calculations seem to show that this displacement would equate to about 36 knots @ 254KSHP.

Appendix I:

What were my "semi-reasonable" off-loads?

The USS New Jersey's weight table of 1943 showed a Full Load Displacement of 58,132 tons. 45,155 tons of this is basic structure and is not subject to reduction per my definition. Offloading parts of the remainder:

70% of fuel oil: 5,659 tons (in reality, this would not be practical)
80% of munitions: 2,074 tons
36% of crew: 104 tons (The Navy estimated 250 lbs. per crewman, incl. equipment)
33% of Reserve Feed Water: 164 tons
80% of all stores: 1,179 tons
100% of aeronautics: 52 tons

Total Reductions: 9,232 tons

"Semi-reasonable" Light Ship Displacement: 48,900 tons

Appendix II:

Other maximum speeds achieved.

1) When the Iowa and New Jersey attempted to run down the fleeing Japanese destroyer IJN Nowaki near Truk in February 1944, both ships reached 32.5 knots with the throttles wide open, according to the Iowa's pitometer log. With clean bottoms, they probably could have gone a bit over a knot faster. There is no mention of what was the SHP or the displacement on that day.

2) During her Korean tour, the Iowa's Captain William Smedberg remembered getting his ship over 33 knots on at least one occasion. There is no mention of what was the SHP or the displacement on that day.

3) Before her Vietnam deployment the New Jersey obtained 35.2 knots at 207 RPM during machinery trials. There is no mention of what was the SHP or the displacement on that day.

4) In 1985 the Iowa slightly exceeded 32 knots at 205 RPM. There is no mention of what was the SHP or the displacement on that day.

Re: Fuel consumption Bismarck

Posted: Wed Jan 18, 2012 5:04 pm
by delcyros
These are outdated data based upon theories and anecdotes in absence of primary sources, which have been classified during the wrote downs of Speed-Thrills I to IV.

IOWA´s and NEW JERSEY´s trial data have been declassified in the meantime and thankfully submitted to a broad public by Mr. Steven Toby, who was in charge during the 1985 series trials of USS IOWA.

The informations can be found here:

(with reference to first of class trials conducted by USS NEW JERSEY in 1943)

These are data to base arguments on, not what some sailors claimed from uncalibrated readings under conditions, displacement´s and state´s (depth of water) generally unknown.

Mr. Toby came to the conclusion that USS IOWA in 1985 (with a special, low drag underwaterpaint unaviable in 1943) would have been good for ca. 32.5kts:
That speedometer had been calibrated against range speeds during the standardization trial, and accordingly, the model basin trials crew was able to reconstruct an additional data point at 31.0 knots of 198.2 RPM and 186,400 SHP. This being substantially closer to full power than the World War II data, extrapolating it as a cubic is correspondingly more accurate. The result is 32.36 knots, in very good agreement with the classic design number of 32.5.** Since this trial was run 71 days after the last drydocking, suggesting there could be some hull fouling, I am inclined to believe that 32.5 knots at 212,000 SHP is within experimental error of what actually happened on the sea trial in 1985. "
However, by personal communication with him, I pointed to problems with a cube extrapolation and submitted the MMF model drawn from above to him. His response agreed with the issue in outlining that a cube prediction is to low:
"There has been lots of interesting discussion on this thread since my original article was posted. The biggest questions seem to be extrapolation from trials data since there was in neither sea trial a point at 212,000 SHP.

I have looked at this more carefully and indeed the commonly used cubic interpolation method does not work well in the region around 30 knots for the BB 61. In the sea trial numbers, taking the point at 28.08 knots and extrapolating it to 29.41 knots, the next point measured on the trial, the cubic results in a power about 12.3% less than what was measured. Coincidentally, extrapolating the 29.41 knots to the reconstructed 31 knot point gives a result that is about 12.5% short of the measurement. The reason why these numbers are so similar is "coincidental" because of the shape of the drag coefficient curve for the ship. This can be modeled somewhat (resistance only, ignoring what happens to the propeller efficiency) by making a Taylor series calculation.

The Taylor Series is a large number of model tests, first published in 1910 as “Speed and Power of Ships” by RADM David W. Taylor, USN, that can be interpolated to create a resistance curve for a ship with a wide range of dimensions and coefficients. Modelling an Iowa class battleship this way results in the following table (I can’t seem to make graphs as some of the others in this thread did).


If we look back at the table as a model for the resistance behavior implied by the trials curve, however, there is a difference. Extrapolating the EHP curve in the table from 29 to 31 knots (representing, approximately, the last pair of points on the trials) as a cubic results in a predicted EHP at 31 of 91,417, or 6.6% short of the calculated resistance – about half as bad, in short, as the trials behavior. The trials behavior is quite complicated, with propeller efficiency steepening the curve in the region of 30 knots. To get SHP from EHP we add in the appendage drag and still air drag and then divide the total by the propulsive coefficient, PC, which is typically around 0.64. If we take the next pair of speeds, 31 and 33 knots to represent the extrapolation I performed as a cubic on the trials data, we find that the result is 117,585, or about 5.3% less than a cubic. There is no reason to assume that the propeller efficiency will decrease less in this speed range than it did between 29 and 31.

Accordingly, I agree that the Iowa’s top speed in the conditions of the trials will be less than the cubic extrapolation, maybe about 32 knots. However, this changes the stature of these battleships very little since this is still a very creditable speed for a ship this size.

The question of the difference between Iowa and New Jersey is one I didn't really look into when I first saw the DTMB report. The Rockland measured mile was in use for a substantial time and was considered deep enough to get good results for most ships. While the displacements were different, the differences were small, and I tend to agree with the authors of the report in saying ship surface smoothness was probably the biggest difference that could affect results.

However, one of my main reasons for requesting the new trial was that I had access to the original BuShips report of the New Jersey trial. I analyzed it and concluded it was inadequate. I don't recall why I concluded this -- possibly I didn't like the fact that the highest speed point was so far away from full power. (I didn't realize, of course, that "my" sea trial would end with the same basic defect). I'm a naval architect with no special training in statistical analysis and I didn't want to do the kind of fancy extrapolations that delcyros has done in this thread. But, it's also possible I found some other problems with the data. Anyway, I do not think it is correct from a physical standpoint to attempt to make a composite curve from the two trials. The two ships were different for one reason or another and the two trials must be analyzed separately. If that means Iowa in her last commission was a little faster than New Jersey was in her first, so be it. The ships of this class were built in two different yards, which means the lines were lofted by two different teams and the "as built" hull forms may not have been identical. The underwater paint was certainly different. While propellers were to the same design, those used in the Iowa trial might have been reconditioned using modern facilities; I looked at them in drydock on one of the ships after renovation and they were certainly beautifully polished. Accordingly, I would caution against lumping the two curves together. Iowa in 1985 was a little faster than New Jersey in 1943, but those differences were relatively small and did not affect the ships' tactical usefulness had they been operating together. They still deserve bragging rights as the fastest (well, maybe just one of the fastest) battleship classes ever built.
I have to say that I submitted a unified curve, using data from both trials to get an average and Mr. Toby rightfully challanged this as beeing incorrect. If that is true, the data from NEW JERSEY in 1943 apply to this ship only and maybe this class as of ww2 state while those of IOWA in 1985 apply to this ship only and more broadly, to this class in general as of 1985 if treated to IOWA´s conditions.

That beeing said, the speed differences of NEW JERSEY and SCHARNHORST as of ww2 state are entirely negliable. The IOWA class would have been incapable to achieve 35, 34, or even 33 kts in ww2 at anything except unrealistically low displacement, even forcing the engines to the point where caviation overcomes any additonal power generated by the plant. NEW JERSEY, according to her first-of-the-class series trials would have been able to achieve 30.8 to 30.9 kts at legend power and 31.8 to 31.9kts at 250000SHP forced power (=62,500 SHP per shaft, with cavitation already started). 32.0kts are possible forcing the engines even more, to 255,000 to 260000SHP but much beyond 32.0 kts is highly improbable, because of the cavitation issues involved.
USS NEW JERSEY was able to achieve 29.30kts at 163,400 SHP and 56,900ts displacement in 1943. This in combination with her slower dpeed datapoints translates according to her official report to
"As best as can be determined by extrapolation of the existing data, the NEW JERSEY in 1943, at a displacement of 57,813 metr. t (56,900 tons) was capable
of a speed of slightly less than 31.0 kn at the design horsepower of 212,000 shp.

Note that my MMF model based on USS NEW JERSEY´s trial results in 1943 predicted 30.84kts. at 212,000SHP, and is by this evidence in good agreement with the findings of the official USN trial reports.

Re: Fuel consumption Bismarck

Posted: Wed Jan 18, 2012 6:19 pm
by alecsandros
I appreciate very much your efforts, but without specifying the loads for those *proposed* speeds and powers, the situation is not clear at all.

And it's even more fuzzy when comparing it to data points coming from Richelieu or Vittorio VEnetto with 25-30% loadings and maximum output (and in the case of Ricehlieu, even forced output). Iowa with 25% load would displace ~ 49000t, which, at 240000shp may theoreticaly exceed 34-35kts, clearly faster than any competitor. IN the same time, Richelieu/Littorio/Tirpitz with 75% load (45.000/45.000/49.000 tons respectively) would be stuck in the 30-31kts area at best, while Iowa with 75% load would displace ~ 55.000t and possibly exceed 32kts.
Thus we have a faster ship, allthough it carries a larger load than her contemporaries at the same % displacement .

Stoping by at the New Jersey example (allthough the chase of Nowaki is also of particular importance), 30.84kts@212000shp@57.000tons is a formidable result. The Iowa's had 20% overload capacity (so up to 255.000hp) AND New Jersey was 85% loaded (12.000 load / 14.000 tons maximum load). So, again, the IOwa class is demonstrated to be the fastest BBs ever built...

One critical factor which I don't see in your post is the prismatic coefficient for Iowa. This is critical for assessing a ship's submerged volume@various loadings, and thus the probable resistance through water the ship's engines need to overcome in order to propel the vessel.

For reference:
Prismatic coefficient Richelieu at 43000tons: 0.58
Bismarck prismatic coefficient at 45.000tons: 0.56
Bismarck prismatic coefficient at 50.000tons: 0.59

Re: Fuel consumption Bismarck

Posted: Wed Jan 18, 2012 8:14 pm
by dunmunro
One factor that needs to be looked, is that the minimum loading of various designs, will depend on the minimum allowable liquid loading within the TDS. This will place a lower limit on displacement for all designs, but on some, more than others. For example Iowa would not be able to allow her displacement to fall below ~55000 tons due to the need to maintain liquid in the outboard layers of her TDS. Similary Bismarck and KGV needed to keep the liquid layers in their TDS at an optimum level (~85% of capacity).

Re: Fuel consumption Bismarck

Posted: Wed Jan 18, 2012 9:07 pm
by alecsandros
dunmunro wrote: For example Iowa would not be able to allow her displacement to fall below ~55000 tons due to the need to maintain liquid in the outboard layers of her TDS.
What % load of fuel oil and ammunition did you have in mind to arive at this displacement ? Remember only Friedman gives IOwa's total maximum late-war displacement at ~ 59.000tons, with 8000 ton fuel and 2000 ton ammo on board... Other sources mentino full loads at ~ 57.000 tons.