Speed - Bismarck versus Scharnhorst/Gneisenau

[foeth]

That is quite typical of any shipyard - shipowner relationship. The yard is subjected to contractual fines if the specs are not met within a certain margin. The owner can even reject the ship and leave the yard with a new yacht. This does happen, although I guess the owner will have a good standing point for forcing the yard to heavier fines and so forth. But in case of a brand new battleship in a war situation, I'd take her sailing nonetheless (and levy fines). With these expensive projects, the design phase and model tests performed beforehand are more extensive that for other ship types. No guarantees in WWII of course.

[hammy]

Mmmm , the point I was making was that in the case of Italy and in France their procurement was unsound prior to WW2 in that the trials were run in unrealistic conditions ( armament not fitted , ships run in very light condition and trimmed for maximum speed , fair weather , propulsion plant considerably over-pressed , etc ) to achieve a high speed figure and obtain a fat bonus for the ( ephemeral ) extra performance .
These high speeds were then reported widely as the ships normal war loaded performance , hollow claims that would show up when the ships finally went into combat and proved to be far more ordinary than their reputations would lead you to expect .

The fundamental law of Naval Design which is " that Foriegn Rivals must always be given credit for having solved problems which your own design teams find impossible " , kept admirals awake and worrying for years though

[dunmunro]

21/7/40 Bismarck = 38840/38540/38678 MT,during inclining test so empty Mean = 38646 MT

12/11/40 FO= 4439 cu/m = 4217 MT (.95 specific gravity) + 616 tons FW =5055 MT + 38646 tons = 43701 MT + whatever additions have been made between the inclining test and the speed trial.

minimum probable weights include:

ammo = 200mt
consumable = 50mt
crew = 120mt
provisions = 60mt
Drinking water = 40mt
diesel/lube oil = 90 mt
---------------------------
560 mt

43701mt + 560mt = 44261 tons - fuel burnt prior and during the test = minimum probable displacement = ~44050 mt = 43354 tons on 12/11/40

[Herr Nilsson]

Duncan,

I think we both agree that there were no noticeable changes of the ships equipment between November 12th and December 11th.
Bismarck reached Hamburg December 9th with 1833 cbm fuel oil and 423 cbm feed water.
Bismarck left Hamburg March 6th 1941 with 1454 cbm fuel oil and 507 cbm feedwater.
There is no report of any fuel oil transfer between these dates.

On Dezember 11th we have a document, which states:

Draft on Dezember 11th

Front port 8910 starboard 8910
Middle port 9350 starboard 8960
Rear port 9560 starboard 9365

~44500 t

On September 14th 1940 the KTB states:

2330 cbm fuel oil and 436 cbm feedwater

There is also a document of that day:

Draft on September 14th

Front port 9255 starboard 9255
Middle port 9330 starboard 9335
Rear port 9480 starboard 9480

~45000 t

Even with the information of the rough estimates made by Blohm and Voss it doesn’t make much sense to try to extrapolate the weight from fuel oil and feed water. We simply do not have enough informations about the other weights.

[Dave Saxton]

I have access to some photos of Tirpitz during it's trails period. There is a great deal of fluctuation of the draught. At times its has virtually no boot topping left showing at all, while at other times most of the boot topping. During some of test shoots it is still lacking the after firecontrol rangfinders (both the surface and Flak, and the aft radar), but there's very little boot topping showing at all. It seems they manipulated the displacement and draught for the situation. I can't imagine them running consumption and speed trials riding high. What would be the point of that?

[Thorsten Wahl]

according to this thread in the german forum-marinearchiv

http://forum-marinearchiv.de/smf/index. ... 419.0.html

Harold
....
So weit mal der "Befund".
76 m sind also l /2, lambda demzufolge 152 m => 29.94 kn. Da unsere Schätzung ohne weiteres zwischen 73 und 78 m schwanken kann (achteres Maximum sehr unscharf!), liegt die "Bandbreite" von 29.3 bis 30.3 kn.-
....

Speed roughly 29,94kn; bandwidth 29,3 - 30,3kn

[Thorsten Wahl]

According Report
Chef Hauptamt Kriegsschiffbau Fuchs
K/K III A Nr. 231/41 g.Kdos. Vergleich zwischen "Richelieu" und "Bismarck"
page 3
Bismarck
Constr. Speed 28,0 kn
achieved Speed 30,6 kn
(where and when are unknown)

[dunmunro]

According Report
Chef Hauptamt Kriegsschiffbau Fuchs
K/K III A Nr. 231/41 g.Kdos. Vergleich zwischen "Richelieu" und "Bismarck"
page 3
Bismarck
Constr. Speed 28,0 kn
achieved Speed 30,6 kn
(where and when are unknown)

Again, the critical info is displacement. Richelieu, for example could achieve extreme speeds on trials; " during a brief builder's trials she achieved 32.6 knots with an overload of 178000 MHP and 31.9 knots with...157000HP at a displacement of 43500 tons." At 41244 tons she achieved 30.38 knots with 135300 SHP.(allied BBs, p140) Richelieu's full load displacement was about 48000 tons.