Naval History Forums

dunmunro wrote:09 December 1940
06 March 1941 Ship receives finishing touches.

06-08 March 1941 Leaves Hamburg, sails to Scheerhafen.

08 - 17 March 1941 Camouflage paint added. Supplies embarked (ammunition, fuel, water etc). Two Arado 196 floatplanes (T3 + DL, T3 + Mk) embarked.

Anatomy of the Ship - Bismarck, page 8, and there are entries in War Diary that correspond to this.

That's correct. What are you trying to tell us?

José M. Rico wrote:Another photo. Bismarck anchored in Kiel 24-28 September 1940 (a month before the Baltic speed trials).
Approx. draft: 10 meters.

Note the lack of main armament directors.

dunmunro wrote:Note the lack of main armament directors.

Yes, I know.
Now compare that color photo with this one taken just a month before on 24 August 1940.
Approx. draft: 8.20 meters.

The War diary records the fuel and water loads, and of course it varied, but the point is that Bismarck was not completed during her trials and there is a high probability that her displacement was very low, maybe even less than 44000 tons during her fastest trial speed runs.

Alternatively, as these were the all important acceptance trials, they could also have ballasted the ship's trim tanks and empty fuel cells with sea water to bring her to the required draft, and so made up for missing equipment and stores.

tommy303 wrote:Alternatively, as these were the all important acceptance trials, they could also have ballasted the ship's trim tanks and empty fuel cells with sea water to bring her to the required draft, and so made up for missing equipment and stores.

That's highly unlikely. It would have been terribly risky and exposed the ship to great danger if she were torpedoed or mined. The simple fact is that Bismarck was not completed during her November trials and, therefore her displacement may have been very light during those trials.

I also think that would be unlikey but not for mining or torpedo damage (I wouldn't trail a vessel in such an area). I doubt you want seawater in your fuel tanks. But running at a trial depth is not uncommon. Nearly all ships have a trial draught and several service draughts during the design.

Ciao all,

some references you used above for Bismarck are wrong.

Bismarck Baltic camouflage scheme was added while still in Hamburg on late 1940 - Early 1941, photos are available.

In fact on 6-8 March 1941 sailing from Hamburg to Kiel anchoring after at Scheerhafen she was wearing the Baltic camouflage already sailing into KW kanal, and photos are available too.

Than if you want to take a look at Bismarck during the autumn speed trails, there are 2 photos on Breyer-Koop book at page 102.

http://www.hmshood.org.uk/forum/phpBB3/ ... 6&start=40

Bye Antonio

It seems to me from looking at the discussion here , and that over on the Hood site , that you are chasing something that is a bit of an illusion , an actual speed performance on any particular day which accords exactly with a ships "Official top speed", figures .
Given that displacement loading of the ship , trim , wind direction and strength , water depth , temperature , salinity , sea state , cleanliness of the ships bottom , and power plants that run , in actuality , without the constant precision implied by the mathematical data reports arising from trials , and you can see where your two or three knots differences are coming from .

Another thing you may be overlooking is that "FULL AHEAD" "FULL POWER" and "MAXIMUM POWER" are three different things to the Chief engineer .

Overpressing the power plant to obtain 2 or 3 knots over the "contract" speed was a regular pre-WW2 bad practice indulged in in Italian and in French warship trials ( the Firms constructing the ships obtaining financial bonuses thereby ) .
One reason it is bad is because it overstrains the plant , like over-revving your motor car unduly .
You cant do it for long without breaking something , but you CAN do it for a little while , in an emergency situation .
I would think that the command team in Bismark recognised at the start of the Denmark Strait action that they had been well and truly caught ( Believing themselves to be up against KGV as well as Hood ) , and in that situation it is small wonder that they didn't put a spurt on , either arising from a direct request from the Bridge , or as an action on the initiative of the Engine room command on receiving the order for "Full ahead" by opening the valves that last half-inch and letting the guages go a fraction into the Red sectors .
Its the equivalent of those Spitfire pilots regularly shoving the throttle through the limiter to get the last bit of emergency boost power . Naughty , but you get away with it usually .

foeth wrote: I doubt you want seawater in your fuel tanks.

There is ( or should be ) a sump or pipe stub at the bottom of the tanks with a drain cock to open and get any water out . This is because fuel oil always has some water in it anyway due to condensation factors , and you need to get that out or surprising and distressing things start happening in the boiler rooms .
Water and Oil proverbially dont mix , ( or at least not very much ) , which is how submarines used to have their external fuel tanks open to the sea at the bottom .

Where you are taking fuel from bottom tanks this is normally pumped into a header tank , to allow any water to settle out and be tapped off .
I think there is a "sight glass" provided , and the staff have to check it and log it regularly , like you do for testing the condensed water the plant is returning to the boilers to make sure there is no seawater that has got into it ( with Silver nitrate )

Antonio Bonomi wrote: Than if you want to take a look at Bismarck during the autumn speed trails, there are 2 photos on Breyer-Koop book at page 102.

http://www.hmshood.org.uk/forum/phpBB3/ ... 6&start=40

Bye Antonio

A bit of a departure from topic; but that photo shows really well the high speed wave forms with a trough partly uncovering the belt at around compartment XIV.

dunmunro wrote:The War diary records the fuel and water loads, and of course it varied, but the point is that Bismarck was not completed during her trials and there is a high probability that her displacement was very low, maybe even less than 44000 tons during her fastest trial speed runs.

Well Duncan, according to the data currently available, the inputs here presented by Marc, the KTB, and photos of the period, there is no evidence at all to indicate that her displacement was very low (less than 44,000 tons).

On the contrary, this discussion and the photos presented, proves beyond a shadow of a doubt that Bismarck was not fully completed during her trials, and did not have her MA directors installed. This also points to a very high probability that she had no MA ammo on-board either.

Bismarck was not fully completed back then, I know, but the color photo that I previously attached taken in late September, shows the ship with an approx. displacement of 50,000 mt. The stores on 28-9-1940:
Fuel Oil: 5,932 m3
Feed Water: 628 m3

A load that is basically the same as that of 29 October (75% Zuladung). Stores on 29-10-1940:
Fuel Oil: 6,285 m3
Feed Water: 327 m3

José M. Rico wrote:Bismarck was not fully completed back then, I know, but the color photo that I previously attached taken in late September, shows the ship with an approx. displacement of 50,000 mt. The stores on 28-9-1940:
Fuel Oil: 5,932 m3
Feed Water: 628 m3

A load that is basically the same as that of 29 October (75% Zuladung). Stores on 29-10-1940:
Fuel Oil: 6,285 m3
Feed Water: 327 m3

We have an idea of its draft but not its actual displacement, and the ship may have been flooded down on 28-9-1940 using the trim tanks, this is something that we just don't know.

On 29-10-1940, the displacement could easily have been less than 45.5k tonnes.