Bismarck Speed

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

Moderator: Bill Jurens

User avatar
Herr Nilsson
Senior Member
Posts: 1433
Joined: Thu Oct 21, 2004 11:19 am
Location: Germany

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by Herr Nilsson » Sun Jan 31, 2010 10:09 pm

Duncan,

what do you think, why consumption trials were actually made?
Regards

Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)

User avatar
Dave Saxton
Supporter
Posts: 3087
Joined: Sat Nov 27, 2004 9:02 pm
Location: Rocky Mountains USA

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by Dave Saxton » Sun Jan 31, 2010 10:39 pm

How many tons do the rangefinders assemblies account for? Assuming no munitions were embarked, how many tons do the munitions account for?
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

dunmunro
Senior Member
Posts: 3965
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by dunmunro » Sun Jan 31, 2010 10:43 pm

Herr Nilsson wrote:Duncan,

what do you think, why consumption trials were actually made?
You can run trials and consumption tests at any displacement and then extrapolate the performance and consumption for different displacements, you certainly don't have to run tests at every possible displacement.

dunmunro
Senior Member
Posts: 3965
Joined: Sat Oct 22, 2005 1:25 am
Location: Langley BC Canada

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by dunmunro » Sun Jan 31, 2010 10:50 pm

Dave Saxton wrote:How many tons do the rangefinders assemblies account for? Assuming no munitions were embarked, how many tons do the munitions account for?
Main armament ammo = 1000 tonnes, the directors are quite heavily armoured, so probably 1200 tonnes at least.

User avatar
Herr Nilsson
Senior Member
Posts: 1433
Joined: Thu Oct 21, 2004 11:19 am
Location: Germany

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by Herr Nilsson » Sun Jan 31, 2010 10:59 pm

So what would you do, if the directive says, that the displacement of a ship at the middle of the trial run has to be the same like a ship that is fully equipped with 75% load. Would you run it at let's say 20% load? And if yes, would you report it was made at 75% load?
Regards

Marc

"Thank God we blow up and sink more easily." (unknown officer from HMS Norfolk)

User avatar
Dave Saxton
Supporter
Posts: 3087
Joined: Sat Nov 27, 2004 9:02 pm
Location: Rocky Mountains USA

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by Dave Saxton » Sun Jan 31, 2010 11:40 pm

dunmunro wrote:
Dave Saxton wrote:How many tons do the rangefinders assemblies account for? Assuming no munitions were embarked, how many tons do the munitions account for?
Main armament ammo = 1000 tonnes, the directors are quite heavily armoured, so probably 1200 tonnes at least.
The Germans didn't use large heavy traversable directors in the same sense of American or British practice. The armoured firecontrol station was located just below the range finders and they also housed the directors. All that is missing was the hooded range finder assembly. These weights would not be significant. Furthermore, on Tirpitz during the trails period, these rangefinder assemblies were at times removed and they used very small rangefinders in their places. They still carried out shoots so it's very unlikely that no ammo was embarked. Either way, I can't see a ~6000 ton difference. Besides we have ample evidence for the loadings and we need not be guessing so much.
Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

User avatar
tommy303
Senior Member
Posts: 1528
Joined: Mon Oct 18, 2004 4:19 pm
Location: Arizona
Contact:

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by tommy303 » Mon Feb 01, 2010 2:03 am

During the trials and working up period, the Bismarck embarked practice munitions and some war munitions for the main and secondary guns. I do not know the actual amount, but the ship only received the full supply of war munitions in February or March after the Krupp-made shells received their fillings from Westfaelische-Anhaltische Sprengstoff AG, Werk Reinsdorf. As to the weights of the rangefinder cupolas, they were approximately 50-80 tons each

Their shoulders held the sky suspended;
They stood and Earth's foundations stay;
What God abandoned these defended;
And saved the sum of things for pay.

User avatar
hammy
Senior Member
Posts: 288
Joined: Tue Oct 27, 2009 6:52 pm
Location: by the Norfolk Broads , England .

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by hammy » Mon Feb 01, 2010 5:34 pm

The stores and full crew wont have been aboard for the trials either .
That actually doesn't matter , because you can dump a lot of sandbags aboard to mimic missing weight , or as posted previously , let some water in to bring her to her designed tonnage , but you are missing the main point of the trials which is not so much to establish the maximum speed , as to ensure that this huge complicated machine all works as it was intended , and under a wide variety of conditions , stresses and strains .
Sure , you run her over a measured mile several times , but quite a lot of the figures for her are worked out from the data that gives , you dont have to run an actual test for each figure published , in operational use the approximation is good enough as prior knowledge , you take an exact reading at the time you want it .
Most of the time the trials data would be irrelevant anyway , because most of the time at least one , more probably several major factors affecting speed / horsepower / quantity of oil burned per knot , etc , are going to be varied from the conditions she was in when the trials were done .
In fact , she changes constantly , from hour to hour .
" Relax ! No-one else is going to be fool enough to be sailing about in this fog ."

Bgile
Senior Member
Posts: 3658
Joined: Wed Mar 09, 2005 7:33 pm
Location: Portland, OR, USA

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by Bgile » Mon Feb 01, 2010 6:25 pm

The USN didn't even do measured speed runs with it's fast battleships. It just wasn't all that relevant to actual combat conditions and wasn't considered necessary under war time pressure.

User avatar
RF
Senior Member
Posts: 7593
Joined: Wed Sep 20, 2006 1:15 pm
Location: Wolverhampton, ENGLAND

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by RF » Tue Feb 02, 2010 8:56 am

Bgile, I am puzzled by your last sentance. The USN at the time must have known that the IJN - their potential enemy - had fast battleships. Surely speed trials would be relevant, as it would be better to find out how your battleships perform at speed on trials than in battle and discover that they perhaps are not as good as expected?
''Give me a Ping and one Ping only'' - Sean Connery.

Vic Dale
Senior Member
Posts: 903
Joined: Fri Jul 04, 2008 7:53 pm

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by Vic Dale » Tue Feb 02, 2010 11:44 am

Bgile wrote:The USN didn't even do measured speed runs with it's fast battleships. It just wasn't all that relevant to actual combat conditions and wasn't considered necessary under war time pressure.
In order for the builders to sell their product they would have to demonstrate in some way that it measured up to specification. Speed was one of the commonest specifications in all warship design as it would determine the speed of the fleet for battle, cruising and fuel consumption at given speeds. In the RN such tests and trials are exhaustive and I would not think the USN was any less exacting in it's standards for front line weapons.

Vic Dale

User avatar
foeth
Supporter
Posts: 231
Joined: Mon Oct 18, 2004 8:19 am

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by foeth » Tue Feb 02, 2010 11:58 am

Really? And what are you going to do once you find out it's a knot too slow while the war is going on? Send it back under warranty? Reject the ship? Sell it to a third party?

Or you could accept the results from the shake-down cruise and deploy it. Once you've ironed out all showboat problems, you'll find out how well it performs while underway to the Pacific. Running the measured mile isn't that crucial.

Bgile
Senior Member
Posts: 3658
Joined: Wed Mar 09, 2005 7:33 pm
Location: Portland, OR, USA

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by Bgile » Tue Feb 02, 2010 12:45 pm

They had full power runs of course, and they knew what the pit log showed, but they didn't have any runs two directions over a measured mile under the conditions required for such a standard. It didn't happen.

User avatar
tommy303
Senior Member
Posts: 1528
Joined: Mon Oct 18, 2004 4:19 pm
Location: Arizona
Contact:

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by tommy303 » Tue Feb 02, 2010 5:05 pm

Really? And what are you going to do once you find out it's a knot too slow while the war is going on? Send it back under warranty? Reject the ship? Sell it to a third party?
If I recall correctly concerning a lawsuit filed by the builders of HMS Cossack against the Admiralty, the Admiralty paid a sizable bonus to builders when a new ship exceeded the design specifications, but levied a similar penalty if the ship fell short of specs.

Their shoulders held the sky suspended;
They stood and Earth's foundations stay;
What God abandoned these defended;
And saved the sum of things for pay.

User avatar
foeth
Supporter
Posts: 231
Joined: Mon Oct 18, 2004 8:19 am

Re: Speed - Bismarck versus Scharnhorst/Gneisenau

Post by foeth » Tue Feb 02, 2010 6:37 pm

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.

Post Reply