Diameter of the extendable boom in the nose of Bismarck

BB_57 · Post by **BB_57** » Sun Jun 19, 2005 8:16 pm

I'm building a 1:100 scale ship of the Bismarck and I have completed the bow but I'm looking for the diameter of the paravane? Would anyone know? Thanks, Bob.

BB_57 · Post by **BB_57** » Sun Jun 19, 2005 8:24 pm

Sorry, I met the diameter of the extendable boom.

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Sun Jun 19, 2005 9:31 pm

I am sorry, I am a little confused. I don't think I have ever seen this device on any 1:50 or 1:100 model of the Bismarck or on any bow picture or on any 1:100 plan. Could you refresh my memory? If there is a photo of it with some reference points you could probably extrapolate the diameter of the thing. Did the Tirpitz have that too?

BB_57 · Post by **BB_57** » Mon Jun 20, 2005 4:14 am

I have a good photo of Battleship G (Tirpitz) being launched and I can barely make it out in the photo. If I were to take a guess at the size maybe 5/16" Imperial at 1:100 scale by looking at the photo.

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Mon Jun 20, 2005 12:08 pm

If it is 5/16 at 1:100 it would be enormous on the real ship. 1.3 cm x 100=1.3 m, if I am doing this right. [4.3 ft].

BB_57 · Post by **BB_57** » Tue Jun 21, 2005 4:46 am

My friend is guessing at 1/4". I'm thinking maybe he is right. That would put it at 2.08'. 5/16 should be 2.6'.

BB_57 · Post by **BB_57** » Tue Jun 21, 2005 4:51 am

Imperial calculation would be 5/16x100/12=2.6' The only way I can estimate this is to examin the picture and then compare a 1/4" or 3/16" rod to the front of my model.

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Tue Jun 21, 2005 1:27 pm

I still have a problem how a large ship like the Bismarck would have been able to deploy minesweeping gear or attach a temporary bowsprit. There is no indication the ship ever had training in minesweeping.

That 2.6 ft. spot you are talking about is huge; it is larger than the giant "J" type torpedo (2.3') diameter!

Could it be some kind of mooring hook-up? Do you know when this photo was taken? Could you post a scan?

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Tue Jun 21, 2005 2:28 pm

Oh, I see. I looked at the above posts. It was seen at the launching of the Tirpitz, right? Well that could be some provision for a temporary cable hook-up device and have nothing to do with a paravane deployment boom extension or "bowsprit". I still can't picture how a ship the size of the Bismarck could be rapidly converted into a minesweeper. Crazy!

BB_57 · Post by **BB_57** » Tue Jun 21, 2005 9:43 pm

Yes It would be crazy to think it could be used for mine sweeping duties. I still wonder as the Bismarck I think had something like this. I know I have something in all those plans I have on Tirpitz and Bismarck about this. I'm going to have to research this more. I'm certain I've seen this in my B&V plans somewhere.

Ulrich Rudofsky · Post by **Ulrich Rudofsky** » Tue Jun 21, 2005 11:21 pm

http://pigtrail.uark.edu/people/rcordel ... avane.html

http://pigtrail.uark.edu/people/rcordel ... SweepGear/

Do you have a copy of Elfrath and Herzog's The Battleship Bismarck handy? On page 64 are the puported minesweeping paravanes or otters; the authors are not even sure what they really are. They look to me more like some kind of acoustic drone. pp 88-89 there are maxishots of the bow, no spot. There is a small black round dot on the plate on page 89, and also on the bow on page 91 (is that where your mark is?)

BB_57 · Post by **BB_57** » Tue Jun 21, 2005 11:58 pm

I'll look at that too. This is an interesting idea if it were something to do with accoustics.

tommy303 · Post by **tommy303** » Wed Jun 22, 2005 12:13 am

The bowspirite referred to is actually an extendable boom which is underwater (Ausfahreinrichtung für Stenge Bugschutzgerät), and it appears in drawings of Bismarck in von Müllenheim-Rechbergs book. It is also in plans of Scharnhorst and Hipper Classes. It is a boom which can be extended from a tube or channel in the bow and angles down at about 45 degrees. How it was rigged with cables and such for towing paravanes is something of a mystery to me, although it looks as though the cables might have been extended with the mast or boom.

trf

_Derfflinger_ · Post by **_Derfflinger_** » Wed Jun 22, 2005 2:32 am

FYI, I just took a very quick spin through Jose Rico's Bismarck e-book looking for photos of Bismarck's full bow while out of the water. At the launch, when she had her original bow configuration, I can see no evidence of the boom at the base of her stem. However, there is a later photo of Bismarck, bow on, while in drydock, after she had the "Atlantic" bow modification. There, at the very base of her stem, is a light round disk, I'd "guesstimate" it is roughly 18" in diameter. Could this be the point of the boom housed in her bow that was intended to trail the "Otters" after it was extended?

Perhaps this was a feature added with the bow modification? Just a thought.

VdT

_Derfflinger_ · Post by **_Derfflinger_** » Wed Jun 22, 2005 2:47 am

As noted by Ulrich in a prior posting, Page 91 of the Elfrath-Herzog book "The Battleship Bismarck" clearly shows the full bow of Bismarck while in drydock. The boom tip, if that is what it is, is clearly seen in this photo.

From the look of this photo, it is perhaps a bit bigger in diameter than what I suggested in the posting above.

VdT

Naval History Forums

Diameter of the extendable boom in the nose of Bismarck

Diameter of the extendable boom in the nose of Bismarck

Extendable boom and not paravane.

Diameter

3/16" Maybe

Calculation.

Bowsprit?

Research.