Naval History Forums

How about the H42 design: 280,000 hp + 5 props + 4 rudders?

Not only did GS have bow thrusters, they were retractable Voith-Schneider propellers. They could have used them for low speed propulsion, should there be a problem with the main propulsion. This is such a rare bow thruster to use, something that Israel's didn't even mention in his book, IIRC. These thrusters are pointed downward and can generate thrust 360 degrees around but aren't optimized to go at any high speed, even though some do!

Chief Naval Constructor (Marineoberbaurat) Hadeler, the designer of GZ, says that the Voith-Schneider bow thruster arrangement was similar to that installed on ferries, as shown in this illustration:

Wilhelm Hadeler: Kriegsschiffbau, volume B, 1968, pp. 544-545
8.222 Athwart Drives (Bow-thruster Rudders)


........................
“1. The turning ability, particularly at low speed, can be considerably improved.
2. Athwart acting power can be applied so that the ship, without assistance of the main propulsion, can turn or even move sideways.” ............................................

“In fact the use of an independently acting VSP [Voith-Schneider Propeller] below the forecastle, such as are in the ferry ships “DEUTSCHLAND” and “THEODOR HEUSS” and the aircraft carrier “GRAF ZEPPELIN”, provides for low speed ahead, but such speed can never be called up a priori [from a dead start?].”..............

From: Weyers Taschenbuch der Kriegsflotten 1940.
http://i18.photobucket.com/albums/b138/ ... y/GZad.jpg

Ulrich, do you have anything on multiple shafts? I've looked through our old archives but not much there.

Hadeler has only a detailed description of the USS Lexington turboelectric system. PP 142-144. I can send you that.

There is this diagram of the GZ screw/rudder arrangement in “Seemannschaft” [Seamanship] by Adm. Walter Gladisch and Captain Alfred Schulze-Hinrichs, 1943, in the chapter on steering characteristics and helmsmanship. It gives an overview of how to handle variously configured ships, e.g., 2 screws, 1 rudder; 3 screws, 1 rudder; 3 screws, 2 rudders. They say: “A three-screw ship with one rudder is very handy in open water as well as for maneuvering in tight spaces”. (There is also a description on how to handle the Voith-Schneider system).


I don’t know if this diagram of GZ arrangement is to scale. There is no text on how to drive a 4 screw ship, but there is a chapter on general aircraft carrier seamanship.

I did not realize that the Voith-Schneider thrusters were used as early as 1928; that was in the pusher-tug "Uhu" [owl]. And the Kriegsmarine installed them in various minelayers and sweepers in the 1930s, e.g., M 25, R 17, R 27, R 150 classes. The Voith company history is quite amazing. http://voith.de/media/vz_de_geschichte.pdf
Partial English version: http://www.voithfabrics.com/vf_e_grpdiv_history.htm

Hi!
I wrote last Friday:

But only 19 knots? Was that it? With 200k hp? And all that fuss about lenght against width ratio to achieve more speed and wave resistance?

which was my own misunderstanding: the 19 knots speed was the ideal for fuel consumption being 34 knots the maximum speed that GZ can achieve.

Soooooo......anyone have any info on that mystery ship I mentioned earlier in this thread? I only guessed it was the Franken -- and I myself don't think it was that educated a guess!

Here is the story of the FRANKEN. Her wreck is a few miles from the harbor of Hela (Hel, Poland), not too far from the GRAF ZEPPELIN wreck (50 km N), http://www.german-navy.de/kriegsmarine/ ... index.html

http://www.balticwrecks.com/en/map.html (click on the yellow dot in the center between the two red lines in the Bay of Danzig)

Thanks very much, Ulrich. Actually, the first link on the history of the Franken -- that's where I got the info to make my guess! It's a very impressive site!

I guess I was just looking for some sort of confirmation from someone that my guess was actually correct. In a way, I was hoping that someone would say I was wrong, that perhaps we had stumbled upon some new discovery or something.

Your link to the wrecks of the Baltic made me wish I could take a trip there and explore them! Also makes me wish Google Earth could see underwater!

foeth wrote:Not only did GS have bow thrusters, they were retractable Voith-Schneider propellers. They could have used them for low speed propulsion, should there be a problem with the main propulsion. This is such a rare bow thruster to use, something that Israel's didn't even mention in his book, IIRC. These thrusters are pointed downward and can generate thrust 360 degrees around but aren't optimized to go at any high speed, even though some do!

Isn't it the same kind of propellers F. O. Busch describes to be installed on the little coast guard ships (he called them "Voith-Schneider ships") in Norway in his book about Operation Ostfront?

Someone wrote to me about plans for Graf Zeppelin. Here is one plan of the sprinkler system in the hangar halls. Perhaps the Dreadnaught Project has more sheets.