Shipbucket
http://shipbucket.com/forums/

Germany - H Class Battleship
http://shipbucket.com/forums/viewtopic.php?f=13&t=6038
Page 10 of 11

Author:  Krakatoa [ July 26th, 2016, 10:55 am ]
Post subject:  Re: Germany - H Class Battleship

My thoughts after working with the 3 shaft arrangement is that it would just not work.

The best way the large, presumably armoured, skeg would work is as a separator for a four shaft arrangement. take a torpedo on either side and the skeg would protect the shafts/rudder on the other side. That would also make a better power distribution for the four shafts working the total 220,000 horsepower propulsion system however it is broken up into diesel / turbine amounts.

So something like the SoDaks with an extra skeg through the middle.

Author:  apdsmith [ July 26th, 2016, 11:40 am ]
Post subject:  Re: Germany - H Class Battleship

Hi all,

First, not an engineer, feel free to ignore...

However, that said, I understand that the purpose of the skeg is not to save the shaft that gets hit but rather the neighbours - this kind of makes sense when you look at the armour and torpedo protection systems necessary to defend the sides of battleships. Such a weight and more importantly size of protection wouldn't seem feasible for a prop shaft? The structure of the skeg would absorb the blast from the torpedo, reducing the impact on neighbouring shafts and the rudders associated with them - could it be that the designers were resigned to accepting the loss of a shaft and rudder in the event of a torpedo strike (hence the ability to explosively disconnect rudders) and instead designed the system to protect the rest - if Bismarck had even one rudder operational her sortie might have ended very differently.

Regards making the centre prop larger, I'd guess that whomever the designer was, they were trying to strike a balance between propulsive efficiency and structural concerns - the KM was certainly aware of the structural issues of the three-shaft layout after the failures on the Lutzow and the Prinz Eugen.

Regards,
Adam

Author:  erik_t [ July 26th, 2016, 4:04 pm ]
Post subject:  Re: Germany - H Class Battleship

I am in complete agreement with Garlicdesign, although I am an engineer, but I still might be wrong ;)

Author:  Colombamike [ July 26th, 2016, 7:08 pm ]
Post subject:  Re: Germany - H Class Battleship

@ maomatic & all others contributors of this "H41 stern/skegg/shafts debate"

Because all the H41 drawings/refs were subject to cautious (& were dubious or subject to hotly debates)
Maybe a more austere (& realistic) version...
- Rudders with explosive charges to separate them from the hull in even of a torpedo-hit
- large skegs added to the outboard shafts
[ img ]
:?:

Author:  erik_t [ July 26th, 2016, 8:40 pm ]
Post subject:  Re: Germany - H Class Battleship

I think that's a reasonable interpretation of the intent of the design engineers.

Author:  maomatic [ July 27th, 2016, 6:06 pm ]
Post subject:  Re: Germany - H Class Battleship

Thank you all for the very construcitve discussion and comments!

I agree that the line-drawings are of questionable credibility and that they simply cannot be correct regarding the skeg arrangement.

But sometimes some 1970s vintage line-drawings are all that you can work with. Not all original plans have survived the war or are easily optainable.
In fact the only two drawings in this thread based on official plans are of the 1938 & 1939 projects.

After that is said, I guess some good old common sense and educated guesses will have to do this time.
I quite like Colombamikes suggestion, since it combines the skegs with a more traditional German layout.


A corrected drawing will follow. Since I'm going on vacation, this will have to wait a few weeks, though. The current one has been (subtly...) marked as "WIP" so as to avoid any confusion to people not following this thread closely.
So stay tuned and thanks again for all the helpful input!

Author:  Tempest [ July 27th, 2016, 9:40 pm ]
Post subject:  Re: Germany - H Class Battleship

"subtly" lol, hope you enjoy yourself

All the best

Tempest.

Author:  maomatic [ August 14th, 2016, 1:39 pm ]
Post subject:  Re: Germany - H Class Battleship

Alright, so here's my next try concerning the "skeg issue" of H41.

What do you think of this version?

[ img ]

Author:  Krakatoa [ August 14th, 2016, 2:19 pm ]
Post subject:  Re: Germany - H Class Battleship

If you are keeping with the three screw layout, then what you have drawn is as good as it is probably going to get without even more guesswork.

Author:  emperor_andreas [ August 14th, 2016, 2:44 pm ]
Post subject:  Re: Germany - H Class Battleship

Very nice work!

Page 10 of 11 All times are UTC
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/