Calling all WWI German U-boat fans

[chuck]

I�ve been trying to look for some pphotographic references for Das Werk�s 1/72 U-9. The kit is excellent and clearly contains the kit maker�s independent research. But a couple of questions bother me:

1. The kit shows no ballast/trim tank flooding valves/gates under water, nor any seacocks and other water intakes. Without these the submarine would not be able to submerge or trim herself while submerged, Where would these be?

2. The upper walls of the riveted conning tower pressure hull seems to be exposed and not covered by any hydrodynamic fairing as on later u-boats. The exposed pressure hull has three openings on each side. Are these windows? If so, wouldn�t glass scuttles on the pressure hull present serious points of weakness?

[Vepr157]

Those are great questions! A great resource is this article in Schiffbau by Goswin Fl�gge which details the construction of WWI U-boats:

https://babel.hathitrust.org/cgi/pt?id= ... up&seq=833

I would also highly recommend the books Eberhard R�ssler has written on WWI U-boats.

Flood holes/valves

You are right that each main ballast tank must have a flood hole or flood valve (Kingston):

To flood the diving tanks, located at the lowest point...are so-called flooding flaps [Kingstons] with a cross-section of about 20x30 cm which are opened and closed by means of a crank inside the pressure hull (Fl�gge p. 743).

If you decide to modify the kit, here are a few references to guide you:

https://i.imgur.com/Pt3vvlc.jpg Outboard drawing from Eberhard R�ssler's Die Unterseeboote der Kaiserliche Marine

https://i.imgur.com/7X2qYpz.jpg Inboard drawing from the same book, an original German Navy drawing. The divisions between each main ballast tank are shown in the plan view, and probably every one of them had one Kingston per side.

https://i.imgur.com/IoCNdgv.png Notional section of a double-hull U-boat like the U-9 showing the Kingstons (Flutklappe) from the aforementioned article by Fl�gge.

As for the trim tanks, the variable ballast system, as on modern submarines, is internal and there are no flood valves except a small suction and discharge for the trim pump. But I have no references for that. There should also be small suctions and discharges for circulating water systems, but you would need a docking plan or other detailed drawing for that, and probably none of those survive today.

Conning tower

Many WWI German U-boats, particularly early ones like the U-9 class, had conning towers that were not enclosed in any sort of bridge fairwater. They also had sightglasses in the conning tower:

About at eye-level, small oval windows made of 30-mm thick glass are built into the walls of the conning tower, which can be closed with shutters (Fl�gge p. 742).

Conning tower sightglasses were quite common in this era; many American submarines through the S-class had them. Looking at photos of the U-9 class in service and the wreck of the U-12, it seems that the conning tower is modeled quite accurately.

Hope this helps!

Jacob

[wefalck]

The basic source on constructional information would be

TECHEL, H. (1922): Der Bau von U-Booten auf der Germaniawerft.- 103 p., Berlin (Verein deutscher Ingenieure Verlag).

Techel has been one of the main engineers behind U-Boat construction during WW1. The book has been reprinted several times, but I am not sure that there is a digital copy on the WWW.

I have no access to my library at the moment, so I cannot check with respect to the specific questions raised here.

[wefalck]

Has any one here built Micro Mir's 1:144 scale kit of UBI-class U-Boats? Are these kits of acceptable quality?

[chuck]

I have not built the UB1 kit specifically, but have build several other Micromir kits. They are all very simple, with soft surface details, lots of flash, dimensionally somewhat inaccurate, and mediocre fit. Photos of UB1 kit sprues on Amazon show much the same thing.

They offer kits of submarines not otherwise obtainable as injection molded plastic, but their general standard of molding quality is amongst the worst seen of contemporary injection plastic brands.

[wefalck]

In other words: not really worth the money ... Thanks!

[Vepr157]

I had a look in the Techel book about flood holes/valves. There's little information on that subject, and of course because the book is specifically about submarines built at Germaniawerft, the U-9 class is not mentioned at all.

Jacob

[JoeP]

Hello,

I'm interested in building U-117, the WW1 UE II minelayer, as part of my New Jersey naval history collection - she laid mines off Barnegat. She'll join a few WW2 U-boats with connections to the Jersey shore.
I've been looking for plans of her, nothing elaborate as the scale I work in is 1/600 - 1/700. It's intended for a history display in a small, space-limited museum.

Merci d'avance,
Joe C-P

[Tom Dougherty]

I have the drawings of U-117 in Eberhard Rossler�s �The U-Boat� book. A two page spread on minelayers U-117 thru U126 with side, top, internal views and 8 cross sections. It also has a separate page large drawing of frame lines. Can copy from book if you are interested.

[JoeP]

I have the drawings of U-117 in Eberhard Rossler�s �The U-Boat� book. A two page spread on minelayers U-117 thru U126 with side, top, internal views and 8 cross sections. It also has a separate page large drawing of frame lines. Can copy from book if you are interested.

Hi Tom,

I'd just need the externals, since I'm going to be working at 1/700 scale, likely scratchbuilding. I checked the Internet Archive and other sources but don't see that book available, so I would be very grateful for those scans.

Thank you,
Joe

[Tom Dougherty]

Unlike many of us, you don't have a direct email link button on this board.
Your PM to me also did not provide an email address for me to use.

I can�t send scans of the drawings without an address.

[Vepr157]

Joe,

There's an excellent German article on the large U-boat minelayers:

https://babel.hathitrust.org/cgi/pt?id= ... q1=hochsee

R�ssler used the drawings from this article in his book. I am able to download the pdf via my institution, so here are the drawings:

Body plan: https://i.imgur.com/UupdOcI.png

Inboard Profile: https://i.imgur.com/WxeiqpY.jpg

Lines: https://i.imgur.com/pQNs40v.png

Jacob

[sirmaumau]

Thanks a lot! vepr! I have got those two plan from a french book except the third one. But it seems omitted......

[JoeP]

Joe,

There's an excellent German article on the large U-boat minelayers:

https://babel.hathitrust.org/cgi/pt?id= ... q1=hochsee

R�ssler used the drawings from this article in his book. I am able to download the pdf via my institution, so here are the drawings:

Body plan: https://i.imgur.com/UupdOcI.png

Inboard Profile: https://i.imgur.com/WxeiqpY.jpg

Lines: https://i.imgur.com/pQNs40v.png

Jacob

Thank you kind person!

Regards,
Joe C-P

[TK1]

Hi all,

Not sure how active things are here, been a while since the last post.

Anyway, I'm a bit behind the times, but finally tackling Das Werk's U-9. For a display idea I had, I'm interested in more information on the engine that powered these U-boats. The book included in with the kit only gives passing information on it, showing an electric engine at the rear, coupled to an 8-cylinder 2-stroke petrol engine (300HP), then a double electric engine and finally a 6-cylinder 20stroke petrol engine of 225HP.

Does anyone have, or know where I might find, schematics (ideally) or pictures of the engine details and arrangement?

Thanks in advance,
Darren

[Vepr157]

Hi Darren,

I would highly recommend Eberhard R�ssler's The U-boat as a reference for these old and obscure submarines. Here is a profile and plan view of the class:

https://i.imgur.com/wxHAKEO.png

And here is the sidebar reproducing a German document that compares the propulsion systems of early U-boats:

https://i.imgur.com/VxnRjaG.png

https://i.imgur.com/vBEQ0n7.png

Note that the kerosene/paraffin engines are essentially normal gasoline engines (i.e., carbureted and using spark plugs) running on a heavier fuel. There is sometimes a bit of confusion because the fuel in German is called Petroleum which gets mistranslated to petrol (which would be Benzin). The heavier fuel was chosen because it was far less dangerous than gasoline.

Jacob

[TK1]

Thanks Jacob, that's excellent! That gives me a good starting-point to see if I can recreate them.

Darren

[Vepr157]

Hi Darren,

I forgot to include these drawings of the 300-HP K�rting engine. They are from Han Techel's Der Bau von Unterseebooten auf der Germaniawerft.

https://i.imgur.com/t2KEfLW.jpeg
https://i.imgur.com/jLFqGhs.jpeg

Jacob

[JoeP]

In September the Monmouth County (NJ) Historical Association will present an online lecture about U-Boats off the coast of New Jersey during WW1.
I'm a follower of them but not directly associated.

Here's the link:

https://www.monmouthhistory.org/historically-speaking

Regards,
Joe