type IX's with a cut back fore deck?

[Freiwillige]

Got me a coppy of Squadron signals U-Boats in action recently. They talk breifly about cutting the forward deck or removing it all together to increase diving time. It seems that the standard deck was so wide that it trapped air and kept the nose up longer than with the cut back decks.

Anybody have any pictures or more info?

[Mittelwaechter]

There were two types of modification (A+B)

Those U-Boote were modified (U-Boot;Type, Date and Location of modification):

> U 170 Typ A Werftliegezeit 18.12.1944 – 01.03.1945
> bei Deschimag Seebeck
> U 190 Typ B Werftliegezeit 15.10.1944 – ??.01.1945
> bei Deschimag Bremen
> U 516 Typ A Werftliegezeit ??.10.1944 – ??.01.1945
> bei Howaldt Hamburg
> U 518 Umbau während Werftliegezeit bei Oderwerke
> (not sure)
> U 530 Typ A Werftliegezeit ??.10.1944 – ??.01.1945
> bei ???
> U 539 Typ B Werftliegezeit ??.10.1944 – 25.01.1945
> bei Schichau Königsberg
> U 548 Umbau während Werftliegezeit in Kiel möglich
> (not sure)
> U 804 Typ A Werftliegezeit ??.10.1944 – ??.??.1945
> in Kiel
> U 805 Typ A Werftliegezeit 01.10.1944 – 22.01.1945
> bei Deschimag Seebeck
> U 853 Umbau während Werftliegezeit bei Schichau
> Könisberg (not sure)
> U 857 Umbau während Werftliegezeit bei Howaldt
> Hamburg (not sure)
> U 858 Typ A Werftliegezeit 24.10.1944 – ??.02.1945
> bei Howaldt Hamburg
> U 866 Typ A Werftliegezeit 09.01.1944 – 18.03.1944
> bei Holmwerft Danzig
> U 867 Typ A Restarbeiten 06.06.1944 – 10.08.1944
> bei Oderwerke Stettin
> U 868 Typ A Restarbeiten 15.09.1944 – 04.12.1944
> bei Oderwerke Stettin
> U 869 Typ A Restarbeiten 29.06.1944 – 23.09.1944
> bei Oderwerke Stettin
> U 878 Typ ? Restarbeiten 14.08.1944 – 20.12.1944
> bei Deutsche Werke Kiel
> U 879 Typ ? Restarbeiten 23.08.1944 – 14.01.1945
> bei Deutsche Werke Kiel
> U 880 Typ ? Restarbeiten 22.08.1944 – 15.11.1944
> bei Oderwerke Stettin
> U 881 Umbau während Restarbeiten bei Oderwerke
> Stettin (not sure)
> U 1226 Typ A Restarbeiten 24.06.1944 – 22.08.1944
> bei Howaldt Hamburg
> U 1232 Typ A Restarbeiten 09.07.1944 – 09.09.1944
> bei Howaldt Hamburg
> U 1233 Typ ? Restarbeiten 27.07.1944 – 26.09.1944
> bei Howaldt Hamburg
> U 1234 Umbau während Reperaturliegezeit bei
> Oderwerke Stettin (not sure)
> U 1235 Typ ? Restarbeiten 09.09.1944 – 26.10.1944
> bei Howaldt Hamburg

[UberTorpedo]

Here's some others

[Weiss Pinguin]

Wow... I'm guessing the crew probably didn't do that themselves?

[Mittelwaechter]

Nice pictures, UberTorpedo!

It was called "Schnelltauchback" - Fast Diving Back.

[UberTorpedo]

Hey look,

I found a few others...



and in the lower right-hand corner...

[kurfürst]

Interesting thread!
Here are some more photos:




and a drawing with the top view on the deck and a sideview of the hull with the "Schnelltauchback":


Would be great if this feature could be modded into the hull of a IX C!
Perhaps somebody can do it?

Cheers, Kurfürst

[UberTorpedo]

kurfürst

Where did you get that blueprint diagram ? Most excellent!

cheers

[kurfürst]

Danke, UberTorpedo!

It´s taken from the book "Vom Original zum Modell: U-Boottyp IX" (From the original to the model: U-boattype IX).
Highly reccomendable book with lots of drawings and photos!

Cheers, Kurfürst

[Freiwillige]

Thank you both Uber torpedo and Kurfurst. I really enjoy learning such things. It was not untill I got said book that I learned of the type I Unterseeboot exsistance.

Kurfurst from IL2? If so good to see you here too.

[Jimbuna]

Some cracking photos guys

[Murr44]

U-190, an IXC/40, had this modification done at the Deschimag yard at Bremen sometime between October 1944 and January 1945.

Source: Another Place, Another Time: A U-boat Officer's Wartime Album
Werner Hirschmann with Donald E. Graves
Robin Brass Studio/Chatham Publishing 2004
pg. 217

There are several photos in this book showing the modification to good effect. This is a really worthwhile title. Lots of previously unreleased photos and an appendix entitled "The Type IXC/40 U-boats: U-190 and U-889: A Pictorial Tour". Everything that you ever wanted to know (and then some) about this type.

[UberTorpedo]

Maybe someone that has one of the above mentioned books could answer this question for me...

I thought I remembered reading somewhere that the Allies didn't know that this U-boat variation even existed
until the first sub surfaced and surrendered at the end of WWII?

[kenijaru]

Originally Posted by Freiwillige

....to increase diving time....

it would actually to decrease diving time (or increase diving speed)
but... interesting subject... i had seen one picture but had NO idea what it was made for. I does look like it might slow down submerged speed a 'lil bit.

[Freiwillige]

Originally Posted by kenijaru

it would actually to decrease diving time (or increase diving speed)
but... interesting subject... i had seen one picture but had NO idea what it was made for. I does look like it might slow down submerged speed a 'lil bit.

Yes that is what I meant, faster dive time of course.