Type XXI U-Boat turrets

[blohmundvoss]

Hi. I’m looking for images, plans, data on the turrets fitted to Type XXI U Boats. They were to carry a Rheinmetall-Borsig 3cm Doppelflak twin barrelled Flak gun code named BRUNN. In reality the gun was either not successful or not available in sufficient numbers so the turrets ended up with 2cm Flak guns. In the second photo you can se the hatch is open . I believe this is how they were used in action, the gunner looking out the top.

 

[TJDougherty01]

Like these?

 

[TJDougherty01]

And some photos of the Type XXI U-Boat. Not the best exposures, but it was wartime.

Notice the "Balkon" sonar turret under the bow. A set of hydrophones arranged in a semicircle to allow target bearings for torpedo attacks to be determined underwater. The telescoping snorkel was innovative but had serious problems. The two MAN 6 cylinder , 2000 HP diesels were underpowered and recharging the batteries was a lengthy process.

The submarine was built in 9 sections at different manufacturing sites, moved on barges through inland waterways and sections joined in the shipyard. An optical alignment system was used to match each section's longitudinal axis prior to welding

 

[Arjen]

Fritz Köhl and Eberhard Rössler wrote a book about the Type XXI:
In German - Vom Original zum Modell: Uboottyp XXI. Eine Bild - und Plandokumentation , Bernard & Graefe 1988
https://www.antiquariat.de/?i=BF15153432

English translation - The Type XXI U-Boat (Anatomy of the the Ship), Conway 1991, ISBN 0-85177-570-5

I have a copy of the English translation.

 

[Dilandu]

The submarine was built in 9 sections at different manufacturing sites, moved on barges through inland waterways and sections joined in the shipyard. An optical alignment system was used to match each section's longitudinal axis prior to welding

One important note - the quality of section welding was quite often abysmal (due to lack of skilled labor, constant bombing and logistic collapse), so the majority of type XXI U-boat, evaluated by Allies, were considered unsuitable for military duty (the section wields would not hold the designed pressure, and any close depth charge explosion would likely cause Type XXI to fell apart at seams)

 

[TJDougherty01]

Fritz Köhl and Eberhard Rössler wrote a book about the Type XXI:
In German - Vom Original zum Modell: Uboottyp XXI. Eine Bild - und Plandokumentation , Bernard & Graefe 1988
https://www.antiquariat.de/?i=BF15153432

English translation - The Type XXI U-Boat (Anatomy of the the Ship), Conway 1991, ISBN 0-85177-570-5

I have a copy of the English translation.

One of my Type XXI sources, along with these Type XXI books. The sources for the above post, along with other digital files.

Also photos of my submarine library, which along with large scale drawings stored in rolls and about 12 Gb of digital files, are the source of the article I write for American Submariner magazine, the SubCommittee Report, and details for some of the Iron Shipwrights submarine models.