Type IIa

[Piet]

Did any of the type 2 a Uboots from the 21. Flottille  ( U-2, U-3, U-4, U-5, and U-6) , before they were Decommissioned and sunk  a conning tower and armament updates?

Thanks
Piet.

[Anakin]

Hi.

From what i've been reading, the front deck anti aircraft gun was a single 20mm and was later upgraded to twin 20mm. No major changes to the CT.

Regards,
Anakin

[Piet]

Thanks for your reply.......sounds good a twin 20mm

Regards,
Maarten.

[dougie47]

Hello gents,

I haven't seen a twin 20mm on the front deck of Type IIs yet. I suppose this could have occurred but have yet to see evidence of it. If anybody has a photo then please let me know as it would be good to see one.

In regard to the conning tower, in 1943 the Black Sea Type IIBs (U 9, U 18, U 19, U 20, U 23 and U 24) had a 20mm added to a rebuilt rear tower area. This was necessary as they were involved in combat operations. A few such as U 9 had the single 20mm on the tower replaced with a twin 20mm. Some of the Black Sea boats also got a 7.92mm single MG34 machine gun or similar type on either side of the tower bulwark.

I think that the 20mm (or twin 20mm) on the tower was exclusive to the operational Black Sea boats. As far as I can see, all the training boats back in Germany did not get the 20mm on the tower.

Cheers,

Dougie 

[Anakin]

Hi Dougie and Maarten.

I can't remember any pics about twin 20cm on type IIa boats but i've read it somewhere...

And you are right about that the later versions had more changes to the original lay-out. Larger winter gartens etc. Type IIc U-58 had fitted a schnorchel system... There could be lots of interesting experimental lay-outs but very few of them was photographed...

Anakin

[Piet]

I appreciate the feedback guys !

Are there any Photo's of the typ II 2 from 1943/44? i only see pre 43 pics ,
I have a realy good collection of Uboot books but only two on the type 2 ( Rössler  and Kagero ) are there any other books (would love to know )

And what about the observation periscoop..... was it installed on the A version ?
The reason i ask is ......the where training boats so should there not be an  observation periscope ?
Or was the UZO unit detachable and mounted on the observation tube  ? I doubt it because it was a precies piece of machinery.

The collor drawings is from the Karego book shows no observation periscope.... and the side B&W view is from the Rössler  book and shows a observation periscope .

Thanks
Maarten.
 

[falo]

Hi Piet,


I don't know if you visited this thread here on AMP?


http://models.rokket.biz/index.php?topic=192.15


Regards
falo

[Piet]

Hi Piet,


I don't know if you visited this thread here on AMP?


http://models.rokket.biz/index.php?topic=192.15


Regards
falo

Hi falo,

   Believe it or not ............this topic was the reason i sign up .

Regards,
Maarten.

[dougie47]

Hello gents,

There is a distinct lack of photos from 43/44 of training IIs. Would be nice if a book had photos but I don't know of one.

There are quite a few photos showing that IIAs had an smaller attack periscope at the front and also a larger sky (observation) at the rear. But what I cannot see on a IIA is an UZO, which we would expect. I suppose it is possible that at a later stage (mid-war) the larger sky periscope column was replaced with an UZO column.

I see the UZO on IIDs but not on the earlier sub-variants.

Cheers,

Dougie

[Anakin]

Hello.

I found an interesting site containing tons of information about torpedo aiming and firing techniques...

http://www.tvre.org/en/development-of-torpedo-fire-control-systems-for-the-kriegsmarine

Here is something i copy pasted from there:

In mid-1935 the first U-Boats of the restored U-Bootwaffe were commissioned. These were type IIA U-Boats – small submarines with a displacement of 250 tons, armed with three bow torpedo tubes. Soon after – in 1936 – two type IA U-Boats with four bow and two stern torpedo tubes were commissioned. In the initial period of their service, the torpedoes were not able to turn after leaving the tube. To calculate deflection angle the tables and the torpedo calculating disc were used. Aiming was done by periscope (during a submerged attack) or sight column TUZA 1 (Germ. Torpedo-U-Boot-Zielapparat) – while attacking on the surface. The sight column TUZA 1 transmitted the target bearing to the control room by means of the Bowden cable. An attack with this set of instruments was conducted as follows: first, the target course parameters were determined (on the basis of a plot or by estimating). In the control room, the torpedo officer read the target bearing from the mechanical receiver (in the case of the sight column) or directly from the periscope scale and on the basis of this information and knowing own and target course he calculated the angle on the bow. Then, by means of tables or using the torpedo calculating disc, the deflection angle was determined and transmitted verbally to the bridge – to the officer who operated the sight column or to the commander at the periscope. After setting the deflection angle on the sight column or periscope, the U-Boat was turned to get the target in the crosshairs of the sight or the periscope. Then the launch order was passed to the bow torpedo room where the torpedo mate manually triggered the torpedoes. A salvo of torpedoes was launched by firing torpedoes while the U-Boat was turning. The obvious disadvantage of such a system was the long delay between passing the target bearing to the control room and receiving the deflection angle – especially when using the sight column on the bridge. Therefore the Zeiss Company was ordered to develop an improved sight column, which – apart from transmitting target bearing to the control room – could determine the deflection angle. The completed instrument was called TUZA 2 and was similar to the BNZA torpedo director used on surface vessels. The sight included the torpedo triangle, which – apart from calculating deflection angle – allowed it to calculate the maximum distance to the target while incorporating the correction for angular speed of turn. The main disadvantage of this sight (as in the case of TUZA 1) was the necessity to demount the instrument before submerging the U-Boat. Therefore Zeiss developed a new version – TUZA 3 – which was pressure-proof up to a depth of 100 meters.

And more:

In 1939 a calculator designated T. Vh. Re. S2 manufactured by Siemens entered service. Moreover, instead of the sighting column TUZA 3 a new sighting column designated UZO (U-Boot-Ziel-Optik) 1 developed by Zeiss was installed. These columns were not embedded with the torpedo triangle, but featured electrical transmission of the target bearing to the torpedo calculator by means of a synchro link. Zeiss binoculars of the type UDF 7x50 were used as the sighting device. When TUZA columns were exchanged for the UZO 1 columns on the type IX U-Boats, it was found that the UZO 1 column was not tall enough to see over the bridge casing. So in the case of these U-Boats, the column was installed with an additional base and this version was designated UZO 2. Becausthis e the sighting binoculars of the UZO 1 and UZO 2 columns were not water-resistant and pressure-proof, they had to be dismounted before every dive. The mountings for the UZO binoculars were constructed such that when needed (in the case of a torpedo calculator malfunction) the TUZA 3 sight with torpedo triangle could be installed.

So this is the reason why the UZO is not seen on any pics of type IIa boats. Also the torpedo aiming "computer" or calculator was available after 1941. Fitting the UZO and the calculator to the bridge and tower of early II boats could be impossible job. Late type IID might be possible to add the equipments while being constructed in the yard. How does this sound?

Regards,
Anakin

[Piet]

Hello.

I found an interesting site containing tons of information about torpedo aiming and firing techniques...

http://www.tvre.org/en/development-of-torpedo-fire-control-systems-for-the-kriegsmarine

Here is something i copy pasted from there:

In mid-1935 the first U-Boats of the restored U-Bootwaffe were commissioned. These were type IIA U-Boats – small submarines with a displacement of 250 tons, armed with three bow torpedo tubes. Soon after – in 1936 – two type IA U-Boats with four bow and two stern torpedo tubes were commissioned. In the initial period of their service, the torpedoes were not able to turn after leaving the tube. To calculate deflection angle the tables and the torpedo calculating disc were used. Aiming was done by periscope (during a submerged attack) or sight column TUZA 1 (Germ. Torpedo-U-Boot-Zielapparat) – while attacking on the surface. The sight column TUZA 1 transmitted the target bearing to the control room by means of the Bowden cable. An attack with this set of instruments was conducted as follows: first, the target course parameters were determined (on the basis of a plot or by estimating). In the control room, the torpedo officer read the target bearing from the mechanical receiver (in the case of the sight column) or directly from the periscope scale and on the basis of this information and knowing own and target course he calculated the angle on the bow. Then, by means of tables or using the torpedo calculating disc, the deflection angle was determined and transmitted verbally to the bridge – to the officer who operated the sight column or to the commander at the periscope. After setting the deflection angle on the sight column or periscope, the U-Boat was turned to get the target in the crosshairs of the sight or the periscope. Then the launch order was passed to the bow torpedo room where the torpedo mate manually triggered the torpedoes. A salvo of torpedoes was launched by firing torpedoes while the U-Boat was turning. The obvious disadvantage of such a system was the long delay between passing the target bearing to the control room and receiving the deflection angle – especially when using the sight column on the bridge. Therefore the Zeiss Company was ordered to develop an improved sight column, which – apart from transmitting target bearing to the control room – could determine the deflection angle. The completed instrument was called TUZA 2 and was similar to the BNZA torpedo director used on surface vessels. The sight included the torpedo triangle, which – apart from calculating deflection angle – allowed it to calculate the maximum distance to the target while incorporating the correction for angular speed of turn. The main disadvantage of this sight (as in the case of TUZA 1) was the necessity to demount the instrument before submerging the U-Boat. Therefore Zeiss developed a new version – TUZA 3 – which was pressure-proof up to a depth of 100 meters.

And more:

In 1939 a calculator designated T. Vh. Re. S2 manufactured by Siemens entered service. Moreover, instead of the sighting column TUZA 3 a new sighting column designated UZO (U-Boot-Ziel-Optik) 1 developed by Zeiss was installed. These columns were not embedded with the torpedo triangle, but featured electrical transmission of the target bearing to the torpedo calculator by means of a synchro link. Zeiss binoculars of the type UDF 7x50 were used as the sighting device. When TUZA columns were exchanged for the UZO 1 columns on the type IX U-Boats, it was found that the UZO 1 column was not tall enough to see over the bridge casing. So in the case of these U-Boats, the column was installed with an additional base and this version was designated UZO 2. Becausthis e the sighting binoculars of the UZO 1 and UZO 2 columns were not water-resistant and pressure-proof, they had to be dismounted before every dive. The mountings for the UZO binoculars were constructed such that when needed (in the case of a torpedo calculator malfunction) the TUZA 3 sight with torpedo triangle could be installed.

So this is the reason why the UZO is not seen on any pics of type IIa boats. Also the torpedo aiming "computer" or calculator was available after 1941. Fitting the UZO and the calculator to the bridge and tower of early II boats could be impossible job. Late type IID might be possible to add the equipments while being constructed in the yard. How does this sound?

Regards,
Anakin

[dougie47]

Hi gents,

That's great info, Anakin, thanks for posting it. The part which is of particular interest says "The main disadvantage of this sight (as in the case of TUZA 1) was the necessity to demount the instrument before submerging the U-Boat." So I guess there was some equipment which was taken through the conning tower hatch when in use.

The part about the column not being tall enough on the early IXs makes sense because it does look a bit too short on U 39 and U 40.

Cheers,

Dougie

[Anakin]

Hello.

I've been thinking and reading now few short times... The type 2a boats had the 20mm AA gun at the front of the ct and might ( only might ) been upgrated to twin 20mm.

There has been always both periscopes in type 2a boats. Only later c/d prototype schnorchel replacements...

Type 2d boats , at least later ones had or possibly had uzo aiming  and calculating systems. Earlier had only periscope aiming and removeable type bridge used TUZA aiming system without calculator.

The tuza had to remove before diving beacause of not to be waterproof.

And now my wife start to nag so i think i'll get back tomorrow! 

Anakin

[Piet]

And now my wife start to nag so i think i'll get back tomorrow! 

Anakin

I hear ya .