Author Topic: VIIC/41 - Schematices drawing  (Read 512479 times)

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Offline tore

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Re: VIIC/41 - Schematices drawing
« Reply #1185 on: 15 Feb , 2014, 03:24 »
Hi Simon!
Sign of life from Africa.
The usual high quality of the drawings,but I have a few remarks. If we return to the original U 995 version having the schnorkel installed in March -April 1945 you see the sketch of same below.
Of course you are aware of the lockingpins in upright and lowered position.
Knowing your interest for details I shall point out the schnorkel position indicator placed in the forward controlroom, see photo and don`t be confused by the red drain cock on the voicepipe. The double indicatorpointers are very much like some pointers on boardvalves.

I have still avoided the lions ;D
Tore
« Last Edit: 15 Feb , 2014, 14:16 by tore »

Offline NZSnowman

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Re: VIIC/41 - Schematices drawing
« Reply #1186 on: 15 Feb , 2014, 17:40 »
Update: Corrected the base of the mount.



The rare Twin 3.7 cm Flakzwilling M43U on the DLM 42 U mount. This was one of the best AA weapons used by the German Kriegsmarine during World War II. It was mainly used on the Type IX as it was rather heavy for the Type VII U-boats.

Offline NZSnowman

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Re: VIIC/41 - Schematices drawing
« Reply #1187 on: 16 Feb , 2014, 17:53 »
3.7cm Flak M42U
The 3.7cm Flak M42U was the marine version of the 3.7cm Flak used by the Kriegsmarine on Type VII and Type IX U-boats. The improvement was base on the earlier 3.7cm Flak SK C/30 developed by Rheinmetall. The 3.7cm Flak M42U used several types of mounts and entered service in autumn 1943.

LM 42U Mount
The LM 42U mount was developed specifically for the 3.7cm Flak M42U. It was man by a 3 man crew, with a fourth man, the loader.

LM 43U Mount
The LM 43U mount was the final deign of mount used on U-boats. It further improvement on the LM 42U. The LM 43U was only known to be installed on three U-boats (U-1171, U-1305 and U-1306).

DLM 42U Mount
The twin mount was base on the  design, in which the 3.7cm Flak M42U guns were mounted side by side.


Fig. 1. A Single 3.7cm Flak M42U gun on the LM 43U mount.


Fig. 2. A Twin 3.7cm Flak M42U guns on the LM 42U mount.

Offline SG

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Re: VIIC/41 - Schematices drawing
« Reply #1188 on: 17 Feb , 2014, 07:19 »
GREAT WORK SIMON!!!!

Offline Rokket

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Re: VIIC/41 - Schematices drawing
« Reply #1189 on: 18 Feb , 2014, 00:36 »
as always!
AMP - Accurate Model Parts - http://amp.rokket.biz

Offline SnakeDoc

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Re: VIIC/41 - Schematices drawing
« Reply #1190 on: 20 Feb , 2014, 12:40 »
Hi,


Simon, great drawings, as always and interesting conclusions about two styles of the piston.


Schnorchel mast is raised and lowered by the Schnorchel piston that is controlled by two hand wheels in the control room which activate a hydraulic mechanism. One hand-wheel is turned to "Open" for rising, when the Schnorchel is to be lowered, this wheel must be in the "Closed" position and the other wheel turned to "Open".


I will quote your post from another thread:
 
While doing some more research on the Schnorchel today, I came acoress this:

"Raising and lowering are controlled by hand wheels in the control room which activate a hydraulic mechanism.  One hand-wheel is turned to "Open" for raising; when the schnorchel is to be lowered, this wheel must be on "Closed" and the other wheel turned to "Open""

From the NAVY DEPARTMENT OFFICE OF THE CHIEF OF NAVAL OPERATIONS WASHINGTON Final Report - G/Serial 32 REPORT ON THE INTERROGATION OF SURVIVORS FROM U-575 SUNK 13 MARCH 1944 http://www.uboatarchive.net/U-575INT.htm

I was able to location the two 'Hand wheel' on U-995 ;D





http://www.kubische-panoramen.de/index.php?id_id=5379
 


http://models.rokket.biz/index.php?topic=121.msg10505#msg10505


Actually, now I think, that valves you had identified are hull valves for the hydraulic oil lines. The control valve is the valve here:

It's kind of change-over valve. It is also visible on the drawing provided by Tore (item no. 6, the hull valves - items no. 5).


Of course you are aware of the lockingpins in upright and lowered position.
Knowing your interest for details I shall point out the schnorkel position indicator placed in the forward controlroom, see photo and don`t be confused by the red drain cock on the voicepipe. The double indicatorpointers are very much like some pointers on boardvalves.



Tore, it seems you have great time in Africa :)
Great drawing anyway. The information about indicator pointers is also very interesting.
What is the heating connection (item no 11)?


--
Thanks, regards
Maciek

Offline NZSnowman

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Re: VIIC/41 - Schematices drawing
« Reply #1191 on: 20 Feb , 2014, 13:33 »
Great timing!

I was just starting to look for the hull opening for the hydraulic.

Maciek, have you seen this drawing from http://thebattleofatlanticmuseum.ca/page20/page20.html.

The drawing seen accurate. I had estimated the pressure cylinder as 165 mm and accordingly to the drawing its 150 mm. Look like I am only out by 15 mm
 
Do you think the “St 20 · 2.5” is the diameter of the pipe and thickness?


Offline NZSnowman

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Re: VIIC/41 - Schematices drawing
« Reply #1192 on: 20 Feb , 2014, 13:44 »
I just checked the hull opening for the hydraulic on U-955 and drawing, they are the same, between ribbing number 47 and 48 :)

Offline tore

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Re: VIIC/41 - Schematices drawing
« Reply #1193 on: 20 Feb , 2014, 13:54 »
Hi Maciek.
Just returned from Africa today and a bit off track after some 15 hours flight incl. waiting at airports. However before I returned I made a sketch showing my assumption of the reality matching the sketch. You are of course Right that the shape of the handwheels shown on the photo indicated pressure oil or even luboil. Any how the rising/lowering schnorchel handle is the "ringhandle" as you pointed out, the two boardvalves of the system having luboil handwheels are the supply- and return boardvalves of the system, the returnpipe has a shutoff valve ( lowering speed valve) joining the hydraulic returnpipe from the navigation periscope hoist, whereas the schnorchel supply shutoff ( lifting speed)valve having a wheel of drinkingwater or pressureoil ( hydraulic oil) has of course its own connection to the hydraulic pressure oil system. We find these mixing of handwheels quite often on the U 995. For the schnorchel system I guess this might be because the installation was done in March- April 1945 in Trondheim and the supply of parts were short and they used the closest available handwheels. The indicated heating cable I cannot remember as the U 995 was an artic operating boat it could be for deicing of the ringfloat, we never used such a deicing. My idea would be a wire connection for the radardetector.
Tore

Offline SnakeDoc

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Re: VIIC/41 - Schematices drawing
« Reply #1194 on: 20 Feb , 2014, 14:00 »
Maciek, have you seen this drawing from http://thebattleofatlanticmuseum.ca/page20/page20.html.
No, I haven't. Thanks for notifying.

Do you think the “St 20 · 2.5” is the diameter of the pipe and thickness?

Can be. St can stand for Stahl (Steel). Although I have met designation of diameter only as Leitungsdurchmesser innen and Leitungsdurchmesser außen. But it means nothing in this case. I do not know diameters of the hydraulic oil lines, but they can be estimated from photos.
 
I just checked the hull opening for the hydraulic on U-955 and drawing, they are the same, between ribbing number 47 and 48 :)


:)


--
Regards
Maciek

Offline SnakeDoc

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Re: VIIC/41 - Schematices drawing
« Reply #1195 on: 20 Feb , 2014, 14:03 »


Just returned from Africa today and a bit off track after some 15 hours flight incl. waiting at airports. However before I returned I made a sketch showing my assumption of the reality matching the sketch. You are of course Right that the shape of the handwheels shown on the photo indicated pressure oil or even luboil. Any how the rising/lowering schnorchel handle is the "ringhandle" as you pointed out, the two boardvalves of the system having luboil handwheels are the supply- and return boardvalves of the system, the returnpipe has a shutoff valve ( lowering speed valve) joining the hydraulic returnpipe from the navigation periscope hoist, whereas the schnorchel supply shutoff ( lifting speed)valve having a wheel of drinkingwater or pressureoil ( hydraulic oil) has of course its own connection to the hydraulic pressure oil system. We find these mixing of handwheels quite often on the U 995. For the schnorchel system I guess this might be because the installation was done in March- April 1945 in Trondheim and the supply of parts were short and they used the closest available handwheels. The indicated heating cable I cannot remember as the U 995 was an artic operating boat it could be for deicing of the ringfloat, we never used such a deicing. My idea would be a wire connection for the radardetector.
Tore, thank you for your explanation and the sketch. It confirms my assumptions.
--
Regards
Maciek

Offline NZSnowman

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Re: VIIC/41 - Schematices drawing
« Reply #1196 on: 20 Feb , 2014, 21:57 »
I was able to workout the openings for the hydraulic



Offline tore

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Re: VIIC/41 - Schematices drawing
« Reply #1197 on: 23 Feb , 2014, 01:41 »
Simon
Schnorchelmast.
Looking at your  three positioning drawings of the schnorchel mast I believe you have the hydraulic connectingrod and the mastcrank a bit displaced. There are considerable forces to rise the mast and you want to have the rod and mastcrank at the optimal position for transferring the forces. Hence the connection should be 45 degrees on both side of the fulcrums vertical as I have tried to indicate on the sketch. The details of the German sketch are pretty much accurate.
Tore

Offline tore

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Re: VIIC/41 - Schematices drawing
« Reply #1198 on: 23 Feb , 2014, 04:09 »
Simon.
In order to try to explain a bit more about the mechanical physics behind my last comment, I have copied the drawing which I believe might be your source for the schnorchel crankposition. When you decompose the graphic of the forces on the connectingrod when the mast is almost upright you see that a substantial part of the liftingforce is wasted in sideforces which has to be taken up by side thrust on the pistonrod guides which you don`t want. On the 2x45 crank degrees to the vertical of the fulcrum you have some minor sideforces but substantial more shall be utilised as lifting force. I believe the  German sketch below is incorrect and the other German sketch in my previous post is correct.
Tore
« Last Edit: 23 Feb , 2014, 04:12 by tore »

Offline NZSnowman

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Re: VIIC/41 - Schematices drawing
« Reply #1199 on: 23 Feb , 2014, 12:09 »
Hi Tore

Thanks for the information angle!

I original never used any source for the schnorchel crank position, I do not think it was important.