VIIC/41 - Schematices drawing

[SnakeDoc]

Hello Simon

Nice work.

* Smaller rod is unknown to me, I think set something near the torpedo warhead

I think the small rod is a drive for a mine stop bolt, but I suppose that only from descriptions - I have never seen the drawing or photo
of that part of tube.

* Large pipe (right) at top of torpedo tube is used to let sea water in.

On the top of the torpedo tube is pipe for tube venting. Pipe for flooding is in the bottom part (and I think it's missing here).

* Oil lines to bearing, I believe run to upper deck, as there no evidence that they go back into the Pressure Hull & there no access into the Bow Diving Tank. I am thinking they run up to around Frame 96 (which is near the end of wooden deck) as there a hatch in is area.

http://www.uboatarchive.net/U-570BritishReport.htm
CHAPTER III, Maintenance Arrangements, paragraph 63, 64, 65, page 18 - few sentences that can be helpful for you.

--
Regards
Maciek

[NZSnowman]

Hi Maciek

Thanks for the information 

You could be right about the 'drive for a mine stop bolt' as I remember seeing something similar to this, in this area of the U.S. Navy torpedo tube. I will go back to check this out.

I have no pictures of the underside of torpedo tube, so I consider that is pipe must be the sea water inlet.

One things:
Do you know where the sea water came from? Did they just get it from within the bow casting?

Thanks for the link. I special like number 63 

[SnakeDoc]

Hi Simon

I have no pictures of the underside of torpedo tube, so I consider that is pipe must be the sea water inlet.

According to:
http://www.uboatarchive.net/U-570Plate25.htm
as well as to US Navy tubes:
http://www.maritime.org/fleetsub/tubes/index.htm
and drawings in the "The submarine Alliance" (the Anatomy of the ship series)
the the flooding and draining pipes were at the bottom part of the tube.

On this photo of the U-995 forward tubes

http://img709.imageshack.us/img709/3299/torpedorohr2.jpg
the part marked by number 1 is a flooding/draining valve (marked as i on the
U-570 Plate25) of the tube no II (upper left). There is also marked with thin red
line a link connecting this valve with interlock (number 2), which prevents opening
the drain valve when external torpedo doors are open.

One things:
Do you know where the sea water came from? Did they just get it from within the bow casting?

According to
http://www.uboatarchive.net/U-570Plate25.htm
the tube was flooded with water moved (by means of the pressured air) from Torpedo Compensating Tanks (respectively 1, 2, 3).
In such case the trim of the boat till the firing of the torpedo is not changed.

--
Regards
Maciek

[SnakeDoc]

One more thing...

Fig. 2. Outer Torpedo Tube within Bow Diving Tank.

On your drawing it seems like the tube consists from four parts - one inside and three outside pressure hull bolted together.
In British report mentioned above (chapter III, paragraph 5) is written that tube is bolted from three sections.

--
Regards
Maciek

[NZSnowman]

Hi Maciek

Yes you are right. I have only three sections

3 sections within the Bow Diving Tank.
Plus a very small section (about 200m long) between the Bow Diving Tank bulkhead and the Torpedo outer door

The bit that looks like another section within the pressure hull is the 1st section (Mid Grey) going through the bow cap (Black) and bolting on to a mounting ring. On the mounting ring there two rows of bolts. I believe the 1st outer section is bolted to the mounting ring first then on top of this is added the inter Torpedo tube (Light Grey). I still doing research in the area so is may not be 100% correct

     

[SnakeDoc]

Hi Simon

To be honest, I can not imagine these construction. Could you attach a sketch with lines marking the connection between these parts of tube?

--
Regards
Maciek

[NZSnowman]

No problems, will also post some pictures. Will do it tomorrow, off to bed now

[NZSnowman]

Maciek, did not get time today to do the sketch, busy at work, doing avalanche control work Will get around to it on Tuesday now, sorry.

[NZSnowman]

Balcon Gerät – Update

I have redrawn the Balcon Gerät to what I believe is more correct and accurate to the Balcon Gerät that was on U-995. The new dimension at base foremost on the internal framing of the Type VIIC. I believe the complete structure of the Balcon Gerät is deigned around the two support shafts that attach it to the bow of a Type VIIC. Believing this and knowing the internal framing I have resize and relocated the Balcon Gerät. In addition, the fore support shaft acted to carry all the wiring through the Bow Diving Tank to ‘E’ Deck which holds all the GHG junction boxes (seen in an earlier drawing.



I believe these are the steps that they perform to install the Balcon Gerät.

• Cut two holes in the under side of the bow for the support shafts.
• Disconnect all old GHG wire to the junction boxes, leaving all wiring in the Bow Diving Tank.
• Remove the upper decking, cut a hole into ‘E’ deck so the fore support shaft with wiring inside can be lowed through the Bow Diving Tank.
• Raise the Balcon Gerät into position with rear support shaft already in Balcon Gerät .
• Lowed the fore support shaft through the Bow Diving Tank and into Balcon Gerät.
• Weld support shaft into place.
• Connect all Balcon Gerät wiring to junction boxes and connect wiring to the sensors.
• Replace upper decking.

Fig. 1. New shape of the Balcon Gerät (upper) and older Balcon Gerät (lower). Also from this drawing you can see the support shafts, wiring and no support ribbing (no rivets) I believe they welded the outer shell of the Balcon Gerät directly on to the internal framing of the Balcon Gerät to reduce all under water noises.


Fig. 2. Balcon Gerät with support shafts and Bow Diving Tank.


Fig. 3. Bow section with Balcon Gerät, with fore Outer Torpedo Tube.

[NZSnowman]

It was a dreadful day at the shipyard, the weather continues getting worse. The morning started with only light rain but by late morning the weather was awful, driving rain and strong winds. The dockworkers refuse to work outside today. They were keen to finish the deck of U-1308, the newest VIIC/41 in the fleet, nevertheless they all voted to work inside due to the weather. They decided to work in the aft battery room.

They installed the new 33 MAL 800 batteries and connected them all up, next they install the small maintenance trolley. They were nearly done with the aft battery room, when they heard the end-of-day whistle blow. Before the whistle finished, they had drop there tools and were halfway out the gate on there way home. There is always tomorrow to finish it

Now all the dockworkers were standing before the large iron gates of the shipyard that have been locked for the last few months. They were all keen and yearning to go back to work on U-1308 and finish this last boast of the VIIC’s series however the gates had been firmly locked now for the whole of the winter. One of the dockworker had heard that the foreman had to got a ‘real world job’ during the winter. Other dockworkers were heard asking what was this ‘real world job’ but none of them know that is was. One dockworkers also heard that a few eager guys had climbed the gates a month back and spend an hours working on the boat. As all the dockworkers decided were was no point waiting by the gates a little boy run by the group to the gates and pin up a small note that reads “The shipyard will reopen in spring”. All the dockworkers were happy and delight. This was good news to go home with! 

Again the large iron gates of the shipyard are locked for the winter and the boatyard is closed. The dockworkers look back over there work for the last six months. They finish the engine room for U-1308. They finish the upper deck, ribbing, framing, pressure hull and casting. They add the latest Diesel Exhaust Outlets style, and UZO. They started layering all the piping under the decking, and putting in the torpedo tubes.

Thanks everyone for your help and information with my drawing. I will still found a little bit time to check the boards over the next few months. Wish you all the best for your summer or winter, Simon.

PS. I will post a few more update during next week

[Pepper-mint]

Hi Simon,

That is great job !!!
U-1299 crew is thankfull ! 
Awaiting U-1308 shipyard news...

Take care

[NZSnowman]

Stern Update


Fig. 1. Stern Section without and with hull systems

[NZSnowman]

Propeller Shaft & Stuffing Box - Update


Fig. 1. Stuffing Box.

Hi Pat.
How does this look for a Stuffing Box I could not found any drawing of a U-boat Stuffing Box, so used drawing for large ship Stuffing Box from the 50's. Do you think the lignum vitae wood should be extended

[NZSnowman]

Hi Simon

To be honest, I can not imagine these construction. Could you attach a sketch with lines marking the connection between these parts of tube?

--
Regards
Maciek

Fig. 1. Top Drawing - Side View with bolts holes & Bottom Drawing - Top view cross-section.

Sections

Green = Internal torpedo tube section (bow section)
Red = Section 1 of outer torpedo tube (within Bow Diving Tank).
Purple = Section 2 of outer torpedo tube (within Bow Diving Tank).
Orange = Section 3 of outer torpedo tube (within Bow Diving Tank).
Copper = Small section of outer torpedo tube (within torpedo outer door).
Yellow = A small gasket I believe
Blue = Bow cap Casting

[NZSnowman]

Torpedo Tube Oil Lines - Update

Drawing base on CHAPTER III, Maintenance Arrangements, paragraph