Tores mailbox VIIC and VIIC/41 operation and technical details

[maillemaker]

Hi Tore,

Thanks for the non-canning photo.

Sadly I have already followed many other modelers on my hull and completed this effect.  However I was already aware of your comments on it so I tried to go lightly.

You can see my build progress here:

http://www.shipmodels.info/mws_forum/viewtopic.php?f=28&t=163319

Steve

[tore]

Karel.
The black valvewheel close to the navigation periscope belongs to the shut off valve of the schnorchel exhaustmast system.
When the schnorchelmast was installed they used the ballasttank exhaustblowing pipe as the schnorchel outletpipe. branching off directly before the exhaust blowing panel outside the pressurehull. The branch pipe goes up above the casingdeck following the towercasing and ends in the schnorchelmast shut off valve having a valvspindle down in the controlroom connecting to a black valvewheel as shown on your image. Again I have to use one of Simon Moriss excellent drawings to illustrate the system. The other smaller black wheel next to the periscope is the locking pin wheel for the schnorchel mast homing on the tower casing.
This pipe on the deck is often forgotten by the modelbuilders as it is not incorporated in the Revell kit
Tore.

[maillemaker]

I think I have downloaded this "working drawing V05.pdf"  - can't remember the guy's username.

Ah, yes, it is Simon Morris' drawing.

But I only see a top view.

Is there a way to get a side view?

Steve

[VIC20]

Simons username is usually NZsnowman (his profession is snow & avalanches)

[tore]

Steve.
I believe the lower part of Simons image shows the side view, including the exhaust blowing panel valvewheels and the schnorchel shut off valve wheel in the controlroom.
Tore

[maillemaker]

Steve.
I believe the lower part of Simons image shows the side view, including the exhaust blowing panel valvewheels and the schnorchel shut off valve wheel in the controlroom.
Tore

Hi Tore,

Yes, I see that.  I am talking about his entire drawing of the uboat.  I have downloaded a PDF (version 5) of his drawings, but when you open it all I see is a top view.

From your picture, I gather there is also a side view.  I'm wondering how to access that - is it in the same PDF file or is it a different one?

Thanks,

Steve

[maillemaker]

Hi Tore,

I have been looking at this picture and I have just realized from your version of it that what I thought was the snorkle head is actually the hydraulic cylinder; the snorkle is actually either raised or missing in this picture:



I have drawn a dotted outline where the snorkle would lie when lowered.

My question is:  The lateral braces that I have drawn arrows to - I assumed that these were the deck support struts/braces.

But there is no cutout for the snorkle!

So instead, are these braces below deck, running from the top of the port saddle tank to the top of the starboard saddle tank?

Are these braces what the snorkle lies on when lowered?

It is hard to see the perspective here. 

If I am seeing correctly, the casing is missing above the saddle tanks.  It appears to be cut off just behind the life raft cannisters.

So I think the braces we see from the life raft canisters forward are for the wooden deck, but the braces we see aft of there are below-deck.

But maybe this is just an illusion and I can't see the casing over the saddle tanks because it is being viewed edge-on.

But if the braces are for the deck, how does the snorkle get through them to lie down?

The more I look at it (follow the starboard side of the deck line) it looks like the casing over the tanks is in fact there.

So if all those horizontal braces are at deck-height, how does the snorkle lie down?

Thanks,

Steve

[tore]

Steve.
I should not go into details of the image you are referring to as it shows the U 995 in Kiel during the first stage of the rebuild and to me it looks as if the girders and deck beams are of wood. The Germans ripped of the old original Schnorchel arrangement and installed a different type of schnorchel making a mock up of a raising cylinder etc. Below is a cross section view located at frame 55 about the area above COs cabin. I guess it gives a good impression of the casing sidesupports as well as the flood slit and knee plates between the casing side and saddle tank.
Tore

[tore]

Steve.
Simons drawings isa massive job which I guess would still take years to finish. I don`t think he has a complete sideview of a VIIC as yet. Below is an image, not complete, which I got so far.
Tore

[maillemaker]

Thanks, Tore, great stuff.  Thanks for the clarification on the snorkel. 

I have done mechanical design work for 20+ years, using 3D CAD software.  In fact I currently work for Solid Edge, a leading maker of CAD software.

Simon's drawings are fantastic, but it breaks my heart to see that much effort put into a 2D drawing when an actual 3D model could have been made instead. 

Imagine the potential!  Accurate computer game/simulation models.  The ability to 3D print actual scale components of a uboat for model making at any scale you desired.  The ability to make cross-sectional views at any desired point.

Perhaps some day another Simon will come along and do it in 3D. 

Steve

[VIC20]

Simon already works on the 3D model.

[maillemaker]

I'm glad Simon is working on a 3D version!

Tore:

I have updated my build progress here:
http://imgur.com/a/Z6K9m

I have laid in saddle tank extensions (which will be trimmed back greatly) and crafted a false pressure hull roof.  I did not go to the trouble to model the sharp ramp transition from the saddle tank down to the pressure hull.  I did not feel it worth the effort for the little view through the snorkel slot.

At the front of the Revell snorkel "box" there is another solid area where the head of the snorkel would rest.  I have also removed all of that so the entire opening gives a straight shot down to the saddle tanks/pressure hull.

Does this look acceptable?





Thanks,
Steve

[tore]

Steve.
I guess your schnorchel recess is OK. There are of course limits how far you want to go as to the details using a commercial kit, the Revell kit is  not accurate in the details. For instance the anchorbay is, if not corrected on the newer kits, too far aft, the consequence would be the anchor is hitting the fore stb. hydroplane when lowered. I am afraid it is too late for a correction on your model. However the flood gates as we consider are the fingerprints of a VIIC can be corrected. The most significant would probably be the fore flood gates of the peaktank which on the real VIIC are asymetric as there are two on the stb. side and three on the port, not three on each side as on the kit. As for the ejector drains may be you should drill the holes in the aft end. Otherwise there are small deviations to various details depending on at which yard and year the Uboat was built.
Tore

[maillemaker]

Hi Tore,

Thanks for the comments!

Yes, there are many details that I have seen people do, like moving the anchor bay forward as you note.  Fairly significant surgery that requires re-adding rivets, etc.

I may plug the flood as you indicate on the starboard side, as that is pretty easy to do.

My intent with this kit is to build it fairly out-of-the-box (hah, famous last words).  I do not want to go too crazy with modifications and/or upgrades.  I burned out of model making 20 years ago when I kept raising the bar higher and higher to where I could never undertake anything because it was too overwhelming.

I'm probably going to display this as a "generic" VIIC/41 rather than label it as a specific uboat.  This gives me some "out" for inaccuracies. 

What do the ejectors eject?

Steve

[tore]

Steve.
I see your point of view but you are nevertheless deviating from the box with regards to the schnorchel casing recess, in that case I  would perhaps make the schnorchel lay- out correct as well, adding the missing deck exhaustbend and schnorchel shutoff valve both very visible on the stb front side of the tower casing, se my image below.
As to the ejector draining, there are very narrow free flood areas between the casing and the pressurehull, aft of MBT 5, marked blue on my image. When diving, a submarine should not leave a trail of bubbles on the surface thus you want to get rid of the trapped air in the void spaces as quick as possible. I guess the "blisters" on both side next to the difficult areas are creating an ejector suction effect to fill difficult the free flood area  with water when diving eliminating the bubble trails.
Tore