VIIC/41 - Schematices drawing

[Rokket]

Only with general info from various reading...the TDC was a pretty amazing thing at the time, a compact computer! There was only ONE on any boat, any navy. They were a Big Deal. The USN had one that could update all info automatically. The Kriegsmarine's was a bit limited. They could input a problem and get a firing solution, but when things changed they had to re-input new info.

Periscopes were a Big Deal, too, but more of a Medium Deal - hi-tech optics and construction, but nowhere near as tricky and complex as a mechanical computer. The USN TDCs were big, about the size of a small fridge (not bar fridge, just a bit smaller than a double door). We're talking big stuff. VERY impressive though, from what I've read there were no major problems with them (as opposed to US radar and anyone's hydraulics at critical times).

[NZSnowman]

Here the other part of the TDC, the two switch boxes in the Control room.

[NZSnowman]

Update:


The atteck periscope (middle); the FuMB-9 Wanze (left) and the FuMB-35 Athos (right) (both passive radar detection) with pictures of U-249.

[NZSnowman]

  Drawing: The full search periscope housing 




There is a cable (red arrow) that runs from the bottom of the search periscope into the search periscope housing. Does anyone know that happen to this cable in the periscope housing

[Bad Karma]

Well what I think is that this ''retraction cable'' has the same lenght(or shorter not longer) as the ''search periscoop housing'',this housing goes
right into the main diving tank.So i think this cable goes straight down in the housing,I think it will not bend in the housing.

More thoughts on this is always welcom

[NZSnowman]

Do you think there was a small motor at the bottom of the housing to help the search periscope retract

[Rokket]

Yes. I say this from physics and USN boats (had motors). A long steel tube filled with bits of this and that, there's no way to quickly and safely continually move it manually up and down.

[Bad Karma]

I have looked at the drawings of David Westwood,is this than a motor for the attack scope (number 16)

[NZSnowman]

Bad Karma, you are right about the motor, I knew about this motor. You can just make out the cables warping around periscope in the picture (from the other post) and then going up the periscope. In the picture (below) you can see the two cable on the side of the wall running down the to the motor. The red arrow is the up/down control arm for the periscope. I thought this motor may only rise the periscope and there was a small motor at the bottom of the housing to help lower the  periscope, but maybe there enough weight in the periscope that it would lower itself

[kagero43]

Wow - throughly researched! I like the fact that you have colors included as well. Thanks for sharing. - Harvey

[NZSnowman]

A update of the bow pressure hull around the torpedo tubes 

[Rokket]

all comes together quite nicely!

[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

[NZSnowman]

The shipyard has reopened

I have started to update the diesel engine, as I was luck enough to get some additional technical drawings of the diesel engine from Tomi_099 from over at SUBSIM Forums. Thanks mate!! 

Picture (left) is the old diesel engine drawing (right) is the update drawing and (center) is the real thing

[Rokket]

That's a lot of excellent work!

[NZSnowman]

A small update 

[Rokket]

excellent additonal layer, adds to it!

[NZSnowman]

Add the acceleration bar to the front of the diesel engine, the tap for purging of the cylinders, the return spring for the smaller pusher rods and change the colour of the main pusher rods.

[Rokket]

You're going to have to sell these to museums you know...

[NZSnowman]

Update:

[Rokket]

Hey I was serious, you should put this on CD and make money while wowing folks.

[NZSnowman]

Hatch Cover 

[Rokket]

because I know what they look like, this is my fav so far, very well done.

[NZSnowman]

Auxiliary oil pump

[Rokket]

Auxiliary-Schmauxilary, it's so nice it should be the primary!

[NZSnowman]

Does anyone know that the word is at the top is? This it "Delrieb" Thanks.

[JAORSA]

Betrieb = Operational???

[Rokket]

Anlassen is START, so some form of pause or stop or hold? START/OPERATE/ finished (as uin above, "operatED")?

[NZSnowman]

Oil pump & controls of starting and acceleration of the motor

[Siara]

Lovely work Simon!

[NZSnowman]

I just finish the front of the diesel engine today. As you can see its made up of four layers. Happy viewing

[Rokket]

get some fuel and start her up!

[NZSnowman]

Does anyone know that happen to the Balconger

[NZSnowman]

Updated and make the search periscope more accurate


Old (left) and newer (right)

[dougie47]

Hi Simon,

Great drawings, as always. If you find an answer to the Balkongeraet question please do let us know.

Cheers,

Dougie

[NZSnowman]

Hi Dougie

I was just reading that you write in Type VII modifications under "Part VI - Final Thoughts, Museum boat U 955". You said "The boat did not have the Balkon-Ger

[NZSnowman]

Update: Balkon-Ger

[NZSnowman]

Updated: Hatch

The original drawing was base mainly on the United States Navy USS Gato (SS-212) hatch and a few pictures of U-995 hatch I had at the time. With far better pictures of the hatch on U-955, that I got today. I have made a few changes to correct the drawing to a German style hatch.

However, half way through the drawing today I realizes the were is a different locking system for the Tower Hatch & the Access hatch to the tower.


* Added brass contact rings to hatch rings.
* Added a O-ring to the contact rings
* Added split pins.
* Added a check valve to only the access hatch to the tower, must be used to check if there water in the CT.
* Remove handle from hatch handle.
* Added completely different locking system.
* Corrected the hatch hinge.

     
  Newer -German Style            Older - USN/German Style

[Rokket]

The hatch is operational...nice work

[Greif]

Simon, your drawings are good enough to use for research.  Fantastic work my friend!

Ernest

[NZSnowman]

Does anyone know that these are That they are use for Thanks.

[NZSnowman]

Does anyone know that the size of the rivets are on the hull

[Rokket]

too small to really do accurately! But I think oversize ones are better than none, very personal I guess.

I think they were like skyscraper building rivets, quite large, but beyond that I have NO info. I would GUESS, if forced, about 1 inch/25mm head, maybe 3/4. Dougie probably knows!

[NZSnowman]

I was also thinking about 30mm wide. In my drawing I have them at 27mm so far The thing I would real like to know, what is the spacing between the rivets, I am thinking about 100mm.

[billp51d]

             Hello, Simon....You've got mail...Bill

[dougie47]

Hi guys,

The rivets can be seen on this photo of U 228 below -



Going by the vertical line of rivets directly in front of the upper torpedo door, maybe the spacing between rivets is about 75mm to 80mm? Note the staggered double line of rivets along the stem.

Hope this photo helps.

Cheers,

Dougie

[NZSnowman]

Can anyone can confirm that the engine are 0.7

[NZSnowman]

Sad news

My engine is approximately 108 mm (real world) to small or 2.5 mm on my drawing at 1:43 scale Will have to fix that tomorrow! Can not have the engine drawing 2.5 mm too small 

[NZSnowman]

I thought I would show you the steps I take while doing my drawing I want to add the pipes for the engine outlets.


The pipe outlets on the engine.


The plans.
After spending 6 hours looking at piping plans I worked out the pipe layout for the two outlet pipe from the engine. The outlets (Green arrows) and the flow (Red arrows) to the valve and out into the two oil tanks (Orange arrows).


The finish drawing.
Then 2 hours to draw the pipes.

[Greif]

Awesome work NZ.  I know its been asked before, but what computer program(s) do you use to make the drawings?

Ernest

[NZSnowman]

CorelDraw X4 

[NZSnowman]

I know that these pictures are of poor quality, but I was wondering if anyone know that these words are (red arrows).

Thanks, Simon



 

[Greif]

I know that these pictures are of poor quality, but I was wondering if anyone know that these words are (red arrows).

Thanks, Simon



 

Hi Simon, the middle word in the small picture is:  Gl

[NZSnowman]

Thank Ernest Any help would be great!!

I know that these pictures are of poor quality, but I was wondering if anyone know that these words are (red arrows).

Thanks, Simon



 

Hi Simon, the middle word in the small picture is:  Gl

[NZSnowman]

Hi Dougie

In your Type VII modifications report on page 45 under 'Late UZO', do you have any more pictures of this later UZO? Or a better picture of the one in the report? As I would like to draw it for my U-Boat 

Thanks, Simon

[NZSnowman]

Does anyone know anything more about the Lime-water (acid neutralizing) system for the battery compartments?

I have seen the drawing from U-boat Archive http://www.uboatarchive.net/U-570Plate26.htm but that the extent of that I know about this system.

[NZSnowman]

If anyone is using this drawing as a reference, I just realize it is incorrect In Battery Room 1, I drawn the batteries as 4x3x4, this is incorrect! It should be 3x3x4 Port side and 4x3x4 on the starboard side.

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

[NZSnowman]

Torpedoes Loading Plans

While doing some research on the Lime-water system. I come across two set of plans for loading torpedoes. I had not seen these before, so though people may want to have a look. Happy viewing 

Plan 1
http://www.uboatarchive.net/DesignStudiesTypeIXCS75-3PlateI.jpg

Plan 2
http://www.uboatarchive.net/DesignStudiesTypeIXCS75-3PlateII.jpg

Full Report
http://www.uboatarchive.net/DesignStudiesTypeIXC.htm

[NZSnowman]

Yesterday I did a test print out of my posters to check the sizing. There will be two posters, one of the inside of the U-Boat and the other of the outside. Each drawing of the U-Boat will be 1600mm by 600mm (9 x 2 A4 pages for the test print as my printer will on do A4). The posters are for my new house for my officer. Here are a few pictures of the poster in my office. Can not wait til both the house and posters are finish


This wall will have inside view of my U-Boat


This wall will have outside view, I have not print it out yet.


And this is my house in winter The mountain behind my house are the Craigieburn Range. This is where I work as a avalanche forecast

[Greif]

Torpedoes Loading Plans

While doing some research on the Lime-water system. I come across two set of plans for loading torpedoes. I had not seen these before, so though people may want to have a look. Happy viewing 

Plan 1
http://www.uboatarchive.net/DesignStudiesTypeIXCS75-3PlateI.jpg

Plan 2
http://www.uboatarchive.net/DesignStudiesTypeIXCS75-3PlateII.jpg

Full Report
http://www.uboatarchive.net/DesignStudiesTypeIXC.htm

Hi Simon, thank you for this information, it will come in handy for me.  I have sent an email to the Museum of Science and Industry in Chicago asking for detailed photos of U-505's periscope.  The two detailed pictures I have are the front and bottom/front, neither of which shows the words you are looking for.  I hope the museum can help us out with a couple of photos.

Your drawing is beautiful!

Ernest

[NZSnowman]

Hi Ernest

I had some feedback also from Uboat.net, someone suggest the three words are: Farb (A color len), Gl

[Greif]

Hi Ernest

I had some feedback also from Uboat.net, someone suggest the three words are: Farb (A color len), Gl

[dougie47]

Hi Simon,

My apologies for my delay in replying, I have been on paternity leave recently and have had no spare time. Below are a few shots of the late UZO. They aren't great - as always we need better resources. Your house looks brilliant, as do your posters on the wall.







Cheers,

Dougie

[Rokket]

That is SOME fine house and location! And of course your dwgs!

[NZSnowman]

I have added the wiring, the insulating cork (the light brown layer next to the Pressure Hull) and a control rod that run along the starboard Pressure Hull (I believe the control rod is for the aft hydroplane ). Pressure Hull and Ribbing are now to scale (Pressure Hull is 21 mm - because this is a Type VIIC/41) and ribbing is 200 x 70 x 11 mm.


Fig. 1. Top view - Starboard only.


Fig. 2. Side view - Port - Pressure Hull, Ribbing and Plate Steel (Not to scale - yet  )

[NZSnowman]

Exhaust manifold

I am look for any pictures of the Exhaust manifold. If anyone know of any pictures on the net or have any I would be very kind to have a look at them. The best picture I have found so far is from www.u-historia.com


Picture from www.u-historia.com

[NZSnowman]

Ventilation System


Fig. 1. Main valve with interconnecting pipes between port and starboard ventilator.


Fig. 2. Main valve with the port ventilator.


Fig. 3. Main valve, port ventilator and pipes & valves.


Fig. 4. Port Ventilation system with control arm.


Fig. 5. Starboard ventilation system from U-995. Picture from http://www.uboataces.com/u995.shtml

[NZSnowman]

Fuse Boxes


Fig 1. Several type of fuse boxes that are found within a U-Boat.

[NZSnowman]

Hi All

I have seen this marking on a few switches, it look like a 'V' within a 'A' (lower right corner). Does anyone know the marking or the company?

Thanks, Simon.


Picture from http://www.uboataces.com/u995.shtml

[NZSnowman]

Small Electrical boxes and switch


Fig 1. Several type of electrical boxes found within a engine room.

[NZSnowman]

Auxiliary Oil Pump


Fig. 1. The Auxiliary Oil Pump found in the engine room on the port side of the boat.


Fig. 2. The Auxiliary Oil Pump found in the engine room of U-995. Picture from http://www.uboataces.com/u995.shtml


Fig. 3. Electrical boxes and switches found in the engine room.

[NZSnowman]

Does anyone know the diameter of the two pipes (red & green) for the air trunking Thanks, Simon.

[Greif]

Hi Ernest

I had some feedback also from Uboat.net, someone suggest the three words are: Farb (A color len), Gl

[NZSnowman]

Hi Ernest

I had some feedback also from Uboat.net, someone suggest the three words are: Farb (A color len), Gl

[NZSnowman]

Hi All

I was wondering if anyone has any pictures or information on the exhaust silencer?

Thanks, Simon

[NZSnowman]

Hi All

Can anyone please conform this for me. In a cross section view we know that the stern angles down to the very stern, but is there a second angle change above the end of the pressure hull?

[Siara]

As far as i know- theres only one angle.

[NZSnowman]

Thanks Siara for you help I have never seen any original German measurements for the area between the top of the deck and the pressure hull/stringer. A few of my scan plans looked like they had a second angle , but maybe it was just the way they were scanned.

I thought it was unusual to have a second angle, as the different between the two angle is only about 2-3

[NZSnowman]

I have to change my mind now. I recheck all my measurements and there must be a second angle in the stern deck. As the rudder post will not fix under the deck, in fact the top of rudder post stick through the deck

I believe the second angle was at the end of the wooden deck (Frame No. -3).

Here are the stern deck numbers I believe.

Frame Number +19 to +60.1; Deck angle 0.0

[Siara]

Interesting.
What i was goin to say is- the change of angle on the rear of the deck is not sharp, but kinda soft- thus making the deck sloping gently.
On your drawings it looks almost like suden change of angle. What about rounding it a little- will it make the difference?

[NZSnowman]

Yes, I think you are right, the angle does like a little sudden I will look into this tomorrow morning, getting late in NZ, time to go to bed now

[NZSnowman]

Hi All

I have seen this marking on a few switches, it look like a 'V' within a 'A' (lower right corner). Does anyone know the marking or the company?

Thanks, Simon.


Picture from http://www.uboataces.com/u995.shtml

Found the answer to the marking - Voigt & Haeffner A. G.  

[dougie47]

Hi gents,

You may be right about the second angle, Simon, but it is so hard to tell. I can't tell a noticeable second angle change in period photos. I'd favour Siara's advice on rounding it off as this would be a safer bet.

Cheers,

Dougie

[NZSnowman]

Fig. 1. Exhaust System.

The exhaust system is nearly finish it taken me a lots of research, reading, asking questions (thanks again to everyone who is helping me!!!) and drawing to get it all correct. There is lots of detail in the drawing, like the correct scaling of nuts, rivets, piping, plate steel etc... I have added detail of the building hatch (you can see this in the change in the ribbing, and the change in the pressure hull). I have added the forward diesel exhaust valve that leads to the schnorochel (This took me some time to get the correct valve and handle). I am currently working on the exhaust outlet with help from Dougie. When I will finish I will start working again on the Ventilation system in the Engine Room.

[NZSnowman]

Interesting.
What i was goin to say is- the change of angle on the rear of the deck is not sharp, but kinda soft- thus making the deck sloping gently.
On your drawings it looks almost like suden change of angle. What about rounding it a little- will it make the difference?

Hi gents,

You may be right about the second angle, Simon, but it is so hard to tell. I can't tell a noticeable second angle change in period photos. I'd favour Siara's advice on rounding it off as this would be a safer bet.

Cheers,

Dougie

Hi Dougie & Siara

Was looking for pictures of the Diesel Exhaust Outlets today, I came across two really good pictures of the stern that show the profile very well. You can see the second change of angle, plus both you guys are right, you can see that this second change of angle is rounded. I will start working on the new profile and post it when it finish.

Simon

[NZSnowman]

Using a 1:15 scale original German Hull Section plan, I realign them in a lateral view to workout the deck profile. From this I could see that the rounding of the second angle was between frame number -6 and -3. Here the new update of the deck profile

[Siara]

Thats more like it Simon.

[NZSnowman]

Hi All

I have two plans that illustrate the aft Battery Hatch, but they are both in different location Does anyone know the correct location for the aft Battery Hatch?


Fig. 1. Battery Hatch location between frame number 41 and 42.


Fig. 2. Battery Hatch location between frame number 44 and 45.

Thanks, Simon

[NZSnowman]

Question: Compressed Air Bottles

I have see the values for capacity, pressure etc... for the compressed air bottles but I have not see the dimensions of them. Does anyone know there dimensions

Thanks, Simon.

[NZSnowman]

Assembly & Building Hatches


Fig. 1. Step 1: Pressure Hull.


Fig. 2. Step 2: Pressure hull with Assembly and Building hatches.


Fig. 3. Step 3: Assembly opening, building hatch, Exhaust piping & Ventilation piping.

[NZSnowman]

Ventilation System - Finish




http://www.mediafire.com/?no0tt33z4ti (3.8 MB - PDF of Ventilation and Exhaust System)




I was laying in bed this morning and wondering why are the models 1:72 scale, why not 1:70 or 1:75 scale? Anyone know why 1:72 scale.

[dougie47]

Good question, Simon.

Aircraft model scales tend to be in 24th, 32nd, 48th, 72nd, and 144th scale. All numbers that we can divide by 8. This allows Airfix's new 1/24th Mosquito (with 617 parts by the way!) to be exactly twice the size of a 1/48th Mosquito. If 1/72nd had been rounded off to 1/75th we wouldn't be able to make such a comparison.

Armour and some helicopters tend to use 35th scale. Not sure why they are in this different size. Anyone know?

Ship models tend to be in 72nd, 96th, 144th, 192nd, 350th, 700th, 720th and 1200th (other scales are used too). Obviously all of these scales don't conform to the same neat systems that aircraft scale conform to. Some are multiples of 8, while 350th and 700th have been rounded off to the nearest big numbers.

Are you thinking of printing your drawings off in various scales?

Cheers,

Dougie

 

[Anakin]

Looky looky---> http://en.wikipedia.org/wiki/1/72_scale_Plastic_soldiers   

[dougie47]

Hi Anakin,

Wiki does have its uses! This explains the origin of 35th scale -

http://en.wikipedia.org/wiki/1:35

This link has a list of scales -

http://en.wikipedia.org/wiki/List_of_scale_model_sizes

Cheers,

Dougie

[Anakin]

Hi Dougie.

Actually i also scratched my head for a while... And the my friend Mr. Google gave me some answers.. 
I hope you can get a sleep tonite!      

-Anakin-

[NZSnowman]

Are you thinking of printing your drawings off in various scales?

As the drawing is a vector base and I have scale all the nuts, bolts, rivets and steel to scale. I can scale the drawing to any small from 1:1 to 1:20,000 But I will keep my poster to 1:43 scale which will make the drawing about 1,600 mm long.


Thanks, Dougie & Anakin for the information about the scaling

[Siara]

 I think the set of drawings in 1/72 its a good idea.

[Anakin]

I found something while searching balkon gerat... Thought there might be something useful knowledge.
http://www.cdvandt.org/schluessel_m4.htm M4 Enigma
http://www.cdvandt.org/Metox.pdf Metox
Also info about GHG and balkon gerat + tons of stuff.

http://www.cdvandt.org/

-Anakin-

[NZSnowman]

I found something while searching balkon gerat... Thought there might be something useful knowledge.
http://www.cdvandt.org/schluessel_m4.htm M4 Enigma
http://www.cdvandt.org/Metox.pdf Metox
Also info about GHG and balkon gerat + tons of stuff.

http://www.cdvandt.org/

-Anakin-

Thanks Anakin for the links!   I had seen some of the links but did not realize how much information there was.

[Pat]

Hi.  New member here.  Please excuse me if I screw up the proper format for posting since this is a new forum software that I'll have to learn how to use yet.

I've been building a 1:72 scale U-boat and had been searching for trunking and piping detail under the casing, since it's all going to be accessible in my model, and when I found NZSnowman's drawings they just blew me away.  He's got exactly the data I've been looking for all this time and his drawings are terrific!!!!

Anyway, so much for introduction.  Now to take a stab at answering a recent question.

NZSnowman asked: "I was laying in bed this morning and wondering why are the models 1:72 scale, why not 1:70 or 1:75 scale? Anyone know why 1:72 scale."

And dougie47 replied: "Aircraft model scales tend to be in 24th, 32nd, 48th, 72nd, and 144th scale. All numbers that we can divide by 8. This allows Airfix's new 1/24th Mosquito (with 617 parts by the way!) to be exactly twice the size of a 1/48th Mosquito. If 1/72nd had been rounded off to 1/75th we wouldn't be able to make such a comparison."

I think dougie is on the right track when he said that all the aircraft scales can be divided by 8.  It was simply that in the early years of commercial model kits, (at least the ones that were mass marketed in the English speaking world and thus became well known, that they were all measured in inches and the full size item was measured in feet.  It's much easier to divide inches by 1/4, 1/8, etc. than it is to divide by 10s, and this also works out easily with a foot.

Even though metric is used in most places now and measurements divisible by 10 make more sense, the scale standard had already been set in the largest model-making countries of the time.
 
 

[Pat]

While I'm at it, there was another question posed early in 2009 that perhaps I can also shed more light on.

Sorry I can't find the original post (I have a VERY slow dial-up and it took me about 3 days to go through this thread the first time) but the question was regarding a couple of metal tanks on either side of the casing near the bow.  somebody was wondering what the tanks were for, and it was suggested that they might have been for a net-cutter that had since been removed.

I think there was also a comment that a couple of similar tangs further back had had the hole welded shut.

As a sailor myself for 30 years, I find it hard to believe that any seaman would weld closed a hole in anything without a strong reason.  Any holes serve as attachment points for all sorts of things in an emergency, such as heavy seas where they wanted to clip off a lifeline in a hurry.  So unless they HAD to be closed (in which case, while you had the equipment out why not just cut the tang right off?), the openings would still be there.

My quess is that the tangs might be attachment points for the handwire that goes from bow to stern on the stanchions when the boat is in harbour.  They'd simply clip on the wire at the bow and string it through all the removable stanchions until they get to the stern where there must be some other attachment points for the wire.

[Pat]

Sorry to post so often so close together, but I'd been saving them up until I reached the end of the thread in case somebody else came up with the answer I was going to give.

Another question had been asked about the "grapnels", the long poles attached at bow and stern of U-boats.

At least on the water and in marine supply stores, these "grapnels" look like what we call 'boat hooks'.  Most modern ones are made of lightweight aluminum tubing, semi-sealed so that if they fall in the water, they'll float for about 5-10 minutes, or enough time to hopefully retrieve them.

Older ones, (and by older I mean 30+ years) were made of wood for the same reason.  They wouldn't have been made of aluminum during the war because the aircraft industry needed all the aluminum it could get, so it wouldn't have been wasted on U-boats when wood would do.

This seems to be confirmed by the length of the boathook/grapne;s on the U-boats.  Modern ones telescope down to about 1-2 meters in length but stretch out to as long as you can handle.  Since wooden ones can't telescope, then they'd be made as long as possible right from the start.

Boathooks of course have all sorts of uses, but commonly are used to catch things floating on the surface (U-boats used to check garbage to see if they could learn anything about the ships they were hunting), catching and holding small boats that would come alongside (like inflatable rubber dinghys used to land operatives on shore), or men who had fallen overboard.

Modern boathooks have a straight point with a blunted tip and a curved, blunted hook underneath but I've seen variations on this in drawings of older boathooks, some with semicircles for the tips, some with Y-shaped ends, etc.

[Pat]

I might as well empty out all the things I've been saving up.

A while ago, Simon and Siara were debating about a couple of projections on either edge of the deck forward of the Turmembau (CT) near the large round hatch.

I'm not sure, but I think they're a variation on attachment points for the torpedo loading frame. 

Take a look at a book called "Kreigsmarine U-boats, 1939-45 Vol1", by Gordon Williamson, Osprey Publishing (sorry, I don't have a scanner) on page 39 there is a photo which shows something similar in that location on the stb side and slightly forward of it on the pt side.  Then on page 46 of the same book, there's a photo of men loading a torpedo through the deck hatch and the outside leg of the framework they're using is connected on the same point.

The only reason I can think of that the points might not be directly across from each other is that the torpedo loading hatch was slightly offset to stb and therefore the leg for the portside of the framework was longer and might have needed slightly different geometry for strength.

[Pat]

I thought of another one.  Sorry if I'm being a pest with so many posts right together.

There was another exchange between Siara and Simon earlier asking about placement of cleats along the deck and trying to get the exact points of attachment.

While things such as the trunking and decl hatches would be pretty standard from one boat to another (especially ones from the same yard), cleats are something that probably weren't specified so exactly by the government.  (Free flow holes are another and they vary considerably from one boat to another and from one year to another when the boat was built).

Just like the camouflage patterns were subject to the individual skipper's whim (although the colours available were standard, where they were applied was not), cleats are often welded or bolted to wherever the skipper felt a need and would probably be different from one boat to another.  Like the holes in the tangs, once attached, it would be unusual for a cleat to be removed, so a new boat might have fewer cleats than one that's been in service for a long time.

I've seen lots of class boats of different types where the hull was the same for every boat in the class but minor things like cleats could be found in different places on different boats.

Some cleats probably were in standard locations (the ones at the back edges of the CT just under the point where the rails attach) but ones along the side of the deck amidships might be in different locations depending where bollards were on shore or on the submarine tender ships like 'Black Watch' (the ship that looked after my U-boat).

[NZSnowman]

Hi.  New member here.  Please excuse me if I screw up the proper format for posting since this is a new forum software that I'll have to learn how to use yet.

Welcome to the AMP Forum

I've been building a 1:72 scale U-boat and had been searching for trunking and piping detail under the casing, since it's all going to be accessible in my model, and when I found NZSnowman's drawings they just blew me away.  He's got exactly the data I've been looking for all this time and his drawings are terrific!!!!

Thank you for your kind words. I have enjoy doing the research and the drawing. I have start working on my 'Working Drawing' again http://models.rokket.biz/index.php?topic=124.0

NZSnowman asked: "I was laying in bed this morning and wondering why are the models 1:72 scale, why not 1:70 or 1:75 scale? Anyone know why 1:72 scale."

And dougie47 replied: "Aircraft model scales tend to be in 24th, 32nd, 48th, 72nd, and 144th scale. All numbers that we can divide by 8. This allows Airfix's new 1/24th Mosquito (with 617 parts by the way!) to be exactly twice the size of a 1/48th Mosquito. If 1/72nd had been rounded off to 1/75th we wouldn't be able to make such a comparison."

I think dougie is on the right track when he said that all the aircraft scales can be divided by 8.  It was simply that in the early years of commercial model kits, (at least the ones that were mass marketed in the English speaking world and thus became well known, that they were all measured in inches and the full size item was measured in feet.  It's much easier to divide inches by 1/4, 1/8, etc. than it is to divide by 10s, and this also works out easily with a foot.

Even though metric is used in most places now and measurements divisible by 10 make more sense, the scale standard had already been set in the largest model-making countries of the time.

Thanks for the additional information. I saw the the inches to a feet things....Long live the metric system  

Sorry I can't find the original post (I have a VERY slow dial-up and it took me about 3 days to go through this thread the first time).

I know what a very slow dial-up this like!!! A few years ago at the place I work, it would take about 5min to download a email - no joking!!!

but the question was regarding a couple of metal tanks on either side of the casing near the bow.  somebody was wondering what the tanks were for, and it was suggested that they might have been for a net-cutter that had since been removed.

I think there was also a comment that a couple of similar tangs further back had had the hole welded shut.

As a sailor myself for 30 years, I find it hard to believe that any seaman would weld closed a hole in anything without a strong reason.  Any holes serve as attachment points for all sorts of things in an emergency, such as heavy seas where they wanted to clip off a lifeline in a hurry.  So unless they HAD to be closed (in which case, while you had the equipment out why not just cut the tang right off?), the openings would still be there.

My quess is that the tangs might be attachment points for the handwire that goes from bow to stern on the stanchions when the boat is in harbour.  They'd simply clip on the wire at the bow and string it through all the removable stanchions until they get to the stern where there must be some other attachment points for the wire.

Post http://models.rokket.biz/index.php?topic=106.msg1201#msg1201

This is good thinking, about the attachment points. I think you are right about closing the openings, the holes would serve as great attachment points. Also I just look at the book U-995 by Eckard Wetzel http://cgi.ebay.de/U-995-Eckard-Wetzel_W0QQitemZ370313170051QQcmdZViewItemQQptZSach_Fachb%C3%BCcher?hash=item5638628c83 it look like U-995 never had a net-cutter 

Another question had been asked about the "grapnels", the long poles attached at bow and stern of U-boats.

At least on the water and in marine supply stores, these "grapnels" look like what we call 'boat hooks'.  Most modern ones are made of lightweight aluminum tubing, semi-sealed so that if they fall in the water, they'll float for about 5-10 minutes, or enough time to hopefully retrieve them.

Older ones, (and by older I mean 30+ years) were made of wood for the same reason.  They wouldn't have been made of aluminum during the war because the aircraft industry needed all the aluminum it could get, so it wouldn't have been wasted on U-boats when wood would do.

This seems to be confirmed by the length of the boathook/grapne;s on the U-boats.  Modern ones telescope down to about 1-2 meters in length but stretch out to as long as you can handle.  Since wooden ones can't telescope, then they'd be made as long as possible right from the start.

Boathooks of course have all sorts of uses, but commonly are used to catch things floating on the surface (U-boats used to check garbage to see if they could learn anything about the ships they were hunting), catching and holding small boats that would come alongside (like inflatable rubber dinghys used to land operatives on shore), or men who had fallen overboard.

Modern boathooks have a straight point with a blunted tip and a curved, blunted hook underneath but I've seen variations on this in drawings of older boathooks, some with semicircles for the tips, some with Y-shaped ends, etc.

Again thanks for the additional information 

I might as well empty out all the things I've been saving up.

A while ago, Simon and Siara were debating about a couple of projections on either edge of the deck forward of the Turmembau (CT) near the large round hatch.

I'm not sure, but I think they're a variation on attachment points for the torpedo loading frame. 

Take a look at a book called "Kreigsmarine U-boats, 1939-45 Vol1", by Gordon Williamson, Osprey Publishing (sorry, I don't have a scanner) on page 39 there is a photo which shows something similar in that location on the stb side and slightly forward of it on the pt side.  Then on page 46 of the same book, there's a photo of men loading a torpedo through the deck hatch and the outside leg of the framework they're using is connected on the same point.

The only reason I can think of that the points might not be directly across from each other is that the torpedo loading hatch was slightly offset to stb and therefore the leg for the portside of the framework was longer and might have needed slightly different geometry for strength.

Pat, are you talking about these holes?

I thought of another one.  Sorry if I'm being a pest with so many posts right together.

There was another exchange between Siara and Simon earlier asking about placement of cleats along the deck and trying to get the exact points of attachment.

While things such as the trunking and decl hatches would be pretty standard from one boat to another (especially ones from the same yard), cleats are something that probably weren't specified so exactly by the government.  (Free flow holes are another and they vary considerably from one boat to another and from one year to another when the boat was built).

Just like the camouflage patterns were subject to the individual skipper's whim (although the colours available were standard, where they were applied was not), cleats are often welded or bolted to wherever the skipper felt a need and would probably be different from one boat to another.  Like the holes in the tangs, once attached, it would be unusual for a cleat to be removed, so a new boat might have fewer cleats than one that's been in service for a long time.

I've seen lots of class boats of different types where the hull was the same for every boat in the class but minor things like cleats could be found in different places on different boats.

Some cleats probably were in standard locations (the ones at the back edges of the CT just under the point where the rails attach) but ones along the side of the deck amidships might be in different locations depending where bollards were on shore or on the submarine tender ships like 'Black Watch' (the ship that looked after my U-boat).

Again thanks for the additional information  Also that U-Boat are you doing? My drawing is of U-1308, the last VIIC/41 build. It would be the height of VIIC's, it had all the newest U-boats toys like FuMT 1 Aphrodite, FuMT-2 Theti, Tarnmatte and Alberich. I will be add FuMO-61 Hohentwiel-U and a Schnorchel, I am unsure if U-1308 had these last two things as there is no document  



 

[Pat]

Simon, yes, this dial-up id driving me crazy.  I think there

[NZSnowman]

Simon, yes, this dial-up id driving me crazy.  I think there

[Pat]

Thanks for the suggestion but I don

[NZSnowman]

Thanks for the suggestion but I don

[NZSnowman]

Electrical System - Bow section of the Engine Room

[Greif]

Very nice Simon.  I am using your drawings as on of the references while I build the Type VII interior by the way.

Ernest

[NZSnowman]

Ernest, if you want to look at any other sections of the interior, let me know, as I can post you the latest drawing.

[Greif]

Thank you Simon, I'm working on the galley/PO quarter at present.  If you have any drawings of that area I would be glad to have them at my fingertips so to speak.

Ernest

Ernest, if you want to look at any other sections of the interior, let me know, as I can post you the latest drawing.

[NZSnowman]

I have not research that the original colour (sorry color for you other people  ) of the galley. Would be nice to know that is the original colour was.

[Sniperonzolo]

woooof NZ!!!!
looks fantastic!!!
ps why u looks like a sailor in your pics???
do i see your face around regattas?

ceers

[Greif]

Thank you Simon.  The galley was painted the same interior color as the rest of the uboot.  The upper portion, the part above the blue in your drawing was painted RAL9001, which was an ivory white tone.  The lower hull, the blue in your drawing, was RAL 9002 Greywhite.

Ernest

I have not research that the original colour (sorry color for you other people  ) of the galley. Would be nice to know that is the original colour was.

[Pat]

Simon, it's not that I haven't been trying to post those pix for you, but when I tried to sign up to the hosting site, it all went well until the end.  The confirmation email didn't come.

I still haven't received the confirmation email so that I can get started and when I tried a second time, it said that it already had another member with that email so I couldn't register again.

[Pat]

Does anybody know what the colour of the deck in U-boats? 

Looking in through the main CT hatch, the deck, ladder and some of the equip on the bulkheads will be visible in my model. 

Photos of the inside of U-995 show the bulkheads as white as well as most of the piping and wiring, with the equipment being various colours depending on use and wheels being either red or black.  The ladder is black, although I've seen it bare metal in other sources and white in still others.

But I don't recal seeing anything about the deck.

Anybody have other information?

[Greif]

Hi Pat, the interior decks were painted RAL 9002 Grauweiss, with exceptions for things like the walkway between the engines which was left plain metal.  UbootWaffe painting orders were for the upper part of the inner hull to be painted RAL 9003 Signalweiss; however, the color was actually much closer to RAL 9001 Elfenbeinweiss.  You right about ladders being painted different colors; it seems they were often painted at the discretion of the uboat commander.

Ernest     

Does anybody know what the colour of the deck in U-boats? 

Looking in through the main CT hatch, the deck, ladder and some of the equip on the bulkheads will be visible in my model. 

Photos of the inside of U-995 show the bulkheads as white as well as most of the piping and wiring, with the equipment being various colours depending on use and wheels being either red or black.  The ladder is black, although I've seen it bare metal in other sources and white in still others.

But I don't recal seeing anything about the deck.

Anybody have other information?

[NZSnowman]

Does anybody know what the colour of the deck in U-boats?  

Looking in through the main CT hatch, the deck, ladder and some of the equip on the bulkheads will be visible in my model.  

Photos of the inside of U-995 show the bulkheads as white as well as most of the piping and wiring, with the equipment being various colours depending on use and wheels being either red or black.  The ladder is black, although I've seen it bare metal in other sources and white in still others.

But I don't recal seeing anything about the deck.

Anybody have other information?

There are very few pictures of the original deck of U-995, or I think most of the original deck of U-995 has been replace over time. The few pictures I have seen of the original deck are in the Galley, CT and Engine room, In the Galley it is painted black however, unsure if it was painted black by the Kriegsmarine or the Royal Norwegian Navy. The other place I have seen good pictures the original deck of U-995 was in the CT, here is also painted black, with small drain holes (about 20mm). All the deck plate had the same deck plate pattern.  

It looks like Ernest got the right answer for you 

[NZSnowman]

Simon, it's not that I haven't been trying to post those pix for you, but when I tried to sign up to the hosting site, it all went well until the end.  The confirmation email didn't come.

I still haven't received the confirmation email so that I can get started and when I tried a second time, it said that it already had another member with that email so I couldn't register again.

I know how you are feeling, I hate it when confirmation email didn't come The only thing I can think of that this time is to go to the Login page and click the 'Forgot Password' link, they may send you a new one.

[NZSnowman]

Thanks for the information Greif. I had a look at my U-995 by Eckard Wetzel and there one picture of the galley and it painted in RAL9001 & RAL 9002

Thank you Simon.  The galley was painted the same interior color as the rest of the uboot.  The upper portion, the part above the blue in your drawing was painted RAL9001, which was an ivory white tone.  The lower hull, the blue in your drawing, was RAL 9002 Greywhite.

Ernest

I have not research that the original colour (sorry color for you other people  ) of the galley. Would be nice to know that is the original colour was.

[NZSnowman]

Does anyone know if the keel of the Type VII is solid or made up of frames?

[billp51d]

       Simon...I do recall seeing some photos of the keel, Sorry I don't recall where, but they were of hatches/access doors that were open on the keel.
                  Inside were large blocks of ballast, probably iron or steel.
                                                   Cheers/Regards..Bill

[NZSnowman]

Yes, I have also see this picture and also can't recall where, but I think it was a Type IX. I seen and have a few good pictures of the keels of the Type IX but I never seen in detail a Type VII keel That is why I was thinking it maybe solid

[Rokket]

same for me, sure I've seen a pic. I THINK it's solid (or solid from big chunks) for weight.

[Pat]

Just a guess, but the standard material for ballast keels is lead.  They want the heaviest but cheapest material they can get to take up the least amount of space while lowering the centre of gravity so the boat rolls less.  It would definitely not be iron as that would corrode too quickly, and not likely steel because it isn't heavy enough and they need it more elsewhere.

If there are access hatches to the keel, that sounds like they might want to at least inspect it once in a while for corrosion and to clean out the limber holes so that any water will drain to a sump where it can be pumped out.  The limber holes on many ships often have a small chain running for and aft that could be pulled to drag out any gunk that got stuck in the holes, blocking the free flow of water.

[NZSnowman]

While looking at the keel of U-995, I noted 3 small holes in the Pressure Hull. There are over 80 holes in Pressure Hull in the Control Room. I was wondering what other people think about these small holes are for Could they be used for the Depth gauges or Speed indicator , or just for a sigin

[NZSnowman]

Lime-water was used as a acid neutralizing system for the battery compartments. To make lime water was it made with fresh water or can it be made with sea water?

[NZSnowman]

Drainage System

Step 1: Engine Room Drainage System (in red) from Design and Specification Books, Volume M, a original German plans from U-570.

http://www.uboatarchive.net/U-570Plate6.htm

Step 2: Original German plans.


Step 3: My Drawing

[Pat]

Snowman, I don't know what the holes are, but one of them probably somehow does work for depth.  Extremely unlikely to be for speed though.

A depth guage would work by letting water into a tube wich would somehow move a float or liquid in a calibrated tube.  Not sure how this happens since any sight tube made of glass would break if the pressure got to be too much.  However, at 200 meters, I think the pressure would be approx 300 psi, and maybe glass can take that if it's thick enough.  (1 atmos = 14 psi    every 30 ft in depth adds another atmos  1 meter = 39"          so 200m = 7800" divided by 12 = 650 feet divided by 30 = 21 atmospheres times 14 psi = 303 psi)

The way a boats speeometer works in most cases is that there's a small paddlewheel in a little depression in the side of the hull, in an area where the flow of water is not disturbed by propellers or rudders.  (or dive planes)  The paddles stick out only a fraction of an inch into the flow, but enough that the passing water spins it.

One of the paddles has a small magnet on it and every revolution, the magnet passes another magnet on the inside of the hull and causes it to register.  The number of turns per second gives you the speed.

There's also some speedometers that work somewhat like an aircraft pitot tube, but that requires a hole in the very bow of the boat facing forward.  The holes you show are on the side.

There will also be holes somewhere near the engine room since the diesels would be water-cooled.  Even with a radiator, (which is typical of salt-water boats) the heat has to go somewhere.  This is done by raw sea water going through a heat-exchanger at the radiator, and the raw water gets ejected mixed with the diesel exhaust to cool the muffler and exhaust pipes as well, while the radiator coolant is kept in a closed system with the engine itself.

Usually the raw water intake hole will look like a small blister on the side of the boat with holes in it to strain out any seaweed or marine organisms.

[NZSnowman]

While read your reply I just remember seeing something similar on a Type XXI plan, I checked it out.

Pat, I think you are heading in right direction with the holes....On the Type XXI plan were are three small holes in the identical line, size and position on the U-boat (Starboard only and opponent the control station). On this plan they are label

[Pat]

Snowman, that hole you point out on the side of the hull is almost definitely raw seawater inlet for the engines.  That's the same style that is used on ships today and it's in the right location and seems about the right size that I'd expect for that size diesel.

Probably there is also one on the other side for the port engine, although they could use just one.

BTW, the paddle wheel for the speedometer doesn't need to be large.  The entire thing may be no more than about an inch or two at the most in diameter, aand a little less deep since it needs perhaps 1/8" or 1/4" sticking out.

[NZSnowman]

I know the inlet and and valve are at the right location! As the opening is at 24,800 mm from the stern and 2,100 mm above the keel. This match the inside valve, right on!!

Also you right there is also a inlet opening on the Port side of the boat.

Thanks for the information about the paddle wheel for the speedometer. I will have a look at my pictures and I hope I can find it.

[Pat]

Unfortunately, there's no sort of standard location where the paddlewheel might be, other than at least far enough under water that it won't be affected by wave action.

They mostly seem to be near the keel, but I've seen them higher up.  Lengthwise, they could be anywhere from near the bow (far enough back not to be affected by plunging into the waves) to just before they'd get interference from the propellers and rudders.

The one thing to think of is that they will be in a somewhat protected place, so that they don't get damaged by rubbing up against docks or fenders.

They're often a differnt colour than the hull, since they can't be painted with anti-fouling paint because that might throw them off.

[NZSnowman]

Thanks again for the information. My initial search was very narrow area of the pressure hull. I will widen my search of the hull 

[Pat]

Another question.

What are the rectangular patches in the saddle tank just above and to the right of the raw water inlet?  I know the water goes in via a square grill further forward, but those patches have me babbled.  They don't seem to open up.

[NZSnowman]

Another question.

What are the rectangular patches in the saddle tank just above and to the right of the raw water inlet?  I know the water goes in via a square grill further forward, but those patches have me babbled.  They don't seem to open up.

They are the water intake for the Saddle tanks   Check out a working drawing from U-570 (Lower middle picture) http://www.uboatarchive.net/U-570Plate28.htm

[SnakeDoc]

Hello Snowman

I've got question - what did you pattern after, when you were drawing torpedo tubes installations (pipes, rods etc)?

[Pat]

Snowman, I had another look at your photo of Jan 31, showing the raw seawater cooling inlet, and there's a small bump just above the inlet.  I wonder if that's the paddlewheel opening, just covered over for preservation reasons?  It looks possibly about the right size, and appears to project about the right amount.

[NZSnowman]

Hello Snowman

I've got question - what did you pattern after, when you were drawing torpedo tubes installations (pipes, rods etc)?

The first time I drawn the torpedo tubes installations it was base on Anatomy of the ship - The Type VII U-Boat by David Westwood, a few original pictures taken during the war and pictures from U-995. It not very detail but it was the best I could do that the time.

I am planning to completely redraw the whole bow torpedo section & torpedo tubes, as over the last year or so I have collection some great pictures, plans and things. I think the next drawing should be a heap more detail. I am sure it will show all the pipes and working parts 

[NZSnowman]

Snowman, I had another look at your photo of Jan 31, showing the raw seawater cooling inlet, and there's a small bump just above the inlet.  I wonder if that's the paddlewheel opening, just covered over for preservation reasons?  It looks possibly about the right size, and appears to project about the right amount.

Hi Pat, It could be the opening for the paddle-wheel......but to tell you the truth I have no idea that a paddle-wheel for a speedometer look like . I just been looking for something different on the hull. However, I have been looking for something a lot smaller.
Below are the best pictures I have of this area. One is of the outside of the hull and the other is from the inside. I am almost sure that those pipes and fixer are the fixer from the other side. Does this look like a speedometer system  

I have two other questions for you; Would you put the paddle-wheel so near to a inlet Also would you put the paddle-wheel in the Engine Room or Control Room section



Pictures from U-995 http://www.uboataces.com/u995.shtml

[SnakeDoc]

The first time I drawn the torpedo tubes installations it was base on Anatomy of the ship - The Type VII U-Boat by David Westwood, a few original pictures taken during the war and pictures from U-995. It not very detail but it was the best I could do that the time.

I have seen this picture - it's the best drawing I have seen till now (unfortunately, I didn't have seen many of them). The same is
in Urlich Gabler's "Submarine Design", and I think that the latter is more correct subtitled.

I am planning to completely redraw the whole bow torpedo section & torpedo tubes, as over the last year or so I have collection some great pictures, plans and things. I think the next drawing should be a heap more detail. I am sure it will show all the pipes and working parts 

I'm specially interested in the interolocking and firing rod details. Is it possible that you would share some of these details before your work will complete?

--
Regards
Maciek

[Pat]

Ok, on looking at the closeup snowman, it doesn

[NZSnowman]

The first time I drawn the torpedo tubes installations it was base on Anatomy of the ship - The Type VII U-Boat by David Westwood, a few original pictures taken during the war and pictures from U-995. It not very detail but it was the best I could do that the time.

I have seen this picture - it's the best drawing I have seen till now (unfortunately, I didn't have seen many of them). The same is
in Urlich Gabler's "Submarine Design", and I think that the latter is more correct subtitled.

I am planning to completely redraw the whole bow torpedo section & torpedo tubes, as over the last year or so I have collection some great pictures, plans and things. I think the next drawing should be a heap more detail. I am sure it will show all the pipes and working parts 

I'm specially interested in the interolocking and firing rod details. Is it possible that you would share some of these details before your work will complete?

--
Regards
Maciek

Happy to post any pictures of the new drawing, unsure when I will start them, but they are a area I am keen to redraw.

Had you check out these pages, they maybe useful.

(These 3 pages have be translated in to English)

http://66.163.168.225/babelfish/translate_url_content?.intl=us&lp=es_en&trurl=http%3a%2f%2fwww.u-historia.com%2fuhistoria%2ftecnico%2fvisitaguiada%2ftzr%2ftzr.htm
http://66.163.168.225/babelfish/translate_url_content?.intl=us&lp=es_en&trurl=http%3a%2f%2fwww.u-historia.com%2fuhistoria%2ftecnico%2fvisitaguiada%2fproa%2fproa.htm
http://66.163.168.225/babelfish/translate_url_content?.intl=us&lp=es_en&trurl=http%3a%2f%2fwww.u-historia.com%2fuhistoria%2ftecnico%2fvisitaguiada%2fpopa%2fpopa.htm

http://www.uboatarchive.net/U-570Plate25.htm

[NZSnowman]

You

[Pat]

Actually, it's amazing how little water a diesel on a boat needs.  Keep in mind that in a closed system (like a car with a radiator), the coolent is recycled over and over again and so it gets hot, sometimes boiling hot as you might be familiar with if you've ever had a rad cap leak.

But with a boat, it's a constant supply of fresh, cool water, in the ocean, usually never more than about 16 degrees C.  So it doesn't need a lot. 

While the engine in my boat is admittedly a lot smaller than those of a U-boat, it just uses a trickle of water, no more than a cup or two a minute, even at top speed.

Also, diesels run cooler than gasoline engines.  I can always rest my hand on the engine block of the diesel in my boat.  But I wouldn't attempt that with my gasoline driven car.  I once by accident grabbed the exhaust of my bike and am I ever glad I was wearing leather work gloves.  I had to toss the gloves out, once I ripped them off the pipes.

The wires I was talking about are the connection between the paddlewheel and the knotmeter gauge.  The paddlewheel is where the speed of the boat is measured, but there has to be a connection between that and the gauge.  That connection is electrical, not mechanical like a car.  The magnets in the paddlewheel just send impulses to the remote gauge.  So yes, I guess you'd say that the paddlewheel (or more correctly the magnets in the wheel and the boat) create a current that is read by the gauge.

[NZSnowman]

I was thinking that the connection between the paddle wheel and the knot meter gauge was a cable that was why I thought it would be located as near to the control room If it is electrical it could be anywhere. I will need to recheck all my pictures again.

[SnakeDoc]

Hello

I think that speedometer was not kind of paddlewheel.
Accodring to Underwater Log System section in Design Study Type IXC
http://uboatarchive.net/DesignStudiesTypeIXC.htm
that was a kind of Pitot Tube.

The 'dynamic pressure' inlets were at bow section (red arrow) as at this photo of U-54 on launching day,

the 'static pressure' - at midship - maybe it is where Simon marked.

The main device was in forward bulkhead of Control Room, at steering station

(photo from U-historia.com).

Note please the piping above speedometer - it looks like described in Design Study.

The principle of operation is shown on my simple drawing.

[Pat]

That's a REALLY bad location for any sort of instrument like speed.

Firstly, in rough weather, the bow of almost all ships frequently sticks out of the water, so no speed measurement taken.  When the next wave hits, the bow plunges down into the water - hard, and could damage instrumentation and the plunging would give a false high speed.

When the torpedo outer door is opened, it would change the water flow and therefore the speed measure.  Just when it's needed most to input into the targetting computer.

Being at the cutwater (the pointy part of the stem) means that any floating logs or wreckage can hit it and damage it.  Even weeds could jam into it and plug it up.

It also needs an outlet not far behind it.  Otherwise, the water gets in, can't get out and no speed is registered. 

[SnakeDoc]

It also needs an outlet not far behind it.  Otherwise, the water gets in, can't get out and no speed is registered. 

I don't think that Pitot Tube needs outlet - As far I know it needs two inlets to compare static and dynamic pressure.

[NZSnowman]

Thanks Maciek, The pictures and information is fantastic!!

I had seen the Underwater Log System (No but did not put things together 

I had also seen Design Study Type IXC but have not thought about search it for information. I read the Underwater Log System section. It great to know how the speedometer work now. I recheck my pictures but I could not find the Pitot Tube on any of my Type VII bow. This started me thinking that maybe they used a different system on the Type VIIC's. I check some pictures of Type IX bows and found the Pitot Tube (See below U-534). I also recheck the information about openings in the pressure hull for Type VIIC and there nothing about a opening for the speedometer system in the bow

I wonder if they change the speedometer system for the Type VIIC  

[SnakeDoc]

I wonder if they change the speedometer system for the Type VIIC  

I also wonder, why these nozzles are clearly visible only on few photos.
I think, that the system (Fahrtme

[NZSnowman]

Maciek, would changing the location of the inlets affect the speedometer? Would shipyard need to reset system (e.g. does the length of the pipe affect the speedometer?)

Why do you think the shipyard would feel the need to change the location?

I tried to check the bow of U-995 but the whole bow of U-995 as be replace 

[SnakeDoc]

Maciek, would changing the location of the inlets affect the speedometer? Would shipyard need to reset system (e.g. does the length of the pipe affect the speedometer?)

In the Design Study is written, that speedometer had to be calibrated to the each
hull shape, so I think that inlets position should affect the installation.

Why do you think the shipyard would feel the need to change the location?
I tried to check the bow of U-995 but the whole bow of U-995 as be replace 

It's my guessing, why these inlets are so hard to locate.
As I wrote above, these could be installed ones a little higher, ones a little lower,
ones as a sticking out pipes, ones as a little holes in outside casing.

--
Regards
Maciek

[Pat]

That makes sense that the pickup could be in different places in different boats.  We already know that different shipyards had different patterns of drainage holes from each other and even from one year to the next, and knotmeter pickups could be the same.

Even the type of instrument could differ from one boat to another as they'd use whatever was available at the time.  Modern boats are not necessarily the same.  There are 3 boats the same as mine in my YC, and each of them have different spars and slightly different rigging.  Mine has 1 dorade over the head, another has 2 in the saloon, another has none.  One has 6 opening portholes, mine has none, the other has just 2.  The blocks and mainsheet traveller are different for each boat, and often the manufacturer of cleats and blocks are different for each boat.  So are the instruments.

[Jooy]

   Well, hi to everyone...  I'm a novice in your forum and I'd like starting telling this crazy thing:   

   I've been giving rounds in my mind to build slowly (I'm not in a hurry... ), a U-boat in scale 1/6 for my soldiers, and althought I'm conscious it may be a suicide idea, I wouldn't like to leave at least without trying it before...
   Over all, I had thought for solving the problem of the large size of the length (we would be talking about almost 11 meters), I'd made it by parts: 6 parts of 1,5m and the last: the middle in 2m.   
    Anyway, all these ideas are focus to the same idea: to build an u-boat in scale 1/6...  and I was wondering if someone could help me get some decent levels but then had to expand or something similar.

    That's all... Thanks in advance.   

[NZSnowman]

Check this out

http://www.vulcaniasubmarine.com/KRAKA.htm

http://www.vimeo.com/976560

http://ing.dk/artikel/89591

   Well, hi to everyone...  I'm a novice in your forum and I'd like starting telling this crazy thing:   

   I've been giving rounds in my mind to build slowly (I'm not in a hurry... ), a U-boat in scale 1/6 for my soldiers, and althought I'm conscious it may be a suicide idea, I wouldn't like to leave at least without trying it before...
   Over all, I had thought for solving the problem of the large size of the length (we would be talking about almost 11 meters), I'd made it by parts: 6 parts of 1,5m and the last: the middle in 2m.   
    Anyway, all these ideas are focus to the same idea: to build an u-boat in scale 1/6...  and I was wondering if someone could help me get some decent levels but then had to expand or something similar.

    That's all... Thanks in advance.   

[Rokket]

NZ -that top link is WOW!!! thanks! many folks here would share that dream I'm sure!

Jooy - it IS possible. Someone near me has started building a full scale Spitfire. keep us posted. When you say "get some decent levels" what do you mean?

[NZSnowman]

NZ -that top link is WOW!!! thanks! many folks here would share that dream I'm sure!

Jooy - it IS possible. Someone near me has started building a full scale Spitfire. keep us posted. When you say "get some decent levels" what do you mean?

Yes it a fantastic build...I watch the build a few years ago...had forgotten about it til today 

[NZSnowman]

Hi Maciek

In this picture you can see the Pitot Tube right on the bow line.

[Jooy]

   Yeah, these links are  really incredible !!!   Perhaps I wasn't too ambitious...  I had thought building it by parts, with the idea of making easier to transport at the end of the proyect...  But I could only let to build a model proyect, not a real one... It should be very expensive...
    Well, first I should try to get some plans more bigger than a 1/72 scale if what I want is to build a 1/6 one...  Maybe this is the next step...

   Anyway, all this post is really amazing... I'm reading slowly and learning a lot on it... Thanks a lot for your comments.   

[Pat]

Simon, what is it that you think is the pitot tube in that picture?

I see what might be some sort of flat opening on the bow line, with a ring in front of it.  The ring would change the water flow and thus the readout. 

Also, the bow of a sub on the surface, unless it's very calm water, will be diving up and down, in and out of the water.  I've been on boats even with waves only about a meter, that going the right direction, the bow came out of the water so much one second I was looking down about 4 meters to the water surface, and a couple of seconds later the water was up to my waist as the bow plunged.  That would also mess up the readings. 

Finally, that's a fairly small ring protecting whatever that is.  It wouldn't take a very big log or bit of ship's wreckage to bash it in when the bow plunged down onto it.  The front of a boat is not nearly as protected from obstacles as the leading edle of an aircraft, since the water is not compressible and gives a lot of backing to whatever force gets delivered to the bow from a floating obstacle.

Not saying that it's not a measuring device of some sort, but if it was, that location would most likely be experimental and not a regular location.


The one that looked more possible was a picture that somebody posted recently that showed a vertical gap between two hull plates set back perhaps 1/2-1 meter from the bow.

[NZSnowman]

No. 1 is the S-Ger

[NZSnowman]

Engine Room Piping

[Pat]

Simon, my crappy computer is striking again.

The picture is coming through so poorly here that I can't see anything at #2.  Just a joint between two hull plates maybe.  #1 and #3 do show up.

And this session, the picture for the engine room piping isn't opening up either.  Perhaps the next time I log on.  (Last night, I couldn't even get into the website)

But anyway, as I've said, the cutwater is a poor place to put any sort of speed measuring device, for several reasons.  It's just a slight improvement on putting it at the stern around the propellers and dive planes.  It won't give an accurate reading at the stem and if a boat was to spend any time on the surface, in cloudy weather where they can't take a sextant sighting, then it could throw them off course.  It can't be a standard location.  I'll go with a pitot tube type measuring device, but not there other than experimental on a few boats.

[SnakeDoc]

Hello Simon

In this picture you can see the Pitot Tube right on the bow line.

Thanks for the photo.

But anyway, as I've said, the cutwater is a poor place to put any sort of speed measuring device, for several reasons.  It's just a slight improvement on putting it at the stern around the propellers and dive planes.  It won't give an accurate reading at the stem and if a boat was to spend any time on the surface, in cloudy weather where they can't take a sextant sighting, then it could throw them off course.  It can't be a standard location.  I'll go with a pitot tube type measuring device, but not there other than experimental on a few boats.

I've checked in "Submarine Design" by Urlich Gabler (http://de.wikipedia.org/wiki/Ulrich_Gabler) that pitometer log of that type was used as standard device. I've also some records describing Fahrtme

[NZSnowman]

Thanks Maciek for the additional information

[Rokket]

Hi Maciek,

That last held true into the 1960s in the USN. My 2nd Dad was a young Lt in 1957 on Grouper, and later worked at a living hisotry museum of the 1600s (Mayflower II in Plymouth Massachusetts, USA), where he used a quadrant (not even a sextant yet in 1620). He said the 1600s navigation was pretty close to his 1950s nav. Shooting the sun and stars the old fashioned way!

[Rokket]

This is a Gato, but has some good general sub speed log info.

http://www.maritime.org/fleetsub/log/chap1.htm

[NZSnowman]

Thanks for the additional information I will read it after I come back from my field work this week.

I was wondering have you seen any information for either magnetic or gyro compass for the Gato? I been looking for information for the U-boat but not having much luck

Simon

[Rokket]

I am NO expert, but belive both navies had similar - a gyro for the "real" cource, and mag as well, and repeaters. What did you need to know?

[Pat]

Yes, pretty much all navies used gyrocompasses, and since the technology was invented in (1885, 1908, 1911 depending on source), it was well out of patent and the primary mechanism was known by all nations by the time of WWII.

http://en.wikipedia.org/wiki/Gyrocompass

"The gyrocompass was patented in 1885 by the Dutch Marinus Gerardus van den Bos; however, his device never worked properly. In 1889, Captain Arthur Krebs designed an electric pendular gyroscope for the experimental French submarine Gymnote. It allowed the Gymnote to force a naval blockade in 1890. In 1903, the German Hermann Ansch

[NZSnowman]

rokket & Pat thanks for the information  

Was after anything information that this time, as I would like to add them both to my drawing.

I am reading U-Boat 977 by Schaeffer, Heinz and he said that while a depth charge attack the gyro-compass came out of it housing and across the Control Room at 10,000 rpm

Has anyone else read this book?

[Rokket]

As a side note - and it might have been mentioned and I didn't see it - magnetic north is not true north, and it varies. The VIICs had a mighty big compass in the boot at the foot of the fairwater, but now that I'm pressed, I can't say if it's mag or gryo...

[NZSnowman]

The 'mag' is at the foot of the fairwater (I must say I had to look up 'Fairwater' ) & the gryo is in the Control Room next to the Attack Periscope Shaft (below red outline).


Picture from U-995 http://www.uboataces.com/u995.shtml

[Pat]

I couldn't find 'fairwater' referring to subs, but isn't that the bulge in the front of the CT?  (At least when referring to the gyrocompass - there can be many fairwaters on a boat)  I'd thought the gyro was inside the fairwater but according to Snowman's pic, it's inside the control room.  Is one of them a repeater?

Yes, rokket, you're correct.  Magnetic north is not true north.  The difference between them is called "variation" and it changes depending on what part of the world you're in at the time.  Not only is it different because of geometry, but also there are large deposits of magnetic ore in some places of the world (there's a big hill in New Brusnwick, Canada for instance where the magnetism is enough to move a car) and there are also parts of the world (one I know of is east of the southern tip of Africa) where the magnetic compass is unreliable.

BTW, variation also changes with time, so that all nautical charts have a record on them of the year printed and the current rate and direction of variation.  You have to make a calculation by date and location both to offset the compass.

But the reason magnetic compasses are almost useless on steel-hulled boats is because of 'deviation', which is where the mass of metal on the boat throws off the compass even more.  There is a process called "swinging the compass", whereby you take the boat out to a known position that can be checked by triangulating shore references, and then go in a tight circle, all the while taking compass readings on a fixed point on shore and recording how it deviates from what it should be depending on what direction the boat is facing.   (and also taking into account the variation previously noted).

Even small bits of metal close enough to the compass can change it, like a battery driven watch or a pair of steel-framed eyeglasses in the case of hand-bearing compasses.  The engine of course is a huge mass of metal, but then also, there's more metal fore and aft of a compass then there is to either side, so the deviation changes accordingly.

Navigation is a very complex process (until GPS came along).  I did well to never be off more than 1/4 km on any trip I've been on, but then, I've never sailed more than 200 NM in any one direction either.

[Rokket]

Good Pic, NZ!  Good info, Pat. I wasn't sure if the variation was set for a time or not, but I do remember seeing dates or "changes XXX degper year" on some charts now that you mention it. Hey, great navigating, too!
Here's a link to a pic of a binnacle with small magnets either side to overcome the magnetic deviation:


I don't know how they compensate the small floaty mag compasses small boats use, but do know the bulby indicator is "backwards" in that the reading is made easier for the helmsman (heading N the "N" is at 6-o'clock, S at Noon, rather than other way, because often viewed from side/edge and not top-down). Interesting stuff.

"Fairwater" - I was being nitpicky, sorry. On a WWII sub (or at least in USN talk) it is the only real exposed part, the superstructure, the bridge.  Post-WWII it is called a "sail". Often it is incorrectly called "conning tower", and I have done it myself. But technically, the CT is ONLY the pressure-hull inside, not the outer superstructure.

[Pat]

Ah, thanks for the correction on "conning tower" rocket.     This forum is great for learning something new almost every time I log in.

Yeah, navigating across the water is a lot more complicated than on land.  True vs magnetic north, variation and deviation are just the beginning of the navigation courses I took and actually some of the easiest parts of it.  I still have 2 years to go to get the celestial nav part down, but since I've only sailed on the ocean within about 50 miles of the continent, I don't think I need those.  After all, even if I got lost, just head west and I'm bound to find N. America eventually, right?

BTW, the two balls in your pic are called "Flinder's balls" after Cap't Matthew Flinder, who was the one who invented the idea.  They're made of soft ferro-magnetic iron, and they're mounted on little slots in the arms ao they can be slid in and out.  You'll only find them on the binnacles of steel hilled ships, even in WWI torpedo destroyers, dreadnaughts, monitors, etc. (all these interesting types that we no longer have) so if you ever do a model of a tall ship, make sure you know what the hull was made of (or in the case of a ship like say, Cutty Sark, where the hull was wood but the frame was steel, so it would have had Flinder's balls).

Anyway, how they work is that as I'd mentioned before, in a steel hulled ship, there's more mass of metal lengthwise along the direction of the keep than there is athwartships, and that means the compass deviation is greater when the keel is lined up with magnetic north than when it's pointing east or west.  The Flinder's balls compensate for this by adding to the metal abeam of the compass, but they're placed much closer to the compass so even though small, their affect is greater.

Note also that the post in your binnacle picture is wood.  You don't get metal binnacles until more modern times when aluminum became sheap enough to make binnacles out of that.  I think some old ships might have had brass binnacles, but that would be a rarity.

My own boat haas an aluminum one but I made a teak covering for it to make it look reminiscent of the old style in your picture (only a LOT smaller!)

Oh yeah, the reading being backward in the binnacle you see would be specific to the design of that particular ship because of where the helmsman was expected to stand for whatever reason.  Some are backwards, most are regular.  Most mag compasses have different posts and markings on them to help read the direction from different positions around the compass, depending on where the helmsman is standing at the time.  On my own boat, the entire top is clear, like a snow globe, so I can read it from 360 degrees around.  About half the time, I wouldn't be standing directly behind because if the boat is heeling, it's just too uncomfortable so the helmsman might sit off in the corner to one side or the other where he has a backrest and cushions and better visibility forward around the mast.

[Rokket]

Flinders balls - I'm sure there were no jokes about that! Very cool. I never thought of the keel, but makes sense. Your teak cover sounds lovely Pat! You have to get some pix posted of all kinds of things!

[Pat]

Yes, I'm sure there was a joke or two going around about Matt Flinder's balls.

Flinder's balls haven't disappeared on modern marine compasses either BTW.  They've just shrunk (again, I'm sure there are comments there too) and moved internally. If you take the cover off a modern compass, there are usually two small pieces of ferrous iron on slides that can be adjusted the same way as the big balls that the old tall ships sailors had on their binnacles.  (I just KNOW what's going through your mind now)

The modern ones are smaller I think because magnets can be smaller through better methods of making them with perhaps purer iron.

BTW, the teak sheathing on my binnacle (hey, no more jokes here please) aren't fastened on.  I didn't want to take the chance of interfering with the mechanisms inside the binnacle.  (The gearshift, throttle control, steering cables and compass lighting all go through a very narrow tube).  I drilled holes in the teak planks and then lashed them on with small line and covered the lashings with Turk's Head knots so that it looks fancy, but can be removed with a flick of a sharp knife if needed. 

[NZSnowman]

I couldn't find 'fairwater' referring to subs, but isn't that the bulge in the front of the CT?  (At least when referring to the gyrocompass - there can be many fairwaters on a boat)  I'd thought the gyro was inside the fairwater but according to Snowman's pic, it's inside the control room.  Is one of them a repeater?

Just come back from 4 days field work counting grasshoppers It's what I study in the summer.

Pat, the bulge in the front of the CT is the magnetic compass, however, there is a second gyrocompass in the U-Boat but I am unsure where. 

[SnakeDoc]

however, there is a second gyrocompass in the U-Boat but I am unsure where. 

According to U-570 British Report
http://uboatarchive.net/U-570BritishReport.htm
and Type IXC Desing Study
http://uboatarchive.net/DesignStudiesTypeIXC.htm
on boats type VIIC and IXC were set of one magnetic compass and
one gyro compass (Anschutz type).

--
Regards
Maciek

[NZSnowman]

Hi Maciek

Thanks for the additional links

It does look like there is only one gyro-compass on the U-boats. I saw the gyro-compass labeled as "Master Gyro-compass" in Anatomy of the ship: The Type VII U-Boat by D. Westwood and I just assume there was a second one on U-boats.

[SnakeDoc]

Hello Simon

I saw the gyro-compass labeled as "Master Gyro-compass" in Anatomy of the ship: The Type VII U-Boat by D. Westwood and I just assume there was a second one on U-boats.

I have also met this term, but I think, it means something like "master gyro" and some number of slave repeaters.

--
Regards
Maciek

[NZSnowman]

Does anyone know if the keel of the Type VII is solid or made up of frames?

same for me, sure I've seen a pic. I THINK it's solid (or solid from big chunks) for weight.

Just a guess, but the standard material for ballast keels is lead.  They want the heaviest but cheapest material they can get to take up the least amount of space while lowering the centre of gravity so the boat rolls less.  It would definitely not be iron as that would corrode too quickly, and not likely steel because it isn't heavy enough and they need it more elsewhere.

If there are access hatches to the keel, that sounds like they might want to at least inspect it once in a while for corrosion and to clean out the limber holes so that any water will drain to a sump where it can be pumped out.  The limber holes on many ships often have a small chain running for and aft that could be pulled to drag out any gunk that got stuck in the holes, blocking the free flow of water.

Going back to the keel ballast question. Would the lead blocks be painted with anything, e.g. like anti-corrosion?

[UrpoK]

Hi NZ,

I think painting with anti-corrosion is a good guess.

There is a mention in the overhaul papers of submarine Vesikko that

[Pat]

Simon, I don't know if there'd be any anti-corrosive coating on lead keel blocks or not.  My guess is not, because they're carried inside the steel of the keel so aren't exposed directly to water. 

The reason that the lead would be totally enclosed is because it's both very heavy, AND very soft.  You can't weld it to steel, since it melts at a much lower temp. and you can't bolt it either, since the boltholes would just wear away rapidly.  That means it any seam between steel and lead would quickly leak.

In my own boat, the lead is encased in fibreglass, and the only place it can be seen is through inspection ports on top.  I think some keels are through-bolted to outside of the hull, and the seam always seems to crack and let water in, making regular maintenance of the seam is a necessity.

Urpak's comment about scrubbing the ballast plates makes sense, in that lead does get powdery white on the outside and gets soft.  In fact, sailing ships before the invention of copper plating in the middle of the 18th century, were painted with a mixture of tallow and lead powder that made the underwater parts of the hull white (something to remember whenever making a model of a sailing ship.  You have to kow the date and location of the ship to determine what colour it would be below the waterline).

In a book I have, there's a colour plate of U-596, in Mediterranean camo, with the hull red below the waterline.  The saddletanks and the first what looks like 2 feet of the waterline are black or very dark grey, while below that is red.  Looks like the picture on Silent Hunter II.

I can't imagine that the KM didn't paint their steel hulls with anti0corrosive paint, which is that same dull red you often see the beams for bridges and buildings during construction.  The hull of Greif's Bismark is probably that colour below a dark band at the waterline. 

The dark grey of U-boat hulls would be an anti-fouling paint applied on top of the anti-corrosive paint.  It's the antifouling additives that make it turn dark after a few weeks immersion in water, it usually starts out a different colour, but of course, during wartime, they might also have used specif colours for camo reasons too.  The anti-fouling I use starts out a bright, copper colour when I first apply it, but about 2 weeks after launch, it looks about the same colour as a school blackboard that's been used a lot.

[NZSnowman]

Simon, I don't know if there'd be any anti-corrosive coating on lead keel blocks or not.  My guess is not, because they're carried inside the steel of the keel so aren't exposed directly to water. 

Two things:

I can not remember what it call but it happen when two different metal touch. Would this not happen with lead and steel

&....

I can not imagine the keels for the U-Boats were water poof    

I can't imagine that the KM didn't paint their steel hulls with anti0corrosive paint, which is that same dull red you often see the beams for bridges and buildings during construction.  The hull of Greif's Bismark is probably that colour below a dark band at the waterline. 

I believe they painted anti-corrosive paint inside the saddle tanks.

[NZSnowman]

I was thinking, I imagine most or maybe all the ballast must be fore of the Engine Room

[Pat]

Simon, you're correct that there would be "galvanic corrosion" between lead and steel.

Galvanic corrosion occurs when two dissimilar metals connect, especially when immersed in a conductive liquid such as sea water.  The baser metal (the lead in this case) corrodes, not the more noble metal (the steel).

However, it's actually preferred that the lead WOULD corrode, rather than have the lead protected.  The reason is that there are many different kinds of metal used on any ship, and a submarine might have some specialized metals not found on most ships, and since they take water into ballast tanks and have all sorts of piping inside not found in surface ships, there's probably more different metals than surf-side.

So the idea is to have lots of the baser metals available for corrosion, so that it won't go on to attack the next metal up the scale.

All boats with any metal in contact with the water have what's called "zincs" or sacrificial anodes in several places to save the more expensive , vulnerable and important pieces.  These are just what they sound like, a piece of zinc, bolted to the sides of metal parts because if there's any stray electtrical current in the water, it will corrode the less noble metal (the zinc in this case) first and ignore the more noble metal.  The zincs have to be inspected once in a while and replaced when getting thin since as soon as the zinc is gone, the galvanic action will attack the next least noble metal.

On my own boat, there is a zinc inside the raw cooling water inlet before it gets to the engine, to protect the inside of the engine.  There is also a zinc on either side of the hull beside the propellor shaft to protect the shaft and propellor.

I've seen pictures of type VII's under water with a zinc on either side of both rudders, up near the top of the rudder close to the shaftand another zinc on each side of the propellor shaft struts, just by the hub that the shaft goes through.  These zincs are rectangular and 2-3 inches thick. 

The exact size and placement of the zincs would not be the same on each boat since they would use whatever was available at the time from whatever manufacturer had stock, and the location is not precise, just "close to where something needs protection".  On different years of my own boat, the zincs are always there, but could be as much as a foot different in location.

There would almost definitely be zincs somewhere around the diesel engines as well, and possibly somewhere near the electric motors to protect against stray current there.

One other point, the zincs should NEVER be covered over with the anti-corrosive paint.  The whole idea is that if there IS any corrosion, it would be the zinc that gets it.

The zinc itself is a dull silvery-grey colour, perhaps with some whitish corrosion on it.  You could make zincs for your model out of a strip of plastic, perhaps 1/4 mm thick, 1/2 mm high and 1.5-2 mm long.  The long axis is parallel to the motion of the boat.  Some zincs have rounded edges, some squared.

[NZSnowman]

Thanks Pat for the information 

[SnakeDoc]

Hello Simon

Going back to the keel ballast question. Would the lead blocks be painted with anything, e.g. like anti-corrosion?

According to
http://www.ubootarchiv.de/dieboote/farben_maerz_1940.html
http://www.ubootarchiv.de/dieboote/farben_juli_1944.html
keel ballast was painted grey.

--
Regards
Maciek

[Pat]

Did a bit more research and see that I had one thing wrong about the galvanic corrosion.

http://en.wikipedia.org/wiki/Galvanic_corrosion

Anodic index (edited)
Gold, solid and plated, Gold-platinum alloy 0.00
Silver, solid or plated; monel metal. High nickel-copper alloys 0.15
Nickel, solid or plated, titanium an s alloys, Monel 0.30
Copper, solid or plated; low brasses or bronzes; silver solder; German silvery high copper-nickel alloys; nickel-chromium alloys 0.35
Brass and bronzes 0.40
High brasses and bronzes 0.45
18% chromium type corrosion-resistant steels 0.50
Chromium plated; tin plated; 12% chromium type corrosion-resistant steels 0.60
Tin-plate; tin-lead solder 0.65
Lead, solid or plated; high lead alloys 0.70
Iron, wrought, gray or malleable, plain carbon and low alloy steels 0.85
Aluminum, cast alloys other than silicon type, cadmium, plated and chromate 0.95
Hot-dip-zinc plate; galvanized steel 1.20
Zinc, wrought; zinc-base die-casting alloys; zinc plated 1.25


From the above chart, lead is more 'noble' than iron/mild steel, so the lead in ballast will not corrode.  Zinc is the lowest one on the scale (higher number means it corrodes faster), so that's why it's used as a sacrificial anode.  You can see from the chart why stainless steel (high chromium) is used in so many marine applications, and why brass was used in the old sailing ships, before stainless steel was invented. 

Powdered copper and tin are what is put into anti-fouling paints to keep barnacles, algae and marine life from attaching to the hulls.  Why it changes colour to slate grey/black after it's been in the water for a while, I don't know.  But it's because of that I suspect that even though at launching the hull of a U-boat might be dark grey, I think it will probably get darker with immersion.

[NZSnowman]

Hello Simon

Going back to the keel ballast question. Would the lead blocks be painted with anything, e.g. like anti-corrosion?

According to
http://www.ubootarchiv.de/dieboote/farben_maerz_1940.html
http://www.ubootarchiv.de/dieboote/farben_juli_1944.html
keel ballast was painted grey.

--
Regards
Maciek

Thanks Maciek. Great link I had forgotten about these pages.

The information on the 1944 version was great Ballast keel inside = 3 layers of tar varnish So they may have just put the lead blocks straight in without painting them.

[NZSnowman]

Did a bit more research and see that I had one thing wrong about the galvanic corrosion.

http://en.wikipedia.org/wiki/Galvanic_corrosion

Anodic index (edited)
Gold, solid and plated, Gold-platinum alloy 0.00
Silver, solid or plated; monel metal. High nickel-copper alloys 0.15
Nickel, solid or plated, titanium an s alloys, Monel 0.30
Copper, solid or plated; low brasses or bronzes; silver solder; German silvery high copper-nickel alloys; nickel-chromium alloys 0.35
Brass and bronzes 0.40
High brasses and bronzes 0.45
18% chromium type corrosion-resistant steels 0.50
Chromium plated; tin plated; 12% chromium type corrosion-resistant steels 0.60
Tin-plate; tin-lead solder 0.65
Lead, solid or plated; high lead alloys 0.70
Iron, wrought, gray or malleable, plain carbon and low alloy steels 0.85
Aluminum, cast alloys other than silicon type, cadmium, plated and chromate 0.95
Hot-dip-zinc plate; galvanized steel 1.20
Zinc, wrought; zinc-base die-casting alloys; zinc plated 1.25


From the above chart, lead is more 'noble' than iron/mild steel, so the lead in ballast will not corrode.  Zinc is the lowest one on the scale (higher number means it corrodes faster), so that's why it's used as a sacrificial anode.  You can see from the chart why stainless steel (high chromium) is used in so many marine applications, and why brass was used in the old sailing ships, before stainless steel was invented. 

Powdered copper and tin are what is put into anti-fouling paints to keep barnacles, algae and marine life from attaching to the hulls.  Why it changes colour to slate grey/black after it's been in the water for a while, I don't know.  But it's because of that I suspect that even though at launching the hull of a U-boat might be dark grey, I think it will probably get darker with immersion.

Pat, the Wikipedia page on galvanic corrosion was the start thing I did after your late post

[NZSnowman]

Turbo blower for the Port Diesel Engine

[Greif]

Nice picture Simon.  I wanted to build a turbo blower for my engine room interior, but I just could not gather the spare parts to build a realistic looking one.

Ernest

Turbo blower for the Port Diesel Engine

[Rokket]

Not very submarine-ie but my solar hot water heater (and apparently most hot water heaters) has an anode that is designed to decay. It gets used up and prtoects the tank. has to be replaced every 5 years. Same principle.

[Pat]

Well, at least your anode IS under water all the time rokket.  That's sort of submarine-ie.

And yes, it's definitely the same principal.