Two marks on the hull of Type VII

[Mr. Bill]

Hello Jaorsa,

I am very interested in the second photo you posted at the beginning of this thread.  It appears to be a very early pre-war VIIB boat (bronze eagle and shape of the conning tower). 

Do you have any details about this photo such as which boat or the date it was taken?  Do you have a larger image?  I am especially interested in the lower flooding vent pattern at the bow.

Thank you!

Bill

[JAORSA]

Hi Bill!

This picture sent me Dougie. I think he has a better quality picture. It is the U53, I believe that is the day of its launched (06-05-39 in the shipyards of F. Germaniawerft).

There is another photo of the U54 (15-08-39) where you can see more clearly the pattern of holes of flooding of the earliest type VIIB.



To my U47 of Amati, I used the pattern VIIB "U-Brass "(Dougie and Wink). It gives a good result.



Cheers!

Javier

[Rokket]

nice work Jaorsa!

[dougie47]

Hi Javier,

It really is great to see the U-Brass VIIB cheek used on an Amati U 47. Thanks for posting, you've made my day!

Cheers,

Dougie

[Mr. Bill]

Hello Javier,

Very nice work on the Amati U-47!  This is a very ambitious project.  Thanks for posting the additional photos, I am also interested in the flood vents under the forward dive plane - these are almost never seen in photos of VIIB's.  I also noticed a third "bump" in the photo of U-54 located near the extreme bow edge just below the lower torpedo tube door.  Does anyone know what this is?  It looks similar to the two "bumps" located further aft.

Bill

[NZSnowman]

Hello Javier,

Very nice work on the Amati U-47!  This is a very ambitious project.  Thanks for posting the additional photos, I am also interested in the flood vents under the forward dive plane - these are almost never seen in photos of VIIB's.  I also noticed a third "bump" in the photo of U-54 located near the extreme bow edge just below the lower torpedo tube door.  Does anyone know what this is?  It looks similar to the two "bumps" located further aft.

Bill

Bill, it is the Pitot Tube for the speedometer for the Underwater Log System. Check out the discussion we had about it between Reply #348 & Reply #369 http://models.rokket.biz/index.php?topic=106.msg4505#msg4505

[Pat]

Yes, that would have been my take on that bump also.  Especially since the opening is facing forward, not aft.

And that seems to be a lot better location for it since it's to the side, not right on the cutwater, and low enough down that it would be in the water under most conditions and wouldn't be hit by floating debris.

Another question comes up from that pic though.

Up just behind the cutwater at about the waterline, there's one opening in the hull.  I'd thought from Dougie's article, that the port side usually had 3 holes there, (as in the Revell kit) and the starboaurd side had 2.  In this pic, there seems to be only 1 hole on the port side.

Anybody any ideas why?

And what are those holes for anyway?  They don't seem to be located anywhere that it would help a dive or access any equipment.  And it seems odd to have a different number on each side.  They just don't seem to fit in with the other holes along the casing, which make much more sense.

[NZSnowman]

Pat, you are right, 3 on the starboard and 2 on the Port. Not sure why only one Maybe the dockworker were is a hurry to get home that day .

I checked my drawing and plans and you are right! Nothing is in that area of the bow. The only real thing in this area is 'Stringer II'. The holes must be used to drain the water from the bow but you would think it would be lower near to 'E' deck

[Siara]

Maybe that the holes are for draining the chamber where the tow hook is located?

[NZSnowman]

I also initial thought they were to help with the draining of the tow hook well, but these hole are approximately 1,050mm below and 500mm forward of the tow hook well 

[Mr. Bill]

I believe the single vent hole that Pat mentioned in the photo is standard for the early VIIB boats, maybe all B's.  I could be wrong, but I think there is a single flood vent hole on each side.  At least that is what I have seen in photos.  The pattern of vents in the area changed with the VIIC's.  I think this is all described by Dougie in his article, maybe he can confirm for us.

Cheers,

Bill

[Mr. Bill]

Hello Simon,

Thanks for the message references regarding the pitot tube.  It does seem that this was not a standard configuration for VIIB boats, at least I don't see it on the photo of U-99 on page 25 of Steve Wipers book.  Maybe it is located somewhere else on U-99, but I can't see anything that looks right?

Bill

[NZSnowman]

Hi Bill, The location for the pitot tube seems to be different on lots of boats. I can not found any pattern yet

[dougie47]

Hi lads,

Yes, Bill, I can confirm that in all VIIB photos I have seen, there is one hole on either side of the stem. And in all VIIC photos I have seen, there are 2/3 holes on either side of the stem. Why they chose 2 on one side and three on the other is unclear. I presume they could count. 

The other difference in vent patterns between B's and C's regards the main set of holes ahead of the saddle tanks - all C's had fewer holes than on B's.

Perhaps the extra holes on the stem of the C's were to compensate for the fewer holes in the main pattern? Just an idea though - I know the holes at the stem were reasonably far away from the main set of holes.

Cheers,

Dougie 

[Rokket]

No that this adds much useful info, but in principal, the Gatos went from HUGE "sails" ("fairwaters") and FEW flood holes ("limbers") to eventually MINIMAL faireaters and HEAPS of floods.  They found that the bridge and fairwater were huge silhouettes, and cutting them don and even exposing th periscopes  was best, and as for diving, more holes to vent air was better.
I assume - on different scale - the KM went through the same process. Interesting, the Gato bow view is remarkably simila to the VIIC, despite different Navies and SIZE. And really, the 2 silhouettes aren't THAT differnet,