In my humble opinion - I think the skeg keel has a heavy metal lower base where the metal vertical rudder protection structure is attached besides the hydroplane drive shaft and the dual prop support. The skeg keel only has internal vertical frames and flooding holes on each side. There are no stringers internal to the skeg keel... It looks to me that Stringer #1 is only internal to MBT 1 and attached to the aft pressure hull.
The 1st image Stringers 1 shows stringer #1 and it looks to be at an angle (possibly several stringer #1's). The 2nd image MBT 1 shows a vertical slice of the U-Boat at frame +2 and the stringers are all internal to MBT 1, and at frame -6 there are no stringers visible.
Hi Don,
Yes, the images you have posted are quite helpful.
Stringer #1 is what I was after.
From the images you have posted, I believe that Stringer #1 does not lie on the centerline of the boat. It probably radiates away from the pressure hull to the outer hull at angles, probably roughly in-line with the prop shaft supports, as I had previously guessed and illustrated here:
I think thiis is corroborated by your image:
So the stringer #1 that I thought I was seeing in vertical section as lying on the section plane is actually placed radially out from the pressure hull.
This means that the skeg is
hollow and there seems to be nothing in between the floods on one side of the boat to the other.
The modeler I was following on the U552 blogspot site was incorrect.
I think I understand now.
Steve