Re: [PSUBS-MAILIST] K-sub work

["John R. Farrington" <jrf@austin.ibm.com>]

Hi Dan.  Sounds like you're making progress on your sub.

I was wondering if you could give me a little info into the 
kinds of problems you were having.

I'm about to start machining my viewport frames, and all of
the thru-hull fittings.  I imagine that after we're done with
the machining, we'll be welding the viewports into the conning
tower, and the hull, then attaching the conning tower to
the hull.  So, it looks like you might be able to provide some
foresight that would help us avoid some pitfalls.

Any insight would be very much appreciated!

Thanks.
-John



> Hi Vance,
> As I think I told you a few weeks ago, I decide to do a "do-over."  The
> materials arrived for another attempt at the conning tower last week.  I
> machined four more viewports and had another plate rolled.  This time I
> also burned out a 23-1/2 inch disk to hold the conning tower true round
> while I tacked in the hatch seat ring.  Than I moved the disk to the
> lower end of the conning tower to hold it true round through the rest of
> the welding process.   It's working so far.
> 
> I plan to leave the disk in place till I have the tower tacked to the
> sub hull.  That way I won't warp anything while it's chucked in the
> lathe to machine the hatch seat either.
> 
> Also, instead of just freehand burning out the conning tower viewports
> holes, I drilled the center of each with a half inch hole, placed a rod
> through as a pivot and rigged a swing arm to rotate my torch and let it
> slide up and down as necessary.  The viewports fit he burned out holes
> as if they were machined.  When welding them in, I got a bit of warpage
> in the viewports because of the intersecting geometry of the joint but
> not over .020 on the diameter.  I also kept the heat accumulation down
> as low as possible.
> 
> I think I'm out of that woods!
> 
> Thanks, Dan H.