Re: [PSUBS-MAILIST] wooden hull Psub revisited

[Michael Holt <mholt@richmond.edu>]

> John Gaertner wrote:
> 
> I recently rejoin the Psub mail list after a two year break. I have
> been looking into the use of wooden "doughnuts" as a means of building
> a 1 atm. 100 ft max diving depth psub for personal use. I reviewed the
> archives but unfortunately those who commented on it, their email
> addresses bounced back. So I would like to open the floor up for
> discussion...

Welcome back, John.

The wooden donut idea goes all the way back to the 60s, with
Helle Engineering the Submanaut.  It's in Busby on page 221
and on page 250.  Busby lists a collapse depth of 2000 feet
and an operating depth of 200 feet.  

Jerry /Stachiew even wrote about it, in Underssea Technology 
magazine (Sept., 1968).  I've never read that article.  
Busby's review of the article notes that Stachiw felt plywood 
has a place in submarine hulls where budget (and presumably 
depth) is limited.

I talked with Mr Helle (his first name eludes me right now), 
in about 1989.  The boat was out of the water but in good
condition.  His wife wanted to give me the boat, but he 
hesitated (of course it works like that).  He said there 
never were any problems with it.  

According to Busby, the technique is to cut 4-inch wide
ring panels from the wood.  The rings are glued together
and the whole is glassed over.  

I suspect a problem would arise if the boat were going
to spend all its life in the water, or if it were cycled 
too often.  ne might have to very careful about how 
the boat were launched, because the plywood might crack
internally if the stress were not evenly distributed as
it began to float.



Mike