Re: Survey

[Rick <nexus@intergate.bc.ca>]

Ray Keefer wrote:

> Hi Rick,
>
> Vancouver! Can you drop by and visit International VentureCraft Corp.
> and gives us a report to the news group. Photos if possible. I have
> their information video and info pack but a first had account would
> very much be of interest. At least to me. They have ambient pressure
> SportSub and ResortSub designs that I am strongly leaning toward as my
> first
> submersible.

Hello!  I can be of some help as it turns out.  Some years ago I
actually did visit them.  Their Sport Sub concept is based
[intentionally or otherwise] on a sub featured in Popular Mechanics back
in June/'71.  Kent Markham [Florida] had converted an airplane wing tank
[as in fuel] into the main fuselage.  Below that he constructed a casing
to hold some railway track as dead ballast and to hold the battery box.
Like the Sport Sub, entry was from the underwater portion of the boat,
in this case, from the side.

To blow variable ballast in the cockpit, the operator would rotate a
plumbing pipe set at 90 degrees into the sub's wall.  Same with
flooding.  [your local library may even have the P.M. back issue; the
illustrations of the ballast system are quite straightforward].

What the Sport Sub has that our highly [?] volatile fuel tank did not
was a self contained life support system.  The usual O2 bleed/CO2
scrubber routine if I remember correctly.  What I do remember was that
the lifting points [for hauling out] were built into the fibreglass.
They seemed quite happy with it. Apparently, there was no internal
construction to support the load.

I have one major critique to pass on.  I don't understand their design
rationale with regard to the ballast box.  Markham at least streamlined
his to some extent.  The Sport Sub's has this horrifically inefficient
box that creates vortices something awful.  Hydrodynamically, the sub
could do better.  At the resorts they're dealing with, it's expensive to
run around buying batteries, recharging, etc.  The design rationale of
"We had to fit the personnel in somewhere" could, perhaps, have been
dealt with differently.  The side ports are hemispheres and could have
been tear dropped in shape.  The windshield [wind? :-) ] could have been
curvier and more wraparound.  What all this says in terms of lost income
[as in increased use of resources to overcome the inefficiencies] who
can say . . . a study was done by the Germans in the second world war.
One of their midget subs, the Neger, I believe, had a dome rather than a
plane shape [e.g.: a fairwater] or teardrop, for the viewport.  What
seems so clear in retrospect is that the teardrop shape the Germans did
explore did, of course, turn out to be much more efficient.  Ever try
moving a ball quickly underwater? I believe it was at least twice as
efficient as a dome.

The video you have is probably the next best thing to being there in the
water with it.  We can always "improve" on a good design.  That's the
bane of many engineers - "let's just tweak this over here . . ." The
basic concept of the Markham boat is easy to reproduce and does what it
was intended to fairly well.  It remains one of my favourite subs.

All in all, it's nice to see that some guys got together, followed up on
Markham's design and are making some money at it.

I hope this helps you out.  Vancouver is a sort of Mecca for the
commercial submersible industry.  A guru, and a very friendly one, that
we have is none other than Phil Newton [Newt Suit among other numerous
credits].

Warm regards to all . . .

Rick Lucertini
Vancouver, CANADA




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