Hello Group,
I wish to introduce myself and my proposed project to this group in
an effort to illicit some knowledgeable input.. My name is Joe and I am
lucky to live in S. Florida where I have been a diver since 1977 (when
everyone was still afraid of Jaws). Retirement for me is 11 years away
and I own a home on some acreage in central Florida which will be my
construction base. (Nemo's Vulcania Island as it were).
Some years ago I came across a working 1 atm replica of Nemo's
Nautilus on the web, (a welded steel two man boat I believe). Another
fellow in Ca. Built an epoxy-ply semi-submersible replica of a WW1
S-boat. This vessel has a number of view ports amidships and does not
submerge. A very clever design with an outboard well. Simple, elegant
and functional as basically a "glass bottom tour-boat. Above water she
looks like a working S-boat.
Considering the nature and quality of marine plywood in conjunction
with modern epoxy composite construction, I believe that it may perhaps
be possible to take the concept one step further, (albeit for private
uninsured use) and construct a fully submersible ambient pressure
boat.
This started the wheels turning and I realized that I could duplicate
this with the Nautilus, complete with those side view ports we all know
so well. Then I came across both the Venture craft Sportsub and several
other commercially available designs and the thought of an ambient
pressure diesel-electric boat has been swirling about ever since.
The Nautilus would be easy enough to duplicate in this material and
of course, the selection of material rules out a 1 atm boat so ambient
it is. One simpler option depending on DWL would be a semi-submersible
design where the view ports would be lowered a bit, but why bother with
the complexity if not to make her fully submersible.
I know some of you will be horrified at the thought of a "wooden"
submarine but, modern epoxies and quality marine-ply should make it
doable for an ambient pressure design. With proper consideration of
scantlings, I believe the ship would be robust and seaworthy with the
majority of maintenance considerations being focused on systems. She
would basically be as a WWII fleet boat, a surface ship capable of short
term submersion.
Operational rules would be as follows.
#1 The boat never submerges unless those aboard are certified divers.
Internal pony bottles and at least two points of egress would be
provided. (Most likely Freeman hatches).
#2 The boat never submerges without an escort surface vessel in
communication.
#3 The boat never initiates a dive in water depth greater than 30'
nor ventures where the bottom is greater than 50'.
In S Florida, that means most of the premier diving locales in N
America are within a short distance and quite accessible.
I do have some questions in mind that are unanswered at this point
and input would be most greatly appreciated.
#1 I need more info on the air systems in ambient designs, most
online material and books appear geared more to 1 atm design. Please
point me towards some material. How much airflow in cfm is required to
maintain ambient pressure from the surface to 50'? The compressed air
requirements have the potential to be a "deal killer" for a fully
submersible design, I have not yet done the calculations.
#2 Does some manner of scantling rules exist for GRP designs?
#3 Has anyone else built an ambient design of marine-ply?
And finally, general input as to the concept and choice of materials
would be appreciated. I envision this being done with "off the shelf"
components but, if I am overlooking something unworkable I may stick to
the surface design.
Incidently, another Hurricane, (Wilma) is heading my way tonight. We
are shuttered up and hunkered down so I may not see any responses until
after power is restored (could be a week or more). I thank you in
advance in that event.
Thank You
Joe