[PSUBS-MAILIST] launch cart redesign

[T Novak via Personal_Submersibles]

Hank,

Further thoughts on launching as I want to be able to launch my sub directly
from the trailer:

You may recall my current trailer also needs to be disconnected from the
truck and allowed to fully submerge to float the sub off and on.  This
trailer requires about 55 inches of water to launch and recover the
submarine.

With respect to a new purpose built trailer (to replace my current utility
trailer), I am planning on a low slung boat trailer with a 5 foot vertical
stanchion welded onto the tongue between the coupler and the boat winch.
This would allow the operator to detach the electrical plug from the truck
and clip it to the top of the stanchion, thus keeping it dry out of the
water while the trailer is detached from the truck and rolled fully
submerged into the water.

Another mod that I have planned is to weld two straight c-channels from the
front of the trailer frame back to the front of the wheel fenders such that
they hang down from the frame in front of the wheels below the wheels'
equator to act as skid plates.  This way if the launch ramp ends at a drop
off the wheels will fall  off the ramp but the c-channels will then support
the weight of the trailer as it slides further into the deep water.  As
well, I think that the bottom of the c-channels would benefit from having
sacrificial oak or plastic strips on the bottom to take the damage caused by
dragging the trailer up and over the drop off.  I currently have three
single-wheeled jacks on the tongue to provide sufficient floatation of the
tongue on the substrate while the trailer is disconnected from the truck.  A
tongue jack with a double ended ski like plate may also be a good idea.

While launching my sub from my current trailer I found that the buoyancy of
the three tires keeps the unit sufficiently light on the bottom such that it
doesn't get stuck in the muck.  The bottom substrate must still be
reasonably solid, but with the addition of the c-channel skid plates
providing further floatation on the substrate it should work reasonably well
in most cases.  I am also considering adding the same c-channel skid plates
behind the wheels to the rear trailer frame to give the trailer some
tendency to lift itself onto the top of the substrate if the substrate is
softer and the wheels want to sink into the mud while it is being backed
into the water.  I found that submerging the trailer and recovering it with
tow straps works quite well.  

Since my submarine is operated by divers, it is no problem for the divers to
set an anchor out into deep water, run a line from the back of the trailer
through a pulley attached to the anchor and then back to the truck.  As the
truck pulls forward the disconnected trailer is pulled back to the anchor
into the deep water while a diver helps keep it on track.  Obviously this
would not be an option for your one dry-man operation.

I have bearing buddies on my trailer now, and the new boat trailer will be
aluminum or galvanized steel so that salt water launches are not a problem.

Just my thoughts, perhaps you may find them useful. 

Tim

-----Original Message-----
From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org]
On Behalf Of hank pronk via Personal_Submersibles
Sent: September-28-14 6:33 AM
To: personal_submersibles at psubs.org
Subject: [PSUBS-MAILIST] launch cart redesign

I am back to my launch cart because lake levels are dropping.  I am making
big design changes to make it more user friendly and to allow super shallow
launches.  First I am changing the axel arrangement so the cart steers. The
biggest change is ballast tanks.  I am adding two ballast tanks above the
wheels.  The idea is to back the cart and sub into the water with ballast
tanks full of air.  The cart and sub should float away in 36 inches of
water, or less. Once the sub and cart have floated into deeper water, I
simply open two valves to let air out of the cart ballast tanks until the
sub is free to float away.  I simply throw an anchor out to keep the cart in
that spot until I return.  When I return the cart will be pointing up wind
making it easy to drive into.  I raise the cart with air and use the sub to
drive it to shore or boat ramp.  

I am not working on my support boat because I have no support,lol.  There is
no need for a large boat because I am a one man sub operation.  Gamma has
such good range on the surface, I can simply cruise on the surface to my
dive sites.  
Hank
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