RE: [PSUBS-MAILIST] safety systems

The JSL subs have releasable buoys like that. A reel on the sub lets it out and a grappling hook from the support vessel follows it down to grab the sub.

Greg Cottrell

Project Manager

greg@precisionplastics.com

http://www.precisionplastics.com

P please consider the environment before printing this email

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Alan James
Sent: Wednesday, August 25, 2010 5:05 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] safety systems

Hi Jon,

Re the marker bouys; below is a sub escape paper by Dr Phil,

wich has a simple marker buoy system that enables a heavy line to be

attached to the hull. I'm sure this has been covered before & may be in the

Busby book, but will bring it up again as I think it is easy to implement &

could be added to our list of standard safety equipment.

In addition to what is said I'd suggest that the emergency marker buoy line

be of a floating type, as you wouldn't want excess line wrapping round rocks

or portions of your hull & stopping the load line attaching.

See also attached diagram.

Alan

Ascent Buoy and Remote-latching Load Lines

Over the years, considerable thought has

been given to an emergency ascent float similar

to the system used in submarine rescue by the

U.S. Navy. While it is hardly possible to salvage

a full size submarine by the attachment of

a single load line, it is a fairly simple matter

to re-attach a severed load line remotely. One

device to accomplish this task is comprised of:

A buoy capable of withstanding full operational

depth repeatedly (an aluminum or

plastic trawling float does well) and provision

to release the float from inside

the SDC. A reel of light line sufficient

to reach the surface from rated depth.

This reel should be free-wheeling, con-'

structed of a corrosion proof material,

such as plastic and have a wire sling run

through the centre of the reel and attached

to a lifting padeye. A spare load line

fitted with a spring loaded latching device.

In practise, the buoy is detached from the

disabled SDC by a mechanical handle operating

through an a ring sealed penetrator. The buoy

ascends, spooling off line or light wire from

the reel. The line is terminated around the

reel drum. The surface crew retrieves the buoy

and brings the line taut. A load line is

shackled to the light line with a clevis latching

device on the end. The load line is carefully

lowered to the SDC until the clevis

latches around the reel drum. The load is

tightened until the reel drum breaks and the

centre sling is held by the clevis. The SDC

is then retrieved in the normal manner.

This type of system has been fitted to

several miniature submersibles and Figure #(2).

shows this system installed onboard the deep

submersible "Sea Otter". The author has participated

in numerous open water tests of this

safety device and has been particularly impressed

with the consistent results. The remote

latching device is most applicable to a

situation where the normal load line is severed

or otherwise detached, but the SDC is unencumbered

for ascent. Such a controlled ascent

is always preferrab1e to release of the SDC's

ballast clump and an emergency, uncontrolled

ascent with the inherent dangers of striking

the bottom of the drilling vessel, etc.

----- Original Message -----

From: Jon Wallace

To: personal_submersibles@psubs.org

Sent: Thursday, August 26, 2010 1:43 AM

Subject: Re: [PSUBS-MAILIST] safety systems

Perhaps marker buoys on all subs, period. It appears to be little overhead for large gain even as a backup for a sub with tracking ability. However, rather than an unofficial list let's do this via our guidelines RFC procedure so we have a record of both the proposal and vote, and can then make it part of our official guidelines. Some of the things you've mentioned we may want to be mandatory equipment, others optional.

Jon

On 8/25/2010 7:49 AM, vbra676539@aol.com wrote:

All,

Some of the psubs have emergency marker buoys installed. I think that should be another tool on all subs that operate without the benefit of tracking systems and the like, which is most of us. It's another thing that should be considered in the planning stages, but could also be an add-on. Maybe we ought to start a list: Drop weights; jettisonable thrusters; marker buoy; good communications, emergency life support, etc.

Vance