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Curt W. Smitka, Administrative Manager Phone: (313) 936-0702
Department of Environmental Fax: (313) 764-9424
and Industrial Health E-mail: CWSMITKA@SP*.UM*.ED*
School of Public Health
University of Michigan
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---------- Forwarded message ----------
Date: Mon, 12 Sep 1994 09:18:24 PDT
From: Curt Smitka <cwsmitka@sp*.um*.ed*>
To: Techdiver <techdiver@opal.com>
Subject: Bailout Reels
Four score and several weeks ago I promised information on bailout reel
options.
Background:
A bailout or emergency ascent reel is a piece of safety equipment used in
wreck diving. It is used to provide a stable platform for emergency ascent
when it is not possible and/or feasible to use the mooring line. An efficient
bailout reel must be capable of several things:
1. Easy quick deployment.
2. Provide a stable platform for the diver to decompress.
3. Allow the surface support to readily locate and provide assistance to
the divers.
4. Not interfere or be burdensome to carry on a normal dive.
Options:
I am currently aware of two basic designs of bailout reels being used for
wreck diving. These are the "Jersey Reel" and the "Great Lakes Reel".
These reels evolved from two distinct types of diving. East coast divers
developed their emergency ascent procedures from material that they
typically used on dives to recover artifacts (wreck raping). Great Lakes
diving does not typically involve the recovery of artifacts since most
wrecks are protected under either state or provincial law. (Take only
pictures - leave only memories) Therefore the "Great Lakes Reel" is
designed only to handle emergency ascents.
"Jersey Reel"
The "Jersey Reel" is typically an aluminum spool with handles on each side
to facilitate linedeployment of the line. Typical line is usually 5/16 hemp of
sufficient length to reach the surface. This large reel is usually mounted to
the back or side of a set of double tanks. In an emergency situation the
diver attaches a small (50 lb.) lift bag to the hemp line, inflates the bag, and
sends it to the surface. After the lift bag reaches the surface the diver cuts
the hemp line from the reel and ties it to the shipwreck. After surfacing,
the diver cuts the lift bag free from the hemp line and leaves line to rot
away. (In salt water the line will rot quickly, in fresh water the lines may
take years to rot.). Alternatively the diver may begin their ascent while
deploying the lift bag and then hang off the lift bag to decompress. In
either use the diver has a high task load in deploying the line and must
either; 1) remain on the bottom for an extended time to deploy, or 2) try to
deploy while performing a control ascent and then hang under the lift bag.
In the second scenario the diver hanging under the lift bag also has two
more problems: 1) they are no longer held in a fixed easily found location,
and 2) to hang under the lift bag the diver is usually maintaining negative
buoyancy and often sacrificing thermal protection by under inflating their
dry suit. Also, either method requires the diver to use gas to inflate the lift
bag which may not be desirable based upon the reason for the emergency
ascent.
"Great Lakes Reel"
The Great Lakes reel is a small plastic wire spool that is normally carried
on a harness D-ring. The core of the bailout reel and line is buoyant and
will float the line to the surface when released. The line should be 30-50
feet longer the your maximum planned dive depth. The additional length
allows the line to reach the surface under the typical current conditions in
the Great Lakes. The line is usually a thin (1/8 or 3/16 inch) diameter high
strength synthetic line that has a clip attached to the loose end (bound to
the reel with surgical tubing). In an emergency ascent situation the line is
clipped around a "firmly" attached part of the ship and released to float to
the surface. The diver then performs a normal ascent to the surface. The
reel and line is normally retrieved on a subsequent dive. These reels are
quite small and only slightly positive. The line can be easily tied into loops
at any depth to provide hand holds while performing decompression stops.
To provide an example of dimensions for giving line quantities I have the
following reels:
175 ft line - diameter = 4 inches, length = 8 inches.
300 ft line - diameter = 5 1/2 inches, length = 8 inches.
500 ft line - diameter = 7 inches, length = 10 inches.
===========================================================================
Curt W. Smitka, Administrative Manager Phone: (313) 936-0702
Department of Environmental Fax: (313) 764-9424
and Industrial Health E-mail: CWSMITKA@SP*.UM*.ED*
School of Public Health
University of Michigan
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