[rollei_list] Hard-Hat Diving
- From: Marc James Small <msmall@xxxxxxxxxxxxxx >
- To: rollei_list@xxxxxxxxxxxxx
- Date: Fri, 07 Jul 2006 15:58:15 -0400
I've really enjoyed this discussion of hard-hat diving -- for the
uninitiated, that is diving in a canvas suit with a brass helmet, air being
piped dowsn from the surface through an air hose. As a mere lad, some
forty-five years back or so, I read widely on the subject. In those days,
the quality gear was either from the British firm of Seibe, Gorman, who had
developed the stuff, or from the US Navy built to Seibe designs. The diver
had an air hose and a line to the surface. In the days prior to the
development of telephonic communications during World War I, the only means
of communicating was by the lifeline. One tug from the surface was a query
whether you were still around. One tug from the bottom meant that you were
okay. Two tugs from the bottom was a request for more free line. Four
tugs from the bottom was "bring me up". I forget the rest of the code on
this.
The deepest dive ever made on normal air was that of Tom Eadie off of
Hawaii in 1914 during the salvage of the US submarine F-4 at 304 feet
(about 95m or so). In the 1930's, the US and British Navies began
experimenting with Heliox mixes -- helium and oxygen instead of the
nitrogen-oxygen mix of the normal atmosphere. That allowed a British diver
to reach 600 feet (roughly 190m) depth in 1960. (The record today is
classified, as it is held by the US Navy team out of the Norfolk Navy Base
in Virginia, but it is in excess of 3,000 feet (about 980m). These guys go
down to about 600 feet (190m) on Heliox, then convert to Hydrogen-Oxygen.
But these guys are not in hard hats: they use the deep-water equivalent of
SCUBA gear. I have spoken with a couple of these deep divers and they
assure me that such descents are a grand adventure but admit that it gets
really lonely down there in the dark. They have to wear electric warming
gear as both Helium and Hydrogen cause the body to lose heat more rapidly
than does the standard Nitrogen basis.)
Those interested in hard-hat lore are encouraged to dig up copies of Edward
Ellsberg's books, especially ON THE BOTTOM and MEN UNDER THE SEA, as well
as his four volumes of juvenile fiction. A couple of British divers also
published memoirs worthy of a quiet read with a glass of unsweetened ice
tea on a Saturday afternoon.
Marc
msmall@xxxxxxxxxxxx
Cha robh bàs fir gun ghràs fir!
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