US Divers RAM in Antarctica

[luis]

Take a look at the Antarctica Journal on the link below:
www.nsf.gov/pubs/1996/nsf96121/nsf96121.pdf

There is an article about “Regulator Performance”. It is based on a study of regulator failures in Antarctica in the early 90’s. According to the article, the USD RAM was the regulator of choice until 1992 (due to its reliability and resistance to freezing).

The study was conducted in order to find a suitable replacement for the aging RAM’s they had in service (they were all probably over 20 years old). What I found somewhat surprising is that in 1992 when they started to record failure rates on all the regulators, the RAM’s had 35 failures on 126 dives (27.8%). That is a very high failure rate.

The article mentions that in general the failures were related to free flows and water in the regulators, but I think this comments were mostly associated to the newer single hose regulators (but, can’t tell for sure). My suspicion is that most RAM failures were more related to the aging of components (such as rubber parts) that have not been replaced for a while (due to lack of availability), but the article doesn’t say.

IMO, a leaking mouthpiece valve allowing water into the case could easily be a source for ice in the mechanism, followed by free flows.

So here are my questions:

1. When did USD quite supporting the RAM?

2. Specifically when did they quit making hoses, duckbill, mouthpiece valves, and diaphragms (most of the other parts were available from the Conshelf)?

3. When was the fire at the USD manufacturing plant?

4. After USD quit supporting the RAM, was there a reliable source of after market replacements for hoses, mouthpiece valves, and duckbills (such as Marvell or others)?

5. Does anyone have more information directly related to this study or the use of RAM’s in Antarctica (or other cold weather operations)?

[Seahuntjerry]

Hi Luis,
I saw a report years ago on free flowing regulator in Undercurrent.They discussed the nylon coated rubber high pressure diaphram freezing and causing the free flow in ice diving.
The water leaking by the one way valve won't cause a freeflow unless some how it was stationary and not being used.

I started Ice diving in 1964 and never had a double hose freeze up,now the Calypso piston single hose regulators were famous for freeflowing and causing the termination of a dive.
Sometimes i would shut the divers air off underwater ,while he breathed fron my octopus and then slowly turned it back on again.
Sea you at Portage?I-AM-SPAM/
Jerry

[dbg40]

Same here, Started ice diving in 68, never a single, solitary, failure from my DA, or RAM. Not so with my singles. In fact, I never dove with an occto before singles, and never felt in the least bit insecure about it. However, there is no way that I would considder going under ice with a single, and not having a backup.

[scubadiverbob]

Alot of single hosers are made for diving in the tropics (well, most were designed for that). For ice you better have a sherwood blizzard or a dacor pacer 900xl enviormental (if you use a single hose). Most of the regs mentioned were open piston (if it has holes in it, and you can look inside and see a big spring, it's a piston reg that might freeze up with ice water in it; it's that simple) and when you dive them the water is inside the first stage. If you got a piston reg and the first stage isn't sealed, make sure to clean the first stage by squirting fresh water into the holes after each dive in salt water; 'cause, that's usually where the problems are when they need overhaul. DA's and RAM's, as long as they are properly maintained, shouldn't get hardly any drops of water in the cans except the exhaust side of the cans. Simply put, air under pressure doesn't freeze (well, depends on how cold the air gets, and it'd have to get pretty cold to freeze !!!)

[SeaRat]

There was a pretty spactacular airline crash in, I believe, Washington DC area (or was it New York?). Anyway, there were movies of the tail sticking out of the water, and one fellow diving in to rescue a woman who could not cling to a line from a helicopter.

That airliner was salvaged by the US Navy, but they at first tried it with their state-of-the-art Unisuits and Poisden single hose regs. The Uni-suits soon were full of holes by being ripped to shreds by the aircraft wreckage, the regs froze, and the divers also froze. So they re-grouped, and dove the airliner using Navy doubles, with double hose Aquamasters, and wet suits (rip them, and get a little cold on one spot; rip a Unisuit, and you are cold all over). They were successful in getting the black box, and getting lines around the aircraft for salvage, using wet suits and Aquamaster regs in freezing water.

John

[JES]

That was Air Florida Flight 90 that crashed into the 14th Street Bridge across the Potomac River in Washington, D.C. on January 13, 1982. The accident claimed the lives of 78 people, including four motorists on the 14th Street Bridge.

Click the words "Air Florida Flight 90" above to learn more about this tragic accident.

[swimjim]

searat said:

There was a pretty spactacular airline crash in, I believe, Washington DC area (or was it New York?). Anyway, there were movies of the tail sticking out of the water, and one fellow diving in to rescue a woman who could not cling to a line from a helicopter.

That airliner was salvaged by the US Navy, but they at first tried it with their state-of-the-art Unisuits and Poisden single hose regs. The Uni-suits soon were full of holes by being ripped to shreds by the aircraft wreckage, the regs froze, and the divers also froze. So they re-grouped, and dove the airliner using Navy doubles, with double hose Aquamasters, and wet suits (rip them, and get a little cold on one spot; rip a Unisuit, and you are cold all over). They were successful in getting the black box, and getting lines around the aircraft for salvage, using wet suits and Aquamaster regs in freezing water.

John

As an owner of a unisuit I find that hard to believe. Mine is about an 8 mil neoprene and even when the thing leaks, its still warm. I dive at freezing or below all the time so its not like I don't have experience. Posidon regs tend to blow ice down your throat in water thats 33 degrees and less. They don't however freeze up IF properly maintained. I have also dived DA's in the same environment which I have rebuilt and my Phoenix. Niether has given me problems in freezing and sub freezing environments. From what I have seen of so called fire Dept rescue divers, they are generally under trained and over zealous. It's not a surprise to me they had a problem when the metal met the meat.

Jim

[SeaRat]

While looking for more info on Flight 90, I found this issue of Faceplate, which has some really nice articles an vintage diving (including SeaLab).

www.supsalv.org/pdf/faceplatefebruary2005.pdf

John

[SeaRat]

The story I told above about the divers is as I remember it after reading about the diving in the 1980s. I remember how I was smiling to myself about the US Navy going back to the older gear because of the failures of the newer stuff. They actually had to go inside the aircraft, and their Unisuits, from what I've been told, were actually cut in many places, and leaked badly. The aircraft had been shreded by the combination of the crash landing and the ice, and that made for really hazardous diving. They did have trouble with their single hose regulators (which I thought were Poisiden, but may not have been--that was many, many years ago). I do know from that article, which I cannot confirm, that they did switch to double hose Aquamasters and wet suits. Here's the Wikipedia link:

en.wikipedia.org/wiki/Air_Florida_Flight_90

John