US Divers RAM in Antarctica

[luis]

US Divers RAM in Antarctica


Take a look at the Antarctica Journal on the link below (I think from 1996):
http://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,
That study must be m ore about single hose regulators,contact with water in the second stage levers freeze or rubber lp seat is too cold to seal,after a diverstarts breathing from it on the surface,or the high psi diaphram thats way they seal it on the Artic reg..

This also can be a problem on deep dives in Lake DSuperior etc.

Years ago i was diving it was 10 above zero my friend froze up my conshelf.I had my Royal aquamster follishly lying on the ice,I hooked it up
and it breahed stiffly spit into my mask it froze,got into the water and let the ice melt inside of my mask.
The Royal perfomed Flawlessly!!!!!

Usdiers fire was in the early 80"s


I saw Kemp's cow using a Voit Fifty fathom reg

Jerry

[Bryan]

I thought about this after you called me Luis and the only thing I can come up with is that the divers/equipment repair guys simply ran out of good replacement parts for the RAM’s…What else could have caused the failure rate to go up that drastically?? This is just my opinion…..I think it would be really interesting to examine one of those RAM’s right before it was retired. I’d love to scrutinize the internal parts…….
BTW anyone that dives under the ice needs to have their head examined (we already knew that about the Kemps Cow) The only two interesting things I can say about my experience diving under the ice are 1. It is very loud and you can hear ice move/creak/crack as people walk around. It is both exciting and frightening at the same time. 2. If you put you fins against the ice (you are upside down) and lean back against the rope and give three quick pulls the surface tenders will pull you back very quickly and it’s a lot like skiing upside down on ice….

[Nemrod]

I don't think anything of that study, it has no control.

Failure rates are relarted to many things and I imagine this was not personally owned equipment and that it was severely abused and poorely kept.

I don't know when USD quit supporting the regulators but I bought my last new set of hhoses off the shelf around 76 and saw no more after that. Had I only known what I know now. Those were used on my Mistral. The double hose stuff pretty quickly dissappeared from shops, virtually completely by 76 or so and really around 1972 there was very little.

James

[Firebrand]

I read a similar govt. article on a cold water test a fiew years ago. I basically drew the same conclusion as James from it. It had absolutely no control regs to set a benchmark, other than the previous unchallanged reliability on the double. At the end it seems that the Ddoubles were failing at a greater rate than the singles, but it was of interest that the writer mentioned on more than one occasion, that the failures could be a fact of little, or improper maintainence done to them. And also that the doubles were of an advanced age. What impressed me most of all, was that inspite of the obvious proverbial deck being stacked against it, the doubles were still in the mix for testing. I would have liked to see a properly rebuilt / maintained and tuned RAM in direct and fair competetion with the NEW, singles they were compared too. I'm willing to bet that the outcome would have been interesting at least. And an eye opener to the testers to boot!

[luis]

IMO they weren’t trying to make an unbiased (or a biased) study. They were just collecting the data based on the circumstances at the time.

We can observed that it was not a fair comparison since the RAM’s have been in service for at least 20 years and no new rubber parts have been available for probably over a decade, but that was the reality of the early 90’s.

The data collection / study was just evaluating a suitable replacement for the 20 year old RAM’s. The reality is that at the time they didn’t have much choice. What cough my attention was the failure rate on their last year of use, but it shouldn’t be totally surprising.

I just wish we hade more information and details on the kind of failures they encounter, the condition of the regulators, and their service history. It would be very useful information.

In any case, in 1992 they didn’t have all the resources for parts and service we have today. First and foremost we have to thank the Internet (funny how technology is helping us revive the past) for allowing us to get together as a group and from the group we need to thank people like Bryan, Dan, Jerry Moseman, Karl, Stuart, and several others who have contributed with reproduction parts and many who have shared used and NOS parts as they have become available.

I think it says a lot that they were still using them for two decades after they were discontinued, but I am trying to understand what types of problems they could have encountered and the lack of what parts was most critical to their failures.

[Firebrand]

I was trying to find the report I had read but it escapes me for now. I do remember that the actual details of failure b in the doubles were pretty much non exiistant. they just mentioned failure. It's too ad that the details were not recorded, or at least publised, as it would be a damn good read for those of us that continue to use them. There must be more detail on these tests somewhere, but perhaps they were just flashed over because the intention was never to revive the double for use, making the cause of little interest to the tests?

[Firebrand]

There is some interesting reading here.


Defense Technical Information

[JES]

IMO they weren’t trying to make an unbiased (or a biased) study. They were just collecting the data based on the circumstances at the time. ....

Excellent point, we shouldn't throw out a valid report just because we may not like what it has to say.

.... In any case, in 1992 they didn’t have all the resources for parts and service we have today. First and foremost we have to thank the Internet (funny how technology is helping us revive the past) for allowing us to get together as a group and from the group we need to thank people like Bryan, Dan, Jerry Moseman, Karl, Stuart, and several others who have contributed with reproduction parts and many who have shared used and NOS parts as they have become available. ....

This is without question the reason we're able to enjoy our regulators. Just think, with the current availability of reproduction parts the NSF would still be able to dive their RAMs.

.... I think it says a lot that they were still using them for two decades after they were discontinued, but I am trying to understand what types of problems they could have encountered and the lack of what parts was most critical to their failures.

Just a guess, but based upon the useful life of a duckbill, I'd be willing to bet that this simple (but necessary part) very well may have led to number of the failures the NSF experienced. Remember, there were only a small number of divers so they probably didn't stock many (if any) spare parts.

[captain]

I think the last place and time I was able to buy new original replacement parts for my DA was from National Scuba Repair in California in the late 1970's. I bought a supply of duckbills that I stored in the freezer for over 25 years.

[Firebrand]

As I remember, the last parts I could find were from Seawolf divers supply, owned by Charlie Wolf here in Ct. I think it was in 1977.