checking the line

[Widiver_Paul]

The "ball" type may eventually give up and leak but leak doesn't happen suddenly (you will notice that it starts to seep air long before problem happens).

One failure I saw (luckily it was in a pool) just started shooting air out like a freeflow, it would have been pretty scary deeper than 10 feet or in overhead.

[crazyduck]

I'd use a swivel, but that just seems to be another failure point (i've seen these fail on 3 divers rigs).

Recently at DEMA I meet the President of Omni Swivel and was really impressed.
I was talking about diving and the swivel being a “possible” failure point and this guy was great. He could have just ripped of my head for being a moron instead he took out on of the swivels and took it apart. I was so impressed! Come to find out the J&M Mfg has multiple patents and other 3rd world countries are trying to produce knock offs and cheapen the product.

I work in Industrial Automation/ Engineering and I see my fair share of underdeveloped crap! But this was really sweet. He builds both sides of the parts separately, he finishes the parts, plates them, and then assemblies them. If you get a chance I would highly recommend looking at their product. This is going to be more expensive but I think we can possible benefit from the proper design ideas. His product is also for sale at Advanced Diver magazine.

Paul, if you have any questions give me a yell.

Regards, Andrew

J&M Manufacturing or Omni Swivel.


Web site: http://www.omniswivel.com

Check out photos- half way down the page.
http://www.therebreathersite.nl/Boot%202005/various.htm

[Widiver_Paul]

Looked at that swivel, those look pretty nice. Omniswivel seems to have a similar design to a 1-atm suit joint, whereas the failures i've seen have been with the ball-and-socket type design.

[rchrds]

Ok- just a couple of things- one for the original post- and one for the off topic-

Pull checks on the line are not always a good thing. I say this not with the usual places in mind- there are many places off the beaten path where the lines are laid in fragile territory- pulling the line is sure to break the tie-offs- which is fine in an emergency, but not otherwise- many of these lines have been in place for many, many years without anyone yanking them free. I almost never pull the line- the only exception being if it is buried in silt- As another person mentioned bring it to the top- I have actually seen line go in a silt pile on one side and out on the other, but be broken in the middle! Another thing that I used to run into that has become less common, now that people like to shove steel stakes in the pristine sand/clay dunes, is a line that has been laid intentionally slack. This had two purposes- (and of course it only worked in low flow, non-reversing caves.) If the line, when pulled taut would invariably work into a particularly ugly line trap, it would sometimes be laid slack- with a bomber tie off on either end. This allowed the person in zero viz to fish back and forth to find the large part of the passage. There were usually only a few sections laid like this, so you knew that if you were still on the line and you werent able to get through you were in the wrong part of the passage- go right or left. The other was passage where there were no acceptable tie offs for a large distance due to fragile passage, Though I think I've only seen that once.

As for the hose config- I finally had to quit routing the hose around my neck in the fashion that you describe. If you spend a significant amount of time in uncomfortably small passage that left hose is ALWAYS getting hung up when you duck your head to get through- particularly bad if you have one hand full with a bottle partially disconnected and in front, and the other hand helping through the restriction. Even worse if it pulls some slack from your bottle and you dont realize that it has hung until your shoulders are through the restriction and it is hung about the middle of your back. I finally went to a reg that feeds from the left, which I am not particularly happy with, because of the quality of the reg (too bad the G250 cant be swapped for left hand feed) but I have not got snagged up since. Another common answer is to route the hose below you- if you keep most of the slack out, it will stay streamlined, but the real advantage is you can fold your arms to reach your belly and unsnag it- kind of hard to reach between your shoulder blades.

J