Pressure Gauge Failure

[PWCPD Diver]

During training this week one of our team members had a pressure gauge failure at 15 feet. It read 2500 psi but the tank was out and he was sucking rubber. He isn't too experianced and instead of switching to his pony and dumping his weights he emergency ascended.

We put the entire rig and gauge on a fresh tank and it pegged at well over 3000. Then it dropped back to 2500 psi. When I took it to the dive shop after disconnecting from the tank it still read 2500 psi. The gauge is over 20 years old. Now at least we can get new gauges for the team. It was an old Sherwood I'm not sure of the model.

Lessons learned I guess

 

[PerroneFord]

Just a strange question here.

Did he reference the guage at all during the dive? If yes, doesn't it seem strange that maybe half an hour or 45 minutes into the dive, he was still showing 2500 pounds? If he didn't reference the guage at all, then will the new guage help?

 

[DA Aquamaster]

Exactly. The critical issue here is not whether the gauge worked. It was obviously giving him bogus information for a long time before his tank notified him he was out of air. A diver should always kep a running record of the dive and should have at least a vauge idea how much gas he or she has left and compare that mental figure with the SPG reading to see if the two even roughly agree. If the SPG needle has not moved since the last reading, it's a reliable indication of a problem with the SPG. Of course that requires remembering your last reading rather than just blissfully waiting for the needle to get to 500 psi.

The issue of doing an emergency ascent when he had a perfectly useable pony available is also a bigger concern than the equipment failure.

I also don't understand the reference to the preferred approach of switching to the pony AND "dumping weights"? Why would anyone want to do that? Once you dump them you are going all the way up. It's not a big deal at 15', but at 115' would be a serious safety issue. He's got an oral inflator on the BC and knowing how to use it is not a bad idea. Also, most inflators will still work at a reduced flow rate even after you can't draw any more air out of the tank with the regulator so the odds are he still could have inflated more or less normally.

The order is breathe, think and act when solving a problem - you don't just skip to "oh my God, I better punch put before I drown!!".

 

[PWCPD Diver]

He was under less than 10 minutes

 

[PWCPD Diver]

Exactly. The critical issue here is not whether the gauge worked. It was obviously giving him bogus information for a long time before his tank notified him he was out of air. A diver should always kep a running record of the dive and should have at least a vauge idea how much gas he or she has left and compare that mental figure with the SPG reading to see if the two even roughly agree. If the SPG needle has not moved since the last reading, it's a reliable indication of a problem with the SPG. Of course that requires remembering your last reading rather than just blissfully waiting for the needle to get to 500 psi.

The issue of doing an emergency ascent when he had a perfectly useable pony available is also a bigger concern than the equipment failure.

I also don't understand the reference to the preferred approach of switching to the pony AND "dumping weights"? Why would anyone want to do that? Once you dump them you are going all the way up. It's not a big deal at 15', but at 115' would be a serious safety issue. He's got an oral inflator on the BC and knowing how to use it is not a bad idea. Also, most inflators will still work at a reduced flow rate even after you can't draw any more air out of the tank with the regulator so the odds are he still could have inflated more or less normally.

The order is breathe, think and act when solving a problem - you don't just skip to "oh my God, I better punch put before I drown!!".

As far as air checks go we do them every ten minutes. We also have a tender for each diver. The communications officer handles the log book for the dive and monitors the air check times.

He can't use an oral inflator when using an AGA very easily.

As far as dumping his weights I meant to say at the surface not on the ascent.

He doesn't have a lot of training and the "Oh &*^%" factor kicked in. He is aware of what he did and how to address the problem if it arises again.

 

[PerroneFord]

He burned through 2500+psi of gas at 15ft in less than 10 minutes?

 

[amascuba]

He burned through 2500+psi of gas at 15ft in less than 10 minutes?

Sounds more like the guy checked his gauge every ten minutes, but didn't put two and two together when his pressure never fell below 2500 psi after a period of time, which led to the butt puckering feeling of "oh !#@&* I can't breath!".

 

[PerroneFord]

Sounds more like the guy checked his gauge every ten minutes, but didn't put two and two together when his pressure never fell below 2500 psi after a period of time, which led to the butt puckering feeling of "oh !#@&* I can't breath!".

Well thats what I was thinking too until the OP said this:

He was under less than 10 minutes

So now I am confused...

 

[PWCPD Diver]

Well thats what I was thinking too until the OP said this:




So now I am confused...

He went in at 2800 psi. He then started a fan search pattern and before we could even get his first air check at 10 minutes he came shooting to the surface like a humpback whale.

 

[PerroneFord]

Hmmm ok.

So either he went down on an empty tank, or he sucks gas more then even me!