On Thu, 12 Nov 2009 23:47:16 -0600, Jon Slaughter wrote:
I've crossposted this to sci.engr.joining.welding. There's no real
electrical principle involved here, unless the current through sea water
somehow damages one of those auto-darkening hood lenses.
Yes, there is an electrical principal, the electric current passing
through the salt water to the ground (the current will take every
available path) will greatly increase the rate that the chrome corrodes
off the brass parts of your helmet. If you happen to have one of the
really nice all SS helmets, this may not be an issue. I don't believe
anyone uses auto dark lenses for UW welding.
No you can't.
It would violate all safety guidelines by IMCA and the ADC.
You can't have anything inside the hat that wasn't part of it's
Any dive supervisor who allowed it would be fired and have his card
Same goes for ipods.
Intercoms in a good helmet consist of speakers dipped in rubber. The cheap
common way is a condom wrapped around the speaker, and held in place with a
Factory speakers are good, and last a good while, but the cost of
replacement is so high that when the original set goes out, they are usually
replaced by the lesser units, which are far cheaper, and easier to get in
And tested to what depth? I doubt you could find a depth test rating on one
of those. I know I have seen good high dollar watches that were "tested" to
330 feet or something ridiculous, and didn't hold. I had an Omega that I
spent big bucks on, and only wore it topside, never exposing it to pressure
of more than 1 atm. Brought it to the jeweler when it wouldn't work, and he
said the in side was all corroded and flat worn out. Real commercial divers
don't wear a watch. They are another thing to hang up, they are easy to
lose, you can't see the thing 90% of the time, and the surface radio man and
dive master keep track of your time anyway.
Oh yeah, also if you get your body between the ground and the
electrode, in salt water, while the knife switch is closed...
...YOU ARE DEAD!!!.
I teach welding at the Divers Institute of Technology.
In fresh water you just get a small electrical shock, but in salt water
it is lethal.
Also all underwater wet welding is performed in the DC Electrode
Negative polarity to prevent electrolysis from stripping metals from
around you and applying them to your weldment.
The greatest erosion occurs at the bronze jaws of the electrode holder.
No. Control is totally topside with a knife switch. Diver sez make it hot,
and the knife switch is thrown. When done, he's SUPPOSED to say make it
cold so he doesn't get zapped, or the corrosion on his helmet continues. On
the work we did, it was all done with a knife switch topside run by an
assistant of the radio man.
"SteveB" wrote: Control is totally topside with a knife switch. Diver sez
make it hot,
I can think of two reasons for using a knife switch: 1.) It is possible to
see at a glance whether it is on or off. 2.) The switch carries the full
Am I on the right track?
It's for safety. It removes any chance of the welder doing something
stupid, or say a cable gets cut or mashed or pinched, and goes to ground.
Or the diver narcs out or is kayoed. It takes control of the on/off out of
the hands of the diver.
I went to diving school in 1974, and worked for about a total of eight years
after that. I am commenting on methods and equipment used at that time. In
the ensuing years, I'm sure there's been changes and better stuff. Ernie
would know about that. So, my comments are just on the way we did things
back then, and with the new stuff, someone who has used it recently should
comment. Autodark for even above water welding wasn't even a figment of
someone's imagination at that time.
For all other things I say that are wrong, please consider that they are
just in error, and not really wrong.
Commercial diving has changed little in the last 30 years.
The only real change has been greater and greater enforcement of safety
procedures, and equipment maintenance.
Also the hats have gotten better as far as regulator designs.
Divers don't like new stuff if the old stuff works.
There is less and less underwater wet welding due to insurance costs.
They have developed new dry habitat welding procedures for pipeline
It isn't like the insurance companies actually "like" divers.
They just don't like paying their widows large cash settlements.
Looks like what we called a SPAR, or subsea pipeline alignment rig,
seriously heavy, seriously difficult to get into position, seriously
difficult to cut and align a repair pup, and seriously crowded, with an
argon atmosphere where men had to be masked to weld inside. Didn't work
Sounds like stuff hasn't changed a lot except the hats. I see a lot of new
Kirby stuff that was just on the cusp of evolution in 1980. Most were
Kirby-Morgan band masks, and few had neck rings, except some of the old
Descos and Savoies. There was a black one that looks like the current
Kirby, but I do not recall its name. Head protection was something you
strapped on OVER your band mask.
For us, safety practices and equipment maintenance were just a cadre thing.
OSHA rules do not apply in international waters, and we would repetitive
dive out of N, O, and Z groups. We were pirates and kings of the world, and
had our own group. We always did have a chamber, and "hits" were common.
Equipment maintenance and all diving equipment hookup, take down, and
operation was left to the dive crew, and not allowed by any other group.
Got on a union job one time for Bannister Pipelines, the Alaska pipeline
people. They found out that they could put a couple of more mechanics to
work, so insisted that we use union mechanics to service our dive
compressors, even start and stop them. That cost several VERY expensive
delays, waiting hours for a mechanic to be airboated or choppered across the
swamp to start up a compressor for a ten minute dive. That lasted about two
weeks until one of them put regular oil in an air compressor, and sent a guy
to the hospital with lipid pneumonia. After that, we were given special
dispensation from the union to handle our own stuff. The two mechanics did
stay on for the duration of the job, though, "just in case." About two
weeks after that, I saved a laborer from drowning, and we raised another
notch in the pecking order with all the union hands. Before that, they had
used union laborers to swim lines under pipelines, and do in water work
until they had a couple of close encounters with alligators, and the
laborers refused to get in the water any more. People were leech magnets
without a wet suit. At first they were standoffish as we weren't union, but
got Davis-Bacon wages. Then when they didn't have to get wet or dive with
the leeches or alligators, they didn't mind so much. Then when I saved
"Jivin' Joe", a black laborer from Opelousas, we were tight. That was 90
miles of 54" OD concrete coated pipe through the Atchafalaya Swamp from
Centerville to Belle Chasse, LA. Quite a job.
All automated FCAW shielded bug welding except for tie ins. 50% cutout
Gulf of Mexico work was terribly hazardous, not so much from the dive crew,
but the other crews we worked with and around. And weather. I look back at
it now and ask what I was thinking. It was high adventure, though.
Steve, who misses the good old days, but not that much.
You are in constant audio contact with your knife-switch operator
When you are ready to weld, (assuming you are at the Blue station) you
say "blue diver, make it hot"
The communications person repeats that statement "blue diver, make it
The knife switch operator closes the switch and replies "blue diver hot"
Communications relays the info to the diver "blue diver hot.
When you are done with your rod, you go through it again with "blue
diver, make it cold" and so on.
You never change a welding or burning rod with the knife switch closed
or you get zapped.
If you are caught trying to do it on the job, you will be fired.
Employers don't appreciate you endangering their insurance policies.
If one diver screws around and gets hurt, you can lose your insurance
and hence your contract for that work.
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