Surface Supplied Diving: Emergency Procedures, Part I

The absolutely bitching, somewhat new Kirby Morgan KM97 stainless steel hat with the new 455 regulator.  Note the twisted umbilical and the pneumo hose, which is blue.  

Though a variety of arguments can be made for the level of safety in SCUBA diving and surface supplied diving, there is an inherent risk associated with any activity which takes place in a medium wherein the human being cannot survive without mechanical intervention.  For example, the astronaut is toast (or frozen) without his suit outside the Earth's atmosphere and the high altitude pilot, though in air, does not have a high enough partial pressure of oxygen to support life.

In these circumstances familiarity and comfort with one's life support equipment is essential and can mark the boundary between life and death.  In recent weeks my class and I have been trained in some of the essentials of emergency management while diving hard hats and I'll detail what it was like, at least for me!

The intelligent surface supplied diver uses safe, trustworthy equipment they've checked out themselves and understands they have to completely trust topside as their link to breathing gas.  With that being said, the proverbial shit can and does hit the fan.  A good diver prepares for the worst by simulating emergencies and creating muscle memory for problem solving processes which may aid them even when they're running out of air in a zero visibility environment.  A good diver also realizes they play a major role in their safety and whether or not they survive when the worst takes place.  The ability to think clearly in an adverse situation and to stave off panic is an essential skill for a safe diver.

Not a terribly related photo... but a cool one!  And it's of me!  

The out of air emergency is the prevailing concern for the surface supplied diver.  The diver often acts without solid communication with topside and has no choice but to trust the compressor or alternate gas sources above.  99.99% of the time, this is no problem.  However, when the air goes out and breathing becomes labored, the diver has some choices.  For the purposes of this article I'm going to stick to what the diver can do when screwed by the laws of probability.  I'll comment on topsides corrective actions in another post.

The first and best option is the bailout bottle which law dictates the diver must wear on his back.  This provides a secondary air source located with the diver wherever he is.  Even if the diver's umbilical is severed, he can still use whatever pressure he has in his bailout bottle.  The bailout is simply activated by turn a knob on the right side of the diving hat or switching the bailout bottle on by reaching back and turning the knob on the tank valve itself.  However, guidelines state the diver only needs to have enough air on their back for four minutes of breathing at a given working depth.  It's better than nothing but is not a heck of a long time to problem solve and most people on the edge of panic are breathing pretty hard.  We've been practicing this skill a lot.  It's as easy as it sounds.  The second I feel like I'm trying harder to pull air through the regulator I just reach up, turn the knob and breath the sweet, delicious, life giving air I was missing.  Then you inform topside you're on bailout and immediately start yelling at them with the most colorful language you can come up with.

The bubbles all up in my grill are coming from the impact wrench but very much resemble the volume you get out of the pneumo hose.  

Let's say for some reason topside can't supply the diver and air and the bailout bottle is quickly emptying.  There are typically two members of the four part umbilical capable of carrying breathing gas.  One is the main supply hose connected to the diver's hat and the other is the pneomofathometer hose used for determining the diver's depth.  Typically, when there is a gas supply issue, topside will turn on everything meaning they will send air to the diver by all available means to give their guy the largest variety of options.  This means the pneumo hose will already be shooting bubbles everywhere and these are bubbles you can use!  The diver can take the end of the pneumo hose (often cut at an angle for exactly this purpose) and slip it between their neck and the neck dam to send that air up into their hat.  It's not a perfect situation and would probably be loud and uncomfortable, but it beats drowning.

I'll go into some of the other (more death defying) life preserving techniques we learned in a post to follow... My first two part post!