Kit failures - my observations

[Helen F H]

This is a post i put on DIRX a while ago. The DSMB debate made me remember about it and put it here too.

Ok, for someone who has dived briefly in a DIR stylee I thought it might be of interest to some of you the kit failures I have seen over the season and the implications these have had for the divers involved. I have just spent my first season working on board a charter vessel in Scapa Flow, Orkney where the German Fleet lie in anything from 18m to 43m. Divers come from all over the world to view these wrecks, and i think i have learned a heck of a lot. Take what you like from this little collection of calamity.

These failures can be divided into two categories - the equipment itself failing or improper use due to insufficient or incorrect training/practice. I have listed both here. Of course there will be many more failures than those listed here, but these are the ones we got to know about or required action on our behalf.


The divers in question are from all over the world, diving every sort of configuration imaginable.


By far the most common failure is a reel during SMB deployment. I count on at least one a week, regardless of the groups experience, make, model, type of reel or SMB. I can virtually guarantee we will have to pick up a stray one at some point.

Now this kind of failure - simply jamming it as it is going up and letting it go is rarely any sort of problem as almost every diver carries an SMB and reel, and a buddy pair can simply use the other persons to try again.


Many of the cheaper SMB’s, which do not seal will lose gas in rough weather and lie low in the water or even sink. The delayed aid model became detached from the line itself after deployment due to part of the plastic snapping. The small ones (around 2 ft tall and filled orally - used by DIR divers) were pretty unsuitable for diving up here where you can get big swells very quickly and divers very spread out if they have differing run times (not a problem if it is an all DIR group as the run times will be very similar making the divers easier to track by the boat). I guess this is one time that size does matter chaps, Scapa Flow is a big chunk of sea.

I managed to get the teardrop from the metal boltsnap on the bottom of the halcyon SMB caught in the elastic strap of my glove while deploying. I was dragged up around 3m before I detached it (this was in Burra sound in a fierce current - a less than perfect deployment by me, but the first in many months!). Twice we have had minor stress when a buddy pair didn’t send up another blob after losing the first deployed and we were in Hoxa sound, close to a shipping lane. Always good fun.


The other kind of problem is a loss of buoyancy control while deploying an SMB, but this is far rarer, having seen only one or two of these and the diver can seldom recall what caused the actual loss of control.


Next on the list is probably buoyancy control. Although this can’t be pinned down to a specific bit of kit, it tends to be one of two things, a BCD/Wing or a drysuit.

By far the most common of the two is air not being dumped sufficiently quick from a drysuit, having seen at least five rapid ascents because of this. Many people will tend to bulk up their undersuits to combat the cold water of Scapa and not realise the implications this has with the ability of air to migrate to the dump valve and escape.

Other problems with drysuits - numerous leaks leaving divers cold and miserable. Neckseals rolling down to create a garrotte at depth. Very poor placement of valves (being too far under the divers arm meaning it was impossible for them to dump any gas in the top portion of the shoulder.). Divers placing equipment straps (in this case a knife) on either side of a cuff dump. Divers being economic with the truth about their drysuit experience.


Loss of weightbelts - I have only seen on the surface and the belt was recovered without issue. Divers being underweighted caused many problems, but all easily rectified providing they had the sense to notice they were struggling to descend and ask for more lead.


Hoses - I have seen one high pressure hose burst at depth, but luckily for the diver it was only at 6m and they ascended without issue. The hose had shown no signs of wear and the burst was within one inch of the end closest to the first stage.


One wing had catastrophic failure due to a very large number of holes (we are talking double figures here, the guy who repaired it questioned if the diver had just dumped his girlfriend…), some right through both sides of the bladder itself. The wing was a bungeed 100lb wing and appeared to be in good condition. On closer inspection some of the holes in the outer bag were noticeable but only when the bungee was stretched out, otherwise they were hidden in the folds of material.

Another failure occurred when the corrugated inflator hose became detached from the inflator assembly resulting in loss of buoyancy at the surface. My own inflator jammed on but this was sorted out by cleaning the inflator after the dive.

At no point did I see a clip or buckle fail. However, some people would forget to clip up the many buckles found on some BCD’s leaving up to three unclipped (I ponder task loading for this one) or really struggle to undo shoulder buckles when de-kitting as the harness had been pulled tight underwater once the diver had descended.


One person lost a mouthpiece from their main reg causing a minor panic and going onto their buddies alternate air source. This was due to the loss of the cable tie from around the rubber section.


Several people ran very low on gas and ascended on their buddies supply.


The neoprene mask slap straps seem to make it easy to lose your mask when entering the water. Maybe something to check on the surface, as they ride up over the neoprene of the hood.


One person was unfortunate enough to flood his rebreather and therefore render it unusable for the rest of the week (is sorted now thank gawd).

One contents gauge leaked so much that it had to be replaced with my own to save the dive.


Two drysuit hoses leaked enough to cause problems, one freeflowing when it was connected to the suit which didn’t cause to much of an issue and was replaced by my own, the other having an uncontrolled freeflow on the boat losing the diver over 50bar of gas.


One diver reported getting line stuck in the spring of a spring strap, but it was one of the kind that has a partially uncovered section of metal spring that will allow for trapping if flexed.


One interesting trend has been that we seem to have had more incidents requiring some sort of action on our behalf near the end of the season than the start. Also all of the DCI incidents we have seen have been skin bends, but then I do know what a skin bend looks like and might be better at spotting them!


One diver missed 4 minutes of stops simply because everyone else’s computers had cleared and he thought he should go up too.


I now know what every single computer on the market looks like when it is bent..... (see tagline).

[Dangerous Dan]

Thanks Helen, Very informative and interesting.

Can I just ask how this happened on the boat?

Originally Posted by Helen F H

the other (drysuit hose) having an uncontrolled freeflow on the boat losing the diver over 50bar of gas.

Dan

[Helen F H]

Originally Posted by Dangerous Dan

Thanks Helen, Very informative and interesting.

Can I just ask how this happened on the boat?



Dan

Trying to plug the hose onto the drysuit. It jammed open.

[Dangerous Dan]

Originally Posted by Helen F H

Trying to plug the hose onto the drysuit. It jammed open.

OK maybe should of explained my question more:

50 bar seems a lot, was this from main cylinder or inflation cylinder, why was it not shut down immediately?


Dan

[Helen F H]

Originally Posted by Dangerous Dan

OK maybe should of explained my question more:

50 bar seems a lot, was this from main cylinder or inflation cylinder, why was it not shut down immediately?


Dan

From the main cylinder, he continued to try to connect it and it took me a few seconds to drop what i was doing and leg it over to switch the cylinder off. It probably wasnt that long. Diver Mag did a test a few years ago about how quickly a low pressure hose failure would empty a 12l cylinder and it was something scary (anyone find the link?), so 50bar in that time seems about right.

[triplefin]

Useful posting Helen and given the amount of divers/kit and dives it does put things in perspective slightly

[borgy]

sobering stuff Helen. The incident with the high pressure hose makes you realise just how quickly things can go wrong for no apparent reason. What would have happened if that had been deeper? sounds like a lucky escape.

This might sound like a silly question but are all incidents that you are aware of reported to the HSE? I'm not questioning you or your dive operation but just thinking in general. Do all clubs/schools have an obligation to report this kind of stuff to the HSE or is it just the 'hits' or other accidents requiring hospital treatment that come to the HSE's attention?

simon

[DIVE BUDDHA]

very intresting posting helen and find it very informative and honest !!!

yes i too feel that the high pressure hose going, would have been a real problem

if the diver had needed to do any deco stops to the surface ??

and the diver who came to the surface missing stops because he thought it was

ok as his mates had cleared their computer ??? no idea what he was thinking???

[Neil Whitworth]

Originally Posted by borgy

This might sound like a silly question but are all incidents that you are aware of reported to the HSE? I'm not questioning you or your dive operation but just thinking in general. Do all clubs/schools have an obligation to report this kind of stuff to the HSE or is it just the 'hits' or other accidents requiring hospital treatment that come to the HSE's attention?

simon

BSAC maintain a list of incedents. This is compiled from press reports and peoples own submissions. But not everyone fills out an incedent report for everything. The is no obligation to report so this is down to divers doing it off their own back

HSE don't care as this is not an 'at work' situation.

2005 incident report

incident report form

[Scuby]

Originally Posted by borgy

This might sound like a silly question but are all incidents that you are aware of reported to the HSE? I'm not questioning you or your dive operation but just thinking in general. Do all clubs/schools have an obligation to report this kind of stuff to the HSE or is it just the 'hits' or other accidents requiring hospital treatment that come to the HSE's attention?

As far as i'm aware HSE don't collect any information like this.

BSAC do however, as the UK governing body, collate them in their annual incident report (which you can find somewhere on bsac.org).

David