Tank explosion kills one - Cozumel

[kurtluker]

We were there as well relaxing in the hammocks and one of our group was about 15 yards away from the explosion when it occurred. Although much of what happened was being kept hush hush..here is what the talk was among the other dive masters and what we observed first hand:
1) A surgeon was there and ran in to offer assistance and was asked to leave and keep the area clear. He stated that when he saw Juan, he could tell there was nothing he could do..his leg was definitely gone and that there was a heavy chance of extensive internal injury. Juan was awake and appeared agitated..probably in shock. The ambulance was there within minutes after the explosion. When they wheeled Juan out, he was awake and moving.
2) We were told by a couple of other dive masters that the tank that exploded was a steel/aluminum alloy tank. These are banned in the US and can't be filled from what I understand. We believe that there was a good quantity of these alloy tanks at the resort.
3) We were also told that Juan had 3 children and the oldest was getting ready for her quincerria (sp??). We organized a donation effort and raised almost $2000 in less than 24 hours for his family. Juan's elderly mother also lived with Juan and his family. Some of the divers expressed concern that the money may not get to the family if donated....however, most of them knew that sometimes in this life you just have to do the right thing and have faith that others will do the right thing too. We told several people how much money we had raised so that there might be a check and balance on the money getting to his family intact.
4) The people at the resort told us that they were taking care of the funeral expenses. We got the impression that they planned to go further than that in helping Juan's family but don't know for certain.
5) The owner of the resort and the owner of dive shop were supposed to arrive the next day but from what I understand, they did not. I don't know whether they subsequently arrived while we were there or not.
6) The divers that were present were very moved and upset by the accident. Accommodation was made to end dives early so the staff could attend the funeral. It was almost surreal for the remainder of the trip as we tried to enjoy the rest of the trip all the while having the knowledge of what had just happened in our midst.
7) No matter where you dive or how knowledgeable you are about tanks and filling them, the hard truth is that so much of what we do puts us at the mercy of the competence and professionalism of others.

 

[grf88]

2) We were told by a couple of other dive masters that the tank that exploded was a steel/aluminum alloy tank. These are banned in the US and can't be filled from what I understand. We believe that there was a good quantity of these alloy tanks at the resort.

Is there any such thing as an steel/aluminum alloy tank?

 

[flots am]

Except perhaps by more careful visual inspection of the tank and regular hydro testing. It's hard for me to believe that a tank which was capable of exploding didn't have visible corrosion and microfractures from metal fatigue which could have been spotted in a close visual inspection, or that it wouldn't show noticeable (unacceptable) deformation if it had been hydro-tested recently. Tanks do not simply explode at random. They explode as a result of metal failure under pressure - corrosion, microfractures due to metal fatigue, a weak spot caused by abuse, or a flaw in the manufacturing (like a void in the cylinder wall) which would have been caught (should have been caught?) by Xray testing before it left the plant.

I've never had a tank in Coz that looked like it had actually had recent service or an inspection and certainly not an Eddy Current test, which would pick up neck flaws. Nearly all were corroded and all the valves looked like they had a long hard life, even compared to our shop's rental tanks that go out 6 days a week, some from the 1960s.

The fact that tanks aren't killing people there daily is mostly a testament to the design of the cylinder, than their preventative maintenance or handling. I'm a little surprised that more don't explode when being thrown from the boat up to the concrete blocks at the marina. I guess "not being killed" is an incentive to be "good at catching".

flots.

---------- Post added September 2nd, 2014 at 09:06 AM ----------

Is there any such thing as an steel/aluminum alloy tank?

Not that I've ever heard, although I suppose it's possible. This might be a language translation problem.

There was an aluminum alloy (6351) that has since been discontinued in cylinders, that had a higher failure rate for neck cracks. If they're talking about bad metal, this is probably it.

 

[Divegoose]

2) We were told by a couple of other dive masters that the tank that exploded was a steel/aluminum alloy tank. These are banned in the US and can't be filled from what I understand. We believe that there was a good quantity of these alloy tanks at the resort.

Thank you for the update. If this is the case, and there are a quantity of these tanks at the resort, I would hope they remove them all from service as soon as possible. And I would hope that all other resorts check their tank inventory and do the same. Divegoose

 

[redacted]

I have been to Cozumel quite a few times with many of those trips to SCC. I usually check the hydro status on all tanks that I use. First, I have never seen a tank in use in Cozumel that did not have DOT markings. I have never seen one that did not have a current Hydro (US standard of 5 years). And, I don't recall ever seeing a tank that was more than 10 years old that was still in use. Unfortunately, this may just be the difference between zero risk and negligible risk.

 

[kurtluker]

Is there any such thing as an steel/aluminum alloy tank?

I honestly don't know enough about it. When the dive masters there told us, a friend of ours who is a dive master for our local dive shop told us that those tanks had stopped being used in the states in the 70s and that dive shops no longer will fill them. So he had heard of them. The divemaster in Cozumel stated it with certainty..there didn't appear to be any uncertainty. It may have been a different alloy but google does come up with a history of exploding tanks from a bad alloy that was manufactured in the 70s. I just know...I was only reporting what I was told by people who seemed to know a lot more about it than me.

 

[DandyDon]

There was an aluminum alloy (6351) that has since been discontinued in cylinders, that had a higher failure rate for neck cracks. If they're talking about bad metal, this is probably it.

That's the only problem alloy I'm heard of with scuba tanks. PSI-PCI - A short Review of 6351 Alloy Aluminum Cylinders

 

[NAM001]

I talaked to a reliable source who had just hung up with the invesitgators, I wont name the organization. As told....Information is still coming in some is being released and some is not. It was an old 70-71 Walter Kidee AL tank out of hydro and vis. Took a leg off and seriously damaged the other. Accident was fully avoidable with existing preocesses and proceedures. Perhaps there is more info out there that is valid to add. Its too bad lives have to be lost form such preventable events occuring.

 

[james croft]

That's the only problem alloy I'm heard of with scuba tanks. PSI-PCI - A short Review of 6351 Alloy Aluminum Cylinders

That is the only tank alloy I have ever heard of having issues. I am sure there are no steel/aluminum alloy scuba tanks.

I have held a couple of cylinder inspection certs and inspected a lot of tanks but I do not claim to be an expert in all of the techncal aspects that involve high pressure scuba cylinders.

Some of the comments that been stated about the tanks in Mexico concern me. Saying that the tanks never looked like they have been serviced or inspected I what I have an issue with.

Do you mean you checked and it did not have current hydro dates stamped into the tank or it was missing a viz sticker? Or do the tanks just look beat up or rough looking?

I have almost 50 scuba tanks. Some of them are almost 70 years old. I have some where 95% of the paint is worn off from constant use. I bet if you saw them you would think they had not been serviced but you would see a current hydro and viz upon closer inspection. But I would certainly understand you thinking that they had poor care just because they look rough.

A lot of my valves have been roughed up as I did public safety diving in black water and rapids and they have been dinged up.

I have heard of valved being snapped off by falling off tailgates etc. but other than a burst disc popping which has happened to me a couple of times you don't hear about a catastrophic failure of a valve that caused it to explode. More likely you will have a leaking valve or one that becomes hard to turn the valve open or closed. A tank valve with blistered chrome may mean it was not soaked in fresh water after use but that does not necessarily mean it is dangerous.

My point is that a lot of rental gear that is heavily used, especially in salt water may look rough but that alone is no reason to suspect poor servicing or maintainace or that the tanks are dangerous. Obviously you could have a tank with only a year or two of service that could be dangerous if it has gotten water in it.

Unless you can see inside those tanks you have very little idea of what you have unless there is obvious damge to the outside of the cylinder such as deep gouges or evidence of being in a fire, fresh Bondo (I am not kidding) etc.

If I was given a rental tank with an out of date hydro I would not take it. But you should ask about how the tanks are inspected. Sniff your air to see if it smells funny. Some traveling divers carry CO2 detectors to test air. If you have a steel tank tap on the side with the butt of your knife while you hold it up by the valve. It should have a rich bell like tone. In other words do due diligence. But in diving like many other endeavors sometimes bad things without reason or warning.

 

[Ken Kurtis]

I have almost 50 scuba tanks.

I'm just trying to figure out why on earth you need 50 tanks . . .



- Ken