Waterford Garda dead - County Wexford, Ireland

[caydiver]

https://m.independent.ie/regionals/...g-what-he-loved-is-laid-to-rest-38177802.html

I don’t normally cut and paste from newspapers but this was on point. As a Wexford person it is sad news indeed.

 

[DivingPhish]

From what i'm hearing down the grapevines is that O2 was turned off. Not sure of his level of training on JJ, hard to believe PPO2 wasnt noticed.

 

[cathal]

From what i'm hearing down the grapevines is that O2 was turned off. Not sure of his level of training on JJ, hard to believe PPO2 wasnt noticed.

I would imagine a quick analysis of the dive log in his controller would quickly identify whether the O2 was turned off.

 

[telemonster]

From the article: "It is understood that he had been diving to a wreck some 70m deep and was returning to the surface when he lost consciousness."

Doesn't sound like a case of splashing with the O2 off.

It would require custom valves but it wouldn't be that hard to bring valve open/closed monitoring into the controller.

 

[cathal]

From the article: "It is understood that he had been diving to a wreck some 70m deep and was returning to the surface when he lost consciousness."

Doesn't sound like a case of splashing with the O2 off.

Maybe he was returning to the surface at the start of the dive, either way I'd be slow to speculate on what happened based on whats reported in the papers as you won't get the answers your looking for and you'll end up just chasing your tail endlessly.

 

[DandyDon]

Inquest results were published...

Irish CCR diver Dave Hearne died after ‘oxygen spike’

An inquest into the death of Irish CCR diver Dave Hearne has concluded that he died after he had an ‘oxygen spike’ on his closed-circuit rebreather.

Mr Hearne, who was 47 and lived in Waterford City with his wife and four children, was an experienced technical diver, as well as a former member of the Garda Water Unit, and had been responsible for saving the lives of many people during his tenure with the team.

He had been diving on a shipwreck some 20km out of Slade Harbour on 25 May last year with the Hook Sub Aqua Club when the fateful incident took place.

In details recorded during the inquest, it was was revealed that Mr Hearne was found lying on his back, with his breathing loop out of his mouth, by fellow diver Colin Brennan.

He explained that he tried to replace the mouthpiece of the loop, but that Mr Hearne’s jaw was clenched shut.

Realizing there was nothing else that could be done for the stricken diver, they inflated his wing and sent him to the surface, where his body was recovered by the Coast Guard R117 helicopter.

Consultant pathologist Dr Fergus McSweeney performed a post-mortem at University Hospital Waterford and, like the coroner Gerard O’Herlihy, said that death was by drowning.

UK-based technical instructor Dave Gration examined Mr Hearne’s CCR, and found that a number of alarms had gone off to signal a spike in oxygen levels. Mr O’Herlihy said: “Something went wrong down below and it appears to have been a spike in oxygen, for whatever reason. It seems that the late Mr Hearne was not able to deal with that spike, it had caused him to go into a convulsion, the mouthpiece went out of his mouth.”

Inspector Larry Sheahan said Mr Hearne was ‘the consummate public servant’ who is greatly missed by his family, friends and colleagues.

 

[Turtle78]

Very sad to hear about this accident.

What scenarios could lead to a sudden oxygen spike in a CCR? Three which immediately come to mind (assuming the sensors are fine) are: 1. stuck solenoid 2. accidentally flushing with O2 instead of diluent 3. descending too quickly after already setting the high set point (e.g. 1.3). Any others? I'm not speculating that any of these actually happened here, I'm just trying to understand what could lead to an unexpected oxygen spike.

 

[uwxplorer]

Another possibility (freely inspired from a real case) would be the diver having his diluent off and manually adding "gas" on descent to compensate for the counterlung collapsing, not checking which add button he pressed. After a while at the bottom, looking for his buddy, finally glances at his computer and realizes his pO2 is through the roof. Because his diluent is off, can't flush the loop, panics and forgets to/can't bailout and unfortunately, convulses on his way back up.
This would require a lot of mistaken actions in close succession, but again, something similar happened several years ago, so this CAN happen.
A careful examination of the diver gear and computer, as well as witness interviews might be able to clarify the actual scenario, but oftentimes, the truth is only known by a few who tend to remain quiet for perfectly respectable personal reasons.
Rebreather diving is not forgiving. Heck, diving isn't.

 

[helodriver87]

Very sad to hear about this accident.

What scenarios could lead to a sudden oxygen spike in a CCR? Three which immediately come to mind (assuming the sensors are fine) are: 1. stuck solenoid 2. accidentally flushing with O2 instead of diluent 3. descending too quickly after already setting the high set point (e.g. 1.3). Any others? I'm not speculating that any of these actually happened here, I'm just trying to understand what could lead to an unexpected oxygen spike.

You could also have a jammed O2 MAV. Stuck open solenoids are unusual with the JJ. It could happen if the head O2 inlet got a bunch of junk in it I guess. But it's more likely to fail closed. Dual current limited cells could also result in continuous O2 addition with the good cell voted out.

None of it should be unsolvable though. Worst case, it's a sensor or solenoid issue and you shut off O2 and bailout. Either way, as soon as the PO2 starts running away, you should be off the loop and shutting down O2 as an initial action.

 

[Celt]

Well no doubt the manufacturer will put it down to user error. Can’t imagine anyone saying he was using a heap of sh***t and it killed him.