Exploding scuba tank kills one - Florida

[Jax]

While the tank in question may (or may not) have contained oxygen, the presence of oxygen is not necessary to account for the fatality of this accident. A sudden catastrophic release of pressure in an enclosed space results in an overpressure that can be fatal. Such an expanding pressure wave can cause a brief impulse in which the pressure can climb to fatal limits before exploding windows and doors dissipate the pressure.

If we assume that the tank contained 40L of air (56 cu ft) and that tank exploded in the middle of an apartment that was a spacious 6000 cu ft, the overpressure would be (56/6000) x 101.325 kPa = 0.94 kPa which is likely not be enough to kill someone. However, if instead we assume that he was carrying the tank down a hallway where the door (at one end) and his body (at the other end) formed a partial barricade to the expanding gases, the effective volume of the room would be reduced to, say, a cube 8 ft high, 4 ft wide, and 6 ft long (192 cu ft). The resulting overpressure is (56/192) x 101.325 kPa = 30 kPa - a pressure regime where walls are destroyed and fatalities occur. These rough estimates can't tell us why the tank ruptured, nor can they tell us what was inside the tank, but air could have been sufficient.

One more educated guess -- unless it is a solo diver's pony, no one uses 40cf for air. This guy was a reported deep / cave diver. Don't know any that would use a 40 for anything other than Oxygen for deco.

Cave / deep divers?

 

[gypsyjim]

While the tank in question may (or may not) have contained oxygen, the presence of oxygen is not necessary to account for the fatality of this accident. A sudden catastrophic release of pressure in an enclosed space results in an overpressure that can be fatal. Such an expanding pressure wave can cause a brief impulse in which the pressure can climb to fatal limits before exploding windows and doors dissipate the pressure.

If we assume that the tank contained 40L of air (56 cu ft) and that tank exploded in the middle of an apartment that was a spacious 6000 cu ft, the overpressure would be (56/6000) x 101.325 kPa = 0.94 kPa which is likely not be enough to kill someone. However, if instead we assume that he was carrying the tank down a hallway where the door (at one end) and his body (at the other end) formed a partial barricade to the expanding gases, the effective volume of the room would be reduced to, say, a cube 8 ft high, 4 ft wide, and 6 ft long (192 cu ft). The resulting overpressure is (56/192) x 101.325 kPa = 30 kPa - a pressure regime where walls are destroyed and fatalities occur. These rough estimates can't tell us why the tank ruptured, nor can they tell us what was inside the tank, but air could have been sufficient.

But air probably would not have caused the flash a witness reports, while exploding O2 would light up the room a bit. Just a thought.

A dropped tank of pure Oxygen is not a happy thought.

 

[Reef_Haven]

Where was it reported as a 40? I saw it was reported as aluminum, and some speculation it was a 40.

 

[Jax]

Where was it reported as a 40? I saw it was reported as aluminum, and some speculation it was a 40.

This is the very best media report so far.

here's a link:

Clues suggest pure oxygen may factor in fatal St. Petersburg scuba tank blast - St. Petersburg Times

ST. PETERSBURG — A witness getting his morning newspaper told police he saw a bright flash when a scuba tank exploded early Sunday morning.

The man holding the tank, avid diver Russell Vanhorn II, suffered what appeared to be burns in the blast that took his life and destroyed the condo he was standing in, according to St. Petersburg police.

As investigators continued their search Monday for answers in the puzzling blast, those potential clues suggest pure oxygen could have played a role in the explosion that killed the 23-year-old Iraq war veteran.

"That signifies to me that oxygen was involved and not just compressed air," said Doug Jackson, vice president of Bill Jackson's Shop For Adventure and a certified diving instructor and trainer. Jackson said pure oxygen increases the risk of fire and explosion.

Most recreational divers use compressed air — the same mix of 78 percent nitrogen and 21 percent oxygen we all breathe on land — in their pressurized cylinders. But pure oxygen is used for much more advanced and riskier diving, such as cave or deep diving.

Pure oxygen can be used for decompression, for example, to help divers purge themselves of nitrogen before surfacing from deep depths. That's to prevent decompression sickness: gas bubbles that can develop in the body and cause pain, paralysis and even death.

If pure oxygen was being used for a diving trip in the Tampa Bay area, Jackson said, that suggests Vanhorn may have planned to go cave diving.

Because of its explosion risk, pure oxygen should only be handled by skilled divers using special procedures and the utmost care, Jackson said.

Exploding scuba tanks are rare and devastating events. But in cases such as the 1981 blast that cost a Lakeland man his legs, the cause of the explosions appeared to be catastrophic failure of the pressurized metal tanks — not the gases inside the tanks.

Russell Vanhorn Sr. said his son enjoyed cave diving as well as other forms of diving in both Florida and his native Iowa. But his son was always careful.

"He enjoyed deep diving, he enjoyed open diving," said Vanhorn Sr., 55. "I know he did some cave diving, but he didn't do it on a regular basis.

"He would take pictures of underwater volcanoes down there. He said, 'Dad, I don't do it all the time. I do it with a bunch of guys and we're always safe.' "

The complicated nature of the investigation led St. Petersburg police to take over from the Fire Department.

Police spokesman Mike Puetz said investigators will track down the history of the exploded tank, determine who inspected and serviced it in the past, who recently filled it and with what kind of gases.

The tank was found split down the middle from top to bottom, lodged overhead in what was left of the kitchen ceiling. The blast shattered drywall and ceiling, collapsed walls, smashed furniture, blew out the doors and windows and damaged cars in the parking lot.

The Tampa Bay Regional Bomb Squad came in to inspect and empty the 11 other tanks found inside. Authorities did not say what was in the tanks.

Sara Swoch, 27, and Brent Stevens, 22, were inside the condo at 5865 37th Ave. N when the tank exploded at about 6:50 a.m., police said.

Swoch lives in the condo. She and Stevens were in different rooms when the tank blew up, police said, shielding them from serious injury.

Master scuba diver trainer Joyce Hannaseck of Narcosis Dive Shop in Tarpon Springs went diving with Russell Vanhorn II over the summer. She said the Tampa Bay diving community is anxious for answers.

"We're all just holding our breath to find out what caused this," she said.

Times researcher Carolyn Edds contributed to this report. Jamal Thalji can be reached at thalji@sptimes.com or (727) 893-8472.

Carp! This is not the right one!

 

[Rileybri]

The only thing reliable about whiteness is that they are not reliable much like the information in this thread!

 

[Jax]

Tank size not mentioned here, either: Violent scuba tank blast kills Iraqi war veteran at St. Petersburg condo - St. Petersburg Times

Nor here: http://www2.tbo.com/news/breaking-n...man-dies-after-scuba-tank-explodes-ar-256967/

(Can you tell I'm collecting the links?

Nor here: http://abcnews.go.com/US/scuba-tank...war-veteran-russell-vanhorn/story?id=14502395

Claims aluminum: http://www.wtsp.com/news/article/210339/8/Scuba-tank-explosion-raises-questions-among-divers

Video says nothing: http://www.cnn.com/video/#/video/us/2011/09/12/fl-exploding-scuba-tank-death.bay-news-9?hpt=hp_t2

 

[Jax]

Okay, found it, but it is not an authoritative source - TDS.

The individual stated, before the news report came out with the same info, that the 40cf was in the ceiling, and that s/he may get access to photos.

"Sounds good" to me.

 

[cruiser]

Is there a thread where I can get some real, confirmed information (when it is available) so that I don't have to spend so much time reading through pages of postings and a (at this time) pointless debate and excess of Monday morning quarterbacking?

This is as good as it gets.

 

[Jax]

The only thing reliable about whiteness is that they are not reliable much like the information in this thread!

Betcher on a phone with autocorrect.

 

[Reef_Haven]

CNN.com - Breaking News, U.S., World, Weather, Entertainment & Video News

Dolores clearly says there was no flame, or smoke. It looked like a cloud of steam.
I see no indication there was any ignition in the photos available.