Scuba Tanks as Lethal Weapons

On the night of January 3, Cindy Burnham of Fayetteville, NC, was in her pajamas, leaning over the sink to brush her teeth, when she heard the garage door rising. That meant her husband, technical diver and videographer Rick Allen, was home. The next thing she knew, Burnham had been thrown to the floor several feet back, with shards of glass in her face from the shattered mirror.

She ran to the garage to find her husband. "The door was blown out," Burnham later told the Fayetteville Observer. "I could see my husband on fire inside the garage." She grabbed a fire extinguisher to put out the flames on Allen's back, and then called 911. While Burnham only needed 12 stitches to her face, he was put in critical care at the hospital. One hand had been severed by the blast, his left arm needed to be amputated at the elbow and he had burns on his legs and back and left side.

The cause of the tragedy: an 80 cu. ft. scuba tank containing 100 percent pressurized oxygen. According to Steve Burton, a dive equipment technician and editor of ScubaEngineer.com (www.scubaengineer.com), what apparently happened was the tank was knocked over, either by Allen walking by or the garage door bumping against it. "That likely hit the valve against something as it toppled over, and the mechanical shock caused the valve to be explosively ejected, followed milliseconds later by the fiery detonation of the scuba cylinder."

Note that the tank was an oxygen cylinder, and not a typical diver's compressed air tank. "Rick Allen was a technical diver trained in the use of pure oxygen to shorten decompression stops after very long dives," says Burton. "I would guess that not even one diver in a thousand keep compressed oxygen cylinders at home, in comparison with the common compressed-air tanks found worldwide in dive centers."

That may be true, but even the standard diver's air tank can wreak plenty of havoc. For example, two Polish divers were killed and two others seriously injured from a tank explosion last September while on a dive trip at the Croatian island of Vis. Croatia's transport ministry said the tank exploded while being unloaded from a boat onto the dock, and the cause of the blast was most likely a poppedout valve. One woman died on the spot, another died later in the hospital from head injuries.

Back in August 2009, an Australian dive master lost his right hand and suffered major injuries to his right leg when a scuba tank exploded. Murray Amor, the equipment service manager at South West Rocks Dive Centre near Coffs Harbor, Australia, was doing a routine refill of the tank when it ruptured and blew into several pieces, tearing large gouges into the building's brick walls.

A standard tank can also have a "hammer effect." Larry Harris Taylor, diving safety coordinator at the University of Michigan, tells his students that a tank standing alone is a "foot-seeking device" and will most likely fall on the foot of a litigation-seeking attorney. "A single scuba cylinder typically, depending on the composition material and the volume of the cylinder, weighs between 30 and 50 pounds," he comments. "This amount of mass can develop a significant impact force, even when falling only a short distance." On his website, Harris posts photos (www.mindspring.com/~divegeek/toe.htm) of an injury sustained by a diver when a single steel 72 cu. ft. tank standing upright next to a wall was accidentally knocked over and fell on his foot. His big toe was crushed into multiple fragments, and while he didn't need surgery, the guy missed diving for eight weeks while his toe healed. He was wearing leather sneakers at the time of the incident, but one can only imagine if he was wearing dive booties or going barefoot.

Storing a full tank means that in case of a fire, they're likely to explode. Regardless, divers still store full tanks, and Burton offers these suggestions:

Either store tanks on their side, or if standing them upright, secure them with a chain, strap or cable to a stationary building support.

• Close the valves, and keep the protection caps or guards securely in place.
• Store tanks in a dry, well-ventilated area at least 20 feet from combustible materials. Don't keep them in lockers because if they leak, gas can build up in the locker (and woe to anyone who opens the door).
• Put them where they're not subject to mechanical or physical damage, heat, or electrical circuits to prevent possible explosion or fire. Keep tanks away from foot and car traffic.
• Store empty cylinders separate from full ones.
• Get a visible inspection at your dive shop every year, and a hydrostatic test every five years. Retire aluminum tanks after 10 years.

P.S. Rick Allen is now doing better, but will be in the hospital for a couple of months getting skin grafts. As owner of Nautilus Productions, he'll be sidelined from his business for a while, so friends and family started a website to collect donations for his expensive treatments and recovery. Get updates on Allen's status, and donate at http://getwellrick.com.