A routine grass fire in Chetwynd, B.C., spawns a surprise missile after an oxygen tank explodes.
September 14, 2009
By Leo Sabulsky
|Photo courtesy Chetwynd Volunteer Fire Department
Originally the O2 cylinder was 31 centimetres long. The metal shell is now extended to 101 centimetres and resembles a medieval weapon.
Chetwynd, B.C. – Springtime in northeast B.C. brings high winds and very dry conditions. The Chetwynd Volunteer Fire Department usually has 10 to 12 routine grass fires caused by residents losing control of burning grass or brush piles. But a fire on Mother’s Day – Sunday, May 10 – was not routine and could have resulted in injury or death to firefighters and the loss of multiple homes in a rural subdivision.
At 2:30 p.m., the department responded to a reported grass fire within the fire protection rural area from South Peace fire dispatch. Firefighters had left the hall minutes before, since members had just completed two days of an auto-extrication course. Mother’s Day took precedence over an extended day of training and the members returned home with apologies for not being home earlier.
The fire started in dry grass near the front entrance of a house trailer. Within seconds, it had spread to the deck of the trailer and the son of the owner escaped by jumping from an exit. By the time the department arrived, the trailer, a parked car and the grass extending from the trailer were ablaze, fanned by high winds.
The owner immediately disclosed that he had started the fire when he discarded a cigarette by the trailer after he had returned from taking his ailing wife to the hospital. He attempted to put the fire out but it had spread quickly.
Twenty-two firefighters responded with a pumper, tanker, aerial and rescue vehicle. The fire had travelled to nearby lumber and wood piles and threatened to spread to neighbouring homes. Priority was to cool the trailer fire and stop its spread to nearby homes. The fire had spread quickly in tinder-dry conditions.
There were numerous hissing sounds and subsequent explosions from inside the residence. The source of the explosions was puzzling and the owner was asked about the contents of the home. His said he had barbecue tanks and aerosol cans inside the trailer. He forgot to mention one important detail.
At about 2:50 p.m., a remarkable explosion from within the structure shook the scene. A shrapnel missile hurled from the burning trailer toward two firefighters. It was not a propane barbecue tank or an aerosol can.
The missile landed between the fire chief and a firefighter at a distance of 30-plus metres from the trailer. The missile landed about three metres from where the two were standing and the identity of the object became evident. The missile was the exploded remnant of a portable home-use O2 cylinder. One of the occupants had numerous portable oxygen bottles for home use. This explained the hissing noises and the explosions.
The owner later said he had forgotten about the oxygen cylinders since his wife used them routinely. He said there were probably four or five in the home and a central, larger tank for transference to portable bottles.
The photo at left, shows the dangers of a BLEVE (Boiling Liquid Expanding Vapour Explosion) in small cylinders. Originally the O2 cylinder was 31 centimetres (12 inches) long. The metal shell is now extended to a length of 101 centimetres (40 inches) and resembles a medieval weapon.
The O2 cylinder BLEVE at this scene is an example of the power of a pressurized vessel, no matter the size and the dangers involved at a scene. The need to maintain distance and to be cautious at all times cannot be stressed enough and, further, residents, when interviewed, may just forget to mention the dangerous contents of their homes.
The O2 cylinder may have maimed or killed firefighters at the scene. The shrapnel of the remaining cylinder is a grim and vicious reminder to be careful out there at each and every fire occurrence.
Leo Sabulsky is the fire chief and municipal emergency co-ordinator in Chetwynd, B.C.
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