Man
Burned in Lackland AFB Refueling Fire
Jennifer Hazen, Editor
February 18, 2003
On
December 11, 2002, Robert Clewis a 58 year old retired
Air Force Sergeant from Natalia, Texas. was filling gas
cans in the back of his 1993 Mazda truck when he became
a static refueling fire statistic. Mr. Clewis was burned
over approximately 17% of his body mostly in the lower
leg areas. Some of the burns were 3rd degree. Surveillance
cameras pickup the scene as it
unfolded.
Bystanders helped Mr. Clewis extinguish the flames.
This is a classic case of static fire
ignition due to gasoline. Mr. Clewis was filling gas cans
in the back of his pick-up truck. This has been a problem
for years but the public still does not know about it
or does not understand it. When asked if there were warnings
at the gas pumps, Mr. Clewis said," I wouldn't be
sitting here in the hospital if I saw a warning."
The warnings at gasoline refueling stations even when
present in some form continue seem to be less obvious
than is necessary for effective warning of the public.
Mr.
Clewis had 7 gas containers in the back of his truck.
There were 2 - metal 5 gal. "Gerry" cans, one
- 1.5 gal. plastic container and 4 - 2.5 gal. plastic
containers. He filled the first metal can then the 5 plastic
cans in sequence at the highest rate of flow he could
and not run them over. Mr. Clewis stated that he could
see the gasoline in the metal can and had stopped it before
it got to the top. In the plastic cans he could see the
level though the container walls and stopped before they
reached overflowing. When he put the nozzle of the gas
pump into the last metal can, he heard a "whoosh"
and saw flames coming out of the can. He tried to put
it out but could not. People around him were yelling for
him to get out of the truck. He picked up the gas can
and threw it out of the truck. He then jumped out on the
side of the now spreading fire from the can he threw out.
His pants caught on fire as he tried to run away. Bystanders
were screaming for him to drop and roll, which he did.
Some helpful people extinguished the blaze on him by beating
the flames with their shirts and throwing a windshield
washing thankful of water on his legs. Mr. Clewis was
taken to the hospital in the back of another truck. He
remained in the hospital until February 18th. Mr. Clewis
had to leave the hospital with "jello" casts
on both legs. He should make a very good recovery with
time.
When
gasoline cans are filled in the back of a vehicle such
as the bed of a truck, they are insulated from ground
by the bed liner and (if plastic cans) by their materials
of construction. Also and very importantly, they are lifted
off ground by some distance which makes the potential
or voltage on the liquid inside much higher than if they
were on the ground and still insulated electrically. Their
capacitance is reduced significantly by being lifted off
the ground (Q=CV). We have measured approximately 5,000
Volts potential from a 2.5 gallon plastic container of
gasoline being filled at 7 gallons per minute and lifted
25 cm off ground. Mr. Clewis had the possibility of greater
than 30,000 Volts potential on the 5 plastic containers
in his truck. He had also by the time he had filled the
last plastic container, filled the truck bed with over
16 gallons of gasoline vapors from the cans already filled.
This vapor was available for ignition in the truck bed.
The last metal can was filled with gasoline vapors. The
5 plastic cans (as well as possibly the insulated first
metal can) were projecting a high electrical field on
the last can and Mr. Clewis. When he touched the grounded
pump nozzle to the last metal can, the induced field on
the can caused a spark to the nozzle in the ignitable
vapors of the bed and the can….WHOOSH!!! The picture shown
here is an
accurate
re-enactment of Mr. Clewis' situation at the Gaston County
Fire College in North Carolina by Fire Marshall Jim Pharr
and Steve Fowler (Publisher of the ESD Journal).
Mr. Clewis should have known not to do
this. This is a classic case of static ignition with all
the parameters aligned perfectly. The problem is that
Mr. Clewis should not have to be a static expert to know
how to refuel a gas can. The warnings if on the pumps
at the Lackland AFB gas station were not obvious enough
for Mr. Clewis. Would they be obvious to you or me? Larger
and more obvious warnings need to be where the refueling
public sees them. I look for the warning every time I
go to a gas station and sometimes I have a difficult time
finding them if they are there at all.