Oil industry experience may explain TWA air disaster

Date:         20 Mar 97 02:34:57 
From:         Paul Kronfield <pkronfie@intec-hou.com>
Organization: INTEC Engineering, Inc.
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The following was published in the Mar 3 Oil and Gas Journal...

"The oil industry has long been aware of the potential dangers of static
electricity in the storage and movement of petroleum products.  If this
phenomenon caused the downing of TWA Flight 800 off Long Island, N.Y.,
last summer, Standford University Professor Emeritus Sullivan S. Marsden
Jr. believes simple techniques used by the oil industry to prevent
explosions and fires may be useful in averting such disasters.

"In the early years of the petroleum industry, explosions during pumping
operations were fairly common.  Research began, in earnest, in the
1950's, Marsden to Oil and Gas Journal.

"'It was quickly recognized that this behavior was due to a phenomenon
well known in the scientific community as electrostatics of streaming
potential,' said Marsden.  His explanation of the phenomenon is as
follows:

"'Streaming potentials occur when a liquid containing charged particles
, such as ions, is pumped through a tube or pipe made of insulating
material [rubber or plastic].  Some of the charged particles flow more
readily than other, oppositely charged particles because the latter are
stuck to the wall of the tube by... adsorption'.

"'The flow of the charged particles constitutes a kind of electric
current, and an electrical potential is built up between the inlet and
the outlet of the tube'.

"If the liquid conducts electricity, current flows in the direction
opposite of the "streaming" current, says Marsden, and charge does not
build up.  If the liquid is a poor conductor of electricity, as are most
petroleum products, a voltage builds between the two ends of the pipe.

"'This potential can amount to thousands of volts', said Marsden, 'and
can result in a static electricity discharge or spark'.

"In the presence of explosive vapors and air, this discharge can cause
an explosion or fire - a fact, Marsden says, that has been demonstrated
in the laboratory.

"Media reports on TWA Flight 800 have indicated that the transfer of jet
fuel from the airplane's main fuel tank to the wing tanks may have
initiated an explosion.

"'While electrostatics and streaming potential are well known by some in
the petroleum industry,' said Marsden, 'the phenomenon is apparently
unknown in the aeronautical industry.  The pumping of jet fuel through
rubber or plastic pipes... could have generated an electrostatic
potential which could supply an igniting spark.'

"In the oil industry, all storage system components are electrically
grounded, says Marsden.  And, where use of flexible plastic or rubber
tubes is necessary, metallic wire is built into the tubes.

"'Also, materials ahve been found which are both soluble in hydrocarbon
liquids in small amounts and also increase the electrical conductivity
of these liquids significantly.  This diminishes the electrostatic
potential generated as the streaming potential,' says Marsden.

"Marsden says several factors would have to be present simultaneously in
order for this phenomenon to cause an airplane to crash.  For a 25-year
old aircraft such as the one involved in this incident:

+ Rubber or plastic tubing would have to be present (probably added
during maintenance of the aircraft)

+ The jet fuel in the tanks must have lacked conductivity additives.

"Marsden believes the oil industry might be able to provide insight into
the factors that should be investigated to determine if electrostatics
played a role in this incident".

Paul Kronfield
INTEC Engineering
15600 JFK Boulevard, 9th Floor
pkronfie@intec-hou.cmo
tel: 281-987-0800
fax: 281-987-3838