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2. Friction and Mechanical Sources

Mechanical sparks occur when there is excessive friction between metals
or extremely hard substances. As the two substances rub against each other,
small particles are torn from the surfaces.
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At the time of the blowout, the rig floor crew was investigating the drill
pipe pressure differential, an activity not likely to cause friction. Chad Murray,
chief electrician on the Deepwater Horizon, was in the electrical shop on the port
side of the third deck. Murray saw others working on the number 2 mud pump
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prior to the explosion. The electrical shop is approximately 50 feet away from
the number 2 mud pump. None of the individuals working on the number 2
mud pump survived the explosion. The Panel believes that it was unlikely that
the members of the crew who were working on the number 2 mud pump
continued to work as the well blew out and gas rushed onto the rig. If in fact, as
the Panel believes, these individuals stopped work immediately, there would
have been no mechanical friction ignition source in the area.

3. Other Non‐Hazardous Area Sources

If flammable gases dispersed beyond the hazardous areas on the rig to
other deck levels with unclassified equipment, then other ignition sources were
possible. The Panel, however, found no evidence that the source of ignition was
located in any of the non‐hazardous areas of the rig.

4. Electrostatic Discharge

Electrostatic charge or static electricity occurs in many industrial
operations. Static discharges are responsible for many industrial fires and
explosions. Hydrocarbon gases are extremely vulnerable to static discharge
ignitions that may often be undetectable by human sight or hearing. The Panel
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316 For a metal to spark, it must satisfy three conditions. First, the energy that causes particles to
be torn free must be sufficient to heat the metal to high temperatures. Softer metals usually
deform before they spark. Second, the metal must be able to oxidize and burn easily. Generally,
a metal’s sparking temperature is the same as its burning temperature. And third, the metal
must have a specific heat that allows it to spark. A metal with a low specific heat will reach a
higher temperature for the same amount of energy input.
http://www.firesandexplosions.ca/hazards/ignition_sources.php.
317 Testimony of Chad Murray, Joint Investigation Hearing, May 27, 2010, at 336.
318 Static Electricity – Guidance for Plant Engineers, Graham Hearn, 2002.

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