Page 131 - test2

speed devices to initiate shut‐down of the engines was a contributing cause of
the Deepwater Horizon explosion.

The “gooseneck” configuration of the mud gas separator vent allowed for
the venting of hydrocarbons back onto the rig. This increased the risk of ignition.
The location and design of the mud gas separator outlet vents was a
contributing cause of the Deepwater Horizon explosion.

Prior to the two explosions, approximately 20 gas alarms went off
indicating the highest level of gas concentration on the rig. Andrea Fleytas, the
dynamic positioning officer, testified that she received a phone call from the
engine room, but she never informed them to initiate the emergency shutdown
sequence or that there was a well control event. Fleytas’ failure to instruct the
Deepwater Horizon engine room crew to initiate the emergency shutdown
sequence after receiving 20 gas alarms indicating the highest level of gas
concentration was a contributing cause in the Deepwater Horizon explosion.

C. Possible Contributing Causes of the Explosion

Neither the engine room nor the switch‐gear room was a classified area.
Therefore, the equipment was not required to be explosion‐proof or intrinsically
safe. Nor is there a requirement that the area be purged or pressurized. The
classification of engine rooms number 3 and number 6 as non‐classified areas
was a possible contributing cause of the Deepwater Horizon explosion.

The Deepwater Horizon had multiple inspections and surveys during the
ten‐year period it was operating in the Gulf of Mexico. The Panel found no
evidence that anyone identified the location of the engine air intakes as a
potential safety issue. The failure to identify the risks associated with locating
the air intake of engine room number 3 in close proximity (approximately 60
feet) to the drill floor was a possible contributing cause of the Deepwater
Horizon explosion.

The gas sensors in the engine compartment rooms of the Deepwater
Horizon did not automatically shut down the engines when there were high
levels of gas present on the rig. The absence of emergency shut‐down devices
that could be automatically triggered in response to high gas levels on the rig
was a possible contributing cause of the Deepwater Horizon explosion.

126