Post on 15-Dec-2015
THE MEXICO CITY EXPLOSION OF
1984
Nick Chumo
Addy Hellebusch
Matt Kelley
Chris Williams
Introduction
November 19, 1984 San Juanico; a suburb of Mexico City 20 km outside of Mexico City 40,000 residents Low income families Homes as close as 130m to plant
Plant and “Process”
Pemex State Oil Company Storage & Distribution facility for liquefied
petroleum gas (LPG)LPG comes in from 3 different refineries
54 LPG storage tanks- 16,000m3
Daily throughput- 5,000m3
6 large spherical tanks○ 2 largest holding 2400m3
48 smaller tanks of various sizes Built to API Standards
Right Before Explosion
Being filled from a refinery 400km away 11,000m3 LPG on site Fall in pressure
The cause of the pressure drop was unidentified
no one initiated emergency shutdown
Pemex Before
Pemex After
What Happened
One of the deadliest industrial disasters in world history
The initial vapor cloud explosion was the start of a chain reaction of explosions
There were 19 explosions15 cylindrical tanksThe 4 smaller spheres
Many of the explosions were BLEVEsThe relative times can be told from seismic
readings
What Happened cont.
Most of the damage to the city was from fires not the explosions
Fragments from the tanks reached over 1,200 m awayThe fragments were hot enough to start firesPieces trailed raining LPG as they flew
A concentrated rescue effort was put into action with 3000 rescuers on site
200 firefighters risked their lives
Accident Timeline 5:30am Rupture of 8 in. pipe; Pressure drop in
control room 5:40am Ignition of gas cloud; Violent
combustion and high flame 5:45am First explosion on seismograph, a
BLEVE; Fire department called 5:46am Second BLEVE, one of the
most violent 6:00am Police alerted and civilian
traffic stopped 6:30am Traffic chaos
Accident Timeline cont. 7:01am Last explosion on
seismograph, a BLEVE 7:30am Continuing tank explosions 8-10:00amRescue work at its height 11:00am Last tank explosion 12-6:00pm Rescue work continues 11:00pm Flames extinguished on last
large sphere 10:00am Last fires put out (next day)
Root Causes
Official cause of rupture is unknown One report cited
Overfilled tank caused the inlet line to rupture
Failure of relief valve
Results
500-600 deaths; 300+ never identified 5000-7000 severe injuries 10,000-60,000 people made homeless 31 million dollars of damages Destruction of 1/3 of the LPG supply to
Mexico City
Results
Results
Future Preventions
Timely inspections Maintain industrial standards Better maintenance Effective operator training Housing appropriate
distance away
Future Preventions cont.
Proper layout of large LPG storages
Gas detection and emergency isolation
Water system failures Extra water hydrants in the streets Planned evacuation routes
Summary
This deadly disaster struck the morning of November 19, 1984
Lasted from 5:30am till 10:00am the next day
Left hundreds dead and thousands injured and homeless
Many lessons can be learned from the tragedy
QUESTIONS?