Mississauga Train Wreck

1
Mississauga Train Wreck

• Presented to ES-317 at UWO in 1999.
• By Dick Hawrelak

2
The Incident

• Midnight, 10 Nov 79.
• 24 of 106 railcars derailed at Mavis Road.
• 11 propane cars.
• 3 toluene cars.
• 4 caustic cars.
• 1 - 90 ton chlorine car.

3
The Incident Contd

• Fire broke out almost immediately.
• Within 30 minutes, 3 of 4 propane cars BLEVEd.
• Sheets of steel were hurled 2,000 ft.
• Some property damage, no casualties.
• There was no apparent Cl2 release at this time.

4
What To Do?

• First responders decided to perform Cl2
  dispersion studies in case Cl2 had not been
  released at this time.
• Called Dow Chemical for help.
• Worst Case Scenario - 180,000 lbs - instantaneous
  loss.

5
Results Of Dispersion
6
Decision Time ???

• Decided to evacuate 217,000 people.
• Used TV, radio, street patrol, knocked on doors.
• Evacuation took 24 hours for total population.
• Majority returned after third day.
• All returned after sixth day.

7
Evacuation Data
8
The Failure

• It was determined that the derailment was caused
  by a journal bearing failure, or Hot Box on a
  toluene car.
• First responders had to withdraw to 1,500 ft.
• A brave photographer determined the Cl2 car was
  within 40 ft. of propane car.
• The Cl2 car had a major hole 2.5 x 3.

9
What happened to Cl2?

• 160,000 lbs of Cl2 was lost.
• Propane fires created extreme heat island.
• Cl2 drifted upward with heat intense heat rise or
  was consumed in the reaction.
• No one in Mississauga, at any time, ever smelled
  Cl2.
• For once, the Gods were with us this time!!