Tuesday, July 23, 2013
|Mississauga Train Derailment Nov. 1979|
On Nov. 10, 1979 there was a trail derailment in Mississauga ON that involved transportation of dangerous goods, such as chlorine, propane, styrene, butane, propane, toluene, and other highly flammable materials. It resulted in the largest evacuation in North America, six days in duration, but fortunately nobody was killed.
Mississauga Mayor Hazel McCallion said:
“If this had happened a half-mile farther down the track – either east or west – we would have seen thousands of people wiped out. It’s a miracle it happened here.”
This Mississauga accident sparked many investigations and recommendations about the safety of transporting dangerous goods.
- the minimum separation between railcars containing reactive chemicals (eg. liquified chlorine gas) and flammable hydrocarbons (eg. liquified propane gas) were reviewed &/or established.
- Better hot box detectors for imminent bearing failures on railcars were demanded.
- Heavy steel protective shields were designed and installed on hazardous goods railcar tanks so that when a derailment occurred, the railcar coupler couldn't punch through the next car's tank, releasing the dangerous cargo.
- The standard operating procedures for all railroads operating in Canada were carefully reviewed and improved.
Zoom forward 34 years to 2013 and a little farther down the track, and we have another derailment in Lac Megantic Quebec. So far, I have heard no mention or comparison between Lac Megantic and Mississauga. I wonder why?
In Lac Megantic's case, the derailment caused an explosion of light crude oil from shale oil deposits in Montana, set fire to the town, and is likely to have killed 50 people.
Should we remember Mississauga at this time? Did we learn all we could from the Mississauga disaster 34 years before?
The railcars involved in Lac Megantic were DOT-111 railcars (a Department of Transport specifications), also known as CTC-111A cars. These DOT-111 rail tankcar are the most numerous of all the different types of railroad tankcars, which represents over 80% of the tank cars in the North American fleet. DOT-111 cars are relatively cheap to manufacture, and have minimum strength; certainly insufficient to withstand a derailment, so a spill is likely during a derailment.
Poor performance of DOT-111 tankcars in the past, especially during rail accidents, prompted the upgrading of the DOT-111 specifications in 2011, but the vast majority of the North American rail fleet, built before 2011, doesn't have to be upgraded to the new standard. There is minimal maintenance performed on these railcars thereafter, as they often carry innocuous cargos such as vegetable oil.
The operating procedures for trains, the logic of the train crew abandoning a train, leaving the engine running while away from the train, and ensuring the braking system has minimal leakage and working air brakes all need to be reviewed.
However, we are in a Catch-22 in this area.
The Federal Regulations state the minimum requirements, but don't describe how the railroads should meet those requirements. Each railroad can develop its own solution, as Montreal, Maine & Atlantic (MM&A) Railway did prior to the Lac Megantic incident. The railway submits their proposed solution, it is reviewed by Federal bureaucrats, and filed away. Nobody is able to examine the railroad's standards, as they are proprietary and confidential.
Did the railway exercise sufficient due diligence in developing its standard operating procedures?
Did the Federal bureaucrats conduct a sufficient review of the railroad's submissions before they approved them as adequate for meeting the Federal Regulations?
What is the public's right to know before an incident occurs, or after?
There are Risk Management techniques, such as FMEA (Failure Mode Effect Analysis), FTA (Fault Tree Analysis), PPA (Potential Problem Analysis), BPA (Business Process Analysis), and many others that could have been used to identify unacceptable risks well in advance. Were any of these used in this case? Many industries have standardized these risk management techniques as minimum mandatory requirements due to the risks and costs that will follow major accidents.
For transporting crude oil, railways have a much higher risk of a safety incident (eg. a spill, fire, explosion, injury, death, etc.) than a crude oil pipeline on the basis of barrel-km transported (ie. barrels of oil transported X kilometers traveled). Therefore, doesn't it make sense for the railways to do everything possible (even Risk Management prevention efforts such as FMEA, FTA, or other tools) so as to improve their safety record?
It is interesting that Bloomberg published an article on April 9th 2013 warning of rail disasters due to the huge increase in crude shipments by rail. Crude by rail has increased due to the growing bottleneck in crude oil pipelines.
Association of American Railroads ("AAR"), the railroad lobbying group, rebutted this Bloomberg article on April 18th 2013. After Lac Megantic occurred on July 6th, AAR added 2 more articles (here and here) with well chosen statistics that are intended to convince the public that crude by rail is safer than pipelines. When the DOT-111 railcars became an issue, AAR supplemented their media spin with another article on July 18th, extolling the virtue of the new, improved specifications on the DOT-111 cars. Too bad it was the old DOT-111 versions that Lac Megantic got to experience first hand.
How many times must we repeat these major disasters before we learn the necessary lessons?
Glenn Black P.Eng. CQE CQA
Process Quality Associates Inc.