Electronically controlled pneumatic braking (ECP) for trains improves braking efficiency when compared to standard pneumatic air brakes. ECP enables simultaneous application of wheel brakes on all of a train’s cars. Conventional air brakes on the other hand may require as much as two minutes before wheel brakes engage on the trailing units of a long train of more than 100 cars. Besides improved reaction time, ECP offers other advantages such as distributed braking and better control of the system’s air supply reservoir.
The slow brake reaction of trailing cars has been identified as a major contributing factor in oil train explosions. The continued momentum of those cars pushing against the already braking cars in front can cause derailments, broken couplings and subsequent puncture of the tank cars absorbing that momentum.
Following several fiery derailments of oil trains, most notably Lac-Mégantic, American regulators — and to a lesser extent those in Canada — have been trying to advance the adoption of ECP. Railways have resisted because of cost. Today’s Washington Post covers the political battle over this issue in the U.S. with “Railroads, regulators clash over braking system for trains carrying flammable liquids.”
Transport Canada continues to work with the Canadian industry to consider braking provisions, such as electronically controlled pneumatic (ECP) brakes, in train operating rules rather than requirements within the TC-117 tank car standard. Transport Canada is also following closely the new requirements brought forward by the United States FAST legislation, which imposed new research requirements before ECP braking can be brought into effect in the United States.1
- FAST Act (Fixing America’s Surface Transportation Act)
- 1TSB (Transportation Safety Board), Reassessment of the responses to Rail Safety Recommendation R07-04
- Wikipedia, “Electronically controlled pneumatic brakes“