Skip to main content

Reply to "Sad news from Canada"

Gregg posted:

That's a good question, "why did the previous crew put the train into emergency rather than a full brake application?

 

The emergency brake application may not have been initiated by the Engineer nor by anyone else on the crew.  

It could have occurred as a result of an air hose separation or a condition that Distributed Power was designed not to tolerate.  If a "no communication" condition exists between any pair of Lead or Remote consists, Distributed Power will tolerate it for a predetermined amount of time, after which it is programmed to stop the train with an emergency brake application.  One of the conditions it monitors is air flow, which can indicate excessive brake pipe leakage.  Sometimes in curvy territory, air leaks open up and then close if air hoses are defective.  Distributed Power knows the position of the controlling brake valve as well as the brake pipe pressure.  If a brake pipe rise is detected without the brake valve being released, DP will stop the train.  Unintentional brake pipe increases can occur from the air hose problems described above.  If the cars were equipped with Load/Empty sensors which measure truck spring compression, an unintentional release could have begun and DP would have used Emergency braking as soon as the release was detected.  Lots of possibilities exist.

They will be able to determine whether the emergency brake application was initiated by use of the automatic brake valve, by the Conductor's emergency brake valve on the left side of the cab, by Distributed Power detecting an unsafe condition, or by another condition somewhere in the air brake system.  They can determine this by expert analysis of the event recorder data from each controlling unit in the train, i.e., the unit in each Lead and Remote consist which was controlling other units coupled to it in the same multiple unit consist.

The focus, though, is on why the first crew did not secure the train with hand brakes (every car on the train if it was loaded on a 2% grade).  They are Canadian.  Surely they have heard of the Lac Megantic disaster, and surely their rules require securing the train with hand brakes under the conditions present when they stopped with an emergency application.  That is the root cause:  Failure to properly secure the train after experiencing an emergency brake application on a heavy descending grade.  The report indicates that the first crew likely had time to do this, while the second crew may not have been present long enough to do it.  The reason for the emergency brake application is important, but regardless, the root cause is what I highlighted in bold.

Last edited by Number 90

OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
800-980-OGRR (6477)
www.ogaugerr.com

×
×
×
×
×