Remember the notorious CN train derailment near Squamish, BC that took place in August 2005? It spilled 53,000 litres of sodium hydroxide into the Cheakamus River, all but wiping out the fishery there. Along with the Lake Wabamun spill that same month, essentially shredded CN’s reputation. Ever since then, CN’s safety record has been very much in the public eye; for proof, look no further than last February’s W5 documentary. (A Transport Canada safety audit of the railroad was made public in March.)

It continues. A Transportation Safety Board report released yesterday reveals how the Cheakamus Canyon derailment actually happened. Initial reports said that there were five locomotives at the head of the train, with no mid-train power, which observers thought was foolish, because, to quote a November 2005 Globe and Mail article, “if too much power is at the front, the engines can simply ‘straighten out the train’ and pull it off the tracks.” It’s called stringlining, and it is what happened, but it’s not because there wasn’t any mid-train power — it’s because the mid-train power was misconfigured.

[T]he three-kilometre train had seven engines, including two in the middle. But those two middle engines shut down less than 15 minutes after leaving North Vancouver because they were incorrectly set up to pull in the wrong direction.

Alarm bells did go off, but they did not notify the crew that the two locomotives in the middle of the train had shut down. […]

The train eventually started stalling on the steep grade and sharp curves nearing the bridge over the Cheakamus River, the report said.

When another locomotive at the front of the train was powered up to prevent a stall, the light, empty cars behind “stringlined,” pulling them over the inside rail of the curve, resulting in a derailment.

Previously: CN Safety Audit Released; CN’s Safety Record Gets on Television; Internal Documents Reveal Extent of CN Accident’s Devastation; Two More CN Derailments; What’s Up with CN?