Tampering led to 2015 derailment in Montreal's east end, TSB concludes

The Transportation Safety Board of Canada says tampering was the likely cause of a derailment in Montreal's Mercier-Hochelaga-Maisonneuve borough in October 2015.

A group of 26 empty intermodal cars began rolling uncontrolled on a storage track near Canadian Pacific Railway's Hochelaga Yard, and five derailed, including one that jumped an embankment and struck the side of a home.

That home and six others were evacuated as a result, but no one was injured.

The cars travelled about 154 metres along the tracks before stopping.

'Braking force' weakened

A report on the TSB's investigation into the incident, released today, says the cars had been secured on a section of track known as the Outremont spur six months earlier, in May 2015.

According to railway safety rules, between six and nine handbrakes were necessary to secure the 26 cars on that stretch of track, but only five were found to be activated at the time of the incident.

Since the 26 cars had not moved for six months, and handbrakes cannot weaken over time, the investigation concluded that a sufficient number of handbrakes must have been applied when the train was secured.

Given this, the TSB team under lead investigator Guy Laporte determined that "human intervention would have been necessary to weaken the braking force."

The report notes that handbrakes are "relatively simple to release."

"As a result, handbrakes are vulnerable to tampering by unauthorized persons," the report reads.

"If measures to prevent tampering with handbrakes on cars stored in areas frequented by trespassers are not taken, there is an increased risk that rolling stock will move uncontrolled."

Trespassing known issue at yard

The TSB said trespassing in that area of the yard was a well-known issue, and inadequate fencing made it easily accessible to unauthorized people.

Given this, CP should have undertaken special inspections of the cars to ensure they were secure but did not, the report said.

"If no measures are taken to verify that unattended rolling stock is still secured properly, the risk that the rolling stock will move uncontrolled is increased."

The TSB said vandalism was a known risk in the area, but was not "fully considered" in CP's assessment of potential hazards at the yard.

The TSB also highlighted concerns with a derail mechanism on the track, which was torn off when the first car ran over it, allowing the other cars to continue.

The TSB investigation determined that the distance between the derail mechanism and the secured cars gave the cars too much room to gather momentum.

Steps taken

In March 2016, CP was barred from storing cars on that stretch of track until a previous risk assessment was updated and the possibility of an uncontrolled movement mitigated.

The TSB report says CP has taken numerous steps to address concerns raised during the investigation.

Among those measures, CP police increased monitoring and enforcement at the yard and introduced a "zero tolerance" approach to trespassing.