DORVAL, QC, Nov. 13, 2013 /CNW/ - The Transportation Safety Board of
Canada (TSB) today released its investigation report (R12D0063) into
the September 2012 incident involving an unprotected overlap of
authority in Montreal, Quebec.
On 13 September 2012, Agence métropolitaine de transport (AMT) commuter
train No. 94 (operating without passengers) was issued a written
authority to pass stop signal 383C located at Mile 38.3 within the
Seaway Interlocking, near Montréal, Quebec, and to proceed northward on
the west track of Canadian Pacific's Adirondack Subdivision. At about
the same time, AMT commuter train No. 93 (operating with passengers)
received a permissive signal at Mile 40.8 to proceed southward and to
cross over onto the same track as train No. 94. As a result, both
trains had authority to occupy the same portion of track, in opposing
directions. However, the overlap of authority was identified, and the
situation was protected.
The Seaway Interlocking control system was installed in 1959. Since its
installation, there have been no significant changes to how this
control system operates. The traffic control board in the Seaway tower
is manually operated by the signalman who controls track movements and
protects track maintenance activities through the interlocking. Unlike
more modern rail traffic control systems that provide additional
defence barriers, the Seaway Interlocking Control System has no
associated software logic to trigger automatic blocking or to provide a
text-based prompt when there are conflicting movements.
Modern computerized rail traffic control systems provide a defense
barrier against certain errors that can lead to unprotected overlap of
authorities. In these more modern systems, electronic blocking is
automatically generated when the Rail Traffic Controller selects the
proposed limits for the authority.
AMT has started an upgrade project to replace the old Code System (i.e.,
Seaway Interlocking control system). This project is scheduled for
The TSB is an independent agency that investigates marine, pipeline,
railway and aviation transportation occurrences. Its sole aim is the
advancement of transportation safety. It is not the function of the
Board to assign fault or determine civil or criminal liability.
SOURCE: Transportation Safety Board of Canada
For further information:
Transportation Safety Board of Canada
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