 Final
report on Buckskin Derailment
Published: August 8, 2008
Source: Transportation Safety Board of Canada
July 29, 2008
Ms. Wendy A. Tadros
Chairperson
Transportation Safety Board of Canada
200 Promenade du Portage
Place du Centre, 4th Floor
Gatineau, Quebec
K1A 1K8
Dear Ms. Tadros:
SUBJECT: FINAL RAIL INVESTIGATION REPORT R06T0022
MAIN TRACK DERAILMENT
BUCKSKIN, ONTARIO – JANUARY 31, 2006
I am writing in response to your letter of June 2, 2008, which contained
Transportation Safety Board recommendations R08-01 and R08-02. These
recommendations were made as a result of the investigation into the
derailment of a Canadian Pacific Railway freight train 230-30 at mile
114.65 of the MacTier Subdivision in Buckskin, Ontario on January 31,
2006.
I am pleased to provide you with a response as required under subsection
24(6) of the Canadian Transportation Accident Investigation Safety Board
Act.
Yours truly,
Original signed by
The Honorable Lawrence Cannon, P.C., M.P.
Enclosure
TRANSPORT CANADA’S RESPONSE TO TSB RECOMMENDATIONS R08-01
AND R08-02 - TSB FINAL INVESTIGATION REPORT R06T00220 – MAIN TRACK
DERAILMENT IN BUCKSKIN, ONTARIO ON JANUARY 31, 2006
From the TSB Final Report – Removal of Suspect Transcona Wheel Shop
Wheel Sets:
In 2000, loose wheels began to occur on CN's coal rail car fleet. By
fall 2001, CN had traced the problem to a modified wheel boring process
that had been used in the assembly of 36-inch wheel sets at its
Transcona wheel shop between April 1998 and February 2001. The modified
boring process resulted in wheel sets with reduced contact area between
the wheel bore and axle wheel seat. Under normal service conditions, the
reduced contact area led to higher stresses in the remaining areas of
contact that initiated fretting at the tips of the bore spirals when the
car was negotiating a curve. This resulted in brinell indentations
occurring on the axle wheel seat that progressively loosened the
interference fit. All of the wheel sets that were produced using the
modified wheel boring process (approximately 43 800) have a high
susceptibility to loosen, particularly in heavy-curvature territory.
Since loose wheels were first detected, CN and the Association of
American Railroads (AAR) initiated an industry recall that included
issuing AAR Early Warning letter (EW) 5183 and AAR Maintenance Advisory
(MA) 74. However, due to shortfalls in the recall process, the risk has
not yet been completely mitigated. Consequently, at least 25 per cent
(10 000 to 12 000) of these wheel sets remain in service six years after
the initial recall and loose wheel derailments continue to occur.
To date, at least 15 derailments in Canada have been attributed to
suspect Transcona wheel shop loose wheels, 12 of which occurred after
the recall process had been initiated. Since most of these two-wear
wheel sets have an extended service life and the mode of failure takes
time to develop, the risk of failure for these remaining wheel sets
continues to increase the longer they remain in service.
Therefore, the Board recommends that:
“The Department of Transport ensure that all 36-inch Canadian
National Transcona wheel shop wheel sets assembled between April
1998 and February 2001 be removed from cars operating in Canada.”
(R08-01)
Transport Canada (TC) accepts the Recommendation R08-01. On June 13,
2008, TC issued an Emergency Directive (copy attached) to Canadian
National (CN) pursuant to Section 33 of the Railway Safety Act (RSA)
whereby CN is to identify and remove the said wheelsets from Canadian
Services, by no later than, October 15, 2008.
From the TSB Final Report - Tracking Wheel Set Components
There were gaps in the initial industry recalls of EW 5183 and MA 74
that did not include approximately 17 000 suspect Transcona wheel shop
wheel sets assembled between January 2000 and February 2001. Aside from
CN, the industry as a whole did not target the full population of
suspect wheel sets for removal until July 2006. As a result, many wheel
sets were permitted to remain in service or, as in this occurrence,
removed from the original car, reconditioned and placed under a second
car.
This was not the first time that a wheel population with a known
manufacturing defect had caused multiple derailments and been subjected
to an industry recall. In 2004, a Southern wheel failure on a Canadian
Pacific Railway train resulted in two fatalities in Whitby, Ontario (TSB
investigation report R04T0008). The AAR had previously issued recalls of
wheels that contained known manufacturing defects produced by Southern
Wheel, by Mafersa, and by Edgewater. In each of these cases, industry
was aware of these wheels' susceptibility to failure, and had initiated
recalls, but had been unable to track, locate, and remove all of them
before failure.
When wheel sets are installed under freight cars, wheel set information
such as month and year of manufacture, manufacturer code, heat treatment
class, wheel flange and tread thickness is recorded. However, there is
no requirement to record wheel mount date and wheel serial numbers even
though the information is readily available. The absence of wheel serial
numbers and mounting dates presented fundamental difficulties during the
Transcona wheel shop wheel set recall process. Had this information been
available, it would have provided an alternate method for locating the
defective wheel sets. An industry-wide search of databases would have
located the suspect Transcona wheel shop wheel sets, regardless of which
car they were under at the time of the recall. In addition, databases
could have been flagged to produce a warning before the installation of
suspect Transcona wheel shop wheel sets.
The testing of radio frequency identification tags to track rail car
components is a positive step towards solving the tracking problem.
However, when compared to the aviation industry, the rail industry falls
short in its ability to locate and remove defective components.
Specifically, the Canadian Aviation Regulations require that, whenever
components are installed into an airframe, the components and the
procedures used for their installation are uniquely identified and
permanently recorded. In this manner, components can be easily located
if a problem develops at a later date with either the component or the
installation procedure. With the transition to a more global supply
network for the North American rail industry, the need for a system that
has the ability to effectively and quickly locate potentially defective
wheel set components in freight cars is essential.
Because the industry has no effective way to track wheel sets once
they are removed from their original car, wheel sets with potentially
defective components cannot be easily located and removed from service
before failure. The inability to quickly locate defective wheel set
components increases the risk of a failure, which can lead to a
derailment.
Therefore, the Board recommends that:
“The Department of Transport ensure that railways adopt
procedures and technologies to track all wheel sets.” (R08-02)
TC accepts the Recommendation R08-02. On June 13, 2008, TC issued an
Emergency Directive to CN pursuant to Section 33 of the RSA, whereby CN
has been directed to put in place a system to record and track major
components such as, but not limited to, wheels, wheel sets, axles,
roller bearings, draft gears, and couplers throughout their service
life, by no later than
December 13, 2008.
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