The
occurrence
On 07 March 2015,
Canadian National (CN) crude oil unit train U70451-02 was proceeding eastward
on CN's Ruel Subdivision near Gogama, Ontario. The train crew was composed of a
locomotive engineer, a trainee and a conductor. The train was equipped with 2 head-end
locomotives hauling 94 Class 111 tank cars loaded with Petroleum
Crude Oil (UN 1267). The train was 6,089 feet long and weighed
14,355 tons.
Around 02:42, while
travelling at about 43 mph, a train-initiated emergency brake application
occurred near Mile 88.70. Looking back, the crew observed a fireball about 700
feet behind the locomotives. They detached the locomotives and first 5 cars
behind the locomotives from the derailed cars, and pulled clear. The
temperature at the time was about -10°C.
The train was
designated as a “Key Train”Footnote 1 operating on a “Key Route.”Footnote 2 The accident occurred about 3
kilometres west of the town of Gogama, Ontario, in the vicinity of a CN rail
bridge that traversed the Makami river. The CN Emergency Response Assistance
Plan (ERAP) was implemented and a full incident command structure was
established in the Gogama town hall. There were no injuries reported and no
evacuation was required. All fires were extinguished by
10 March 2015.
What
we know
Site examination
revealed that the 6th to the 44th cars behind the locomotives (39 cars in
total) had derailed. The 6th and 7th cars derailed to the south, but made it
across the bridge to the east side of the river. The derailed trailing end of
the 7th car struck the south side of the bridge structure as it crossed, the
car rolled down the east embankment and its bottom outlet valve was compromised
and released product. The last 2 cars (43rd and 44th) derailed but remained
upright and came to rest near mile 88.75 on the west side of the river. The
remaining cars derailed near the west end of the bridge. Two of the cars were
submerged in the river, 3 cars were partially submerged in the river and the
rest were in a pile on the west river bank (see Photo 1). A number of the cars were breached,
released product and ignited a large pool fire which destroyed the steel rail
bridge. Most of the remaining cars sustained fire damage ranging from minor to
severe. About 700 feet of track was destroyed.
While firefighters
dealt with the fire, investigators from the Transportation Safety Board of
Canada (TSB) examined the area at the west end of the bridge and recovered a
section of broken rail within a plug rail joint that had been installed 2 days
prior to the accident (see Photo 2). The plug rail was put in place as a
repair for an in-service thermite weld failure identified previously at that
location. The recovered rail components were sent to the TSB Engineering
Laboratory in Ottawa for further analysis.
Tank
cars
The TSB conducted a
preliminary damage assessment of the derailed tank cars. All of the Class 111
tank cars were constructed in the last 3 years, and were compliant with
the industry's CPC-1232 standard. In comparison with the other general service
“legacy” Class 111 tank cars, these tank cars have some enhancements which
include half-head shields, improved top and bottom fitting protection, and
normalized steel.
Preliminary
assessment revealed that 1 tank car at the head-end of the derailment sustained
minor damage and 2 tank cars at the tail-end of the derailment had no damage.
The remaining derailed tank cars sustained more significant damage, releasing
product that sustained a large pool fire. At least 5 of the tank cars exhibited
thermal tears from exposure to the pool fire. Initial impressions are that
these Class 111 tank cars performed similarly to those involved in the
Lac-Mégantic accident. The amount of product released to atmosphere, the river
or ground has not yet been estimated, but will be determined as site mitigation
and clean-up continues.
Transportation
of flammable liquids by rail
The transportation of flammable liquids by rail has
been identified as one of the key risks to the transportation system and it is
included on the TSB's 2014 Watchlist. The TSB has been pointing
out the vulnerability of Class 111 tank cars for many years, and the Board
has called for tougher standards for all Class 111 tank cars,
not just new ones, to reduce the likelihood of product release during
accidents. In Lac-Mégantic, investigators found that, even at lower speeds, the
unprotected Class 111 tank cars ruptured, releasing crude oil which
fuelled the fire.
The tank cars
involved in the previous Gogama derailment (R15H0013) which occurred on 14
February 2015, and the tank cars involved in this derailment (R15H0021) were
compliant with the CPC-1232 standard and were not equipped with a thermal
protection system.Footnote 3 Preliminary assessments of the
tank cars involved in both derailments identified that the derailed cars
sustained significant damage and did not perform as well as expected. Until a
more robust tank car standard with enhanced protection for all tank cars
transporting flammable liquids is implemented for North America, the risk will
remain.
In response to TSB
Recommendation R14-01 issued in January 2014, Transport Canada (TC) adopted the
TP 14877 standard in the Transportation of Dangerous Goods Regulations
on 02 July 2014, requiring all new tank cars built for the transportation of
flammable liquids in Canada to meet the CPC-1232 specifications. At that time,
the TSB warned TC that this standard was not sufficient and that more needed to
be done to provide an adequate level of protection.
TC-117
On 11 March 2015, TC
announced proposed upgraded standards for a new series of tank car—the TC-117.
The new standard would require all new tank cars built for the transport of
flammable liquids to be constructed using thicker and more impact-resistant
steel and to be equipped with jacketed thermal protection, full height head
shields, top fittings protection and improved bottom outlet valves. The
phase-out of legacy Class 111 tank cars (including the CPC-1232 tank cars) in
flammable liquid service would be gradually implemented using a risk-based
approach, taking into consideration the features of the tank cars and the
characteristics of the flammable liquid being transported.
While the proposed
standards look promising, the TSB has concerns about the implementation
timeline, given initial observations of the performance of CPC-1232 cars in
recent derailments. If older tank cars, including the CPC-1232 cars, are not
phased out sooner, then the regulator and industry need to take more steps
to reduce the risk of derailments or consequences following a derailment
carrying flammable liquids.
Quote
“Canadians expect
their government to ensure that the risks posed by the transportation of
flammable liquids are minimized to the greatest extent possible,” said Kathy
Fox, Chair of the TSB. “I am reiterating my concern expressed in letters I sent
to both the Minister of Transport and the Acting Administrator of the Pipeline and Hazardous Materials
Safety Administration in the United States in October 2014, in which
I urged TC and its U.S. counterparts to adopt the highest possible standards
for tank cars carrying flammable liquids, and replace or retrofit existing tank
cars as soon as practicable so that they meet new standards.”
Track
infrastructure
The CN Ruel
Subdivision consists of single main track which extends westward from Capreol,
Ontario (Mile 0.00) to Hornepayne, Ontario (Mile 296.20). It is primarily
composed of continuous welded rail (CWR) and is rated as Class 4 track under
the TC-approved Track Safety Rules. Class 4 track permits track speeds of up to
60 mph for freight trains and 80 mph for passenger trains. However, there were
permanent slow orders on much of the subdivision to protect against various
infrastructure and track maintenance issues.
Preliminary
indications are that track infrastructure failures may have played a role in
each of the Gogama accidents and a 3rd accident that involved a mixed manifest
train on the Ruel Subdivision near Minnipuka, Ontario on 5 March 2015.
Petroleum crude oil unit trains transporting heavily-loaded tank cars will tend
to impart higher than usual forces to the track infrastructure during their
operation. These higher forces expose any weaknesses that may be present in the
track structure, making the track more susceptible to failure. Given the
potential damage of a train derailment, particularly when petroleum crude oil
unit trains are involved, the TSB has issued a Safety Advisory Letter calling on TC to review
the risk assessments conducted for the Ruel Subdivision, assess the track
infrastructure condition and determine whether additional risk control measures
are required when operating a ”Key Train” on this “Key Route.”
Next
steps
The investigation is
ongoing and the next steps include:
- Examination of rail components from the derailment site.
- Sampling and testing of product from select tank cars.
- Review of Wheel Impact Load Detector records for the train and previous trains.
- Review of track infrastructure maintenance records for the area.
- Review of CN Engineering Track Standards.
- Review of TC-approved Track Safety Rules.
- Review and evaluation of ERAP and emergency response.
- Conducting of additional interviews as required.
Once all remaining
product has been removed from the tank cars and they have been cleaned and
purged, the TSB will complete a detailed damage assessment of the cars. The
object of the assessment is to compare the performance of these tank cars
against the known performance of the legacy Class 111 tank cars that were
involved in the Lac-Mégantic accident and the CPC-1232 compliant Class 111 cars
involved in the previous CN unit crude oil train accident. This will include
further failure analysis, testing and metallurgical examination at the TSB
Engineering Laboratory.
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.
For more information,
contact:
Transportation Safety Board of Canada
Media Relations
819-994-8053
Transportation Safety Board of Canada
Media Relations
819-994-8053
Footnotes
Footnote 1
A
“Key Train” is defined as any train containing 1 or more cars of Poison
Inhalation Hazard (PIH) or Toxic Inhalation Hazard (TIH) material, such as
anhydrous ammonia, ammonia solutions, spent nuclear fuel or high-level
radioactive waste, or containing 20 car loads, or intermodal portable tank
loads, of any combination of other hazardous materials (e.g., crude oil).
Footnote 2
A
“Key Route” is defined as any track on which, over a period of one year, is
carried 10,000 or more loaded tank cars or loaded intermodal portable tanks
containing dangerous goods, as defined in the Transportation of Dangerous
Goods Act, 1992, or any combination thereof that includes 10,000 or more
loaded tank cars and loaded intermodal portable tanks.
Footnote 3
The
CPC-1232 standard does not require tank cars to be fitted with a thermal
protection system.