RAIL Reports - 2006 - R06V0183

2.0 Analysis

2.1 Introduction

There was no information to suggest that track conditions played a role in the derailment. The investigation revealed that the train became uncontrolled and reached a speed of about 20 mph before being placed into emergency. The presence of wheel flange markings on the running surface of the east (high-side) rail head indicates that the point of derailment was in the sharp left-hand curve at Mile 36.5. The location of the locomotive, on its side on the outside of the curve, and the absence of wheel flange markings on the ties between the rails are indicative of a wheel lift derailment caused by overspeed.

The following factors collectively contributed to the train becoming uncontrolled while descending the mountain:

• the overloading of the ballast cars and the make-up of the train;
  
  
• the steepness of the grade;
  
  
• the ineffectiveness of the brake systems on the ballast cars;
  
  
• the absence of comprehensive operating instructions for the safe descent of this extreme mountain grade;
  
  
• the speed of the train and the depleted state of charge of the air brake systems on the cars when the grade was crested;
  
  
• the speed that the train was permitted to attain before train brake applications were made, that is, full service (18 mph) and emergency (20 mph); and
  
  
• the absence of a functioning dynamic brake on locomotive 114.

Additionally, safety-critical issues including training, communication, emergency response, and the SMS will be discussed.

2.2 The Accident

Examination of the locomotive showed that the brake system was fully operational before the derailment and that the brakes had been heavily applied and became very hot. Because of the resultant high temperature of the brake shoes, it is likely that the effective braking force of the locomotive brake system had been diminished by the effects of heat fade. The high temperature attained at the interface between the wheel tread and the brake shoes was due to the high speed at which the brakes were initially applied and the extent and duration of the brake application.

Examination of the cars revealed that all the brakes were operational but that only some of the brake shoes had been heavily applied against the wheels. Although this is consistent with normal rolling stock operation, the brake shoe force test results of the two sister cars were below applicable AAR standards for minimum braking force and, therefore, it is likely that the brake systems on all of the ballast cars were functioning at a diminished capacity.

Because the brake system on the cars were not generating their maximum braking force and because the brake system on the locomotive was experiencing the effects of heat fade, the entire train brake system was not functioning optimally. In addition, only three of the eight cars were equipped with retainers, which were set to an incorrect position and were not providing any retarding force. The overloaded condition of the cars, the number of cars marshalled in the train and the steep mountain grade exacerbated the effect of the already diminished braking capacity of the cars. When the train began descending the grade and the locomotive engineer applied the automatic and then the emergency brake, the braking force generated was insufficient to control the train and it continued to gain speed until it derailed on the sharp curve at Mile 36.5.

2.3 Loading of the Ballast Cars

As the roadmaster expected the cars to be loaded as full as possible for operational reasons, the cars typically would be completely filled with ballast. Because the load appeared reasonable for the size of the car and because cars had been handled while overloaded north from Log Cabin many times before without incident, WP&YR employees believed that fully loaded cars could be safely handled. However, based on the AAR-recommended maximum gross rail load of 71 tons for cars equipped with 5-inch-by-9-inch axle journals, each car was overloaded as indicated in Figure 3.

Scenario Bucket (Number of) Yards/Bucket Yards/Car Ballast Weight (lb/Yard) Ballast Load (Tons) Car Tare (Tons) Gross Load (Tons) WP&YR Maximum Load (Tons) Overload AAR Maximum Gross Tons Overload A 13 3.5 45.5 2691 61.2 20.0 81.2 35.5 25.7 71.0 10.2 B 17 3.5 59.5 2840 84.5 20.0 104.5 35.5 49.0 71.0 33.5 C 21 3.5 73.5 2840 104.4 20.0 124.4 35.5 68.9 71.0 53.4 Notes: - short tons used throughout - bolded numbers are those used in the calculation and extracted for the conclusions. Load Scenarios A. conservative scenario - 13 buckets B. most likely scenario - minimum 17 buckets C. most likely scenario - maximum 21 buckets Measured Values Used in Calculations: Ballast Weight (Pounds/Cubic Yard) WP&YR Maximums conservative scaled field observation 2691 2840 2860 yards loaded tons Car Tare Weight Tons 25.0 35.5 20.0 Cubic Yard/Bucket AAR Maximums flush heaped 3.0 3.5 gross tons 71.0

Figure 3.

Calculations of overload.

This information indicates the following:

• Using the most conservative estimate and the AAR maximum gross load, the cars were overloaded by approximately 10 tons each.
  
  
• For the minimum end of the most likely scenario and the AAR maximum gross load, the cars were overloaded by approximately 34 tons each.
  
  
• For the maximum end of the most likely scenario and the WP&YR maximum load, the cars were overloaded by approximately 70 tons each.

The load limit in terms of maximum weight was not stencilled on the side of these cars, nor was it required to be. However, most railways stencil this information onto their cars for the ready reference of crews.

No training was provided on load capacities of ballast cars, nor were there any marker lines or indications on the cars indicating a maximum carrying capacity. Additionally, the WP&YR volumetric limit of 25 cubic yards of ballast per car had not been disseminated among the employees. In the absence of training, guidelines, or indicator markings on the cars to inform railway employees as to the maximum safe load capacity of the ballast cars, WP&YR employees were unable to determine a safe maximum load capacity and, consequently, the cars were overloaded.

2.4 Work Train Equipment Handling Procedures

The crew received instructions to take the loaded ballast cars to Bennett and placed all eight loaded ballast cars and one engine on the train. Although trains with six loaded ballast cars had been handled from Log Cabin before, there had been additional locomotives and empty cars, marshalled within the train, which increased overall braking capacity. Before the derailment, there was no discussion concerning the need for additional braking capacity to safely descend this grade.

Both the locomotive engineer and the conductor were inexperienced in work train service and unaware of the maximum number of cars that could be handled with one locomotive. Work train marshalling practices were not covered in the company's training program and no operating instructions guiding employees on horsepower/braking requirements were provided. While other railways have developed specific train handling instructions guiding their crews on how to safely descend steep mountain grades, there were no such instructions on the WP&YR to guide crews on the safe make-up and operation of trains in this challenging territory. In the absence of a comprehensive set of guidelines in train make-up, there is a risk that trains will be operated in mountain grade territory without an adequate margin of safety.

While all eight cars on the train were required to have retainers, only three of the cars were so equipped. Although Timetable 178 indicated the locomotive engineer's responsibility to determine the need for retainers, there was no instruction indicating how to set them or what each position meant. Due to the lack of familiarity with retainers, the retainers were set incorrectly in the slow direct position, in which the air brakes bled off in about 1 ½ minutes, exhausting all the air from the brake cylinders. Had they been set in the high pressure position, they would have provided a holding force of 20 psi in the brake cylinders when the locomotive engineer released the train brakes. Without a retainer on each car and without adequate crew knowledge of how to properly set them, a line of defence against a loss of control in mountain grade territory was not available to this crew.

2.5 Train Handling Procedures

Approaching Mile 35, the locomotive engineer released the automatic brake from an 18 psi application to avoid stalling the train. Consequently, the train crested the hill at about 12 mph with the brakes released. The braking force required to control a train down a grade is proportional to the speed at which the train crests the grade: the faster it crests the grade, the greater the braking force required. Therefore, cresting the grade at a lower speed would have reduced the braking force required to control the train. These train handling decisions resulted in the train beginning the critical part of the descent with the brake system not ready to counteract the steep grade.

After cresting the grade, the train accelerated to 18 mph before any supplementary application of the brakes was made. At about Mile 35.3, the locomotive engineer increased the automatic brake reduction to just short of a full service application (about 28.5 psi assuming brake pipe pressure was set at 90 psi). Although the train continued to accelerate, the brakes were not placed in emergency until the train speed reached about 20 mph. To prevent a complete loss of control, it is critical that an emergency brake application be made at the lowest possible speed, otherwise friction surfaces will reach temperatures at which braking effectiveness will decline. In this instance, the train was allowed to reach a speed, prior to initiation of the emergency brake application, that decreased the likelihood of its stopping.

The locomotive engineer was inexperienced in handling heavy trains down mountain grades and had no company guidance on safe train handling procedures. In the absence of adequate instructions and training, a number of train handling decisions were made that were inconsistent with safe practices for descending mountain grades and contributed to the loss of control.

2.6 Training

There were several instances where the crew members of the work train demonstrated a lack of understanding of safe operating procedures for work trains. They were unaware of the safe loading capacities of the ballast cars, the danger of riding on the outside platform of a locomotive, safe train handling procedures for heavy trains on mountain grades, and the operation of retainers.

In other modes of transportation, there are specific regulations provided by TC requiring licensing and training of employees (for example, Canadian Aviation Regulations for flight crews). As the railway industry is not governed by TC in this manner, larger companies such as Canadian National and Canadian Pacific Railway provide comprehensive training for newly hired employees and recertification courses for experienced employees. These courses make use of extensive training materials and guidelines, and are taught by CROR-qualified instructors drawn from a pool of employees that have been recognized as having an exemplary understanding of the theory and practice of the CROR.

While WP&YR provides rules instruction yearly to employees, this training can be categorized as ad hoc. There was no formally prepared rules instruction course provided that used detailed training material. The training program relied on the experiences of the most senior trainman, who would not necessarily have the requisite knowledge to ensure that WP&YR employees were adequately trained in safe work train operating practices. Without comprehensive training material and well-established policies and procedures, training at WP&YR was not entirely effective.

2.7 Dynamic Brake

The locomotive in this accident was equipped with dynamic braking. Dynamic braking does not rely on the friction created by brake shoes to slow the train and does not suffer from the effects of heat fade. A fully functioning dynamic brake can generate significantly more braking effort than the air brakes on a locomotive. Therefore, it can be a useful tool to control the train speed, particularly in mountain grade territory. The dynamic brake on this locomotive was not serviceable because it reacted in an unsafe manner by applying maximum effort each time it was activated rather than allowing a gradual build-up of force. Even though it could have been accessed by the locomotive engineer, its use was not considered for this reason. While the condition of the dynamic brake was known to the railway, it had not been disabled and, in the absence of a formal policy concerning its use, locomotive engineers had deemed it non-operational. Because the dynamic brake was not functioning properly, a valuable line of defence against a loss of control on mountain grades was not available to the locomotive engineer.

2.8 Safety Management System

WP&YR's SMS submission to TC met the minimum requirements. However, information obtained during the investigation indicates that a number of the safety management procedures and practices were deficient, for example:

• training of employees;
• maintenance of ballast cars and locomotives;
• use of locomotive event recorders;
• operating on mountain grades without specific train handling and marshalling instructions;
• loading of ballast cars; and
• communications between the dispatcher and work train operations.

The SMS on the WP&YR did not identify the above safety-deficient practices and therefore was not sufficiently developed to have ensured the progression of safety philosophy through to policies, procedures, and practices. Moreover, the 2003 TC audit of WP&YR's SMS, being a general audit, was not designed to identify safety-deficient practices, and consequently, did not lead to the development of a more comprehensive SMS.

2.9 Communication

The train entered the main track under the authority of cautionary limits and, while the crew members were required to contact the dispatcher after departing Log Cabin, they were unsuccessful at doing so. The dispatcher was therefore unaware that the work train was operating. The dispatcher was frequently unaware of work trains in cautionary limits because trains are self governing, within the parameters of the rule in these limits. When the passenger train season ends, typically at the end of September, there would be no dispatcher on duty. As such, the requirement of a work train to report at prescribed locations would constitute a broadcast to open air, for whomever may be monitoring the radio in the area. As a result, there were times when a work train would operate on WP&YR track when its exact whereabouts was not known to others.

On other Canadian railways under federal jurisdiction, it is common procedure that, even within cautionary limits, the dispatcher is aware of trains operating in that territory. As a result, dispatchers have train information such as train type, number, consist, and crew information. Being unaware of the operation of the work train created a risk that the dispatcher could not provide the most accurate information to accelerate the emergency response.

In order to place an emergency call from the locomotive, a crew member must complete a series of steps by first contacting a third party operator who will, once given the correct account number, transfer the call to the intended party. In high stress situations, such as a runaway, it is difficult for employees to complete these tasks in a timely manner. In this accident, the crew was unsuccessful in placing an emergency call to the dispatcher. In addition, there was no emergency response protocol available between the railway and the third party operator, if the dispatcher was unavailable. When a complex series of steps is required to establish communication, there is an increased risk that, in an emergency, an adequate level of safety may not be immediately provided.

2.10 Emergency Response

The emergency responders arrived on scene within a reasonable amount of time, given the rugged terrain and remote location. However, had the dispatcher been notified immediately after the roadmaster first learned of the accident, and had the information in the initial notification been more complete, that is, had they known the accident involved a freight train, not a passenger train, the response time would have been quicker. The rescue took longer than anticipated because of difficulties gaining access to the locomotive cab. The fire department's extrication equipment was not sufficient for cutting open the thick steel. After being revived, the locomotive engineer freed himself from the locomotive cab. The heavy equipment operator who placed the radio call to the roadmaster was freed by the first responders within three and one-half hours of the responders' arrival on site.

3.0 Conclusions

3.1 Findings as to Causes and Contributing Factors

1. The overloaded train derailed after it ran away down the steep mountain grade with its degraded brake system unable to control its speed.
   
   
2. The effective braking force of the locomotive brake system had been diminished by the effects of heat fade.
   
   
3. It is likely that the brake systems on all of the ballast cars were functioning at a diminished capacity.
   
   
4. The overloaded condition of the cars, the number of cars marshalled in the train and the steep mountain grade exacerbated the effect of the already diminished braking capacity of the cars.
   
   
5. In the absence of training, guidelines, or indicator markings on the cars to inform railway employees as to the maximum safe load capacity of the ballast cars, White Pass and Yukon Route (WP&YR) employees were unable to determine a safe maximum load capacity and, consequently, the cars were overloaded.
   
   
6. Without a retainer on each car and without adequate crew knowledge of how to properly set them, a line of defence against a loss of control in mountain grade territory was not available to this crew.
   
   
7. A number of train handling decisions were made that were inconsistent with safe practices for descending mountain grades and contributed to the loss of control.
   
   
8. Because the dynamic brake was not functioning properly, a valuable line of defence against a loss of control on mountain grades was not available to the locomotive engineer.

3.2 Findings as to Risk

1. In the absence of a comprehensive set of guidelines in train make-up, there is a risk that trains will be operated in mountain grade territory without an adequate margin of safety.
   
   
2. Without comprehensive training material and well-established policies and procedures, training at WP&YR was not entirely effective.
   
   
3. Safety management on the WP&YR was not sufficiently developed to have ensured the progression of safety philosophy through to policies, procedures, and practices.
   
   
4. The fact that the dispatcher was unaware of the operation of the work train created a risk that the dispatcher could not provide the most accurate information to accelerate the emergency response.
   
   
5. When a complex series of steps is required to establish communication, there is an increased risk that, in an emergency, an adequate level of safety may not be immediately provided.

3.3 Other Findings

1. Using the most conservative estimate and the Association of American Railroads (AAR) maximum gross load, the cars were overloaded by approximately 10 tons each. For the minimum end of the most likely scenario, and the AAR maximum gross load the cars were overloaded by approximately 34 tons each. For the maximum end of the most likely scenario, and the WP&YR maximum load, the cars were overloaded by approximately 70 tons each.
   
   
2. The emergency responders arrived on scene within a reasonable amount of time, given the rugged terrain, remote location, and the information they received from the railway.

4.0 Safety Action

4.1 Action Taken

4.1.1 TSB Rail Safety Advisories

On 23 November 2006, the TSB issued to Transport Canada (TC) Rail Safety Advisory (RSA) 07/06, Pressure Retaining Valves on White Pass & Yukon Route Ballast Car, indicating that TC may wish to assess the extent to which White Pass and Yukon Route (WP&YR) management ensures that cars are properly equipped and maintained, and that train crews handling these cars have adequate instruction and training to ensure that sufficient control is exercised on mountain grades.

On 30 November 2006, the TSB issued to TC RSA 08/06, Overloading of White Pass & Yukon Ballast Cars, indicating that TC may wish to assess the loading practices of engineering service cars (ballast and air dump cars) on the WP&YR.

4.1.2 Transport Canada

On 12 December 2006, TC issued a Letter of Non-Compliance and a Notice to WP&YR citing their violation of various TC regulations referenced under the Railway Safety Act concerning hazards/conditions related to the ballast cars and to the operation of ballast trains.

On 05 June 2007, TC issued a Notice and Order to WP&YR requiring that trains not operate between Bennett, Mile 40.6, and Carcross, Mile 67.5, unless they are equipped with a system that ensures positive communication directly with the rail traffic controller and that facilitates emergency calling recognizable by the rail traffic controller.

From 04 June 2007 to 07 June 2007, TC conducted an audit under the Safety Management System Regulations of the WP&YR safety management system (SMS). The audit made a number of findings that were communicated to WP&YR. The following are some of the findings that are relevant to this investigation:

• Risk assessments were not being carried out.
  
  
• WP&YR was in non-compliance with the Employee Minimum Qualification Standards.
  
  
• There was no documented process describing how the company carries out air brake tests and how it ensures compliance with the Railway Freight and Passenger Train Brake Rules.

On 11 June 2007, TC issued a Notice to WP&YR concerning several hazards/conditions related to the reliance by the railway on employee familiarity to protect against each other on the main track. This reliance may result in an increased likelihood of a collision taking place between a train and maintenance-of-way forces, which may become complacent and/or not be expecting the movement of a train or engine. This risk is greatly magnified by the lack of reliable radio communications between Bennett and Carcross.

On 11 June 2007, TC sent a letter to WP&YR in regards to train operation monitoring activities, which revealed several safety-related deficiencies.

On 31 July 2007, TC sent a letter to WP&YR directing them to conduct a formal risk assessment on the safe operation of rolling stock when descending grades greater than 2 per cent and to then develop written procedures.

On 31 July 2007, a TC Occupational Health and Safety Officer issued a Direction to the WP&YR concerning their contravention of the Part II of the Canada Labour Code regarding the provision of information, training and instructions to operating employees relating to the following:

• the adverse effects of overloaded rolling stock on braking performance;
  
  
• the safe operation of rolling stock on grades over 2 per cent; and
  
  
• the safe and proper operation of rolling stock including locomotives.

The Direction required WP&YR to take steps to ensure that the contravention does not continue.

TC conducted additional monitored activities on the WP&YR from 27 to 29 May 2008. TC indicates the intention to revise the Railway Locomotive and Inspection Safety Rules as follows:

• Locomotive Design Requirement - all new locomotives shall be equipped with dynamic braking and a dynamic braking holding feature.
  
  
• Application of Safety Inspection and Movement Restrictions - all locomotives with dynamic braking or dynamic braking holding feature defect will be listed as a Part III safety defect.
  
  
• Pre-Departure Inspection - to include in conditions listed in Appendix I a test of the dynamic braking once en route and any defects reported in accordance with company procedures/work instruction.

4.1.3 White Pass and Yukon Route

On 15 February 2007, WP&YR replied to both of TC's Notices dated 12 December 2006, indicating that:

• It would have retaining valves installed on all rolling stock by the beginning of the 2007 operating season.
  
  
• All WP&YR ballast cars would be stencilled with load limit weights.
  
  
• All personnel involved in loading WP&YR ballast cars would be instructed on loading procedures and limits by the operating supervisor before the 2007 operating season, which was to be followed up with a memo from the Superintendent of Rail Operations to all equipment operators.

On 30 April 2007, a WP&YR memorandum was issued concerning ballast car loading procedures including: gross weight of ballast car - 140 000 pounds; lightweight of ballast car - 26 000 pounds; load capacity of ballast cars - 108 000 pounds; and load capacity with Lewes Lake ballast - 2442 pounds per cubic yard. It provides front-end loader bucket capacity - 3.5 cubic yards heaped and 3 cubic yards struck - and dictates that a maximum load level is not to exceed 14 level bucket loads.

In May 2007, 24 trainmen, conductors and locomotive engineers attended a two-day course on the air brake system and pressure-retaining valves delivered by an instructor from the British Columbia Institute of Technology.

As of May 2007, Operating Bulletin 07-10 was issued, reinforcing WP&YR's existing policy requiring trainmen and conductors to perform a set-up and release brake test and an inspection before departure. When defects are found, the cars must be set out and a supervisor notified.

Instructions included in a draft form of Air Brake and Train Handling Rules dated 01 June 2008 include instructions on locomotive inspections and instructions on the operation of retainers for maintenance-of-way ballast trains and passenger operations.

A manual on job duties and safety issues for trainmen and conductors was published.

As of May 2008, WP&YR has installed type Q1067E event recorders on 17 out of 20 of its fleet of locomotives. The remaining 3 locomotives are used in a trailing position, within the train consist.

In June 2007, WP&YR acquired three satellite telephones for its trains and for the maintenance-of-way foreman between Bennett and Carcross providing them with the capability of communicating with each other and with the rail traffic controller. The telephone numbers have been distributed to the employees and an emergency number has been set up at the rail traffic control centre. The crews have been advised by operating bulletin that trains travelling north of Bennett must be equipped with a satellite telephone and have it turned on. Cellular telephones are also available to use if the existing portable telephones and recently purchased satellite telephones fail.

On 17 July 2007, Operating Bulletin 07-25 was issued to protect workers and foremen under Canadian Rail Operating Rules Rule 815. It ensures that work is stopped and cleared before a train is cleared through the limits.

In May 2008, WP&YR issued Operating Bulletin 08-19, a draft of rolling stock handling procedures for operating crews to minimize the risks while operating on grades of over 2 per cent.

WP&YR provided TC with its corrective action plan to address the findings in the report from TC's 04 to 07 June 2007 audit.

WP&YR introduced an annual 12-hour course on railway air brake systems. This course was presented by instructors from the British Columbia Institute of Technology and attended by all locomotive engineers, conductors and trainmen.

A three-hour training session on brake testing of car equipment, followed by testing, was given to all railway certified car inspectors.

Load limits and "restricted service equipment" (RSE) has been stencilled on the majority of dump cars.

From 02 to 04 May 2008, locomotive engineer recertification and testing programs were conducted and documentation has been placed on file.

A consultant has been hired to develop safety training and testing requirements.

A full-time safety manager was hired.

All car and locomotive maintenance is now documented and kept on file.

Retainer valves have been installed on all ballast cars.

This report concludes the Transportation Safety Board's investigation into this occurrence. Consequently, the Board authorized the release of this report on 25 July 2008.

Appendix A - Glossary

AAR		Association of American Railroads
CROR		Canadian Rail Operating Rules
mph		miles per hour
psi		pounds per square inch
RCMP		Royal Canadian Mounted Police
RSA		Rail Safety Advisory
RSE		restricted service equipment
SMS		safety management system
TC		Transport Canada
TSB		Transportation Safety Board of Canada
WP&YR		White Pass and Yukon Route
ºC		degrees Celsius

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1.   All times are Pacific daylight time (Coordinated Universal Time minus seven hours).

2.   See Glossary at Appendix A for all abbreviations and acronyms.

3.   "Dispatcher" is the term used for "rail traffic controller" on the WP&YR.

4.   The brake test included the conductor detraining and observing the brakes apply and release.

5.   A retainer is a manually operated three- or four-position valve that can be used to limit the release of air pressure from the brake cylinder subsequent to the release of the automatic brake. Retainers are often used to retain brake cylinder pressure while descending heavy mountain grades.

6.   "Automatic brake" refers to the train air brake system. This brake is applied on both the cars and the locomotive(s).

7.   The independent brake operates only the locomotive brakes.

8.   In the absence of locomotive event recorder information, the investigation could not precisely determine the brake pipe pressure setting. It was estimated at 100 psi based upon information obtained during the investigation.

9.   Blueing is a term that refers to the appearance of the wheel tread surface that results from subjecting the tread to excessive heat, usually from prolonged or heavy brake applications.

10.   This position permits slow direct exhaust of up to 50 psi of brake cylinder pressure over about 1 ½ minutes.

11.   There is an exception for restricted service equipment, such as ballast cars, provided that they are stencilled "RSE" (restricted service equipment) and the railway has provided operating plans to Transport Canada. The ballast cars used in this accident were not stencilled and, therefore, not exempt from this rule.

12.   A train control system in which Occupancy Control System rules apply.

13.   The air dump cars were used to carry ballast and were smaller than those involved in the derailment.

14.   This rule was superseded in June 2007 with revised wording for this section, but the same intent.

15.   Cinder ballast is much lighter than crushed rock ballast.

16.   Railway-supplied information indicates that the tare weight of the cars was 20 tons. However, similar cars from other railways weigh 30 tons. WP&YR modified the cars by adding smaller trucks.

17.   All tons referenced are short tons, that is, 2000 pounds.

18.   In order to evaluate the load capacity of the ballast cars, investigators loaded an identical car with 15 bucket loads of ballast. The level attained was below that of the cars on the occurrence train.

19.   The maximum weight of a car including its load.

20.   When a train's air brake system is released and fully charged, each car has a stored supply of air ready to be used for the next application. To apply the brakes, air from reservoirs on the cars is used. The locomotive engineer sends a signal to each car by reducing air pressure from the brake pipe. The control valve on each car responds by allowing air from the auxiliary reservoirs (the stored supply) into the brake cylinders, forcing the brakes to come on.

21.   On longer trains, during release/recharging, there will be a difference in the brake pipe pressure value from the front to the rear of the train. This is known as brake pipe gradient. On shorter trains, during release/recharging, brake pipe gradient is less likely to occur because the brake pipe is shorter and there are fewer reservoirs to recharge, and overall demand for air supply is less.

22.   Part 232.407 of the Federal Railroad Administration Code of Federal Regulations defines heavy grade, for a train with 4000 trailing tons or less, as a track grade of 2 per cent or greater for a distance of two continuous miles or more.

23.   Transport Canada, Railway Safety Management System Guide, February 2001 (TP 13548).

24.   "Running around" is industry-accepted terminology for the practice of setting up a train to proceed in the opposite direction by moving the locomotive to the opposite end of the train.