Re: Filling and Transporting Ballast on the C&TS

From about halfway down the report on the fatal ballast train accident on the WP&Y in 2006. (My bold emphasis)

[www.tsb.gc.ca]

"The scaled weight of the ballast was 2840 pounds per cubic yard. The estimated dry weight was 2691 pounds per cubic yard.

On the day of the occurrence, the heavy equipment operator limited the number of buckets to between (a low of) 13 and (more likely) 17 buckets because of concerns about taking all eight cars down the steep grade north of Log Cabin. The 13 buckets weighed approximately 61 tons.

Based on field observations and supported by the photographic evidence, more than 13 buckets of ballast were loaded on each car. The range of possibilities is between 13 and 21 buckets, with a mean of 17.

Information provided by WP&YR indicated that the maximum permissible load capacity of the ballast cars was 25 cubic yards or 35.5 tons of crushed rock ballast.

According to Section B.3.b., Rule 70, Lightweighing and Stencilling, of the 1993 Field Manual of the AAR Interchange Rules (the last year that referenced 5-inch-by-9-inch axle journals), the maximum gross rail load for each car is limited to 71 tons. As the lightweight of each car is 20 tons, the maximum load capacity of each car is 51 tons.

The load capacities were not known to the employees on site. None of the ballast cars were stencilled with their maximum load capacities as is normal industry practice."

Farther down the report:

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.







Edited 6 time(s). Last edit at 10/02/2014 12:48AM by bcp.