M-21—Railway scale test cars

Category: Mass
Bulletin: M-21 (rev. 1)
Issue Date: 2008-09-01
Effective Date: 2008-10-01
Supersedes: M-21


Table of contents


1.0 Purpose

The purpose of this bulletin is to establish the policy relating to the use of railway scale test cars and to provide guidance on the use that can be made of conventional and concrete filled railway test cars.

2.0 Background

For years Measurement Canada has calibrated, certified and used industry-owned railway test cars for inspecting and certifying railway track and combination railway track/vehicle scales.

Some railway test cars are filled with concrete. In order to assess the suitability of this construction method a study was undertaken by Measurement Canada. The study, which used internationally recognized methods for calculating uncertainties, concluded that the added uncertainties attributable to the use of concrete as a ballast material prevented these test cars from meeting the same tolerance as conventional test cars.

Accordingly, the use of concrete filled test cars are restricted to certain specific applications where the applicable limits of error are large enough to accomodate the added uncertainty caused by the use of concrete as a ballast material. Measurement Canada may review the tolerances for mass standards at some time in the future. At this time, the restrictions imposed by this bulletin will be reassessed.

3.0 Test car certification

3.1 Calibration certificates for concrete filled test cars shall indicate the use restrictions as stipulated below.

3.2 New test cars shall be evaluated and approved by Measurement Canada's Engineering and Laboratory Services Directorate before being certified as a standard.

4.0 Test car use

4.1 Conventional railway scale test cars (self-contained composite and self-propelled ) can be used for the acceptance and in-service inspection of:

  1. Class III HD railway track and combination railway track/vehicle scales;
  2. Class IIII railway track and combination railway track/vehicle scales; and
  3. In-motion railway track scales.

4.2 Concrete filled standard railway test cars can only be used for:

  1. the in-service inspection of Class III HD railway track and combination railway track/vehicle scales;
  2. the acceptance and in-service inspection of Class IIII railway track and combination railway track/vehicle scales; and
  3. the acceptance and in-service inspection of in-motion railway track scales, with the exception of static testing.

4.3 Any test car may be used as a strain load to verify the higher weighing ranges of a scale, regardless of the type of test car or the accuracy class of the device under test.

4.4 In order to ensure that test cars are only used for the purposes for which they were calibrated and certified, it is imperative that the calibration certificate be made available, with the test car, and that inspectors consult the calibration certificate prior to using a test car.

5.0 Revision

The purpose of this revision is to simplify the requirements for Railway Scale Test Cars (PBRI2008).

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