Ballast Testing

Ballast is the largest component of a railway trackbed by weight and volume. While it is expected to be cheap and in ready supply, it also has to be capable of performing to the engineering requirements of the modern railway.

Railtrack / Network Rail Specifications are in force, which specify the required properties of the material offered for use as track ballast. ESG’s laboratories are equipped to carry out the full range of tests in the current Line Specifications.

Ballast Tests
The full range of tests required by the Network Rail Standard (NR/SP/TRK/006) August 2000 Track Ballast and Stoneblower Aggregate (Formerly RT/CE/S/006) are:

• Grading (sieve analysis)
• Flakiness Index
• Elongation Index
• Aggregate Crushing Value (ACV)
• Wet Attrition Value (WAV)

ESG carries out all of these tests together with a range of supplementary tests. The tests include:

• Classification of Aggregates
• Aggregate Impact Value (AIV)
• Angularity Number
• Los Angeles Abrasion Value
• Resistance To Attrition (Micro-Deval)

Sieve Tests
Sieve tests are conducted using the sieves specified in BS812 Section 103.1 (1985), using the sieves included in the Network Rail Standard.

Samples
Tests are carried out on samples of ballast procured by the client, supplier or ESG as required. The samples can be from quarry, virtual quarry, rail vehicle or excavated from the track.

Site Investigation
ESG can offer an investigation service into the condition of ballast in the track, to determine its current state and to identify the causes of problems affecting its serviceability. Such problems for example may include poor quality of supplied ballast or contamination by subgrade erosion products.

Cleaned Ballast
ESG conducts the full range of tests that are required for ballast to conform to the Network Rail standard NR/SP/TRK/009 Formally RT/CE/S 009 (1996) Track Ballast Returned by Automatic Ballast Cleaners.

Track Blanketing Sand Testing
ESG is equipped to carry out tests specified in Network Rail standard NR/SP/TRK/033 Formally RT/CE/S/033 Issue 2 February 1998 “Track Blanketing Sand”. Sampling and site investigation facilities are available on a similar basis to those described for ballast.

For further information, contact us.