Railhead Swab Analysis

SOCOTEC’s railhead swab analysis forms an integral part of keeping the railways safe, allowing investigators to pinpoint sources of railhead contamination and to take remedial action.

SOCOTEC offers expert railhead swab analysis support to the rail industry, providing comprehensive sampling kits and carrying out research into the best methods of contamination detection.


Keeping Railways Safe

The presence of contamination on railheads can lead to low levels of adhesion between the train wheels and tracks, extending braking distances and therefore causing trains to overrun stations, signals passed at danger (SPAD), shunting incidents and even derailments. Railhead contamination can also lead to loss of train detection, where the contamination acts as an insulating barrier between the train wheels and rail surface, preventing the wheels from operating the track circuit.


Specialist Railhead Swab Analysis Sampling Kits

To limit contamination, SOCOTEC provides sampling kits containing everything required for investigators to take samples from railheads and associated areas. Following the submission of samples to SOCOTEC via secure return, our highly trained scientists carry out in-depth railhead swab analysis investigations.

Routine railhead swab analysis includes:

• Optical Microscopy - in order to identify the presence of intact vegetation and sand/sandite, samples are examined under optical microscopy to identify the physical properties of the contamination

• XRF/SEM-EDX - the material is analysed to determine the elemental composition, which, in addition to monitoring the amount of iron present to ensure the samples have been taken correctly, identifies  contamination such as sand/sandite

• GC-FID - quantification of the amount of semi-volatile organic material present within the samples such as oils, greases and fuels

• GC/MS - samples are analysed by Gas Chromatography Mass Spectrometry (GC/MS) to identify the presence of organic contamination such as oils, greases and fuels. This method is also used to identify the natural markers associated with vegetation contamination