The system, called RailBAM®, monitors 300trains a day on the busy Wessex Route which carries South West Trains services between London, Southampton and Weymouth. The system – the second permanent application of this technology in Europe after Swaythling near Southampton– employs an array of sensitive microphones mounted at the side of the track that listen to every individual axle bearing on each train as it passes by.

Information of how the bearings sound is filtered before being fed back via secure data link to a database in real time. Sound analysis allows tiny bearing defects to be identified months before they become a problem.

When a train approaches the site, wheel detectors trigger the commencement of the data acquisition process. Data is collected via an array of sensitive microphones (located behind automatically opening protective shutters) to record the sound emitted by bearings and wheels.

The technology will allow South West Trains fleet to further improve their fleet reliability – already operating some of the most reliable trains in the country to even higher standards by reducing technical problems even further.

Christian Roth, Engineering Director for South West Trains, said: “We are continuously looking at engineering innovations to improve even further our fleet reliability by better anticipating train faults. Each device will now be in a position to “listen” to 100% of our trains with only two strategically located systems.”

Nicholas Kay, Manager Innovative Technologies of Rolling Stock at Siemens Mobility, said “With the first installation of RailBAM® at Swaythling being powered up in November 2009, and now the second site at Mortlake coming online this week, we can provide South West Trains, as well as other users, the benefit of this valuable data to support improved fleet reliability and availability”.

“The introduction of the RailBAM® predictive maintenance tool at these strategic sites will go some way to reducing delays on the element of the National Network is covers.  We look forward to expanding this network of systems to provide this service to more users in the future”.