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Rail Laser

October 9, 2006

Lasers may help spot hidden track damage that causes train derailments.


Improving rail safety with lasers. I’m Bob Hirshon and this is Science Update.

[SFX: laser tapping]

This tapping may sound like an old-fashioned news ticker, but it’s actually a state-of-the-art laser system for inspecting train tracks. Structural engineer Francesco Lanza di Scalea of the University of California at San Diego is leading the development team. The system uses a trailer-like vehicle that glides along the track at up to 70 miles per hour, tapping the track with laser pulses at one-foot intervals.

FRANCESCO DI SCALEA (Univ. of California, San Diego):
And this tapping is like a virtual hammer. Just like if you were to hammer on a rail, you’d hear sound going through.

And distortions in that sound, specifically in the ultrasonic range, can reveal dangerous internal cracks that current technologies often miss. Repairing those cracks early could save millions of dollars and prevent derailments. I’m Bob Hirshon for AAAS, the science society.