Rail cleaning method and apparatus

Apparatus for cleaning a rail by removing contaminants from the surface of the rail comprising a laser beam generator arranged to generate a high intensity pulsed laser beam;

• a directing device arranged to direct the laser beam onto the surface of the rail so as to destroy at least part of the contaminants;
• a contaminant detection device arranged to detect contaminants on the rail and to provide an output signal when contaminants are detected;
• and a control system responsive to said output signal arranged to operate said laser beam generating means.

A method of cleaning a rail by removing contaminants from the surface of the rail comprising generating a high intensity pulsed laser beam and directing the laser beam onto the surface of the rail so as to destroy at least part of the contaminants, including the step of selecting the values of the parameters of the laser beam so that the contaminants are destroyed by being converted directly into gases, and further including, in the selecting step, the step of selecting the value of at least one of the following parameters of the laser beam:

• the length of each pulse, the pulse repetition rate, the wavelength of the radiation, the energy in each pulse, the average power of the laser beam, the peak power of the laser beam, the laser beam energy per pulse per unit area, and the size of the laser beam when it strikes the contaminants.

Apparatus for cleaning a rail by removing contaminants from the surface of the rail comprising means for generating a high intensity pulsed laser beam and for directing the laser beam onto the surface of the rail so as to destroy at least part of the contaminants, and further including means for selecting the values of the parameters of the laser beam so that the contaminants are destroyed by being converted directly into gases, wherein the means for selecting the values of the parameters of the laser beam selects the value of at least one of the following parameters;

• the length of each pulse, the pulse repetition rate, the wavelength of the radiation, the energy in each pulse, the average power of the laser beam, the peak power, the laser beam energy per pulse per unit area, and the size of the laser beam when it strikes the contaminants.

A method of cleaning a rail by removing leaf contaminants from the surface of the rail, comprising the steps of generating a high intensity pulsed laser beam and directing the laser beam onto the surface of the rail so as to destroy at least part of the leaf contaminants, the parameters of the laser beam being such that the contaminants are destroyed by being converted directly to gases.