Anti corrosive treatment of plate/rail screw
It has been observed that the plate screws and rail screws provided on PSC sleepers on turnouts, SEJs, bridge guard rail and level crossings are getting corroded due to either aggressive environmental conditions or in stretches where passenger trains reach destinations in the early morning hours. This results in corrosion of screws and often shank of the screw is left inside sleeper and can not be taken out, due to corroded head. This renders sleepers totally useless. Due to excessive corrosion of plate/rail screws, maintenance has been badly affected as the thickness of screws gets reduced and in time they get jammed/loosened resulting in loosening grip with plates and sleepers become useless. Remedial Action To minimize the occurrence of this problem, as a preventive measure, lubrication of plate screws and rail screws should be done. Grease graphite used for this purpose shall be as per IS specification number IS:408 grade ‘O’.
METHOD OF LUBRICATION
Prior survey shall be done to ascertain number of corroded screws. New screws shall be procured as per assessed numbers and provided in place of corroded ones after applying ‘O’- graphite grease/black oil. Plate/rail screws should be removed one by one from track. Then screw as well as dowel be properly cleaned for corroded material from the surface with the help of wire brush and then dipped in black oil uniformly both on the surface of plate/rail screw and dowel and fixed back head of plate/rail screw should also be either coated with hot bitumen to avoid corrosion.
FREQUENCY –
1. At new turnout/SEJ/bridge guard rail/level x-ing renewal site, the greasing of new plate/rail screws should be done while providing in the track.
2. Once a year in areas not prone to corrosion.
3. Once in six month in corrosion prone areas.
RECORD - Each PWI should maintain a record of the location of greasing of plate/rail screws as per Performa given in Annexure- I.
Record for lubrication if plate/rail screws –
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