Some important points which generally help in ensuring the safety and effective maintenance of LWR tracks are the following.
(a) A well-compacted ballast bed should be available below the sleepers at all times to give adequate lateral and longitudinal resistance to the track in order to prevent buckling and excessive alterations in the sleeper lengths of the LWR track.
(b) The track should be left undisturbed as far as possible and only essential track maintenance work should be carried out at temperatures close to the destressing temperature (id).
(c) Regular maintenance should be completed well before the onset of summer and confined to the hours when the rail temperature is below td + 10°C.
(d) The track should preferably maintained mechanically with ‘on-track’ tie tamping machines.
(e) At no time during manual maintenance should more than 30 sleeper spaces be opened in a continuous stretch between two stretches of 30 sleeper lengths that are fully boxed.
(f) Packing or renewal of a single isolated sleeper may be done by a gang mate, provided that at least 50 sleeper spaces on either side are left untouched for a minimum of 24 hours after such work is done.
17.6.1 Special Equipment for Maintenance of LWR Tracks
The staff should be allocated additional equipment as detailed below for the systematic maintenance of LWRs and for emergencies.
Additional equipment with gangs
(a) A pair of joggled fish plates with special clamps
(b) 30-mm-long rail closure pieces
(c) A rail thermometer with markings for temperature ranges
(d) Special 1-m-long fish plates with clamps
Additional equipment with PWIs
(a) Sufficient number of joggled fish plates and clamps
(b) Sufficient number of rail thermometers
(c) 1-m- and 10-cm-long straight edges
(d) Callipers and feeler gauges of sizes 0.1 mm to 2 mm
(e) Special 1-m-long fish plates with clamps
(f) Rail sawing machines
(g) Equipment for thermit welding
(h) Equipment for destressing
(i) Punch and hammer