Short Notes on Maintenance of PRC sleepers

Maintenance of PRC sleepers

(I) Concrete sleepers should normally be maintained with heavy on track tamers. For spot attention, off track tampers may be used.

(ii) Only 30 sleeper spaces are to be opened out at a time between two fully boxed stretches of track of 30 sleeper lengths each in case LWR track exists.

(III) The concrete sleepers should be compacted well and uniformly to give a good riding surface centre binding of mono block concrete sleepers should be avoided and for that purpose the central 800mm. Of the sleeper should be hard packed.

(iv) Both ends of concrete sleepers should be painted with anti corrosive paint periodically to prevent corrosion of the exposed ends of pre-stressing wires.

(v) The laying and maintenance of concrete sleepers should be done by mechanical equipments as far as possible.

(vi) Wherever casual renewal of concrete sleepers is to be done, normally precautions required for LWR track should be taken.

(vii) The elastic rail clip should be driven properly to ensure that the leg of the clip is flush with the end face of the insert. Over driving and under driving should be guarded against as this causes eccentric loading on the insulation and this results in their displacement and of the load.

(viii) vigilant watch should be kept to ensure that not creep takes place in any portion of the concrete sleeper track and there is no excessive movement near SEJ.

(IX) Rubber pads: It must be ensured that the rubber pads are in correct position.Wherever it is found that the rubber pads have developed a permanent set, these should be replaced by new ones. Such examination can be done at the time of de- stressing. Loss of toe load can also be due to ineffective pads.

(x) Insulating liners: Nylon or composite insulating liners used with pandrol clips should be examined periodically for sign of cracking and breakage. Adequate care should be exercised while driving the clip at the time of installation to prevent damage.

(xi) Special attention to prevent seizure of elastic rail clips: One of the biggest problems of maintenance of concrete sleeper track is that elastic rail clips get seized with MCI inserts not only in regular maintenance, but also during de- stressing, other incidental works and derailments etc.

 Following remedial measures are suggested.

a. Measures to prevent corrosion and seizure of ERCs with M.C.I. inserts : At the base depot, all the elastic rail clips and MCI inserts should be thoroughly cleaned. Grease should then be applied on the central leg of the ERC and eye of the MCI insert and then the clip should be driven at the time of assembly of the service panel.

b. All the elastic rail clips are to be taken out during service from the MCI inserts and should be cleaned with wire brush and emery paper specially on the central leg. The eyes of the MCI inserts are also to be cleaned of any debris or rusted material the central leg of the ERC should then be applied with proper quality of Grease.