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LWR-9. Unusual Occurrences. Unusual Occurrences. Rail fracture/weld failure Replacement of defective glued joint Damage to SEJ/Buffer rails Buckling or tendency to buckling Derailments/accidents causing disturbances to LWR/CWR Breaches. Rectification of rail fracture/weld failure.
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LWR-9 Unusual Occurrences
Unusual Occurrences • Rail fracture/weld failure • Replacement of defective glued joint • Damage to SEJ/Buffer rails • Buckling or tendency to buckling • Derailments/accidents causing disturbances to LWR/CWR • Breaches
Rectification of rail fracture/weld failure Emergency repairs – By Keyman / gangman • Provide 1m long fishplate/joggled fishplate and restore the traffic with stop dead & 10 kmph for first train and 20 kmph for subsequent trains • If gap at fracture is less than 30 mm then insertion of closer is not necessary.
Rectification of rail fracture/weld failure (contd.) Temporary repairs – By PWS • Traffic block – as soon as possible when the rail temperature is within the range specified for destressing. • Create a gap equal to rail closer available (not less than 4 m )+ gap at fracture + gap required for two welds. • Insert rail closer and restore the traffic at restricted speed.
Rectification of rail fracture/weld failure (contd.) Permanent repairs – By JE (P.Way) • Welding of one joint of closer rail without rail tensor. • To ensure correct gap during welding of other joint, use the tensor and weld the joint. • After welding equalise the stresses by unfastening the either side for a length of 125 m and tapping by wooden mallet.
Damage to Switch Expansion Joint • Complete SEJ to be replaced and gap adjusted as per specified in para 5.6.1 of LWR manual. • If another SEJ is not available than replace damaged and undamaged SEJ by a closer rail, clamp the joint and allow traffic at restricted speed. • After replacing closer rail by new SEJ and welding in-situ speed will be relaxed.
Buckling of track • When buckling or tendency towards buckling may occur ? • Failure to adhere to the temperature ranges specified for operation on LWR/CWR • Deficiency of ballast section or/and inadequate ballast resistance • Ineffective fastenings or missing fastenings • Excessive settlement of formation • Improper functioning of SEJ
Buckling of track • Tendency towards buckling can be identified through kinks in track. • Kinks may also be arise from incorrect slewing or lifting operation • By tapping sleepers for hollowness, tendency towards vertical buckling can be confirmed • Suspend the traffic and protect the track • Each case of buckling to be investigated by ADEN soon after its occurrence and report submitted to DEN/Sr. DEN
Repairs to buckled track • Minimum supervision of JE/P.way • Emergency repairs • permanent repairs • Destressing • The buckled rails shall preferably be gas cut adequately apart 6.5 m • Slew the track to correct alignment • Insert the rail closer and pass the first train with dead stop & 10 kmph then 20 kmph for subsequent trains. • Permanent repairs:- Same as for repairs to rail fracture
Breaches and Diversions • Affected portion shall be isolated by insertion of SEJ (within the range of td) • Isolated track to be replaced by fish plated track and box anchored if necessary • New formation shall be fully consolidated before laying of LWR again • Destressing in affected portion after laying of LWR