![]() ![]() of traffic carried -The rail shall be planned for through renewal after it has carried the minimum total traffic as shown below. (d) Renewals on consideration of service life in terms of total G.M.T. (iii) Renewals of rail due to hogged and battered rails ends should be considered only if other remedies have not been found to be effective. (ii) The condition of rails with regard to hogging/battering, scabbing and wheel burns and other conditions such as excessive corrugation of rail as can be ascertained by visual inspections, which affects the running quality of track, and make the track maintenance difficult and uneconomical, should be taken into account while proposing renewals. (2) Disproportionate cost of maintaining the portion of track in safe condition. (1) Poor running quality of track in spite of extra maintenance labour engaged for maintaining the same, (i) There may be cases, where renewals may be necessary on the following considerations viz., (c) Maintainability of track to prescribed standards. Worn rail profile should be recorded and superimposed over new rail profile to find out the lateral wear. Lateral wear is to be measured at 13 to 15 mm. (iv) Lateral Wear- Limits of lateral wear from relaying considerations are as under: SectionĪ typical profile of the worn rail showing the measurement of lateral wear is shown as below. In the first case, the wear is the difference between the height of the new rail and the height of the worn out rails. Vertical wear is to be measured at the center of the rail either by measuring the height of the worn out rail by calipers The limits of vertical wear at which renewals are to be planned are given as below.Ī typical profile showing the measure of vertical wear of the rail is given below : (iii) Vertical Wear -When the reduction of the depth of the rail head reaches a point beyond which there is a risk of wheel flanges grazing the fish-plates, such rails should be renewed. Existence of the localised corrosion such as corrosion pits, specially on the underside of the foot, acting as stress raisers from the origin of fatigue cracks and would necessitate renewals. (ii) Wear due to corrosion - Corrosion beyond 1.5 mm in the web and foot may be taken as the criterion for wear due to corrosion. Unfitting joints and taking rail profiles with special profile measuring gadgets. Rail wear may be determined by actual weighment, taking rail profiles at ends after (b) Wear on Rails - (i) Limiting Loss of Section-The limiting loss in rail section, as a criterion for recommending rail renewals shall be as under: In case the rail failures at fish-plated/welded joints are pre-dominant, end cropping with or without welding could be considered. in a year due to fracture and/or rail flaws detected ultrasonically falling in the category of IMR & REM will have priority while deciding rail renewals. (a) Incidence of Rail Fractures/Failures - A spate of rail fractures on a particular sections having 5 Expected service life in terms of Gross million terms carried.Maintainability of track to prescribed standards.(1) Criteria for Rail Renewal - The following are to be considered in connection with the criteria of rail renewals :. Such renewals are not a part of normal maintenance operations and cannot be covered under scattered renewals.ģ02. These are carried out in isolated locations of continuous but small stretches. ![]() (4) Casual Renewal- In this case, unserviceable rails, sleepers and fastenings are replaced by identical sections of serviceable and nearly the same vintage or new track components. Such renewals are a part of normal maintenance operations. These are carried out in isolated locations and not more than 10 rails and/or 250 sleepers in a gang beat in a year. (3) Scattered Renewal- In this case, unserviceable rails, sleepers and fastenings are replaced by identical sections of serviceable and nearly the same vintage track components. (2) Primary renewals are those where only new materials are used and secondary renewals are those where released serviceable materials are used. (11) Through Bridge timber renewal (TBTR) (4) Through Rail Renewal (Secondary) abbreviated as T.R.R. Classification of Renewals - (1) All track renewals can be classified generally into one of the following categories : ![]()
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