SHALLOW SCREENING OF BALLAST
SHALLOW SCREENING OF TRACK BALLAST Objective: It is a process, Which demonstrate the procedure for cleaning of contaminated ballast on track/in-situ. If the contaminated ballast is dumped by hoppers for top ballasting and tamping of track was not done, so we can adopt Shallow Screening method to remove the contaminated ballast from new construction track or in maintenance track also. Principle: In the case of manual maintenance, the crib ballast between sleepers is opened out to a depth of 50 to 75 mm. below the bottom of sleepers, sloping from the centre towards sleeper end. For machine maintained section, the crib ballast in the shoulders should be opened out to a depth of 75 to 100mm. below the bottom of sleepers, sloping from the centre towards sleeper end. The ballast in the shoulders opposite to the crib as well as the sleepers is removed to the full depth. Equipment: Manual cleaning (Conventional method): 20mm sieve with inclined support (At least 1 n