To alleviate track bed dips at bridge abutments and subsequent damage to bridges imposed by train movements, some bridges on the rail network are having precast run on [approach] slabs installed.
On this project, we manufactured precast slabs and associated ballast retaining walls and installed them during a 3 day track possession.
We removed the sleepers, excavated the existing track bed and installed a layer of road base on which the precast slab were bedded. Precast ballast retaining walls were fixed to the base slab. We then placed fresh ballast, replaced the sleepers and reconnected the rails.
We were able to carry out this work without cutting the rails, obviating the need to re weld and adjust the track. Tamping of the ballast was carried out with our hi rail excavator equipped with a hydraulic tamper.
