Rectification of subsurface drainage problems along with stabilisation and revegetation of eroded cut batters on the Kooragang coal branch lines at Sandgate.

Works included installation of a 225mm subsurface drainage line alongside the arrival line with these works being completed by working a number of shifts around the clock over a two day rail shutdown period.

Further earthworks to regrade the cess area, including installation of an additional 150mm subsurface line, were undertaken along side the departure line. These works were carried out as time permitted adjacent to live lines with the use of Rail Protection Officers to oversee the Project safety.

Construction and vegetation of open drainage channels and precast box culvert protection of ARTC’s optical fibre communication cable were also undertaken.

Other minor works including localised drainage regrading, sheeting of rail access tracks and installation of new corridor fencing formed part of the works.

A major element of the project consisted of a 450mm diameter concrete pipe under bore which allowed trapped stormwater to flow below the embankment under controlled conditions. Precast concrete pit structures, headwalls and installation of rock filled gabion baskets and mattresses also formed part of the works.

To prevent further erosion of the cut batters and the associated siltation of the cess areas, reshaping and top-soiling of the batters followed by a turf and jute mesh stabilisation process were provided to allow long term vegetation growth an ultimately a stabilised and established batter.