The design and construction of this project formed a part of the Southern Sydney Freight Line. The bridge became necessary as a means of allowing the adjacent rail level crossing to be made redundant and decommissioned. The bridge spans over multiple live rail tracks and allows RailCorp personnel to access the ‘Sefton Triangle’ storage area.
Arenco was contracted for the complete design and construction of the project. Works included reinforced concrete piers and abutments, variable depth prestressed concrete bridge girders, precast concrete parapets, lighting and an electronic security gate.
The 72 metre long bridge comprised 3 variable spans of 24 metres, 34 metres and 14 metres. One abutment is incorporated into the adjacent Sefton Dive project piled retaining wall and the other abutment has a reinforced soil wall surrounding it with approach roadworks.
This was a highly challenging project undertaken in a live rail environment with nearby running trains, live services and a very limited number of rail possessions available for the works within the danger zone. Arenco overcame these issues through the use of strict site safety processes, variable depth girders to achieve clearances to 1500V catenary wires and precast fascia panels to reduce construction time over the live tracks.
Other challenges included the relocation of existing 33kV power lines and communication services and the restricted duration to deliver the project. Arenco dealt with these challenges through meticulous planning, co-ordination and setting tight milestone dates and goals.
