The structures, over the Forth, Leven, Blythe and Don Rivers were failing because of age. VEC designed and constructed the four new bridges for TasRail between 2011 and 2014, taking proactive steps to ensure their longevity. The business also won an award along the way.
It’s no small task to rehabilitate and replace rail bridges at four different sites as part one project. But not ones to shirk from a challenge, VEC teams took on the project for TasRail.
The original rail bridges dated back to 1885 and had been gradually deteriorating because they were exposed to a high wind and saline environment. Complete replacement of those structures was recommended by VEC.
The Don River rail bridge was originally built in 1886, and like others in the area, had been gradually deteriorating because of exposure to a windy saline environment.
VEC designed and constructed a new 100m, 5 span steel and precast concrete superstructure on existing substructure.
Old riveted wrought iron beams were replaced with a new precast concrete deck to achieve the target load rating of 300LA and a 60 year design life. Precast elements were made in VEC’s precast yard.
After months of extensive planning and preparation the actual works occurred over an 84-hour time frame. Work commenced on Wednesday 26 December and was completed on Saturday 29 December 2012 – without incident and 6.5 hours ahead of schedule.
This project was a winner at the 2013 Tasmanian CCF Earth Awards.
The Blythe River Rail Bridge was first constructed in 1968. Prolonged proximity to Bass Strait, with its wild salt laden winds, meant the structure needed replacement.
VEC’s analysis led to a recommendation for the complete realignment of the existing structure on a new southern alignment. The benefits being better alignment, increased load capacity, reduction in bridge length (by about 30m) and certainty of outcome.
A number of factors brought about a successful outcome to this project. One the use of the VEC Planning System. Another was the modular falsework system our teams used, which allowed for speedy construction, with flexibilities in design to account for site conditions. The overall construction period was reduced by using precast ballast retainers as part of the deck formwork for pouring of the deck. And VEC’s demolition process allowed for the safety most efficient demolition of the redundant structure.
Construction of the Blythe River Rail Bridge finished in April 2014.
VEC worked with client TasRail to replace the Leven River Rail Bridge which had been deteriorating because of exposure to a windy and salty environment. This work was part of a big project to replace four rail bridges in north west Tasmania over three years.
The Leven River rail bridge was originally built in 1939. VEC’s analysis recommended it be completely replaced on a new southern alignment.
A new 160m long bridge was designed and constructed, using a false work bridge to build the new structure over water. This falsework had to accommodate a 70t pile driving rig, a 30t pile driving excavator and a 160t crane. Redundant bridge beams from the Blythe River Rail Bridge Replacement were used to act as support for taking down the old bridge and underwater explosives were needed to remove piers in a deep section of the river.
The VEC Planning System was used for project planning and delivery to make sure the work was done safely and successfully.
The new rail bridge provides improved alignment, increased load capacity and lowest lifecycle costs.
VEC worked with client TasRail to design and construct a new 135m, 4 span reinforced concrete bridge with new concrete sleepers and a full-length walkway, along with 490m of new rail approaches. This work was part of the wider Four North West Bridges project which galvanized VEC’s position as a leader in the bridge construction industry.
The original 8 span Forth River rail bridge was built way back in 1885. VEC recommended that the old timber ballast deck, supported by wrought-iron girders be replaced on a new southern alignment.
The VEC team needed to take proactive steps to design an innovative pilling support mechanism for the new bridge. Workplace Standards inspected our design and, impressed with VEC’s solution, nominated us for a WorkSafe Tasmania Award.
Lessons learned from the Blythe, Don and Leven River Rail Bridge replacements meant this work was completed three months ahead of schedule.
The new bridge increased load capacity, improved rail alignment and delivered a 100 year maintenance free structure.