The Level Crossing Removal Authority (LXRA) was set up by the Victorian Government to manage a program of removing level crossings to improve road safety and traffic flow.
The Skye/Overton Road project in Frankston is a good example of how innovative technologies have been adopted to fast track construction and reduce disruption to the public. The use of Self Propelled Modular Transporter’s (SPMT) and a Lift and Lock (LNL) gantry enabled the Skye Road team to minimise the number and duration of rail occupations required to install the bridges.
The North West Program Alliance (NWPA) of John Holland, Kellogg Brown & Root, Metro Trains and the LXRA was awarded the $170 million contract to remove level crossings at Camp Road in Campbellfield and Skye Road in Frankston, with the former involving lowering the rail under Camp Road and the latter requiring constructing a rail bridge over Skye Road.
The method of construction for the Skye Road project meant that the rail line could remain open for much of the construction period. The twin bridges that replaced the level crossing comprised 24 concrete U-trough beams each 31 metres long, 6.15 metres wide and weighing 280 tonnes. The component “L” beams were cast and stitched together by North-Vic Constructions in Kilmore to form a complete U-trough. These were then loaded onto trailers using two six-axle SPMTs.
Casting yard to site
The transport and erection of U-troughs took place over an intense work period in the second quarter of 2018. Twenty U-troughs were stitched and transported as a whole, while eight “L” beams were transported and stitched on site.
ALE was responsible for transport, and used two 12-axle-line platform trailers (rows of 8 tyres) to support the beams at either end, with a dolly and up to four ballasted prime movers used.
To minimise traffic disruption and bypass bridges that could not support the load, a 146 kilometre route involving the Hume Freeway, Metropolitan Ring Road, Greensborough Highway, Eastern Freeway, Eastlink, Peninsula Freeway and local connecting roads was devised by NWPA, VicRoads and other key transport stakeholders. Average travel speed was 20 kilometres per hour, and an overnight stopover point was used to ensure that transport curfews were not breached
On arrival at Skye Rd the trailer suspension travel was used to place the U-troughs on purpose built trestles. ALE supplied two SPMT arrangements for use on site: a single width 16-axle line spacer configuration unit (8 axle, spacer, 8 axle) for moving beams around site and a double width 14-axle line spacer configuration (8 axle, spacer, 6 axle) that carried a jacking system for erecting the U-beams.
The single width 16 axle SPMT was used to transport U-troughs from the storage trestles to the LNL gantry where they were elevated to a height above their final installation.
L beam handling on Site
The LNL gantry was used to lift the L-beams off the transport and place them on temporary support blocks while the reinforcing was welded together, and then loaded onto the 16 axle single SPMT for transport to the stitching area. A curing time of five days was required before the stitched U-trough reached strength for erection.
The double width 14 axle erection SPMT was configured for each individual U-trough by installing spacer blocks and a jacking system. This SPMT then maneuvered under the LNL gantry with a U-trough suspended above and, once lowered and secured, proceeded to carried the U-trough down adjacent the rail corridor until they reached the erection location. The SPMT wheels were turned through 90 degrees and the SPMT travelled laterally to position the beam between the support piers, after which it was lowered into position through a combination of jacks and stroking of the axles to within a 10mm tolerance.
The method of installation from below meant that there was sufficient clearance for around half of the U-beams to be installed under live power lines – something that is believed to be a world first.
In addition to the time savings this erection methodology offered, the Skye Rd team saw benefits in labour and material efficiencies generated by stitching in a constant more controlled environment and a reduced working at heights risk profile.