As a critical conduit for freight and tourism, the Adelaide-Darwin railway carries freight trains operated by Genesee & Wyoming Australia (GWA) and the Great Southern Rail operated passenger train “The Ghan”.
So when one of the culverts on the newer section of the line, from Alice Springs to Darwin, washed out in heavy rains in January 2014 and the replacement solution of a concrete box culvert bridge was decided, GWA needed to identify a suitable gap between trains to undertake construction.
With a 36-hour window identified – requiring just one train cancellation – planning for the installation began in earnest and an order was placed with Rocla for 24 x 2400 x 2400 x 2.4m 300 LA steel reinforced concrete box culverts (each weighing 10 t) along with pre-cast base slabs (rather than pouring in-situ) to ensure the speediest possible construction.
Rocla’s Rob de Nys was on hand during installation and was impressed with the efficiency of the project. “There were two 12 hour shifts with 50-odd people on the job,” he says. “They had to take out the line, put the base slabs down and the new culverts on top, backfill and put the track back in – and they did it all within 30 hours.”
Whilst the project faced a few challenges – including being 30km from the highway – the track was handed back six hours early because everything went according to plan. With a lot of pre-work undertaken, the construction work during the track closure was centred on the track and formation and getting the track back in place – there was no outlying work to be done.
“This location had suffered in the past with washaways. The option to install a larger culvert bank increases and ensures flood mitigation in the future.”
GWA owns 3,500 + kms of track in South Australia and the Northern Territory, including the 2,200 km Tarcoola-to-Darwin railway. An accredited rail-service provider in six states, GWA provides intrastate haulage of bulk commodities including grain, steel, gypsum and minerals as well as short-haul shunting and terminal operations. GWA is also a major supplier of contracted services, such as locomotives, wagons and crews, for freight forwarding on the interstate and Tarcoola to Darwin rail network.