MCFARLAND BRIDGE

Product: McFarland Bridge Maintenance

Application: Department of Transport and Main Roads

Sectors: Infrastructure; Government

Location: Queensland

Forged In Steel took part in the maintenance of the McFarland Bridge in Grandchester, Queensland. The bridge passes over the Western Creek between Grandchester Mount Mort Road and Rosewood Laidley Road. The maintenance work involves barrier upgrade, removal of disused conduit on bridge, and relocation of road signs.

The east side barrier has a total 24 metres deck. On the east side, the guardrails extend 29 metres on the north end and 21 metres on the south end. On the west side, the guardrails are 29 metres long on the north end and 4 metres on the south, where a QuadGuard is also installed ahead of the footpath at the end of the bridge. The QuadGuard acts as a cushion to reduce the impact of road crashes.

The typical spans consist of a 200×5 square hollow section rail attached on the anchorage and rail support plates and 150x50x3 rectangle hollow section post with M16 bolts. The post is welded on the base plate and fixed into the existing kerb unit with M20 bolts.

Meanwhile, a typical abutment section is comprised of the terminal plates and W beam bridge rails. The rectangle hollow section post is welded to the base plate and attached on the existing kerb unit with M20 bolts.

Each intermediate posts include the rectangle hollow section where the rail anchor plates are welded and bolted to the rail. The top and bottom ends of the posts have capping plates, which are made from 45x146x6 plates and are ground to profile before being welded. The base plate behind the kerb is also welded to the intermediate post and bolted to the concrete.

Two rail types are used, varying by the length of each section. Both types are 200×5 square hollow section and are joined together by connectors which are fabricated from 8mm plates. The connectors have 20mm nominal gap between the two rails and are assembled using M20 x 230mm long bolts with nylon locknuts. The end of the rails leading to the guardrails are connected to the terminal plate by a spigot and M20 x 230mm long bolts with nylon lockouts.

The rectangular and square hollow sections used for the bridge are Grade C450LO, which is known for its excellent load bearing, torsional strength, and impact strength. With its properties, this type of steel is often used in structural engineering. Any steel of lower grade is not acceptable as substitution for this project.

All steelwork for the bridge maintenance is done per AS 1554.1 or the requirements for the welding of steel structures made with combinations of various steel components such as steel plates, sheets, and sections. Controlled hydrogen type consumables, such as G493 or T493, are used to weld the steel parts. The steel components are cleaned of weld splatter and slag prior to galvanising.

Master Steel is a registered steelwork supplier for MRTS78 and has consistently worked with the Department of Transport and Main Roads in various projects in Queensland. We are in compliance with the strict requirements of ISO 9001, which is a testament to the high quality of work that we produce.