Curved Cantilever Tunnel Brackets, Singapore

For this Singapore tunnel project, Array Metal manufactured curved cantilever brackets to carry cables along the tunnel walls. Instead of a straight arm, each bracket is formed to the curve of the segmental lining, so it sits tight against the concrete and holds its tiers of cable at a consistent distance from the wall.

Curved cantilevers are one of our specialities for tunnel work. A straight arm can only touch a curved wall at one point and needs packing to make up the gap. A bracket formed to the radius bears evenly along its length, keeps the cable route clear of the walkway and leaves more room in a tight bore.

The brackets were fabricated at our Shah Alam plant, then stacked, strapped and wrapped on pallets so they reached site ready to fix in long, repeating runs down the tunnel.

Before fabrication, the bracket was modelled in SolidWorks and checked with a static load simulation, with the curved channel fixed to the lining and the cable load on each arm. Under that load the peak stress stayed well below the yield strength of the steel, and the arms deflected by less than a millimetre.