R & D journey for the towable cable arch

A tier one miner asked TEAM to design an enlarged service arch to suit the CAT 797 trucks to enable dual sided loading from their 4100 X PC shovels. The design of the traditional service arch was too low and did not have adequate width to pass the CAT 797 or other ultra trucks safely.

In open-cut mining operations, electric shovels and draglines are often used for mineral extraction and overburden removal. Power is provided from heavy-duty electric cables. As the equipment moves around the mine, so do the roadways for the heavy haulage vehicles that transport the mined coal or ore from the pit. This creates an issue where the cables and roadways intersect. There is a need for the cable to be safely routed across the roadway to ensure they are not damaged or power cut to the mining machines.

Cable Arches are structures used to lift electric cables and other services high enough of the ground so that vehicles can travel underneath without damaging those cables or services. When used with electric shovels they also allow for a second access point to the shovel enabling double-sided loading of trucks which increases productivity. However as the shovel moves along the working face the arch must be frequently relocated.

The challenge was to make a Cable Arch large enough for a fully laden ultra truck to pass through (14m wide x 11 m high internal measurements). It needed to be strong enough and stable enough to be relocated by being dragged across terrain of various different types of surface. The arch must be relatively easy to use as well as have inbuilt safeguards to protect the arch from damage and the users from harm. It also must be highly visible day​

and night and constructed to withstand the rigors of the harsh mining environment.

The solution was the clever use of folding stabilizer arms which prevent the skids of the arch from trying to close together whilst towing. The arms are stored along the inside of the skids and swing into place when required. The arms are reversible being able to be swung to either end of the skids and hence allowing the arch to be towed in either direction.

The result is a towable cable arch that is stronger, lighter, and with a lower centre of gravity than previous designed. It can now be moved safely around the mine site with readily available equipment. This saves time and improves the efficiency of the truck / shovel fleet.

Project Scope

Our scope was to design and supply a Cable Arch meeting specific internal dimensions that would allow a fully laden mining dump truck to pass underneath and be relocated by towing. This would be a considerable improvement over other forms of cable crossings.

Specific objectives included:

  • internal dimensions of 14.5m wide by 11m high

  • able to relocate with minimal preparation or dismantlement

  • 315 mm water poly pipes