The 29 metre long cold box was slowly
and precisely lifted using strand jacks

Vanguard recently completed a project involving the transportation and rigging into position of a cold box and exchanger for use in a smelting plant in Tsumeb, Namibia. The company collected the items from Walvis Bay harbour and transported them to site.

A modular trailer configuration was used which was 40 metres long and featured a custom-made lightweight deck. “While the cold box was only 29 metres long and weighed approximately 50 tons, the added length on the trailer allowed us to correctly position it on the trailer in order to make manoeuvring on site easier. We were also able to transport the cold box on a continuous deck without the use of a turntable,” says James Robinson, Project Engineer, Vanguard.

“The modularity and hydraulic suspension of the trailer worked to our advantage once on site because there were a number of obstacles to overcome.”

Vanguard had to work around machinery and foundations on site, especially narrow foundation bolts that could not be driven over.

“Our modular trailer is extremely versatile and we basically mimicked a caterpillar in moving over the bolts. It was a slow and precise undertaking in which we would use the hydraulic suspension to lift one tyre at a time straddling the bolt, moving over it and then lowering the axle, in effect climbing over the bolts,” says Robinson.

A tailing crane was used to stabilise the cold box during the lift

The trailers were then accurately steered into position, beneath gantry towers which Vanguard used in conjunction with its strand jacks to lift the cold box, and turn it 90 degrees into final position. “We transported and lifted the cold box first, then brought our gantry towers forward and rigged the 17 metre long, 40 ton exchanger into position.”

Robinson notes that it was a seamless project in part due to Vanguard having the correct equipment and in part due to the company’s experience in similar jobs. “Our past projects include the transportation and positioning of a number of similar pieces of equipment, including a 49 metre cold box for a Zambian copper mine. We are also very familiar with the route from the harbour to the site, so we were well aware of the obstacles and how to avoid or overcome them.”

Once the lift was complete, the cold box was turned 90 degrees into final position