Portal placement

Vanguard was contracted to lift and partially transport a series of 18 tonne tanks from the fabrication site in Johannesburg, South Africa, for Tanzania Breweries, part of SAB Miller. Each tank, used for finished product storage, is 21 m long, 5.2 m in diameter and can hold 260,000 litres.

Vanguard used its Goldhofer multi-axle trailer in a 10 axle configuration to transport them from Johannesburg to Richards Bay harbour. From there they were taken by ship to the Port of Dares Salaam in Tanzania and then on to the brewery, where Vanguard took over the operation once again.

“The installation of the tanks was a challenging task and we had to consider a number of things to ensure success. The main issue was the lack of space surrounding the stands on which the tanks needed to be positioned. For this reason traditional cranes were not considered. We developed a new solution for the lift by designing and supplying a portal crane which spanned the foundation and had a hook height of 25 m. This is a unique piece of equipment,” explains Wynand Boshoff, Vanguard rigging and installation manager.

Heavy winds

Designed and constructed in Johannesburg, the 25 tonne capacity portal crane was shipped to Tanzania and took two weeks to assemble on site. It compromised two sections that were built on top of each other and lifted onto rail tracks attached to the tank platform using a 200 tonne capacity Liebherr.

“Having set up the system, the tanks were then brought onto the site one at a time on low bed trucks, lying on their sides. A small mobile crane [50 tonne capacity Grove] was used to stabilise the bottom end of the tank while the top was attached via a hook to the portal crane system. We call this process top and tailing,” continued Boshoff.

Each tank was lifted into a vertical position by the portal crane, which then travelled along its rails until the vessel was above its respective base.

Reflecting on the job, Boshoff said that space limitations made the assembly of the portal crane a challenge. “Moreover, we had to deal with some heavy winds but, overall, we relied on our experience and skilled staff and project engineers from our Johannesburg and Mombassa offices, and the job was completed successfully.”