The eight 8t tanks measure 21m by 5.2m, and needed to be installed in two rows of four in a tight industrial site, with only 50mm clearance in some places. Vanguard rigging and installation manager, Wynand Boshoff, says, “The installation of the tanks was challenging: 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 that spanned the foundation with a hook height of 25m.”
“This new portal crane system was designed and constructed in Johannesburg, packed into containers and shipped to Tanzania,” says Boshoff. On site, the system took two weeks to assemble, and was then lifted onto rails on top of the platform using a crane.
“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 was used to stabilise the bottom end of the tank while the top was attached via a hook to the portal crane system.”
The tank was then lifted incrementally to move it into a vertical position. Once vertical the system rolled on the rails to position the tank above its respective base.
Boshoff notes that in addition to the space limitations that restricted movement, it was also a challenge to complete the portal crane assembly in such a small area. “Moreover, we had to deal with some heavy winds, but overall we relied on our experience, skilled staff and project engineers from our Mombasa (Kenya) and Johannesburg offices, and the job was completed successfully.”
