Steel Services & Allied Industries were commissioned by Ferrochrome Furnaces to build a new factory in Zinniaville, Rustenburg. The new Ferrochrome structure comprised of a multi-bay propped portal with a lean-to, to one side. From a technical point of view, this structure is fairly standard. What makes it outstanding is the size and the fact that there are multiple 80ton overhead cranes running in two parallel bays at a height of 33m, for a 152m long building.

The scale of this project demanded that out of the ordinary strategies be applied to the processes from detailing through to fabrication and erection.
For the fabrication and trial assembly the shop detailing was done in Tekla Structures with the 3D BIM model being instrumental in the planning and execution. The clip-plane feature was used extensively to show only the phase block required at each stage of the process. This provided significant improvements to the way that the fabrication process was managed.

  • Part lengths were optimised where possible to reduce waste and the model erection was phased according to the construction plan.
  • The structure was fabricated in 29 modules that enabled sequenced deliveries to site for construction.
  • Cutting lists for each phase were issued and processed using automated CNC machines.
  • Processing of sections and plates were scheduled to enable fabrication of each phase independently from the others.
  • Trial assembly of each gridline was completed prior to delivery to ensure the correct fit of assemblies. Each phase was stored until required on site.
  • Site erection was completed using our all terrain mobile cranes ranging from 50 to 200 tons and a high reach truck mounted mobile elevated working platform (MEWP) (cherry picker), giving safe personnel access to bolted connections in elevated positions.
  • Erection began in one corner of the structure and then radiated outwards as the phases were delivered.
  • 76 Fabricated plate girders, weighing just under 2 tons each were installed as crane beams for the 80ton overhead cranes.  The heaviest assemblies weighed around 890kg.

The planning and execution of this project shows the versatility and flexibility of constructing in steel with the added value of technology such as Tekla Structures and Fabtrol MRP.