Boltable Twistlock Load Testing — with the CSIR
Twistlock Africa designed and built its own shear, load and tensile test rigs across X, Y and Z axes, in both single and double plate configurations, and had its boltable twistlock foundation welds tested with the CSIR in Auckland Park from 1 to 3 September 2023.
A boltable twistlock foundation is not a bought-in casting with a plate under it. The plate, the weld detail and the fixture that holds the two in register are Twistlock Africa's own — and rather than assume they were adequate, the company built the rigs to load them and had the work tested with the CSIR.
Separate fixtures were designed for each axis: shear across the X axis, load applied through the Y axis, and tension in the Z axis — each in both the single and the double plate configuration, because the double is not simply two singles and could not be argued from the single's result.
The same programme produced the welding and assembly jigs. The jig fixes the casting to the plate in the correct position while it is welded, which is what makes the geometry repeatable from one unit to the next — and repeatable geometry is the only basis on which a test result means anything for the next plate off the bench.
Testing was carried out with the CSIR in Auckland Park, Johannesburg, from 1 to 3 September 2023. The programme confirmed the welding engineering applied to this connection: the twistlock itself failed before the weld between the twistlock and the plate did — the joint is not the weak link.
- Shear, load and tensile test rigs (X, Y and Z axes)
- Single and double plate test rigs
- Welding and assembly jigs
Client: CSIR