June 15 - South African heavy lift and relocation specialist, Vanguard, recently designed a unique trailer and steer configuration to relocate a 220-tonne, 16 m high and 32 m long container-handling crane for a large freight logistics company.
A combination of self-propelled modular trailers (SPMTs), hydraulic controls and precise operator steering, has enabled the team to move the crane 300 me; making way for a revamp of the company's rail depot in Johannesburg.
Vanguard's engineers set up a triangular supporting structure using three modular trailers, and one SPMT which acted as the steering column. The SPMT, coupled with a six-axle modular trailer, was positioned at the back end under the heaviest part of the crane and the front end was supported by two four-axle modular trailers spaced at 3.0 m.
With the use of hydraulic lines, Vanguard set the trailers up as a single continuous trailer with a simulated steering angle. "With the self-propelled modular trailer being remotely steerable, only three operators were needed to co-ordinate the manual steering and levelling of the trailers. Together, we ensured all trailers functioned in unison for the crane to remain stable and level during motion," says Juan Johnson, specialised lifting & transport manager, Vanguard.
Due to the crane's unusual height and length, Vanguard welded extra structural supports to minimise the opening and closing effect of its support legs. "These reinforcements, including a Turfor cable tied between the legs, helped us limit movement to just 0.5 m," says Johnson.
To move the crane onto the prepared trailers, Vanguard used four 50-tonne jacks, two on each corner, to lift the crane by 0.5 m - enough to slide two of its legs away from an electrical power supply on the ground next to the crane. The crane's sill beams, on which it rested, were further protected using a steel header beam to transfer weight from the crane to the trailers.
Overall, mobilising and demobilising the crane took Vanguard about two weeks. "Because of the availability of our self-propelled modular trailers, we managed to complete this move within the said time frames," says Johnson.