There’s something about abnormal loads that thrills the senses. It’s larger than life stuff conducted by a special breed of men who see big problems as mere challenges. This story proves it.
Contracted by Sumitomo Corporation to manage the transportation and rigging of three transformers from Richards Bay harbour to Zeus substation in Secunda for the second phase of the station’s upgrade, Vanguard initiated ground-breaking solutions to ensure expectation exceeding delivery.
“For this project, we utilised our Goldhofer modular trailer, supplemented by additional axles and a 4.5m deck in the middle,’ says Vanguard engineer, Roland Cumings. With a total of 24 axles, the customised trailer configuration was 60m in length with a width of 4.9m. The trailer was pulled by two 8×4 prime movers and pushed by one 8×8 mover.
Due to the current road upgrade along the direct route and the dimensions of the transformers, Vanguard decided to follow the Swaziland route the company pioneered during the first phase project. Through some intensive efforts, the company also succeeded in motivating the inclusion of an abnormal gate at the upgraded Swaziland border post, which will benefit many future projects.
“Further roadworks between Ermelo and Bethal forced us to explore alternatives for that stretch of road as well and, as a result, we cleared a brand new route which has never before seen loads this heavy,’ says Cumings.
The route passes through Middelburg, Stoffberg, Groblersdal, Dennilton, Bronkhorstspruit and Bapsfontein and then joins up with the existing route. All together, the detours more than doubled the mileage to site. Vanguard was responsible for securing route and structural clearance as well as organising police escorts for the 260t transformers, which are 9.9m long, 5.25m high and 4.75m wide.
Crossing a number of bridges along the way, Vanguard also had to ensure the correct weight distribution of its trailer. The deck in the middle was included to give the trailer the extra length needed to guarantee the load was never completely in between two bridge supports, which could have resulted in structural damage. Another technical consideration was the sensitivity of the transformers.
“To protect them from jolts, the trailer did not exceed a speed of 30km per hour and in fact had to drive much slower over the bridges and rough terrain,’ explains Cumings.
Throughout the transportation process, meggering tests were performed on the transformers to make sure they did not sustain any damage. The meggering test checks the state of the transformer by reading the G-force the internal structure has endured and indicates a level at which damage is likely.
“Once on site, we used our new 800t gantries to offload the transformers, then safely turned them 90° with the help of our custom-designed and built turntable before sliding them into position on rails and fine tuning the placement with jacks and metal slide plates,’ concludes Cumings.
All three transformers arrived in Richards Bay harbour safety. A job well done , and one certainly not for the faint-hearted. Well done Vanguard!