Transporting a transformer

A new transformer for the Tiwai Point aluminium smelter was no toy.   HUGH DE LACY reports.

The first of two 165-tonne transformers bound for New Zealand Aluminium Smelters (NZAS) at Tiwai Point, Bluff, proved a challenge – but my no means an insurmountable one – for East Tamaki heavy haulage contractor Multi-Trans.

The Auckland company won the contract in June of last year to shift the first of the transformers from dock-side at Bluff to the Tiwai Point smelter, and with the successful completion of that job over a period of a week in May this year it has also secured the job of delivering the second one, which is due in September.

The transformers have been built in Brisbane and the first arrived at Bluff on April 29, by which time Multi-Trans had had its staff of six inducted into the NZAS site, and had a platform trailer secured on a barge waiting on the wharf.

The transformer – 8.95 metres long by 5.19 metres wide and 4.8 metres high – had travelled in the  lower hold and it took three hours for the ship’s heavy-lift crane to position it on the barge.

This was supplied by the Picton company McManaway Marine, subcontracting to Mulit-Trans, and had been towed the length of the South Island by tug-boat.

Barging of the transformer was necessary because the Tiwai Bridge was under repair and could not have handled the weight.

It took an hour to tow the barge up the Bluff estuary to a dock near the smelter that was installed four years ago especially to handle such heavy cargo.

After a wait for the tide to go out, Multi-Trans’ Mercedes tractor-unit with a 300-tonne towing capacity hauled the transformer off the barge, and a second tractor was positioned behind the platform-trailer to assist in the seven-kilometre drag to the smelter.

The following day the transformer’s header was removed and the trailer hauled round to the switch-yard entrance where preparations were made for jacking and skidding.

Two days after its arrival at Bluff the transformer was manoeuvred the 500 metres through the switch-yard, a process slowed by the narrow driveway – just eight metres wide – and the need for overhead power lines to be raised ahead of it and dropped back behind.

This took a day, and another day was spent jacking the transformer up off the trailer and inserting the beams that allowed the trailer to be removed.

May 3 saw the transformer skidded along the beams to be adjacent to its final resting place on a pad, from where it was skidded into position the next day.

A further day of tidying up the site saw the job completed in under a week.

Multi-Trans general manager Dave Butler told Contractor that despite a raft of potential difficulties the move went smoothly, thanks in large part to the assistance of local firms Kings House-movers, which supplied the support trucks, and Purdues Transport which supplied the Hiabs.

Multi-Trans is a wholly New Zealand-owned company that was established in 1997 and specialises in over-dimensional and heavy road transport.

The company’s range of services includes project management, heavy haulage, quality assurance, transport, handling and methodology schedules, engineered drawings, route surveys and costings.

Its multi-axle trailers and supplementary equipment allow it to handle consignments of up to 1200 tonnes and with load lengths of up to 90 metres.

Though based near Auckland, Multi-Trans has handled a range of South Island projects, including being engaged by Grayson Engineering, which is building Dunedin’s new Otago Sports Stadium, to shift 80 over-dimension loads of componentry from Auckland to Dunedin over the next nine months.

Other major transport projects it has completed include shifting the 160-tonne topside unit and 240-tonne pressure vessels for the Pohokura gas project from local company Fitzroy Engineering’s construction site to the Port of Taranaki, and multiple contracts to shift transformers of up to 150 tonnes to the Haywards and Benmore electricity sub-stations for Transpower.

Multi-Trans’ plant includes 20 prime movers, plus 40-foot semi-trailers, 40-foot step-deck trailers, trombone trailers, steerable bogies and motorised jinkers.

Multi-Trans’ jack-and-skid system can handle loads of up to 400 tonnes, and its ancillary equipment includes eight pilot vehicles, forklifts up to 30 tonne capacity and a range of rigging gear.