The incredible journey

As Tom Smith, ABB project manager explains: “Delivery of any large transformer within London is always a complex exercise with many factors to be considered. Not least, is the need to seek approval and cooperation from a host of bodies such as the police, shipping agents, the Highways Agency, Local Authorities and Transport for London (TFL). However, there were a number of additional factors that made this really out of the ordinary.
“To start with, although stripped of all its accessories, the transformer was still very large – measuring 8.5 x 4.5 x 4.8 metres – and even using ALE’s girder frame trailer that enabled it to be carried at a very low height above the road, the clearance at two bridges on the route was marginal, at just a few centimetres. Next there was the 250 tonne combined weight of the trailer and transformer which was clearly going to be too heavy for the existing elevated roadway on the site using normal means. This required a detailed site survey to determine the maximum safe load, followed by remedial and reinforcing works on the site, as well as the use of a 14 axle rig to spread the load. Then there was the restricted nature of the substation site, in a busy urban area, that called for the 66 metre trailer and tractor combination to negotiate a tight dog-leg turn, crawling through the gates a few centimetres at a time with no margin for error.”
Even after solving the significant logistic and engineering problems, and carrying out a successful dry run with a fully assembled rig, there was another challenge – the delivery took place on one of the busiest traffic weekends of the year in the capital. The British leg of the Tour de France, Live Earth at Wembley and the British Grand Prix at Silverstone were all happening at the same time. Nevertheless, it was ‘now or never’, as otherwise major M25 roadworks would delay delivery for months.

From Rail To Ship To Road
The transformer travelled by rail from the ABB factory at Ludvika, Sweden to the port of Västerås from where it was shipped to Tilbury. Engineers met it at the docks to check that high seas had not caused any damage.
From Tilbury, it was taken by road. The first leg took it to South Mimms service station on the M25. Then at midnight on Saturday it was cleared to start on its final journey into London. The route was approved by the Highways Agency, who had also temporarily removed street furniture and parked cars in strategic places.
Despite careful planning, some quick thinking was needed as recent accidents had damaged the crash barriers on a crucial elevated roundabout on the North Circular Road (A406). Temporary concrete bollards, together with worries about the bridge supports forced the convoy to reverse the wrong way round a roundabout.

Trans-shipment
The convoy arrived at the substation at 3.00 am, but it took three more hours to manoeuvre the trailer on to the trans-shipment mat. A specially constructedMega Lift then raised the transformer from its trailer before it was lowered on to an eight row SPT (self propelled transport) that moved it closer to the transformer pen.
From here, the transformer was put on to Teflon skids so it could be nudged into position, aligned and jacked down on to its antivibration pads.
“This was probably the most complex and demanding transformer delivery exercise ever undertaken by ABB in the UK.” says Tom Smith. “It really is a tribute to the outstanding planning, coordination, teamwork, skill and determination shown by everyone involved. Not just in ABB and ALE, but also National Grid, the police and all the various authorities.”