What are the stand-out memories of 2012? The London Olympics, of course and the Diamond Jubilee celebrations, perhaps. Oh yes, and the rain – the wettest summer in 100 years – and what an impact that had on the construction industry.
Among the many jobs where extra hours had to be put in to catch up – and extra machinery – was the site preparation works for the £750m Jaguar Land Rover engine factory in Staffordshire. BAM Nuttall began its £5.8m, 22-week earthmoving contract in April, but the weather was so bad that one week just one afternoon’s work was possible.
“It was a dreadfully wet summer,” recalls project manager Steve Beech. “The ground was such that when it was raining we couldn’t traffic the heavy plant. We just had to stop work. We had all the drivers chomping at the bit and just wanting to get out and drive. Management needed to stay patient and wait until the ground was ready to take a pounding.” BAM Nuttall’s job was to create a level platform for Jaguar Land Rover to build two large halls – one for production and one for assembly – each 120,000m2.
This was a huge cut-and-fill undertaking, moving a million cubic metres of spoil, including 150,000m3 of topsoil that was up to 600mm thick. The location of the new plant is the i54 business park, a joint development by Wolverhampton City Council, Staffordshire County Council and South Staffordshire District Council, close to Junction 2 of the M54 and just three miles north of Wolverhampton city centre. To cope with the addition of the Jaguar Land Rover plant on the park, the motorway junction is to be remodelled to give direct access. While BAM Nuttall lost out on that contract to Birse, it has contributed to that endeavour by constructing an embankment on the south side of the junction and stockpiling spoil for a future north side embankment. The embankment on the south side used 150,000m2 of engineering fill material, mostly sandstone rock crushed down, and all Class 1. The stockpile for future use for the north embankment amounts to 200,000m3. This currently sits within the bounds of the i54 park site until required. In order to make up for all the time lost to rain, when work could go ahead it was all hands on deck, with a sizeable array of plant put to intensive work. Primary excavators were five 45-tonne tracked Komatsu PC450s, supported by a fleet of 18 Komatsu articulated dump trucks moving to and fro on a just-in-time basis. Various crawler dozers worked to spread and level material, including a Caterpillar D10 with a ripper on the back for tearing sandstone, and Komatsu D61s and D65s.
All the equipment was supplied and operated by Shropshire-based Hawk under subcontract, with 30 machines on site at peak. While BAM Nuttall does still own more plant than most major contractors these days, its kit is mostly either cranes or smaller machinery, not the kind of earthmoving machinery needed for a job like this.
With all this machinery on site, working long hours and weekends to catch up, it was important to minimise the scope for human error. It was also not a good idea to have surveyors walking around, setting up theodolites near the bustling machinery. For these reasons, Hawk’s excavators and dozers were fitted with Leica Geosystems GPS machine control equipment from Scanlaser.
Steve Beech explains: “You upload the Moss model into the software that controls the machines. The sensor on the dipping bucket tells the [excavator] operator how far to go down or dozer driver how far to go up.” Explaining the benefits, he says: “It’s a speed thing. You don’t have to rely on the setting-out engineers. You also don’t have as many people on site on foot, so it’s a health and safety benefit. When you’ve got 30 pieces of plant over the site, you don’t want people on foot.” He adds: “I wouldn’t do a muckshifting job without it now.” Hawk also used the iCON supervisor’s kit. This technology enables site managers to drive around in their Land Rover, Jeep or similar, and check all levels without getting out of their vehicle (pictured below). They can do volume calculations while touring the site too.
And with the Leica telematics system, all information relating to levels can be relayed back and forth between the site equipment and a remote head office. Key to getting the job done, Beech says, was efficiency, maximising equipment uptime and not having trucks sitting idle waiting for something to do. It all relies on having “muckshifting people who understand muckshifting,” he says. “It’s really quite an art.” Hawk Contracts general manager Frank Jones acknowledges the part played by machine control technology on the project. “I think the GPS played a major part in the health and safety on the site and we were more efficient,” he says But, as always, the real secret was plain old hard work. Technology is great, but it cannot be expected to do everything – at least not yet. “It was a good team effort on both parts, BAM and Hawk,” Jones says. “We worked bloody hard to get the job done and put the hours in. Everybody was to the pump.”
Neil Williams, engineering & infrastructure manager for Leica Geosystems, says that the UK construction industry is still at the early adopter stage when it comes to machine control technology, at least compared to our northern European neighbours, and Scandinavia especially. Prior to 2008, he says, the productivity gains that it offered prompted larger UK earthworks contractors to adopt the technology, particularly on road construction schemes. Now, however, he says, its take-up is being driven by the cost savings on materials and fuel, and by the site safety benefits, eliminating an interface between pedestrians and heavy plant.