A MODIFIED Dutch piling rig provided extra power on a site next to Millwall Football Club's New Den stadium in south London.
Contractor Pennine Group used the THW 4019D machine to install piles for an indoor football centre for the Millwall Community Scheme.
The site is confined by the stadium on one side and a mainline railway on the other.
Pennine engineering manager Peter Halliwell says: 'We developed our own rotary head for the rig with a high crowd force and very high torque, making it 30% more powerful than other rigs of the same size.' Restricted space was not the only issue; the contractor needed to complete 102 piles to a depth of 10m in just one week. Ground conditions, including medium dense sand and gravels with chalk at depth, were a potential problem. While the rig can be used for CFA piling, Pennine opted to use its Penpile auger displacement piling system. This displaces soil laterally as it penetrates, resulting in virtually no spoil.
The £35,000 foundation contract, for Hertfordshire-based Trak Build, was finished on St Valentine's Day.
Pennine says the adapted rig proved so useful on chalk, overconsolidated clay and granular materials that it has ordered a second one.