A BSP DX-SP25 excavator-mounted impact hammer is playing a central role on the £225 million Luton Direct Air-Rail Transit (DART) construction project in Bedfordshire, England. DART will provide a rapid link between Luton Airport Parkway rail station and the London Luton Airport terminal building, transferring passengers in less than four minutes.
Construction is being undertaken by a joint venture between VolkerFitzpatrick and Bedfordshire-based Kier. The VFK venture is responsible for building and completing the civils works for the Luton DART Parkway and Luton DART Terminal stations, the Gateway Bridge over Airport Way, a viaduct leading from the Luton Parkway station and tunnels and approaches to the airport terminal.
Elite Sheet Piling, based in Stoke-on-Trent, has been subcontracted by VolkerGround Engineering to install multiple sheet piles and coffer dams along the route of the works, right up to the end of the runway. Sheet piles up to 12.5 metres long are being installed to a depth of 10.5 metres, to provide ground security in the predominantly chalky soil, as the project climbs the hill from the rail
station to the airport.
Elite is driving the piles initially with Movax side grip piling equipment and completing the task with the new BSP hammer mounted on a Volvo EC380EL crawler excavator. The DX range of hammers from BSP International Foundations has been developed to drive steel sheet piles, though they can be adapted for use with concrete, timber, tubular steel and small bearing piles if required.
Mounted on a crawler or wheeled excavator, the DX-SP25 can be rapidly deployed from a horizontal transport position to a vertical operating position, with no requirement for a crane to assist. During piling operations, the DX hammer is automatically guided or crowded in the vertical plane.
There are three models in the DX line-up – the DX20, the DX25 and the DX30, offering drop weights of 1.5 tonnes, two tonnes and 2.5 tonnes. Maximum impact energy is 20 kNm, 25 kNm and 30 kNm respectively, while blow rate at rated energy for all models is approximately 60 blows per minute.
The hammers have low hydraulic power requirements, requiring 130 to 170 litres per minute of flow, and can be operated directly from an excavator. They are also available with a range of BSP Hydro-packs for optimum hammer performance.
“We went with BSP for the reliability, the quality, the strength of the hammer and the good name of the company,” said Elite’s managing director Carl Ingram. “It’s been working brilliantly; I really can’t fault it.
“The DX-SP25 can be interchanged between any of the three larger machines when required. We are also in talks with BSP for a smaller hammer, to work with our smaller excavators, as part of our plan for continued growth.” 