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National Pile Croppers help deliver £10.3m renewal scheme

National Pile Croppers (NPC) has worked with contractor CR Reynolds to complete the piling element of the £10.3 million Holmfirth Town Centre Action Plan in West Yorkshire.

The scheme, a partnership between the council and West Yorkshire Combined Authority, is designed to improve access to the town centre, reduce congestion and improve pedestrian safety. Works include the demolition of the former market hall and extension of the adjacent Huddersfield Road car park, alongside new café and bridge developments.

Hull-based CR Reynolds, which has more than 40 years’ experience in civil engineering and construction, was appointed as the lead contractor.

Piling challenge

The project required a range of concrete piles, predominantly 600mm and 750mm contiguous piles. The piles featured cages containing 10 x 40mm reinforcing bars, with a 1.5m crop section. Drilling depths of 10–11m were required, with no refusal point, meaning some piles had to be drilled deeper.

“ The piles are set in a contiguous wall with 10 x 40mm reinforced bars in each cage. The crop section is 1.5m, with 10/11m drilling with no refusal point so the drilling had to go deeper. Hence, and given the nature of the project, and following discussions with CR Reynolds, it was decided to use a CFA with dog-bones and cylinders removed. For flexibility, the cropper was set up to be changed around by the client as quickly and easily as possible to adapt to each pile,” explains National Pile Cropper sales director Scott Fitchett.

NPC supplied its CFA hydraulic pile cropper, a linked modular system that can be adjusted to suit different pile diameters. The system was used with an NPC lifting frame to crop the 600mm and 750mm piles, with the modular design allowing adjustments in 100mm increments by adding a half link.

The CFA cropper can handle circular augered concrete piles from 300mm to 1,200mm in diameter, allowing the same attachment to be configured for different pile sizes on site.

Working in tight spaces

The layout of the Holmfirth project presented an additional challenge, with large, irregularly shaped piles positioned close together and limited space in which to manoeuvre the cropper.

“CR Reynolds’ attitude throughout enabled us to provide the right and most effective solution,” says Scott. “They worked with us to find the right solution, telling us of the configuration and then we made it happen. By doing this and by being fully onboard, we were able crop 10-15 600mm and 750mm contiguous piles each day. This doesn’t sound a great deal but due to the nature of the project and the piles, we worked with the CR Reynolds team to try out various setups to get the piles cropped in a tight space.”

Different excavators were required on either side of the river, while the cropper’s cylinders also had to be repositioned or removed to allow it to fit between individual piles.

“The NPC team worked tirelessly with CR Reynolds to deliver different setups to achieve a solution. The piles were large, misshapen and very close to one another requiring a large cropper to fit in very tight gaps which varied from pile to pile. Two different excavators needed to be used for different sides of the river, and the cylinders needed to be moved and removed on the cropper to fit between different piles.

“CR Reynolds was happy to do this on site when required, drawing on the pile cropping expertise of the NPC team. We visited the site on a continual basis to check progress, monitor the cropper and try to pre-empt any possible issues,” concludes Scott Fitchett.