National Pile Croppers develops updated pile cropper for contiguous piles
National Pile Croppers has updated the Contig 600 pile cropper.
"We have always stated we are constantly improving the equipment we manufacture, so, the launch of our new Contig 600 cropper is just one development we are justly proud of," says National Pile Croppers Managing Director Simon Price.
The new Contig 600 cropper
The Contig 600 is a cropper built with the purpose of reducing piles in a contiguous or secant wall formation where only two sides of the pile can be exposed and spaces between adjacent piles is tight. Two hydraulic rams are mounted at opposing 180-degree angles to provide the ability to position the cropper over the wall to reduce the piles. The wall thickness of the cropper allows it to slot between contiguous piles with spacing as close as 50 millimetres.
The original unit was larger than anticipated and has the functionality to crop 750-millimetre piles. Whilst this is a good problem to have, it also caused issues addressing a 600-millimetre contiguous pile with 150-millimetre (nominal) pile spacing. NPC has created a cropper that has a reduced width but maintains its structural strength while also keeping the overall dimensions tight to a 600-millimetre pile. Tests and a subsequent stress analysis have provided the optimal jaw-to-pile interface angle.
The new Contig 600 has already undergone field testing. It was recently used by Churngold Construction on a development in Bristol. The concrete piles used in the development had to be dealt with efficiently, speedily, and safely, with the resulting concrete residue reprocessed in an environmentally friendly manner.
"Churngold invited us to the site to see the difficulties faced with cropping of the piles. I must admit the complexities of the site and the way the piles have been laid out presented a challenge. Fortunately, we had been working on an updated version of our Contig 600 cropper. This would prove to be the ideal tool for the job," explains NPC director Lee Aston.
Maintaining structural strength in a tight fit
"With the new Config 600, two hydraulic rams mounted opposing at 180 degrees provide the ability to position the cropper over the wall to reduce the piles. The wall thickness of the cropper allows it to slot between contiguous piles with spacing as close as 50 millimetres," explains Aston. "In order to develop a cropper suited to Churngold's requirements, we aimed to build a cropper that had a reduced width, maintaining its structural strength, whilst also keeping the overall dimensions tight to a 600 millimetre pile."
The design and development of the new Config 600 overcame any issues that arose during stress analysis whilst attempting to achieve the ideal jaw-to-pile interface angle. NPC's latest version is now on site with Churngold cropping 600 millimetre and 450 millimetre augured piles in a contiguous wall format. These were installed leaving a nominal spacing of 150 millimetres between adjacent piles which has proved to be the perfect scenario for using the new Contig 600 V2.
"Feedback from the guys [Churngold Construction] on site has been highly complementary stating the cropper is performing better than expected, and it was expected to do well," says Aston. "The change in width dimension had a major impact resulting in piles in the middle of the wall being able to be reduced where other croppers would foul on the adjacent pile resulting in the need for further cropping from the end of the wall of piles. The weight and centre of gravity of the new Config 600 has also been moved to provide noticeably superior manoeuvrability; all this whilst also maintaining the excellent pile finish expected of the NPC range of pile croppers."
The new Contig 600 is now available throughout the U.K. and will be introduced globally soon.