As part of the utilities refurbishment project at Tottenham Court Road, Barhale Construction plc was contracted to replace a 600mm cast iron water main, possibly dating back to the 1820s, by inserting it with over 300 meters of 500mm diameter PE pipe.
When sliplining a main in the water industry it is customary to use a winch. This involves threading the existing main with a wire cable, which is then attached to the new PE pipe via a securely fitted toeing head. The winch, placed at the finishing section of the main, then pulls the PE pipe through the length of host pipe.
Winching not an option
When they began the sliplining operation, Barhale Construction found a number of tight bends in the water main which meant that winching alone did not provide sufficient force to pull the PE through the host pipe. One solution would have been to use a much larger winch but given the extremely busy location on Oxford Street and the limited space available, this was not an option. The risk of a breaking winch cable under tension can present a serious potential safety hazard for operators and members of the public.
The Pipe Handler, recently introduced by Steve Vick International and developed in association with National Grid Gas, provided the solution for Barhale Construction. The company hired the equipment at the end of March and attached it to the 8 ton excavator on site. “Attaching the Pipe Handler took only a few minutes”, says Mike Faherty, Site Agent of Barhale Construction “so we were able to begin inserting the pipe immediately. The equipment was ideal for the job and we were able to push 220 metres into the main from the launch excavation over three days. Due to the diameter of the pipe (500mm) we needed to butt fuse sections before inserting which slowed down the process, otherwise we would have completed the job very quickly.”
Prior to its introduction, the Pipe Handler underwent extensive trials across the gas distribution network and it is now in widespread use in the UK in gas mains replacement projects. Two models are currently available to handle pipes up to 355mm and up to 500mm. Each model can be used to handle smaller diameter pipe by using shell inserts.
Steve Vick International, best known for its products and techniques for the repair and renovation of gas mains and services, produces a range of pipe handling equipment including pipe pushing machines and pipe coil trailers.
Date published – 12th August 2011