The move is part of WWU’s on-going agenda of reducing pipe wastage and maximising the benefits of insertion techniques as part of the Mains Replacement programme . The company worked with one of its key suppliers, Steve Vick International, on the development of the new trailer.
“Using traditional 120m coils we were experiencing a pipe wastage rate of 20% per year, which is average for the industry”, says Andrew. The wastage of PE pipe, particularly in the diameters 63mm, 75mm and 90mm, is the result of left-over pipe on the coil being of insufficient length for insertion purposes. “Now, being able to use 500 metre coils”, he continues, “has enabled us to cut pipe wastage from 20% to 7% which represents a very considerable improvement on the bottom line”.
Although longer coils are not new to the Gas industry, historically trailers have struggled to handle them effectively. Nigel Tonge, Account Manager of Radius Systems who supplied the 500m coils, comments on WWU’s pioneering investment in the 90/500 trailers, saying, “It’s clear to see there is great potential in working with 500m coils. We look forward to supplying further networks in the near future and collectively assisting in a more cost effective and economic way of working for the industry”
Other cost savings of using 500 metre coils and the new trailer include the time saved in not having to fuse pipe together on long pushes. Fewer pipe fittings are used and less excavation is required for connection pits. Also, the cost of collecting coils from the manufacturer and delivering them to site is reduced as fewer trips are required and time is saved in loading and testing coils.
New hexagonal drum frame
Called the 90/500, this trailer is a completely new design from Steve Vick International, the company which began manufacturing pipe coil trailers in the 1980s and is now acknowledged as the UK’s leading producer. With a hexagonal drum frame, the central drum is moved between the loading, transport and dispensing positions by hydraulics, enabling one operative to carry out these procedures. The method of removing and replacing the drum bars (there are six – two fewer than on previous Steve Vick trailers) in order to load the pipe coil has been simplified and is now also a one-man operation.
The new trailer has a number of key advantages besides its cost-saving 500 metre capacity. Due to the improved central drum configuration, pipe is dispensed quicker, faster and more smoothly compared with trailers with no central drum. Unused pipe is easily re-coiled for use on another project. As the coil is fully supported by the hexagonal drum, re-coiling is a single-handed process.
With safety paramount, all loading and dispensing procedures are carried out from ground level with this trailer avoiding the need for operatives to climb onto the frame or put their hands within the rotating drum area. Once loaded onto the drum, a 500 metre coil of PE pipe can be easily rotated by hand to allow positioning of the leading edge prior to dispensing.
A central drum brake disc, which is mechanically applied, has been fitted to control the stored energy in the coil and avoid free rotation of the drum during dispensing and re-coiling as well as when loading drum bars.
Lightweight and easy to tow
Despite its large capacity, the Steve Vick 90/500 trailer weighs only 1900kg fully laden enabling it to be towed by a typical long wheelbase transit vehicle. The combination of its light weight and single axel make the trailer highly manoeuvrable. The trailer is fully compliant with GIS E49.
Summing up the introduction of the new trailers, which will soon be available in each of the six Western Gas Alliance depots, Paul Breakey, Deputy Operations Manager, says, “We are keen to maximize the use of insertion techniques in our mains replacement programme, particularly using 63mm, 75mm and 90mm PE. We were purchasing coiled pipe in predominantly 120 metre coils although this is not a convenient length for most insertions. On the majority of projects, the unused section of pipe was discarded as it was not suitable to use on the next insertion.
“Taking delivery of the new trailers”, continues Paul, “and using the extended length coils will not only reduce pipe wastage but bring other cost savings in terms of increased productivity. As we are planning to step up the abandonment of small diameter mains during 2012, there will be even further opportunities to cut wastage”.