April 23rd, 2015
The electrification of the Great Western Railway from London to Cardiff is aiming to improve reliability of the service and increase passenger capacity by 20%. One of the key components of the scheme will be provided by Barnshaws Metal Bending, which is supplying a number of anchor booms which are required to support the overhead cables.
Anchor booms are used to support the overhead electrical cables that power the trains and they come in two basic designs, gantry and cantilever. The gantry style is slightly more complicated since there is an increased static load as well as the potential for higher wind loading. These have to be taken into consideration when designing the new components, along with the considerable specification list required by the rail industry.
Although they appear to be a simple support structure, in fact they are both kinked and cambered to provide additional strength. Previously the steel sections were cut to length and then welded together to provide the offset at each end of the booms.
In the past these booms were imported from Europe as IPE sections and the fabricator had to cut and weld each boom four times in order to achieve the correct shape for the finished boom section. By discussing the design requirements with Barnshaws, the fabricator was able to simplify the manufacturing process and make the product more cost effective.
Network Rail aims to use a high output plant system that will allow a more efficient installation process with minimal disruption to the rail network. This depends on all the materials that are required for each shift being ready and available on time. It also requires those components to be exactly as specified so that installation can be completed on time.
Andy Tura – Structural Steels Team Leader at Barnshaws comments: “We explained that it was possible to bend the IPE sections as one complete section with IPE Kinked both ends, slots profiled and the section cambered as one complete unit, this removed the need for the customer to cut and weld individual bars back together thus preventing any unnecessary additional work and saving significant costs whilst still achieving the same end results. The finished beam would have the required offset at each end as well as the slight camber as dictated by the specifications. Furthermore, we can produce these Anchor Booms for any length up to 25 metres and longer if required, which would be sufficient to span the tracks for this part of the project.
By meeting the specification for the anchor booms through bending, rather than welding, Barnshaws was able to reduce the fabrication time as well as remove the welded joints in the beam and any associated heat stress that may have been induced. The new solution has helped contractors to meet Network Rail’s aims and requirements.
For this particular contract Barnshaws delivered approximately 100 tonnes of kinked and cambered beams, all of which had to be delivered to meet a demanding schedule so that they could be installed within the specific construction windows.
Providing curved roof, support and gantry sections that are lighter and stronger than straight section components is a major part of Barnshaws business and sees the company supplying elegant and effective materials to projects as varied as skyscrapers to stadiums, train tracks to truck bodies, including nearly everything inbetween. The work between London and Bristol, including Newbury and Oxford, is scheduled to be completed by 2016, with the route to Cardiff electrified by 2017.