Technical blog – Cable Fixings in the Rail Industry

Technical blog – Cable Fixings in the Rail Industry

Investment in the rail sector has grown rapidly over the last decade and much greater funding is expected going forward. Both UK and worldwide there is a growing ambition for modern, reliable and sustainable mass transit systems. Overground and metro schemes are taking shape in many high population density areas, powered by low carbon energy sources. Decarbonisation of the rail sector is the main driver.

The UK has the oldest rail infrastructure in the world, with much still dating from the Victorian era. A series of spending Control Periods is gradually providing the upgrade an d new-build needed. The current CP6 rail industry spending period is now active and although project spend commitment was initially slow, it is expected to ramp up soon. Huge investment is helping to modernise this industry at many levels with electrification at the forefront. Bi-mode operating trains using either electric and diesel or electric with battery will assist in decarbonising the rail sector. Although hydrogen powered trains are possible in the future, electric motive power will increase and dominate for many more decades.

The costs of operating electric trains are significantly lower than those of diesel trains; and electric trains can provide improved journey time, customer ambience and environmental benefits. The issue is that the cost and delivery risks of conventional (or continuous) electrification are perceived to be too high. The Great Western Electrification Programme (GWEP) and Midland Mainline projects have started the ball rolling in the UK, and much experience has been gained both technically and in handling project risk. It is important that electrification of the rail network continues to realise the ambition to decarbonise the railway.

Rail electrification requires both power cables and Overhead Line Equipment (OLE). Upgrades and new-build schemes must adhere to rail industry National Technical Rules (NTRs) and European Technical Specifications for Interoperability (TSI) and these will provide guidance for cabling. Short circuit fault levels in the rail sector are generally low (compared to other industry sectors) and most installations will not exceed 20kA. Ellis has the most extensive range of cable cleat designs on the market and as such, has a range of offerings suitable for all applications within the rail industry.


Cable Hangers

Overground and underground rail sectors use an extensive range of cable types including telecoms, alarm and control cables, signalling and data and of course, a range of power delivery and electrification cables. Many rail cables are installed using cable hangers. Ellis has improved the design of the basic galvanised steel hanger with reduced weight, radiused corners (to reduce damage to cables during installation) and a convex hanger profile for cable sagging. Further information about the Ellis Patents Cable Hangers can be found here.

Ellis manufactures cable hangers that are curved to fit the profile of a tunnel. These reduce the level of supporting steel structures necessary as the hangers can attach directly to the tunnel profile. Where the kinematic envelope of trains is tight and space is restricted, these profiled hangers provide a neat solution.



Ellis Patents No Bolts Cleat

The Ellis Patents No Bolts Cleat was designed to a specific remit from Network Rail. Contractors had been injured when working live on cables where metallic components in the cable fixings tore through the cable sheath. Network Rail’s design brief for a new-style fixing specified no metal parts and no tools required for installation and maintenance. The No Bolts Cleat was fast-tracked successfully through the development stages using rapid prototyping technology and achieved its Network Rail PADs approval within a year. The product is also fully compliant with IEC 61914 having been short circuit fault tested to 101kA. No Bolts Cleat won the Electrical Times “Best Innovative Product of the Year 2016”. Further information about the Ellis Patents No Bolts Cleat can be found here.


Harsh Environmental Conditions

Ellis were approached in 2016 to supply cable fixings to the Severn Tunnel electrification scheme, part of the GWEP project. The tunnel conditions are severe with sea water ingress and a high corrosion environment. A 60-year design life was specified and as such, Ellis adapted their standard 2F+ product to include a super duplex high-chromium fixing plate which satisfied the project requirements.


References: Railway Industries Association. RIA Electrification Cost Challenge. March 2019.