The traditional method of cable routing is by using ground-level concrete troughs which are heavy to carry and difficult to install without the aid of lifting equipment. Prone to cracking and spalling, which over time will lead to their failure, concrete troughs can’t be easily modified at a later date to accommodate cable entry or exit points.

Other materials have been tried, including wood, asbestos and plastic. All of these were expensive to install. Wood quickly rotted while asbestos was fragile and still presents an expensive maintenance problem for asset managers with its associated safety hazards. Some plastic and polymer-based products suffer from expansion and contraction problems, buckling lids, collapsing lids from ballast compression on the sidewalls. They also burn when ignited or float in water. All of them fail to provide adequate cable protection.

Recognising back in 2002 that cable containment and protection is an essential part of communication, control and power networks across a diverse range of civil infrastructure projects including rail, highways, power and water, the Furukawa Electric Company (Thomson Reuters Top 100 Global Innovators 2013, 2014) began testing a new type of trough manufactured from a 100 per cent recycled polymer.

Their objective was to design and manufacture the world’s first complete polymer cable troughing system. Capable of being deployed rapidly and installed safely by one person without the need for lifting equipment, Green Trough was born.

Made from a 100 per cent recycled polymer, Green Trough is a versatile, environmentally friendly and durable product, designed to carry power and communications cabling anywhere – horizontally, vertically, at an angle, around an obstruction, along a wall, as a walkway, or even in an elevated position. Units have built-in anti-vandal and anti-theft features with lockable lids to help deter cable theft.

As a proven system, it is installed throughout Japan’s railway networks — including the Tokaido Shinkansen, which carries the record-breaking Bullet train. Launched in 2005, following a period of intensive R&D, the complete polymer cable-troughing system is now installed on major global infrastructure projects and was winner of the Best New Electrification Product at the Infrarail and CITE Awards in 2014.

Offering a diverse range of components, the system includes straights, curves, junctions and gradients, all available in a range of sizes comparable with concrete, but with greater internal capacities.

Key Benefits

Connecting the units is simple and any combination of troughs is possible. With a male and female connector moulded at the end of each duct, no joint grouting is required. Pan and tilting flexibility in the joints also means a bending angle of 2° to 5° can be achieved, enabling the route to form a natural minimum radius of 13 to 15 metres. This flexibility makes laying the units on uneven surfaces much easier and they can effectively be installed into various ground types, including ballast, soil (or a combination) and as a free-standing cable-troughing route. Green Trough can also interface with other troughing systems.

Made from a 100 per cent recycled polymer, the system complies with HSE manual handling requirements and was awarded a green rating on Network Rail’s Manual Handling Assessment Chart (MAC). Weight savings of up to 83 per cent mean that Green Trough significantly reduces transport and on-site handling costs.

Troughing units are easy-to-cut with hand tools, without creating smoke or dust. A range of accessories is available, to allow cabling to branch off or interface with existing concrete routes.

The polymer’s thermal coefficient of expansion has been determined and used to design a sacrificial ‘pip’ that is moulded into the connection at the female end of the unit. In extreme temperatures, these ‘pips’ absorb any expansion that might occur without distorting the trough route, so preventing buckling.

If enhanced capacity is required for future proofing with extra cables as part of any upgrade at a later date, Green Trough offers much more internal capacity and design options than many other troughing products.

The whole life costs of installing Green Trough are very favourable, with an expected lifespan of over 50 years.

Delivering value

Green Trough is rapidly becoming the product of choice where versatility and speed of installation is paramount. It offers installers a truly customisable solution and is available from TTS Rail, a leading supplier of polymer cable troughing to Network Rail and UK rail infrastructure companies.

TTS has built-up an unrivalled wealth of expertise in the rail industry over the years and provides off-the-shelf and bespoke polymer troughing solutions. Its configuration team works with organisations, designing tailored solutions for specific project challenges and assisting in product configuration to find the most cost-effective outcome. A unique range of accessories offer more scope for customisation on-site.

A recent configuration project for Balfour Beatty was to install large TTS 430 series troughs on the London Bridge station approach viaduct, part of the Thameslink Programme – Key Output 2. This complex project involved a suspended trough route on both the top and the outside of the viaduct walls, navigating many fixed obstructions and safety recesses along the route. Balfour Beatty designers worked closely with the TTS configuration team to develop the optimum route, keeping the bespoke units to a minimum.

Following the most recent audit, TTS has been awarded the latest ISO9001:2015 Quality Management System standard certified by BSI, demonstrating a continuing commitment to the highest levels of quality management and customer satisfaction.

Green Trough Walkway

Working in conjunction with Network Rail, TTS has designed the Green Trough Walkway system (pictured below). Having recently gained product acceptance, its hard wearing, non-slip and safe surface is ideal for troughing routes where a low-to-zero maintenance walkway is required, often found near depots, stations and signalboxes.

The product was recently installed at a key work section of the Crossrail Anglia project, prompting a Costain section engineer to comment: “The TTS Green Trough Walkway was selected as the ideal product to resolve issues which can be found at many infrastructure sites due to the heavily congested nature of ageing assets. One of the greatest benefits of Green Trough is the flexibility it provides from construction to operation. Light to transport and install, versatile to fit around existing infrastructure; the safe and solid walking route provides a robust and resilient solution.”

Consisting of two TTS 300 series units (the equivalent of two C/1/29 concrete troughs) joined together in parallel pairs with steel straps to ensure stability, individual access and integrity of the lids, this durable, combined walkway and troughing route is easily assembled by a two-man team and offers significant on-site benefits compared to other systems:

  • Non-slip, 780mm-wide walkway surface;
  • Zero-static build-up for pedestrians;
  • UV resistant;
  • 105,000mm2 internal capacity;
  • Easy access without lids buckling or becoming dislodged and unstable.

Elevated System

Network Rail had a requirement for an elevated system specifically designed to provide above-ground level cable management. TTS designed a simple, but effective, supporting mechanism that can carry multiple independent cable-containment trough routes.

Galvanised steel posts, concreted into the ground at two metre intervals, support ladders and horizontal bends bolted to brackets suspended from the posts. One-metre Green Trough units sit in the ladders connected to each other, forming a continuous run. Developed for use with three of the Green Trough series; TTS 90, TTS 150 and TTS 200, the system is simple to install and can carry one, or up to four, cable-troughing routes.

Fast, Flexible and Efficient

Green Trough has proven its capabilities for quicker installation, faster maintenance and improved worker safety over the years in the Rail industry. It is now used across a growing range of market sectors where cable containment and protection is an essential part of the infrastructure. Recent site applications of Green Trough have included a water treatment works for United Utilities, Sellafield nuclear fuel reprocessing, solar farms, Celtic Park football stadium and highways power and comms to name but a few.

Keeping things simple while helping customers solve their troughing problems, Green Trough is delivered in kit form on a pallet, with all the units needed to complete the job.