Running alongside the railway, cable troughs are not just a tidy and convenient receptacle for signalling and power cables. Their lids also often provide a walkway but, with the strong possibility of encountering missing or broken lids in some areas, they can be anything but a ‘safe walkway’, especially at night.
Rail Engineer has reported on the development and installation of cable routes made from recycled materials a number of times. Several suppliers offer such products, but it is believed that Trojan Services is the only UK supplier of locally produced products using UK-sourced raw materials and production of recycled polymer.
Now, Trojan Services has developed an enhancement of its successful combined cable route and safe walkway for the second phase of the East West Rail project, which aims to establish a strategic railway connecting East Anglia with Central, Southern and Western England.
In 2002, Trojan began researching the use of recycled polymers for railway cable ducting as an alternative to traditional concrete. At that time, less than a quarter of plastic waste produced in the UK was recycled, the bulk of which was packaging materials. However, since then, the raw material stream from industry and society has been increased to include end-of-life products, as well as domestic and industrial waste.
Trojan identified that the most suitable polymer for rail applications was polypropylene, due to its high strength and impact resistance. The result was the TroTrof range, approximately five times lighter than concrete troughs.
The range was later enhanced with a combined cable route and safe walkway that has been used on a number of rail enhancement schemes, and which has contributed to safety and sustainability of the materials used by rail. This is known as the TroTred product.
East West Rail ran a ‘troughing challenge’ to select an innovative cable troughing system that would meet its ‘next generation railway’ requirements by combining the welfare of workers along with environmental and sustainable elements. Trojan was successful in the challenge and the result is TroPath, a derivation of the existing TroTred product. TroPath will offer the rail industry an even lighter-weight, durable and long-lasting cable trough and safe walking route. It has health and safety as well as life cost benefits compared with traditional concrete products and, when the product reaches end of life, it, in turn, can be recycled. Currently, the Trojan project is gearing up to commence production in 2018.
East West Rail Route
The proposed East West Rail route can be broken down into three sections – Western, Central and Eastern. The Western Section route is on existing lines between Bedford and Oxford, Milton Keynes and Aylesbury Vale. Phase 1 – Oxford to Bicester Village – has already been upgraded by Chiltern Railways and Network Rail. Phase 2 of the Western Section will upgrade and reconstruct existing and mothballed (no longer in use) sections of line that link Bedford with Bicester, and Milton Keynes with Princes Risborough.
Once completed passengers and freight services can make the journey between Bedford and Oxford without needing to travel via London. It will also link Milton Keynes on the West Coast Mainline with London Marylebone on the Chiltern Mainline via Aylesbury.
The Central Section will extend the Western Section to Cambridge. The line was closed and dismantled in the 1960s. Many bridges have either been removed or are in a poor state of repair and the Bedford bypass severs the line, so there is extensive work to be done on this section.
The railway east of Cambridge, the Eastern Section, is extensively used by freight as well as providing passenger services. An hourly service of passenger trains between Cambridge and Norwich was introduced in September 2002, and one between Ipswich and Cambridge in December 2004.
A specification for the development of line side troughing for the East West Rail Alliance was established with the objective of innovation and continuous improvement in troughing for both East West Rail, UK Railway and beyond. The specification, which was formulated by a multidisciplinary team, concentrated on five key areas:
- Best value for money
- Safest method or option
- Consistent quality level
- Most sustainable method or option
- Reputational advantage.
The specification set qualitative target criteria in 17 areas that covered the behaviours and goals of the project. These included: unit cost, installation cost, time saved, work content reduction, intrinsic safety (Safe by Design), improvement in reliability, and positive reputational impacts on the project and rail in general. The specification required a walking route compliant with standard NR/SP/OHS/069 issue 2 “Lineside facilities for personal safety”, along with the provision of disconnection box stakes and handrails, together with being able to safely contain all forms of cables.
The product design had to enable an operative to install more than 25 troughs per shift under Manual Handling Operations Regulations 1992, and include features to minimise both the risk of injuries during installation and the exposure of staff to hazardous substances during onsite construction and maintenance. The safety requirements included features to reduce minor injuries during operations from slips, trips and falls, such as lid failures.
The solution had to demonstrate consistent quality levels, high durability, a minimum 25-year design life, and compliance with existing troughing product specifications. It needed to be a flexible product range for dealing with obstructions and grade changes by offering different lengths, radiuses and tees.
The comprehensive specification included a requirement for the lowest possible embodied carbon, emissions, and water usage during manufacture, which should be undertaken by a local workforce using locally sourced materials. Cable protection had to maximise rodent protection while minimising the risk of cable theft – with more than one measure of security per system.
Trojan submitted initial design concepts in accordance with the criteria laid down in the specification. These overcame the potential for installation problems associated with the earlier TroTred product, which had led to issues with lid alignment and stability.
This was achieved by eliminating the multi-part base configuration of two sidewalls with a centre section slotted together to form the base. Instead, the new TroPath base was made in the form of two half troughs, giving the unit more stability and strength. Likely expansion requirements have been calculated and finite element analysis conducted. Moulds are now being produced to confirm the physical characteristics of TroPath, after which the new product will be tested in accordance with Network Rail standards prior to full-scale trackside testing to ensure compliance.
TroPath offers a weight reduction compared to TroTred due to the sidewall reducing from 350mm to 200mm, as less cable capacity is required for the EWR project. This will also save a considerable amount of raw material and illustrates how important it is for projects to specify requirements as accurately as possible in order to save costs by not over-engineering the product.
The installation time will be reduced as there is no need for assembly of the base unit on site, resulting in improved productivity/installation rates, and reduced potential for accidents associated with manual handling.
Trojan has also evaluated and introduced a new raw material supplier which offers improved performance of a lower weight per unit whilst maintaining the same physical characteristics. Workforce training will be reduced due to the elimination of on-site assembly and this, together with easier installation of TroPath, will result in lower installation times compared to existing products.
Delivery costs could be reduced as well. Trojan is evaluating the elimination of wooden or plastic pallets as well as removing the need for shrink wrapping which is currently used with existing pallet deliveries.
Ricardo Rail assessment
Ricardo Rail was remitted to undertake an independent Life Cycle Assessment (LCA) for the TroTrof and TroPath products, and to compare TroTrof with a conventional concrete trough and TroPath with a concrete trough and a track-side walkway. This included an Environmental Product Declaration (EPD) for each product.
The conclusion was that the Trojan products out-performed the concrete-based alternatives for every environmental criterion studied, for all life cycle stages. The results took no account of product lifetimes; however, it is anticipated that the Trojan products may last for the entire project lifetime (120 years), whereas a concrete alternative would need two replacements.
In June 2017, TroPath was awarded ‘Best Recycled Product’ at the National Recycling Awards event. The judges commented: “A simply amazing product – it delivers everything you’d want in a best recycled product. Mile after mile of this product will be installed along railways across the world, we have no doubt. There are no similar products on the market, with the standard practice being the installation of concrete troughing and a separate walkway made from wooden batons, membrane and packed type-one aggregate”
Trojan has always appreciated the positive reaction and adoption by Network Rail of its innovative solutions to cable trough/walkway management issues, and the acknowledgement of the benefits delivered by awarding Trojan the Innovation and Environment Partnership Award in 2008 and 2010. The company also welcomes the new generation of designers and project managers who are embracing Trojan’s approach to product innovation and design.
This article was written by Paul Darlington.
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