Infrastructure shapes mobility and influences rolling stock in much the same way that new and better highways impacted automobile design. In this excerpt from a Nexans white paper, the authors explain the latest trends in rail infrastructure and what customers will expect from cable suppliers in the future.
“Infrastructure shapes mobility. No major change in transport will be possible without the support of an adequate network and more intelligence in using it. Overall, transport infrastructure investments have a positive impact on economic growth, create wealth and jobs, and enhance trade, geographical accessibility, and the mobility of people.” – EU Roadmap to a Single European Transport Area, 2011
Infrastructure shapes mobility in numerous ways and influences rolling stock in much the same way that better highways impacted automobile design.
Driven by customer demand for cheaper, safer, more comfortable, and efficient rail travel, as well as national policy objectives for carbon reduction and transportation efficiency for urban populations, railway infrastructures are undergoing significant changes, many of which require advanced cabling solutions.
More Electrical Power in the Rail Network
Increased rail passenger traffic and higher operating speeds for both urban mass-transit systems and high-speed rail requires more power in the network – for traction, catenaries, switches, onboard systems, customer services, and train management and control.
As energy circulates through the system, safety requirements increase, and PVC is increasingly replaced with halogen-free cables at several points within the system (including underground access tunnels, structures, and station platforms) to reduce the danger of smoke and hazardous fumes. Also, fire-retardant power cables are sometimes replaced by fire-resistant cables to allow vital systems linked to warning, exit, and firefighting equipment to continue functioning under fire conditions.
As copper prices rise, so does copper cables’ attractiveness to thieves, and consequently copper theft has become a serious problem in Europe and worldwide, posing a threat not only to daily operations and scheduling, but also to passenger safety.
There are three solutions to the problem: Find a way to better protect the copper in railside infrastructure; make it harder for thieves to dispose of their copper booty; or find a way to replace copper with aluminum, steel, copper-clad steel (CCS), copper-clad aluminum (CCA), or other metal combinations.
A Single Railway Area
Unlike highways and airlines today, railways have inherited six different gauges, which are in day-to-day operation around the world. In fact, some countries have several gauges in their networks (Argentina, Brazil, Japan, and Spain).
In an age of high-volume international travel, standardizing gauges is definitely a costly and difficult challenge. Once again, a patchwork network not only limits productivity and potential traffic, it provides a considerable impediment to train-set manufacturers who would like to sell standard units internationally.
Of course, rail gauge is not the only problem. There are also various voltages and frequencies used as one moves from one country to another, as well as different signaling and train control systems that require layered onboard systems. There are also various infrastructure management issues that touch everything from hardware renewal to daily maintenance and safety issues.
This requires an intelligent and cost-efficient integration of power cables with signaling cables to make cross-border travel a reality.
ERTMS + ETCS + GSM-R
Thirty-four countries have now signed up to phase in rail traffic management technology, making it a prime tool for international “interoperability.”
The European Rail Traffic Management System (ERTMS) implementation is the backbone of the revised TEN-T program, which was adopted by European institutions in December 2013. It would see core routes equipped with ETCS (European Train Control Systems) by 2030.
The ETCS is a signal, control, and train protection system designed to replace the many incompatible safety systems currently used by European railways, especially on high-speed lines. It requires standard trackside equipment and a standard controller within the train cab. In its final form, all line-side information is sent to the driver electronically instead of visually, which would be impossible to decipher at high speeds.
In many countries, we are now at Level 2 implementation, whereby voice communications and data transmission are continuous via GSM-R, which is now operational on 70,000 route-km in Europe, with a further 84,000 route-km to be rolled out in coming years. Upgrades allow additional functionality such as automatic train operation or the use of satellite navigation systems.
An entirely new generation of signaling cables are required to meet this challenge, not only for balise or point machine cables but also for the heavier demands of trackside data communications. It also demands better installation techniques.
Enhanced Information and Communication Systems
In parallel to ERTMS, a real-time closed loop of information and communications will optimize networks, improving productivity, energy efficiency, and quality of service to passengers.
By and large, today’s railways have a rear-view mirror element in their operational structure, determined by timetables. Experienced drivers largely follow a working timetable controlled by trackside signals for safety information. Signalers and controllers also manage the network via timetables, often saying only “stop” or “go.” In short, timetable designers often work in their own silos, meeting pre-set service criteria. Seldom do they make use of modern data communications, which could bring all network operations together in an integrated seamless system that could deliver a higher quality of service and reduce energy use by up to 33% (according to a Japanese railway study).
Passengers also desire enhanced communications, especially comprehensive IP services which include Internet access, travel information, dynamic route maps, and entertainment, whether waiting in train stations or in moving trains. In a world where the Internet is enriching so many of our leisure and work activities, it should come as no surprise that train travel, whether urban mass transit, suburban, regional, or main line, will have to make information access an important part of the travel experience if growth is to be ensured.
What this means is that railway operators have much to gain by upgrading their local area networks (LANs), their metropolitan area networks (MANs), and their wide area networks (WANs) to get the most out of what modern technology has to offer in terms of information, communication, and analysis, which translates into operational efficiency and enhanced public safety. That requires an upgrade of station and trackside telecommunications including latest-generation optical fiber technology to handle heavier data traffic and GSM-R demands.
Predictive and Proactive Condition-Based Network Maintenance
Unlike machinery on the factory floor, trains move long distances and need to be managed remotely. That also applies to tunnels and the physical network, including power supply, drainage channels, and even components like bridges and piers.
Maintenance is complicated because the object is a moving target in terms of space and time, subject to local conditions and events and daily wear and tear.
What is needed is a “data spine” across an entire network to allow an infrastructure manager to introduce route-based maintenance management assessment that can model failure patterns and identify high- and low-risk components for whole-life asset management, especially for power supply equipment and line-side signal cabinets.
This “smart maintenance” concept will shift from time-based to condition-based maintenance and will require sophisticated information and communication technology based on a trackside cable systems, which could even incorporate an automatic track warning system (ATWS) to protect staff working on repairs.
Expectations of a Cable Manufacturer
To meet the needs of the new infrastructure’s performance requirements, design engineers can expect cable manufacturers to offer:
- A full range of power, signaling, and communication cables and solutions to meet all current and future infrastructure needs, both trackside and at stations, control centers, etc.
- A regional supply base, with firm guarantees that a certain percentage of supply will be locally manufactured or easily available
- Innovation to ensure faster and easier installation of key elements like axle counters, and, if required, full compliance of cables with national standards, as well as the ability to evolve and adapt to changing infrastructures (including backward compatibility with existing networks)
- Solutions to problems like copper theft and advanced safety assurances in terms of fire-resistance, not only for safety cables, but also for medium-voltage and telecom cables
- New installation methods that can reduce time and cut costs
- Optical fiber universality in the IP world coupled with ruggedness in the field
- Reduction of complexity in cable and system procurement, a simplification of references for buried cables, and a harmonization of specifications and designs
- Advanced technical knowledge from a trusted supplier since in many cases operators are losing their long-acquired expertise through generational attrition of their own in-house experts
- Special services like inventory management and e-services
To read this white paper in its entirety, click here.
Authors Eric du Tertre, market segment director – railway infrastructure, and Bruno Weidner, product manager – railway infrastructure, work for Nexans.