CLever by name and clever by nature is Alstom’s new CLever Cantilever, showcased at last month’s Railtex exhibition in Birmingham. This innovative development of the overhead electrification cantilever provides a lightweight and cost-effective solution.
Named CLever (a play on the word Canti-Lever), the new cantilever was designed and manufactured by Alstom in Lecco, Northern Italy, for 3kV and 25kV railway electrification systems operating at speeds up to 300km/h.
Developed specifically for use in the United Kingdom and included in Network Rail’s Series 2 and Master Series range of equipment, it comprises a full range of cantilevers for all electrification applications including mast-mounted, from a drop tube for use on two-track cantilevers or portals, or mounted directly from civil infrastructure.
The full range of CLever cantilevers has recently been granted full product acceptance by Network Rail following extensive testing at a trial location between Rugby and Long Buckby on the Northampton loop of the West Coast main line. It has been developed using safe-by-design principals, in line with Alstom’s commitment to engineer a safer railway for the UK, and BIM techniques to ensure an optimal design outcome resulted in a safe product that provides economic advantage and is aesthetically pleasing.
This rigorous design and testing development process focused on minimising the part count to enhance reliability, minimise maintenance and create a lightweight product that provides a safety advantage for manual handling and installation. The minimal part count, as well as the focus on the quality and reliability of components within the cantilever assembly, facilitates an advantageous life-cycle cost with minimal maintenance.
One example of the attention to detail in the new design is that every nut and bolt on the new cantilever is the same size. Technicians, working at height to install the new equipment, therefore only need one size of spanner, making the job easier and quicker.
In addition, the lightweight nature of the product means that an installation team can install a cantilever within around 15 minutes. This ability for the cantilever to be installed efficiently and quickly makes it an ideal partner for a high-output electrification installation system. This is particularly appreciated, not only on new lines, but also on renovation or electrification of lines in service, without disrupting operation.
Alstom has the ability to integrate the cantilever installation with high-output wiring achieved via its other successful innovation – the wiring train.
Introduced into the UK from service in Italy in October 2015, the wiring-train was modified specifically for use on the British network by March 2016 and then successfully deployed on the Edinburgh-Glasgow Improvement Programme. The train consists of seven vehicles, each of which has a specific purpose – a traction crane and MEWP (mobile elevating work platform) unit, drum carrier, wire tensioner, manipulator and MEWP, two independent MEWPs and a traction unit with MEWP and pantograph.
The wiring train has the advantage of being is classed as an OTM (on-track machine) and, as such, can travel loco-hauled. Once the train gets to the work site and into the possession, it can run out catenary and contact wire together at full line tension. The individual units that comprise the train can split, allowing registration activities to be undertaken and the fitment of any in-line items such as section insulators and the like. The wiring train can also be used to run ancillary wires such as earth wires and feeder wires, providing a complete electrification delivery solution.
The advantage with the Alstom electrification installation system is that a wire run can be completed in one shift compared with three shifts conventionally. Also, a higher quality installed tension length is achieved due to the mechanisation and, as with all Alstom innovations, the focus is on safety as the number of workers trackside is reduced.
This innovative and unique electrification delivery system has been developed by Alstom drawing on experience from many years of successful experience gained across Europe delivering high-speed, high-output electrification.
In the UK, Alstom innovations in the field of electrification are focused on making the delivery of electrification projects more cost effective to allow more of the rail network to be electrified and provide value for money.
Developed in Italy
Alstom’s in-house centre of excellence for electrification components, is based in the beautiful Italian city of Lecco, at the foot of the Italian Alps and close to Lake Lecco, a branch of Lake Como. The site was founded here in 1908 – it now has a strong pedigree of mainline railway and tram equipment manufacture and two satellite factories in the local area.
It is this centre of excellence that manufactures and supplies the Alstom high-speed electrification systems that are installed throughout Europe. The Lecco factory has also supplied much of the electrification equipment for the railway systems being installed by the ATC joint venture (Alstom/TSO/Costain) in the Crossrail tunnels. The electrification system for Crossrail is based on Alstom’s OCS3 range of equipment with rigid overhead conductor beams being used throughout the tunnels.
Alstom’s electrification equipment innovations also extend to DC equipment with a high-conductivity third-rail (or fourth-rail in the case of London Underground) composite conductor rail. This consists of a stainless-steel contact surface, with ‘state of the art’ welding resulting in a seamless contact surface for the conductor shoe, topping an underlying high-conductivity aluminium rail which is fully protected from wear by this stainless-steel layer, extending product life and reducing overall lifecycle costs.
Manufacturing this high-integrity product requires advanced fabricating and manufacturing techniques that are specific to the Lecco facility. This new third-rail equipment, not just the composite conductor rail but the complete system, is currently being tested in the extreme temperatures experienced on the Riyadh metro project in the Kingdom of Saudi Arabia, where the equipment must operate from -5oC at night to +50oC in the shade at midday.
Alstom’s innovative reversible power-supply substation (issue 140, June 2016) optimises the power required for light rail and metro traction systems and can capture more than 99 per cent of recoverable energy from regenerative braking. Hesop (Harmonic and Energy Saving Optimiser), of which there are 70 units on the Riyadh Metro, increases the energy efficiency of the electrical system resulting in a decrease in carbon emissions. This is achieved by converting the energy emitted by trains during braking into usable electrical power that can be used by station services such as lighting and elevators.
As the energy is reused, it removes a source of heat. This, when deployed in tunnels, will have the effect of reducing temperature – important in hot summer months or for railway systems installed in hotter climates than that of the UK.
The additional benefit gained from Hesop is that, by optimising the electrical power system, the distance between traction substations can be increased and, potentially, their number reduced by 20 per cent. This reduces the amount of infrastructure and hence construction required, providing a capital and lifecycle cost advantage as well as a safety benefit as less construction eliminates the associated health and safety risks.
Hesop is installed on the London Underground’s Victoria line, as well as the aforementioned Riyadh Metro.
Alstom recently combined three separate groups to form the Systems, Signalling and Infrastructure business unit, allowing the company to offer clients an integrated system.
Integrating the company into one joined-up entity has created an environment that facilitates innovation on a complete-system level, placing Alstom in a leading position in its rail industry sectors. Having in-house centres of excellence, such as the one at Lecco in Italy, supported by a highly competent design capability that allows for agile innovation and rapid prototyping, allows innovative new products to be introduced to the market, sparking much-needed technological progress in the rail industry.
This article was written by Steve Cox, engineering and technical director, Alstom SS&I UK and Ireland