Javelin on target for CTRL: Hitachi is building a fleet of high-speed multi-system emus for operation between southern Britain and London. The first are due to arrive next year, in time for full fleet service in 2009

International Railway Journal, Sept, 2006

HITACHI's latest aluminum multiple unit design, the A-train, was initially placed in service on commuter and suburban lines in Japan, but from 2009, will face a new challenge when a fleet of 225km/h six-car emus enter service on the Channel Tunnel Rail Link (CTRL) in Britain.

The CTRL domestic trains will link London St Pancras and East London with the Kent Coast, sharing the new lines also used by the Eurostar services to France and Belgium. The contract provides for Hitachi to build and maintain 28 A-trains called 'Javelin', owned by HSBC Rail, and leased to London & South Eastern Railway.

From CTRL, the trains will divert onto local lines to destinations in Kent. Trains will operate in 12-car formations during peak times, coupling and uncoupling at Ashford. The new trains will cut journey times into London massively. In addition, following the announcement that London will be the host city for the 2012 Olympic Games, the service will be an integral part of the transport of spectators to the games via Stratford in East London (IRJ July p17).

The Javelin fleet will be configured as six-car units with 361 seats, including space for two wheelchairs and one standard and one disabled toilet. Train configuration consists of two driving trailers, one disabled toilet car, one standard toilet car, and four motor standard cars.

The train will be able to achieve the proposed timetables with a 25% loss in traction system performance. Japanese sliding doors have been retained from the Shinkansen design to deliver high reliability and meet the strict requirement for dwell times of 60 seconds. Coupling and uncoupling will be achieved in just 60 seconds, a common feature in Japanese rail operations. Indeed, a number of systems that were previously unique to Japan will be introduced to Britain on the new A-trains to cope with the demands of the service.

Body Design

The design features an aluminum double-skin body constructed by friction-stir welding (FSW), fully self-supporting interior modules, and an integral hollow extruded mounting rail to which the modules are fastened. In addition to providing a quieter ride, better rigidity, and improved safety, the use of FSW means the bodies have virtually no distortion.

The modular approach for the interior has reduced the car production lead time, simplified refurbishing vehicles, and yielded other cost efficiencies.

Hitachi is making extensive use of FSW to minimise distortion during the manufacturing process in order to manufacture to high tolerances and to minimise weight. Rather than melting, this method uses plastic flow to join aluminium, making the joints stronger than the parent metal itself. This results in a smoother surface finish and a stronger car body at lower weight.

In addition, to cope with high-speed operation on heavily tunnelled routes, the car bodies will be airtight to minimise passenger discomfort from air pressure changes. Hitachi has many years' experience in design for tunnel operations and has a unique air chamber testing facility at its Kasado factory in the south of Japan.

The combination of high-speed running on new infrastructure and low-speed running with tight curves presents a number of challenges to the A-train bogie design. Hitachi has designed and produced a bogie specifically for the British market in collaboration with British experts. This bogie design will be completed during the train design programme and extensive work has already begun with track authority Network Rail to optimise this design and harmonise the interface with the infrastructure.

Whilst a number of key components will be sourced from leading European suppliers to meet British standards and regulations, the trains will be manufactured in Japan and shipped complete to Britain. Hitachi will use its own dock at Kasado so that completed cars can move straight from the test track to the ships for transport to Britain.

As part of the comprehensive on site testing facilities, Hitachi has a real-time simulator, which is used to verify the hardware and software of logic units and traction inverter control algorithms. It simulates electrical systems such as voltage sources, filter circuits, inverter, motors and also mechanical systems such as models of bogies, car bodies, and adhesion characteristics. It is connected with the actual logic unit and verifies the logic unit's hardware and software. A dynamometer testbed will be used during verification of electrical equipment and combined testing of electrical equipment such as transformers, inverters and motors. An equivalent condition to actual running condition is realised by using flywheels as load.

The dynamometer testbed is also used for the testing of mechanical equipment such as bogies and brakes. Soak tests will be carried out to establish running temperatures for electrical and mechanical equipment.

Hitachi recognises that absolute testing can only be done in Britain on its domestic network. It faces a key challenge to complete comprehensive testing and gain approvals for both the 750V dc third-rail network in Kent and the new 25kV ac CTRL lines.