Part 1 What is the 'A-train'?

Innovations in the structure and production methods of rail vehicles!

The 'A-train' is a rail vehicle system that has realized high grade and accurate vehicle production by adopting lightweight aluminum materials, eco-materials, and refurbishing its vehicle structure and production method. It was an endeavor unique to Hitachi that has rewritten the book of vehicle production and eco-activities.

Vehicles were manually made one by one in old times.

[Image] a tank-type steam locomotive in 1920

In 1964, the Tokyo Olympics were held and the country was caught up in a wave of excitement. Hitachi developed vehicles for the Tokaido Shinkansen, which was opened in time for the Olympics. Thus, the company has been an inseparable companion to the history of Japanese railway.

Hitachi has a long history of vehicle production, starting from the production of a tank-type steam locomotive in 1920^*. At that time, most rail vehicles were imported from Britain and a very small number of vehicles were designed and produced in Japan. These vehicles were 'fully handmade', being individually constructed.

The technical innovations of vehicle production were subsequently advanced to meet the needs of the times for faster and more comfortable railways.

'For future vehicles, it was especially important to give consideration to not only cost and efficiency but also to the environment through maintenance and recycling. From this viewpoint, new vehicle structures and production methods, and optimum eco-materials to achieve these, were selected and the 'A-train' was created', said Mr. Hirofumi Sakamoto, Chief Engineer, Vehicle System Design Department, Kasado Transportation Systems Division.

Hitachi developed the 'A-train' with a unique and new processing technology—the modular production system. 'A' in the 'A-train' is associated with 'Advanced', 'Amenity', 'Ability' and 'Aluminum'.

*The Kasado Shipyard, Nippon Kisen Co., Ltd., which started the production, became the Kasado Plant, Hitachi, Ltd. in 1921.

[Image] The 'A' in the 'A-train' stands for Advance, Amenity, Ability and Aluminum

[Image] A-train

To produce vehicles as industrial products.

[Image] The number of parts used reached into the tens of thousands! For the 'A-train', this number was greatly reduced to a hundred and several dozen-odd modules.

If you look at the recent trend in the materials used for railway vehicles, you may find that the mainstream material is lightweight aluminum, which is environmentally-friendly not only for bullet trains, but also for express trains. For commuter trains, stainless steel and aluminum materials are typically used, taking advantage of the merits of both metals.

On the other hand, there has been a major change in the production system. In the conventional vehicle production, we needed to complete a traditional process similar to the construction of wooden houses, such as building a foundation, providing supports, building walls and roof thatching. This required many experts to assemble a vehicle, because it was made up of tens of thousands of parts.

Chief Engineer Sakamoto explained enthusiastically, 'In the development of 'A-train', we aimed to produce vehicles which were as independent as possible from humans. In other words, this was a change in the thinking behind vehicle production from the conventional manual method to automatic production'.

Consequently, the structure that was a complex assembly of the tens of thousands of parts was changed to that consisting of just a hundred-odd modules. In addition, the body structure was changed from the wall plate structure with a single skin to a double-skin structure that did not need a frame. The 'A-train' allowed for vehicle production that was unprecedentedly efficient, by pursuing a simple structure thoroughly.

[Image] The vehicle structure was changed from single- to double-skin.

Sophisticated technology has been digitalized precisely

Further improvement of quality has been pursued in the development of 'A-train', by incorporating traditional expert workmen's techniques accumulated over the years into the next generation of production systems to produce higher grade and more accurate vehicles.

Chief Engineer Sakamoto said, 'The representative example is 3D machined processing to form the shape of the first car. For example, a computerized five-axis processing machine can quickly cut both sides of aluminum board tens of millimeters thick to make the curved surface, which used to be made by expert workers by beating out the board with a hammer'.

[Image] All we need to do is flip the switch? Computers recreate expert workmen's techniques! Highly accurate vehicle production has been realized without relying on experience or skills.

[Image] 3D machined processing

In addition, for the first time, Hitachi has put FSW^*, a revolutionary welding technology, into practical use for rail vehicles. The result is keeping the beautiful form with a slight skew even when the both side panels of the approximately 20-meter length vehicle, which are joined with the aluminum double-skin body structure. Moreover, paintless vehicles have been developed through joining the body without welding seams.

*FSW: Friction Stir Welding

The A-train has established a new vehicle production system.

Hitachi remains at the forefront for the creation of new vehicles in all times. As a result, the A-train has been developed with advanced technologies through the support of many people, resulting in a significantly improved delivery record.
'The A-train has a delivery record of 1,000 or more units, including the 10000-series of the Tokyo Metro, the TX2000-series of the Tsukuba Express and the 50000-series of the Tobu Railway', said Chief Engineer Sakamoto.

[Image] Aluminum is a lightweight and recycling-friendly eco-material! The 'A-train' is a next-generation aluminum vehicle system that meets the needs of the environment.

The new vehicle production system developed with the A-train has received a favorable evaluation, because of its reduction of lifecycle cost and maintenance load and the simplification of recycling achieved through the use of lightweight aluminum material. In addition, the cutting-edge FSW joining technology has allowed for a beautiful shape and form, and production efficiency has dramatically improved through modularization.

We believe in designing a system that will have the eternal affection of the public, because the vehicle will be used for public transportation that serves everyone. Hitachi's A-train will continue to evolve as a vehicle production system that will present the future role of vehicles and lead to the creation of new cultures.

[Image] A-train Basic Concept

The above diagram provides an overview of the 'A-train', an aluminum vehicle system for the next generation.

A-train Family

[Image] A-train Family

A-trains are operated not only in Japan but all over the world.

It has been decided to introduce the A-train to the vehicles of the Strait of Dover link rail line, which is now under construction for the London Olympics to be held in 2012 (Pictured left). This means that Hitachi's world's advanced technical capabilities and product reliability have finally been recognized in Britain, the birthplace of the railway. This introduction represents a milestone in the history of Japanese railways. In addition to this achievement, the A-train family has been introduced to monorails in Chongqing, China, and Sentosa Island in Singapore.

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