Part 2 In-depth exploration of the eco aspects of the 'A-train'

Trains can be more eco-friendly!

'A-train' has attracted attention as a vehicle system with excellent conservation capabilities in regards to the global environment. However, how has it actually contributed to environmental conservation? In fact, it is full of considerations for the global environment, from the use of aluminum materials to its vehicle body structure, and efficiencies in energy-saving, maintenance and recycling.

Aluminum is a representative eco-material.

While trains themselves are excellent in the conservation of the environment, with smaller energy consumption and less CO2 emissions, the 'A-train' is aiming to further offer more eco-friendly vehicles familiar to more people, and has adopted this lightweight eco-material for its vehicle body.

The energy consumption during running has been largely reduced thanks to the decreased weight of the vehicles. This also allows the train to respond to the acceleration of operating speed smoothly. In addition, the lightweight aluminum material makes maintenance work, including mounting and demounting of parts, easier. Furthermore, the realization of paintless bodies has freed the A-train from the negative health impact of organic solvent.

[Image] Aluminum vehicle bodies are... Light and tough, easy to process and easy to recycle.

[Image] Inside the aluminum body A-train

If the 'A-trains' currently in use are scrapped, they will be dismantled and changed to materials to produce new aluminum vehicles. All the aluminum waste generated during the production process has been collected and recycled.

[Image] Eco-friendliness unique to aluminum vehicles

Modularization has made design work smoother!

[Image] Do not waste resources! Recognize the customer's request with eco-friendly ideas. Offering the necessary functions with a combination of modules.

For the 'A-train', the double-skin structure^*2 in which aluminum materials are used for hollow extrusions^*1, including the outer panel, frame and inside panel has been adopted. In addition, the high production efficiency was achieved by combining the use of FSW (Friction Stir Welding)^*3, an innovative joining technology.

Interiors for which individual parts have been mounted previously now consist of several assemblies of parts (i.e. modules) separated by functions such as the driver's platform, toilet and front modules.

The assembly and renewal construction will become much easier through this modular construction. The acceleration of vehicle production has been achieved without the need for the assembly of a lot of parts, as pre-assembled parts are mounted into the preset ceiling and side panels.

As a result of module construction, a simple assembly method has brought eco-friendly ideas like 'Do not waste resources' and 'High generality and easier maintenance' into life. This also provides advantages in responding to customer requests regarding design. Necessary functions are then enabled by the combination of modules.

[Image] Basic structure of 'A-train' made up of modules

Global Warming Prevention and Promotion of Energy-saving Consumption

For the 'A-train', an eco-friendly approach is further promoted as part of its status as a railway vehicle system excelling in environmental conservation. Its progress knows no bounds. In the development, underfloor equipment, which has never before been focused on in vehicle production, has been highlighted from the viewpoint of ecology.

For the main circuit, a IGBT inverter control equipment with high energy-saving capability and reliability is used. State-of-the-art technology that can make the most of electric energy has achieved optimum control.

[Image] Driving stand of A-train

[Image] A-train is the leader of trains for 'Eco'! It has superior ability for achieving the conservation of the global environment and the pursuit of better energy saving performance.

For the air conditioning system, to create a more comfortable in-vehicle environment, a series of devices using new refrigerant that does not have an impact on the ozone layer have been adopted. 'A-train' is a rail vehicle system combining comfort and careful consideration to the global environment.

Riding experience report on the A-train

[Image] A-train

The noise and vibration did not bother me much.
The sophisticated driving is comfortable.

The A-train that entered the platform of the 'Shinkiba' station of the Yurakucho Line, Tokyo Metro had a futuristic appearance that made people understand that it was a new model vehicle at once. Its unique orange color, rounded front panel and seamless side panels are all shining, as they have been polished.

The vehicle interior is bright thanks to the big windows, and passengers can see the interior of the next vehicle clearly, because the doors at the car coupling section are made with clear glass. Moreover, roomy space under the seats provides an open atmosphere to the car interior.
The train left the Shinkiba station on time. It started running smoothly and the noise and vibration did not bother me much. I would emphasize that I could enjoy an astonishingly comfortable journey on the train, though it was for just 12 minutes between the Shinkiba and Yurakucho stations.

*1: Hollow extrusions
Molding materials, including hollow parts, which are difficult to produce, and products with a complex cross-section shape or with a shape that needs very high dimensional accuracy, are made by extrusion in a single operation.
The extrusion process allows for the continuous production of products with complex shapes, because it does not require processes such as welding and bending.
*2: Double-skin structure
Hollow extruded molding materials feature a diagonal rib (a reinforcement material) between two plates. The vehicle body will have two plates inside and outside after assembling these components. This is called the 'double-skin structure.'
*3: FSW (Friction Stir Welding)
Pressing the joining section of the tip of tool that rotates like a drill with stirring heat against the joining parts of aluminum softens it. Then, the softened aluminum becomes like clay. The heat will cool down after the tool is removed and the joining will be completed when the joining part returns to a firm state.

FSW：Friction Stir Welding