Twin-deck bullet trains to ease congestion

China may have come up with a solution to capacity problems on its high-speed bullet trains: simply add another floor. The double-deck fleet will be rolled out to haul more passengers in comfort and style during peak travel seasons like the chunyun, or the Chinese New Year rush.

Engineers told Xinhua that these new, chubby-looking trains would also feature more spacious coaches and could still speed at up to 350 kilometers per hour despite the bigger passenger loads.

Zhang Weihua, a professor with the Chengdu-based Southwest Jiaotong University, told the state-run Science and Technology Daily that there were no major technical hurdles in adding another floor, though design changes would be needed in power distribution and wheels.

The newspaper said one challenge would be how to offset centrifugal forces when the heavier carriages made sharp turns on tracks without passengers on the upper floor experiencing motion sickness. However, Zhang said this could be overcome by lowering the center of gravity of each carriage.

Busy trunk routes running through eastern and southern China, including lines linking Beijing and Shanghai, Shanghai and Ningbo, Shanghai and Nanjing and Guangzhou and Shenzhen, which are also among the most profitable on the network, may be among the first to trial the double-deckers.

It isn’t the first time China has used double-deck trains: one consisting of two locomotives and four bilevel carriages was built back in 1958.

The most obvious benefit is to reduce congestion, but it will also lower operating costs per passenger without requiring costly new infrastructure such as extended platforms for longer trains, extra tracks or upgrades in signaling and safety equipment so more frequent services can be run.

Euroduplex, made by the French rolling stock and rail equipment manufacturer Alstom, is currently the only double-deck carriage in commercial service that can hit the 300 km/h mark. Thanks to its two-floor configuration, an eight-car Euroduplex can carry more than 1,200 passengers through France, Germany, Switzerland, Spain and Luxembourg, 40% more than the capacity of a single-decker of equivalent length and gauge.

Hong Kong’s MTR operates standard double-deck, cross-boundary intercity trains between cities in Guangdong province, using rolling stock  manufactured by Kinki Sharyo in Japan.