China has tested a rail system that links multiple freight trains through a wireless system rather than physical coupling.
On Monday, a test conducted on the Baoshen Railway in Inner Mongolia saw seven freight trains with a combined cargo capacity of 35,000 tonnes – 3½ times the weight of the Eiffel Tower – running together much more closely than would be usually required when they travel as single units.
The technology could increase China’s railway freight transport capacity by more than 50 per cent without the need to put down new rail lines, state broadcaster CCTV said on Monday.
The group control system was developed by the state-owned coal mining enterprise China Shenhua Energy Company and other domestic organisations.
China has been expanding its railway cargo capacity over the decades and moved more than 3 billion tonnes of cargo in the first three quarters of this year, according to state-run newspaper China Daily.
It is also boosting its rail links to other countries, with services such as the China Railway Express offering connections to dozens of nations in Europe and Asia as well as carrying goods.
Building new rail lines to meet growing cargo demands is costly, so measures such as increasing the length of trains or shortening the intervals between train running times could save money, according to a paper published two years ago in the journal Mathematics by researchers from Central South University in Changsha, Hunan province.
In the latest test, the trains – each carrying 5,000 tonnes of freight – travelled in a convoy at a dynamically managed distance, which state media said used a control system that relied on wireless signals and no mechanical coupling.
This allowed the trains to accelerate and brake without collisions or separations, according to CCTV. The report added that this also reduced the braking distance needed between the trains.
In conventional railway operations, trains are required to run at a certain distance apart for safety reasons. Heavier, longer trains – particularly freight trains – and trains moving at higher speeds tend to require a longer braking distance.
However, the virtual coupling tested in China may allow this distance to be shortened by helping the trains adapt dynamically to changes in speed.
The technology could allow for more trains to operate without the need for new lines or building technically challenging heavy-haul single freight trains.
China Shenhua Energy, a subsidiary of the state-owned mining and energy company CHN Energy, has gradually been working towards this feat, testing two lighter rail convoys earlier this year.
“Leveraging train-to-ground and train-to-train communication, the technology employs a two-dimensional control mode integrating relative speed and absolute distance, enabling dynamic close-formation operations,” CHN Energy said in August.
Their technology may also help increase a railway station’s “throat capacity” – the maximum number of trains its entry and exit area can handle. It also made China the world’s first country to “master group train operation control systems,” CHN Energy said in August. -- SOUTH CHINA MORNING POST
