On track: remote monitoring and artificial intelligence ensure more efficient railway systems along belt and road routes
Fibre optic sensors placed on key points and moving parts throughout trains collect data which is transformed into information and then knowledge in a three-stage process
Exciting new green technologies are blossoming along the “new Silk Road”, raising spirits at a time when a climate sceptic is in the White House. Rail is a crucial mode of transport in China – which, in 2015, had 121,000km of railway tracks, the second longest network in the world.
It is also popular with the environmental lobby because energy is produced at a safe distance, but smart technologies make it greener. The economies of scale of the massive roll-out led to cost savings. Remote monitoring and artificial intelligence ensure that systems can run more efficiently, and with large energy savings. New materials are making trains lighter and more fuel-efficient.
“You can be clever about how you control trains,” says Clive Roberts, professor of railway systems at Birmingham University, one of the leading centres of excellence for railway engineering in Britain. Roberts has worked on improving reliability, punctuality and energy efficiency with smart technologies for 20 years.
Roberts describes how fibre-optic sensors placed on key points and moving parts throughout trains collect data which is transformed into information and then knowledge in a three-stage process, through analysis with artificial intelligence. This results in significant energy savings.
Monitoring systems now detect when parts are wearing out so they can be replaced before they do so, avoiding service failures and reducing down time for locomotives.
Software is increasingly used to calculate the most energy efficient train driving techniques and patterns, driving trains automatically while calculating how best to accelerate and decelerate, according to track and locomotive distribution. Automated optimal driving trajectories optimise energy consumption and network capacity usage, by reducing the safety margins required between trains to allow for variation in driving of humans. Power production is now spread throughout the carriages, with driving instructions from the front automatically replicated by “slave locomotives”. When leaves or debris cause wheels to slip on the track, sensors reduce power until a wheel connects with a track again.
Signalling has become more efficient by moving from the track to the cab. According to Professor Toby Jenkins of Bath University, in-cab signalling has several advantages; there is less external infrastructure - no need for “lights on sticks”, more importantly it allows for a dynamic system where trains all know where others are so that the number of trains using a stretch of track at one time can be increased.
Conventional signalling used “blocks” where only one train can occupy a block at a time. In-cab signalling creates virtual blocks which can be much smaller allowing higher capacity. This is important on high-density networks. Regenerative brakes can recover much of a slowing train’s kinetic energy and convert it back into electrical energy.
High-speed rail has triggered a wave of innovation , according to a London School of Economics and Political Science discussion paper by Lin Yatang, Qin Yu and Xie Zhuan, which describes a 20 per cent increase in patent applications after 2004, when high-speed technology from Europe began.
Many of the technologies – from engines, dynamos and electricity transmissions to railway signal control systems – have applications separate from the high-speed-rail system with great potential for technology “spillovers”. The report shows a cascade of patent applications in research areas related to high speed rail technologies. Hong Kong’s Polytechnic University has contributed to this wave with its optical sensor technology, which provides information on vibration, acceleration and temperature change for engineering staff, helping them to monitor the condition of tracks and rail cars.
The rail revolution continues, as faster train technology emerges; speeds of 700km/h to 3,000km/h are promised for vacuum-tube technology. They reduce air resistance to the levels of our upper atmosphere.
Tesla’s Elon Musk says these “will produce more energy than they consume”, by absorbing solar power along the length of the track. Sceptics point out the risks – a 600km tube would need 60,000 expansion joints, and a failure in just one would result in instant death for everyone travelling in the tube.
by Toby Jenkins