A string of fiber-optic sensors running along a 36-km stretch of high-speed commuter railroad lines connecting Hong Kong to mainland China has taken more than 10 million measurements over the past few years in a demonstration that the system can help safeguard commuter trains and freight cars against accidents.
Attuned to the contact between trains and tracks, the sensors can detect potential problems like excessive vibrations, mechanical defects or speed and temperature anomalies. The system is wired to warn train operators immediately of such problems so that they can avoid derailments or other accidents, said Hwa-yaw Tam of the Hong Kong Polytechnic University, who will describe the technology and its test run next week at The Optical Society's (OSA) Annual Meeting, Frontiers in Optics (FiO) 2013, being held Oct. 6-10 in Orlando, Fla.
At least 30 times during the seven-year period, the system detected anomalous vibrations, Tam said. In a few cases, the vibrations turned out to be early warnings of dangerous emerging conditions that could have led to train wrecks. In some cases, vibration due to the use of the wrong type of lubrication oil in axle boxes was detected. The fiber-optic sensor system was designed for maintenance purposes and saves the rail company about $250,000 every year in maintenance costs.
"Using just this one type of technology, we are able to measure many things," Tam said. "This technology is perfect for railway systems." He added that it costs less than a third the price of other warning systems, which typically require data to be integrated from a half dozen different types of monitoring systems.
The system is now being installed in all commuter train routes in Hong Kong and will soon be rolled out in railways in parts of Singapore and Australia. With regular speeds for some of the trains in China topping out above 300 km per hour, the need for effective safety measures is profound, Tam said.
Worldwide, the rail industry is undergoing a major development boom, especially in places like China where tens of thousands of kilometers of new high-speed lines are planned for the next decade at an estimated cost of hundreds of billions of dollars.
How the System Works
The basis for the new sensor system is a technology developed in the 70s and 80s known as a Fiber Bragg grating, a type of sensor that reflects narrow spectra of light whose wavelengths shift due to temperature/strain variation. Coupling fiber Bragg gratings with another device known as mechanical transducers allows pressure, acceleration and other parameters to be measured.
The sensors are imbedded in mechanical compartments of a train or along the tracks. If there is a defect, like a sudden break in the rails or excessive vibrations because the weight of the train is off balance, those changes will alter the reflection spectra of FBGs in a detectable way.
The system is advantageous because it is all-optical, allowing the passive fiber Bragg grating sensors to monitor conditions along a train route, Tam said. It also relies exclusively on optical detection and communication, so there are no problems with electromagnetic interference from power lines that run parallel to many modern rail lines.
Presentation FW2I.3, "Distributed Optical Fiber Sensing Networks for Railway Monitoring," takes place Wednesday, Oct. 9 at 11:30 a.m. EDT at the Bonnet Creek Ballroom, Salon X at the Hilton Bonnet Creek in Orlando, Fla.
PRESS REGISTRATION: A press room for credentialed press and analysts will be located in the Hilton Bonnet Creek, Sunday through Thursday, Oct. 6-10. Those interested in obtaining a press badge for FiO should contact OSA's Lyndsay Meyer at 202.416.1435 or firstname.lastname@example.org.
About the Meeting
Frontiers in Optics (FiO) 2013 is the Optical Society's (OSA) 97th Annual Meeting and is being held together with Laser Science XXIX, the annual meeting of the American Physical Society (APS) Division of Laser Science (DLS). The two meetings unite the OSA and APS communities for five days of quality, cutting-edge presentations, fascinating invited speakers and a variety of special events spanning a broad range of topics in optics and photonics—the science of light—across the disciplines of physics, biology and chemistry. An exhibit floor featuring leading optics companies will further enhance the meeting. More information at http://www.FrontiersinOptics.org.
Founded in 1916, The Optical Society (OSA) is the leading professional society for scientists, engineers, students and business leaders who fuel discoveries, shape real-world applications and accelerate achievements in the science of light. Through world-renowned publications, meetings and membership programs, OSA provides quality research, inspired interactions and dedicated resources for its extensive global network of professionals in the optics and photonics field. For more information, visit http://www.osa.org.
Lyndsay Meyer | EurekAlert!
When AI and optoelectronics meet: Researchers take control of light properties
20.11.2018 | Institut national de la recherche scientifique - INRS
How to melt gold at room temperature
20.11.2018 | Chalmers University of Technology
Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.
Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
20.11.2018 | Life Sciences
20.11.2018 | Life Sciences
20.11.2018 | Physics and Astronomy