By Rhea Wessel
May 6, 2009—
Radio frequency identification is being employed to track the maintenance of escalators used by passengers of the London Underground subway system. Once the application is completely rolled out, at the end of 2010, some 30,000 tags will be attached to the steps of 200 escalators. If an escalator suddenly ceases running during rush hour, those aboard it can be seriously injured by the crowd. The application helps improve escalator safety via providing a more efficient maintenance process.
Before
RFID was implemented, workers had to identify a step by visually reading its ID number prior to performing required annual safety checks or removing an escalator step for repair. To do so, they had to stop an escalator, then read the number written on a metal
tag attached to each individual step until turning the belt to the correct step that needed to be inspected or repaired. It could take hours to locate the desired step, and the work was best performed when the escalators were not used heavily by the Underground's 3 million passengers. This raised the cost of maintenance, as the process was lengthy and conducted during off-hours, when workers must be paid more for their time.
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The underside of each escalator step is fitted with an Ironside EPC Gen 2 RFID tag from Confidex.
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Now, with RFID, maintenance workers utilize a handheld
interrogator placed into a cradle attached to the escalator's frame. The cradle is used to ensure that the
reader is positioned correctly to interrogate the tags in one escalator rotation, and also allows an engineer to carry on with other tasks. It takes approximately 45 minutes to identify every step on an escalator, depending on its length. In the past, workers spent a five-hour night shift manually identifying escalator steps.
The project to outfit escalator steps with RFID began with a trial that ran from September to November 2008. The trial, held at the St. Paul's tube station, was conducted by project integrator
Core RFID Ltd., based in the U.K. city of Warrington. The solution included Core RFID's Step Tracking System software,
Nordic ID's PL3000 handheld computers with built-in RFID interrogators and
Confidex's Ironside EPC Gen 2 RFID tags, attached to the underside of the steps with acrylic adhesive.