- Selective Door Opening/Correct Side Door Enabling
On-board train control systems play an essential role in safety within modern railway infrastructure; and to a large degree this safety has to be afforded irrespective of the age of the rolling stock and of the stations they serve. Such systems need to meet a variety of operator and regulatory requirements, and one in particular became important with the advent of powered doors.
These reduce the amount of time trains stop at stations and improve passenger safety. However, whether opened by or for passengers, the operating doors must be on the platform side of the train: a requirement that has given rise to the term Correct Side Door Enabling (CSDE). However, it is not simply a case of enabling all doors on one side of the train or the other. Many trains are longer than some of the platforms they serve, and accommodating this has given rise to the term Selective Door Operation (SDO).
At a fundamental level, CSDE requires knowledge of which side of the train the platform is on and SDO requires knowledge of how many doors should be opened. Hima-Sella’s solution for conveying the knowledge for both is through the wireless transfer of data, from platform to train, using its Tracklink product; which was first launched in 1996 and is now in its third generation.
Tracklink III comprises two key elements for the transfer of data, namely: a passive tag for storing data relevant to a platform; and a train-mounted reader for reading that data. The ‘passive’ aspect of the tag relates to the fact that it is a beam-powered Radio Frequency ID (RFID) device. It requires no power cable or batteries.
Mounting of the tag can be either platform invert or between the running rails and is dependent on application and clients preference. London Underground have chosen to mount on the Platform invert and Network rail have chosen to mount in the 4-foot.
SDO and CSDE operations using Tracklink III have been implemented on London Underground, London Overground and South West Trains.