The system that measures the system

Abstract

This paper deals with the introduction of acceleration measurement techniques on the Central Line of London Underground. It focuses initially on a series of tests that looked at both rolling stock performance using the Macminder system and track performance using the Mactrack system. Development of the systems use is tracked and integration with the in house automated video inspection system is explained. This initial work underpinned the asset renewal strategy during the mid to late nineties thus meeting the challenge presented in meeting a step change in train operations, moving from 27 trains per hour (TPH) to 33 TPH. The combination of both Mactrack and AVI techniques produces a very powerful tool this is discussed with the combining of the two on a ‘look only’ basis. This led on to the adoption of the system as a key to the prioritisation tool for the maintenance effort as well as long-term renewals planning. The system is now used on an eight weekly cycle and is seen as complementary to track recording vehicle (TRV) data, allowing the maintainer to accurately target the maintenance effort thus steadily improving the overall track standard deviation value. This paper is unusual in that it not only deals with a key system interface track/train but considers the practical application of such a system and relates four years of practical experience in support of the conclusions drawn. The future development requirement is also considered with the limitations of the system recognised.