INTRO: When Madrid Metro extends Line 10 next year, trains will be able to run at shorter headways than is possible with the speed signalling in use today. This is achieved by avoiding the need for an empty ’zero speed’ block between following trains

BYLINE: David Gillan

Director, Business DevelopmentInvensys Rail Systems

MOST MODERN metros equipped with automatic train protection operate in one of three modes: speed signalling, distance-to-go or moving block. This applies regardless of whether manual or automatic driving is used, since it is a fundamental principle of ATO that a functionally independent ATP system must be installed to prevent any collision caused by wrong-side ATO failure.

Westinghouse Rail Systems Ltd and Dimetronic Signals, both members of Invensys Rail Systems (IRS), have developed TBS100, a transmission-based train control system capable of migrating between these three levels of operation. The objective is to maximise return on capital expenditure without constraining future capacity increases. Since 1968, WRSL and Dimetronic have supplied speed signalling-based ATP and ATO systems to London Underground (Victoria and Central lines), Hong Kong, Singapore, Beijing and Madrid.

Most Madrid Metro lines have automatic train operation, but Lines 9 and 10 are equipped with speed signalling using TBS100. At present, Line 10 runs from Fuencarral in the north of the city to Aluche in the southwest. It is currently being upgraded and extended by 8·3 km from Puerta de Bat