DEVELOPMENT OF TRAIN SPACING EQUIPMENT IN THE PARIS UNDERGROUND

In this article the authors, who are respectively Divisional Chief Engineer and Assistant Chief Engineer, Research Department, at the Paris Transport Authority (RATP), set out the principles that have governed the construction of all underground railways right from the outset because of the very nature of the traffic they are designed to carry. Although there has been very little change in these principles, technical progress and alterations in the pattern of traffic, particularly in respect of higher density, have brought about developments which the authors explain, as well as the improvements introduced progressively; they conclude by reviewing the future with special emphasis on technology and signalling policy.