Key Token Signalling for the 21st Century

Grahame Taylor
Conference Day Two
Session: Innovation & Future Development (1), reserve paper
This paper outlines the development of the Networked Digital Key Token System, or NDKTS, that couples 21st century electronics with the principles of traditional, physical key token working.

Simple single line railways, for which sophisticated signalling is not an option, may have passing loops but may not have the personnel nor signalling infrastructure to operate them. Even if conventional token machines are available, then these can require cabling between machines and, most importantly, offer no operating flexibility. Thus train running is tied to fixed timetables and cannot react to passenger expectations, or perturbations of rolling stock performance.

NDKTS, having been developed from scratch, has given the opportunity to use as many Components Of The Shelf (COTS) as possible. Bespoke locks are assembled from stock items with just a few specialist components, all of which can be made using conventional machining.

It has been designed for railways with a mixed, transient rolling stock for which permanent in-cab signalling is inappropriate. This paper will outline the background to the project, the key design considerations that have affected it and the process of evolution from prototype to a marketable product.