NR SSIDIS108 ISSUE 4 PDF

Purpose of paper

To discuss a SSI version of the hardware application and changes to the monitoring on the Technician's Terminal for the new Fibre Optic signal range from Bombardier, specifically for use at Ladbroke Grove. This document is limited purely to the application of the new Fibre Optic signal range which is being used as a direct replacement for the traditional multiple aspect Colour Light Signal (CLS), Full size Fibre Optic Alpha Numeric Route Indicators and PLJI. These signals separate the lamps and associated electrical equipment from the optical arrangements allowing the latter low maintenance head unit to be smaller and located closer to driver's eye level, and closer to the OLE than a Technician can get without an isolation. The Fibre Optic Colour Light Signal displays red, yellow and green through the same lens, as in a conventional searchlight signal. There are no 4 aspect applications on this scheme. There are no flashing aspects on these signals within this scheme, and the dark proving would need re-visiting before using any.

There are 2 types of Route Indicator, an alpha numeric replacement for the ‘Standard' full size Alpha Numeric Route Indicator (Theatre MLRI or older style FORI) which uses a single lamp for each route, and a Fibre Optic Junction Route Indicator [FOJRI] displaying arrows, as a replacement for the conventional PLJI, which uses 2 lamps for each route with a changeover relay. There are no Miniature Alpha Numeric Route Indicators involved. This document was prepared on the basis that Ladbroke Grove would utilise the FOJRI but it is now intended to use the "like 4 like" LED PLJI from Dorman instead.

The mechanism of using a low value external resistor in the current proving path in place of the resistor within the module is also suitable, subject to choosing a suitable resistor, for other applications that draw more current than the standard loads catered for by the TFM's internal resistors