I've finally added dwarf signals at Eastleigh and Portsmouth container yards. In both cases they control exit from the yard tracks to the main line.
The models were kits, from a Chinese source via ebay. You get a plastic mounding and the LEDs; enough for 10 signals for £8 which was excellent value. Superglue holds the LEDs in. I've arranged the LEDs "back to back" so they only have 2 wires. With one polarity the green LED lights; the other way round the red LED lights.
The signals are controlled by SIGM20 boards as usual. The signal heads are programmed as "2 wire searchlight". Because they have no amber aspect, there is no "next signal" number programmed. For the signals at Eastleigh, the next signal should actually be a virtual (among other things to tell you if one of the 3 possible platforms ahead at Petersfield are occupied). Strictly I should add "signal 257 is red" to the "go red when" conditions.
The original plan had been to make some kind of searchlight signal from a red/green bicolour LED and a plastic block. The mouldings for these signal bodies made that ida daft. I've now ordered some 3 aspect versions for a 4 head signal gantry at Portsmouth.
