Signals

Semaphore Signals in Scales from 2mm to 7mm to the foot.

Servo operation, with or without simulated bounce is also possible as well as installing working lights where feasible.

There are also options for jig-built laddering etc and additional detail.

A few notes on construction:

Other Signal Parts:

4mm scale Alan Gibson Workshop, Wizard Models, Modelu, Scalelink
7mm scale Wizard Models Modelu Scale Signal Supply
2 and 3mm scales Wizard Models, Modelu
Working Lamps - I use warm white SMD LEDs (0603), the smallest I can easily get in - they fit in all lamp castings for 7mm and 4mm scale. Even Modelu 2mm scale GWR lamps can just about fit the smallest LED (0402). LEDS are fitted with 1K protective resistors (normally smd) type, They can be wired into the servo leads if required.
Servo Boards of your choice. Each have their strengths and weaknesses. (Megapoints, MERG - Members only, Heathcote, Uhlenbrock, etc)
Gantries can also be supplied but costs vary depending on availability, scale and specification.
Fibre optic cable can be for lighting but prefer not to if I can avoid it. The problems with it are that, it is easily damaged by handling, contact with paint, solvents or adhesives. The amount of light transmitted is less but sometimes it is the only viable option.