Type D trackside signals

The lights in each signal head are arranged in a vertical line.
Each light is a different color.
Older type D signals have a small visor over each light. Modern signal heads have a large continuous hood (snow shield) that protects all the lights.

 Type G trackside signals

The lights of each signal head are arranged in a triangle on a circular 'target.'
Each light is a different color.
These are sometimes referred to as 'tri-light' signal heads.

 Type SA searchlight signals

Each head of a searchlight signal has a single lamp in the center of a round 'target.'
In the full-size signals a movable filter inside the head changes the signal color.
Today's scale models of searchlight signals use tiny LEDs to produce the green, yellow and red colors.

 Position-light signals, PRR and B&O

These are called 'position light' signals because the position of the lights conveys information, just as the position of a semaphore blade does.
The Pennsylvania Railroad developed signals with all amber-colored lights.
The Baltimore & Ohio Railroad combined color with position in their signal system. These are called 'color position light' signals, or 'CPL' signals.

 Ground level dwarf signals

Dwarf signals are low-height signals mainly used at stations and rail yards.
A 2-color dwarf signal can be used to indicate the position of a turnout.
They take on quite a variety of forms -- vertical, position light or searchlight.

 Signal bridges

Place signals over multiple parallel tracks.
Often found at a control point.

 Semaphore trackside signals

Lighted semaphore signals with moveable blade.
Find out what it takes to operate a semaphore automatically here.

Block signals in other scales  >>>  O scale   S scale  N scale