A rabbit warren layout is a model railway layout.[1] A group of designs, more than a single constructed layout, rabbit warrens provide a display of continuously moving trains that appear to pop in and out of tunnels, seemingly randomly.
The rabbit warren design has a number of key, defining features:
- Continuous running in a loop
- Tight radius horseshoe curves
- Much of the track is hidden by tunnels, with many openings.
- Climbing to more than one level, often by spiral tunnels, permits tracks to cross over each other.
They are based on a single running loop, although twisted into overlapping curves. The baseboard is small, typically 4 by 2 feet (1.22 m × 0.61 m), but a long running line fits in, owing to the curves. Their purpose is to show a continuously moving train, lurching from side to side across reverse curves, with unpredictable re-appearances from the tunnel mouths. Points are few, a single decorative siding, or a passing loop to allow two trains to be run in turn. Some layouts in the 1970s used the early transistorised control circuits then becoming available to run automatically, switching between trains as each entered the loop.