Rack railway and Railway

Rack railway noun - Railway for steep mountains; a cogwheel on the locomotive engages cogs on a center rail to provide traction.

Railway and rack railway are semantically related. In some cases you can use "Railway" instead a noun phrase "Rack railway".

Railway noun - A roadway overlaid with parallel steel rails over which trains travel.

Rack railway and railway are semantically related. Sometimes you can replace phrase "Rack railway" with "Railway", this terms are similar.