Here is a helpful diagram showing three basic types of funiculars. The earliest ones were four rail (two track) funiculars, but they are the costliest to build because rails are expensive, they take up a lot of space, and they need double stations. More advanced three rail funiculars are less expensive but a little harder to build because they require a passing switch. The least expensive is the modern two rail funicular. They use less iron rails, don’t need double stations, and occupy less real estate, but have the harder to build passing switch. This unique type of funicular was invented in 1890 by Swiss engineer Carl Roman Abt (1850–1933) for the Giessbach Hotel funicular which is still in operation. It was made possible by his innovative and revolutionary ABT passing switch - the only railroad switch without any moving parts! Abt called it the “automatic turnout” solution. It became an instant success and most funiculars constructed afterwards use the ABT design to this day