Railbus

A railbus is a lightweight railway vehicle designed to carry passengers on lightly used lines where a full-size train is not economically viable. The term covers both purpose-built rail units with bus-like bodies and vehicles that place a bus-style body on a rail underframe. Railbuses are usually single- or twin-car units with simplified propulsion and equipment intended to lower purchase and operating costs and reduce axle load on lighter track.

Design and propulsion: Railbuses can be diesel-powered, electric, or hybrid, using various transmissions such as diesel-hydraulic or electric traction. The emphasis is on inexpensive manufacture and easy maintenance, with interiors often arranged for flexible seating and accessible boarding.

Operation and history: The concept arose in the early 20th century to maintain service on marginal routes. It saw substantial use in Europe after World War II on branch lines and rural networks, where it offered an economical alternative to full-length trains. Over time many railbuses were replaced by more capable diesel multiple units, but some lines continue to operate light-rail vehicles, and several heritage railways preserve railbus-type designs.