coach

A coach is a carriage designed and built specifically to carry fare-paying passengers over distance. In modern rail systems, a coach is either hauled by a separate locomotive or forms one unit in a powered multiple-unit train. Unlike a locomotive, a coach has no engine or driving mechanism of its own; its only function is to provide seating, standing room, and shelter for travelers.

Coaches vary widely by service type and era. A suburban commuter coach may have 80 to 120 seats arranged in rows with minimal legroom, while a long-distance coach typically seats 50 to 80 passengers with wider spacing, tables, and better climate control. Sleeper coaches, fitted with berths instead of seats, serve overnight routes. Mail coaches and parcels coaches are built to similar specs but carry freight instead of passengers. On freight trains, the term coach is rare; those vehicles are called wagons or cars.

Construction and weight

A coach body is typically steel or aluminum alloy welded to a steel underframe. It rides on two bogies, each with four or six wheels, which allows it to distribute weight and navigate curves smoothly. An empty coach weighs between 30 and 50 tonnes depending on length and materials; loaded weight can reach 60 to 70 tonnes. The vehicles are connected by coupler couplings (usually screw couplings on older stock, automatic couplers on newer trains) that transmit pulling force and carry brake pipes and electrical lines between units.

The term coach comes from the Hungarian city of Kocs, where a style of suspended passenger carriage was developed in the 16th century. In North America, the equivalent term is often car or passenger car; in some European contexts, carriage remains standard. The distinction matters: a coach is purpose-built for rail, whereas a carriage historically referred to horse-drawn vehicles adapted to rail.

Common faults in aging coaches include brake rigging wear, bogie frame cracks from metal fatigue, and deteriorated suspension springs. Water ingress through roof seams or around window frames is persistent; coaches operating in wet climates require regular maintenance of roof and side panels. Most coaches in regular service are overhauled or replaced after 25 to 40 years of operation, though heritage railways operate vehicles well over a century old.