Flat wagons (sometimes
flat beds,
flats or
rail flats, US:
flatcars), as classified by the
International Union of Railways (UIC), are railway
goods wagons that have a flat, usually full-length, deck (or 2 decks on car transporters) and little or no superstructure. By contrast,
open wagons have high side and end walls and
covered goods wagons have a fixed roof and sides. Flat wagons are often designed for the transportation of goods that are not weather-sensitive. Some flat wagons are able to be covered completely by
tarpaulins or hoods and are therefore suitable for the transport of weather-sensitive goods. Unlike a "goods wagon with opening roof", the loading area of a flat is entirely open and accessible once the cover is removed.