A railroad crane (North America: crane car or wrecker; UK: breakdown crane) is a type of crane used on a railroad for one of three primary purposes: freight handling in goods yards, permanent way (PW) maintenance, and accident recovery work. Although the design differs according to the type of work, the basic configuration is similar in all cases: a rotating crane body is mounted on a sturdy chassis fitted with flanged wheels. The body supports the jib (UK; North America: boom) and provides all the lifting and operating mechanisms; on larger cranes, an operator's cabin is usually provided. The chassis is fitted with buffing (UK) and/or coupling gear to allow the crane to be moved by a locomotive, although many are also self-propelled to allow limited movement about a work site.