Hopper Car 2 : A rail car, open or covered, with the floor sloping from the ends and sides to one or more pockets or hopper openings on the underside of the car to permit self unloading of bulk commodities
Ilan Kelman (ed.), Vulnerability and Resilience Definitions and References, Version 2, 2007. http://www.islandvulnerability.org/docs/vulnres.pd f, (Vulnr and Resilience - Brit) {524}