An acronym standing for "roll-on-roll-off", referring to the method of loading the cargo on wheeled vehicles or trailers via ramps that lower onto the quayside. Sub types include dedicated vehicle carriers for transport of cars and other vehicles from the manufacturer to the distributor. Such ships can be large and there is no typical size. The characteristics of this ship type are large cargo volume and multiple internal decks. The complexity in building largely arises out of the complexity of the structure, the thin nature of the plate from which the ships are fabricated and sophisticated hydraulic ramps and other cargo loading systems.
First Marine International Limited, "Overview of the international commercial shipbuilding industry, Background report", disseminated on the Web site of Directorate-General "Enterprise and Industry" of the European Commission, May 2003