Sawn Timber ships are unobstructed, box-type, square holds, with large hatch openings, being usually equipped with their own cargo-handling derricks or cranes. Thus, loading or discharging is speedily effected, and the vessels’ configurations enable them to carry containers in addition or as an alternative to packaged lumber. Carriage may also be effected by laden lorries on Ro/Ro Carriers – trailer carriers where port and infrastructure facilities and circumstances permit. Typical timber carriers and Ro/Ro vessels are pusposefuly build to carry this refrangible cargo. Length packaged lumber – sometimes known as flush-bundled – may be sawn into individual pieces of timber each of a particular length, stacked together in such a way as to provide a packaged unit of 32 pieces measuring approximately 50 cm (20″) by 60 cm (24″), secured by wire straps to keep it in one unit, and with flush ends butted neatly together. Such units may be shipped four together, giving overall measurements of 100 cm (40″) by 120 cm (48″) with, of course, flush ends, and complete with wire straps and loops to ease cargo handling. Truck packaged lumber is similar to length packaged in all respects, except that the lengths of each individual piece of timber vary, and so only one end of each bundle is flush, the other comprising variable lengths. The development of the timber market into length and truck packaged lumber has had a profound effect on the type of vessel employed in the carriage of this commodity.