Ore Carriers

Medium and smaller bulk carriers (i.e. bulk  carriers from about 20,000 to about 40,000 dwt known as ‘handy size’) are also equally suitable for the carriage of steel, packaged lumber and bagged cargoes. An important consideration for owners of bulk  carriers is to decide whether or not to equip the ship with cargo gear, that is derricks or cranes mounted on deck to load and discharge the vessel.  On medium and small bulk carriers cargo gear increases their flexibility by enabling them to trade to places where shore facilities are not adequate.  By no means are all small bulkers so equipped but many certainly are, some modern 40,000 tonners having cranes capable of at least 25 tons safe working load (SWL).  Larger vessels seldom have their own gear as such ships tend to trade between modern cargo installations where loading is by shore gantry cranes with purpose-built devices such as spouts and discharge is by grabs or some other equipment designed for rapid unloading.  At such places, cargo gear mounted on the ship would simply get in the way. In certain dedicated trades vessels fitted with integral conveyor systems, so called “self-unloaders” are used. Ore Carriers. To some owners, the large bulk-carrier was too specialised whilst to others it was not specialised enough.  Amongst the latter were those shipowners who wished to tie themselves to the iron ore trade (some of these were divisions of the iron and steel groups) and for them the ore carriers were designed and built.  One may ask, why were they not content with the normal bulk-carrier?  The reason is that a bulk-carrier is built with enough cubic capacity to carry cargoes like grain and coal which require at least 45 cubic feet per ton weight of cargo.  This is of course far too much space for a heavy commodity like iron ore. Not only does a dense material like iron ore, only occupying the bottom half of the holds make a normal bulk carrier very ‘stiff’ but with a bulk-carrier one has simply built far more ship than is required.  There is no point in wasting all that steel providing space that will never be used.