Vessels & Containers
Roll on, Roll off vessels and their Cargoes
Roll on, roll off vessels (ROROs) operate across oceans not just short shipping routes like the English Channel. The ocean going ROROs are much larger and than their namesakes we see around our coasts operating as car ferries. Often they carry a combination of shipping containers, in the cellular section of the ship (that part specifically designed and dedicated to the carriage of containers) trailer loads and other cargo. Deck space is often used to carry containers and heavy or abnormal loads. Often up to five tiers of containers are carried on deck.
Abnormal or heavy cargoes sometimes weighing hundreds of tonnes may also be carried on the RORO decks on special cradles or sledges and moved by heavy haulage vehicles. These huge loads look small within the cavernous Cargo spaces of the RORO decks.
The spaces are divided into smaller compartments by moving bulk heads (water tight walls) and even ceilings when Cargoes have been loaded and secured in place. Typically a transatlantic RORO will carry motor vehicles on the car decks, large plant and earth moving equipment, generators, fabrications, structures, large pleasure craft, heavy steel panels and anything that is too big or too heavy to be shipped in a shipping container.
Containers an their Cargoes
All manner of Cargo, providing it is not too large or too heavy, can be carried in a Cargo container.
A Cargo container is a box that is designed to protect a Cargo from the elements; it is not a 'safe'. They are made of steel, aluminium or GRP although at first glance they all look the same. Some containers are fully enclosed though others have curtain sides or tops to facilitate special loading/ unloading requirements. Containers have wooden floors and a weight limit of less than 30 tonnes.
Containers come in a variety of types, depending on their roles, ones used for carrying fruit and vegetables are 'Ventilated' and allow a circulation of air, whilst frozen or temperature controlled Cargoes are carried in 'Refrigerated' containers, which need to be connected to an electricity supply.
A container load on a 'door to door' basis means that container is 'stuffed' (Cargo loaded into it) by the shipper (the sender of the Cargo) and continues its transit through to final destination where it is "stripped" (emptied) by the consignee (receiver of the Cargo). This means the Cargo is not handled during the transit and there is a reduced risk of theft, pilferage and handling damage.
Containers are seldom locked but numbered security seals of good quality should be affixed to the doors and recorded on the transit documentation these will ensure that any tampering to the container is evident by examination of the seal at each stage of the voyage.