Ro-ro is an acronym for Roll-on/roll-off. Roll-on/roll-off ships are vessels that are used to carry wheeled cargo. The ro-ro ship is different from lo-lo (lift on-lift off) ship that uses a crane to load the cargo. The vehicles in the ship are loaded and unloaded by means of built-in ramps. Normally these ramps are made towards the stern (backside) of the ship. In some ships, they are also found on the bow side (front) as well as the sides. The vessel can be of both military and civilian types.
Ro-ro vessels were being built in the 19th century to transport trains, too wide for the bridges, across rivers. An example of a ro-ro vessel is the Firth of Forth ferry which started operations in 1851. The rails were laid on the ship so that it could be connected to the ones on land. A train would then simply roll onto the ship and then roll off at the other end.
There are various types of ro-ro vessels, such as ferries, cruise ferries, cargo ships, and barges. The ro-ro vessels that are exclusively used for transporting cars and trucks across oceans are known as Pure Car Carriers (PCC) and Pure Truck & Car Carriers (PCTC) respectively. Unlike other cargos that are measured in metric tonnes, the ro-ro cargo is measured in a unit called lanes in meters (LIMs). LIM is calculated by multiplying cargo length in meters by the number of decks and by its width in lanes. The lane width will differ from vessel to vessel and there are a number of industry standards.
The largest ro-ro passenger ferry is MS Color Magic. It weighs 75,100 GT (Gross Ton). It entered the service in September 2007 for Color Line. It was built in Finland by Aker Finnyards. The ferry is 223.70 m long, 35 m wide and can carry 550 cars as well as 1270 lane meters of cargo.
The ro-ro passenger ferry with the greatest car-carrying capacity is the Ulysses. The ferry was named after a novel by James Joyce and is owned by Irish Ferries. It entered the service on 25 March 2001 and operates between Dublin and Holyhead. It weighs 50,938 GT and is 209.02 m long and 31.84 m wide. It can carry 1342 cars and 4101 lane meters of cargo.
Advantages of a ro-ro ship
A ro-ro ship offers a number of advantages over traditional ships. Some of the advantages are as follows:
- For the shipper, the advantage is speed. Since cars and lorries can drive straight on to the ship at one port and then drive off at the other port within a few minutes of the ship docking, it saves a lot of time of the shipper.
- It can also integrate well with other transport development, such as containers. The use of Customs-sealed units has enabled frontiers to be crossed with the minimum of delay. Therefore, it increases the speed and efficiency for the shipper.
- The ship has also proved extremely popular with holiday makers and private car owners. It has significantly contributed to the growth of tourism. A person can take his car from one country to another by sea with the help of a ro-ro vessel.
Variations of a ro-ro ship
The certain variations of a ro-ro ship are as follows:
ROPAX is an acronym for roll on/roll off passenger. It is a ro-ro vessel built for freight vehicle transport with passenger accommodation. The vessels with facilities for more than 500 passengers are often referred to as cruise ferries.
The ConRo vessel is a hybrid between a ro-ro and a container ship. This type of vessel uses the area below the decks for vehicle storage while stacking containerized freight on the top of the decks.
RoLo is an acronym for roll-on lift-off vessel. It is also a hybrid vessel type with ramps serving vehicle decks but the other cargo decks are accessible only by crane.
References: encyclopedia, imo