by Roll-on/roll-off (RORO or ro-ro) ships are cargo ships designed to carry wheeled cargo, such as cars, trucks, semi-trailer trucks, trailers, and railroad cars that are driven on and off the ship on their own wheels or using a platform vehicle, such as a self-propelled modular transporter. This is in contrast to lift-on/lift-off (LoLo) vessels, which use a crane to load and unload cargo.
RORO vessels have either built-in or shore-based ramps or ferry slips that allow the cargo to be efficiently rolled on and off the vessel when in port. While smaller ferries that operate across rivers and other short distances often have built-in ramps, the term RORO is generally reserved for large oceangoing vessels. The ramps and doors may be located in the stern, bow, or sides, or any combination thereof.
Description
Types of RORO vessels include ferries, cruiseferries, cargo ships, barges, and RoRo service for air deliveries. New automobiles that are transported by ship are often moved on a large type of RORO called a pure car carrier (PCC) or pure car/truck carrier (PCTC).
Elsewhere in the shipping industry, cargo is normally measured by the metric tonne, but RORO cargo is typically measured in lanes in metres (LIMs). This is calculated by multiplying the cargo length in metres by the number of decks and by its width in lanes (lane width differs from vessel to vessel, and there are several industry standards).
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 of the shipper.
- The ship has also proved extremely popular with holidaymakers 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 the sea with the help of a ro-ro vessel.
Roll-on/Roll-off Ships Stowage and Securing of Vehicles
Principal Sources of Danger
Though Ro-Ro vessel’s make a very small proportion of the Merchant marine tonnage, there have been many accidents involving these, giving rise to far worse consequences. It is very important to understand the “Sources of Danger “which leads to such petrifying situations. These sources of danger don’t only affect the safety of roll-on/roll-off vessels but also the passenger/crew in it.
- The unacceptable condition of the consignment constraining it to be properly lashed for Sea. Example: insufficient number and incorrect positioning of securing points, Weak securing points etc.
- The free surface effect in tank vehicles and tank containers which are slack;
- Poorly maintained ramps, lifts and bow and stern doors;
- Poorly maintained, inadequately illuminated or badly planned decks;
- Wet Decks;
- Vehicles being moved negligently on vehicle decks and ramps;
- The reversing of road vehicles on vehicle decks and ramps;
- Insufficient or incorrectly applied lashings or wrong use of Lashing equipment or of inadequate strength having regard to the mass and centre of gravity of the vehicle and the weather conditions likely to be encountered during the voyage;
- Free play in the suspension of vehicles;
Lighter Aboard Ship is the name of a type of vessel that carries standardised pushed barges. The pushed barges, that can weigh up to 600 tons when loaded, are loaded and unloaded by means of a heavy-duty gantry crane onboard the ship. Once the pushed barges are loaded in the water, they are interlinked to form major pushed convoys.
LASH vessels are used only in areas with large deltas (the Maas Delta, The Mississippi estuary) as the large pushed convoys can travel deep into the hinterland of these regions.
