Roll-on/roll-off

RoRo port in Jacksonville, Florida Types of RORO vessels include ferries, cruiseferries, cargo ships, barges, and RORO service for air/railway 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 tonnage or by the 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). On PCCs, cargo capacity is often measured in RT or RT43 units, based on a 1966 Toyota Corona, the first mass-produced car to be shipped in specialised car-carriers and used as the basis of RORO vessel size. One RT is approximately 4 m of lane space required to store a 1.5 m wide Toyota Corona. Cargo capacity may also be measured in car-equivalent units (CEU). The largest RORO passenger ferry is , a cruise ferry that entered service in September 2007 for Color Line. Built in Finland by Aker Finnyards, it is long and wide, and can carry 550 cars, or 1,270 lane meters of cargo. The RORO passenger ferry with the greatest car-carrying capacity is , owned by Irish Ferries. Ulysses entered service on 25 March 2001 and operates between Dublin and Holyhead. The 50,938 GT ship is long and wide, and can carry 1,342 cars/4,101 lane meters of cargo. File:Gran_Bretagna_Grimaldi_lines_2_of_2.jpg|Le Gran Bretagna de Grimaldi lines en mer Méditerranée le 13/04/2024 File:Roro faehre.jpg|M/S Tom Sawyer in Trelleborg File:FSRR FBQ 01.jpg|, a roll-on/roll-off train ferry operated between Coatzacoalcos and Mobile File:Ulysses Arriving In Dublin.jpg|ROPAX ferry, MS Ulysses, approaching Dublin Port, Ireland File:SuperSpeed 2.jpg|Fast ROPAX cruiseferry, MS SuperSpeed 2, between Larvik, Norway and Hirtshals, Denmark File:Queenscliff ferry terminal.jpg|Ferry terminal for the Peninsula Searoad Transport service, with cars leaving a ferry File:Magic_in_Oslo.JPG|The largest ro-ro passenger car ferry in the world, MS Color Magic, in Oslo, Norway File:BastøElectric.jpg|Bastø Fosen is a Norwegian ferry company that operates smaller ro-ro passenger car ferries on a short route between the towns of Horten and Moss in Norway. Car carriers The first cargo ships specially fitted for the transport of large quantities of cars came into service in the early 1960s. These ships still had their own loading gear and so-called hanging decks inside. They were, for example, chartered by the German Volkswagen AG to transport vehicles to the U.S. and Canada. During the 1970s, the market for exporting and importing cars increased dramatically and correspondingly also did the number and type of ROROs . In 1970 Japan's K Line built Toyota Maru No. 10, Japan's first pure car carrier, and in 1973 built European Highway, the largest pure car carrier (PCC) at that time, which carried 4,200 automobiles. Today's pure car carriers and their close cousins, the pure car/truck carrier (PCTC), are distinctive ships with a box-like superstructure running the entire length and breadth of the hull, fully enclosing the cargo. They typically have a stern ramp and a side ramp for dual loading of thousands of vehicles (such as cars, trucks, heavy machinery, tracked units, Mafi roll trailers, and loose statics), and extensive automatic fire control systems. The PCTC has liftable decks to increase vertical clearance, as well as heavier decks for "high-and-heavy" cargo. A 6,500-unit car ship, with 12 decks, can have three decks which can take cargo up to with liftable panels to increase clearance from on some decks. Lifting decks to accommodate higher cargo reduces the total capacity. These vessels can achieve a cruising speed of at eco-speed, while at full speed can achieve more than . , the largest LCTC was , the inaugural vessel of a planned class of twelve, each with a capacity of 9,100 CEU. Meanwhile, the Marine Design & Research Institute of China (MARIC) is developing a new vessel class with a capacity of 12,800 CEU. The design has received Approval in Principle (AiP) from Lloyd's Register, which was granted in June 2024. The car carrier , belonging to Nippon Yusen Kaisha, built in 2008 with a capacity of 6,200 cars, is the world's first partially solar-powered ship. File:Roll-On Roll-Off (RO-RO) ship, starboard ramp.jpg|A pure car carrier ship's starboard side showing side ramp File:MV Tønsberg R01.jpg|, a large car/truck carrier File:Cross Sound Ferry MV "John H" interior.jpg|Vehicle bay of John H, of Cross Sound Ferry J32 394 Split, MFS Petar Hektorović.jpg|The front of opens up, allowing cars to enter the vehicle bay. Seaworthiness The seagoing RORO car ferry, with large external doors close to the waterline and open vehicle decks with few internal bulkheads, has a reputation for being a high-risk design, to the point where the acronym is sometimes derisively expanded to "roll on/roll over". An improperly secured loading door can cause a ship to take on water and sink, as happened in 1987 with . Water sloshing on the vehicle deck can set up a free surface effect, making the ship unstable and causing it to capsize. Free surface water on the vehicle deck was determined by the court of inquiry to be the immediate cause of the 1968 capsize of in New Zealand. It also contributed to the wreck of . Despite these inherent risks, the very high freeboard raises the seaworthiness of these vessels. For example, the car carrier listed 60 degrees to its port side in 2006, but did not sink, since its high enclosed sides prevented water from entering. In late January 2016 was listing off France after cargo shifted on the ship. Salvage crews secured the vessel and it was hauled into the port of Bilbao, Spain. RORO variations armored vehicles carrying tractors ==History==

At first, wheeled vehicles carried as cargo on oceangoing ships were treated like any other cargo. Automobiles had their fuel tanks emptied and their batteries disconnected before being hoisted into the ship's hold, where they were chocked and secured. This process was tedious and difficult, and vehicles were subject to damage and could not be used for routine travel. An early roll-on/roll-off service was a train ferry, started in 1833 by the Monkland and Kirkintilloch Railway, which operated a wagon ferry on the Forth and Clyde Canal in Scotland. Invention in the world The first modern train ferry was , built in 1849. The Edinburgh, Leith and Newhaven Railway was formed in 1842 and the company wished to extend the East Coast Main Line further north to Dundee and Aberdeen. As bridge technology was not yet capable enough to provide adequate support for the crossing over the Firth of Forth, which was roughly across, a different solution had to be found, primarily for the transport of goods, where efficiency was key. The company hired the up-and-coming civil engineer Thomas Bouch who argued for a train ferry with a roll-on/roll-off mechanism to maximise the efficiency of the system. Ferries were to be custom-built, with railway lines and matching harbour facilities at both ends to allow the rolling stock to easily drive on and off. To compensate for the changing tides, adjustable ramps were positioned at the harbours and the gantry structure height was varied by moving it along the slipway. The wagons were loaded on and off with the use of stationary steam engines. to settle any dispute over priority of invention with the observation that "there was little merit in a simple conception of this kind, compared with a work practically carried out in all its details, and brought to perfection." The company was persuaded to install this train ferry service for the transportation of goods wagons across the Firth of Forth from Burntisland in Fife to Granton. The ferry itself was built by Thomas Grainger, a partner of the firm Grainger and Miller. The service commenced on 3 February 1850. It was called "The Floating Railway" and intended as a temporary measure until the railway could build a bridge, but this was not opened until 1890, its construction delayed in part by repercussions from the catastrophic failure of Thomas Bouch's Tay Rail Bridge. There were many advantages of the use of train-ferries over conventional shipping in World War I. It was much easier to move the large, heavy artillery and tanks that this kind of modern warfare required using train-ferries as opposed to repeated loading and unloading of cargo. By manufacturers loading tanks, guns and other heavy items for shipping to the front directly on to railway wagons, which could be shunted on to a train-ferry in England and then shunted directly on to the French railway network, with direct connections to the front lines, many man hours of unnecessary labour were avoided. An analysis done at the time found that to transport 1,000 tons of war material from the point of manufacture to the front by conventional means involved the use of 1,500 labourers, whereas when using train-ferries that number decreased to around 100 labourers. This was of utmost importance, as by 1918, the British railway companies were experiencing a severe shortage of labour with hundreds of thousands of skilled and unskilled labourers away fighting at the front. The increase of heavy traffic because of the war effort meant that economies and efficiency in transport had to be made wherever possible. The first purpose-built LST design was . It was a scaled down design from ideas penned by Winston Churchill. To carry 13 Churchill infantry tanks, 27 vehicles and nearly 200 men (in addition to the crew) at a speed of , it could not have the shallow draught that would have made for easy unloading. As a result, each of the three (Boxer, Bruiser, and Thruster) ordered in March 1941 had a very long ramp stowed behind the bow doors. In November 1941, a small delegation from the British Admiralty arrived in the United States to pool ideas with the United States Navy's Bureau of Ships with regard to development of ships and also including the possibility of building further Boxers in the United States. drive-on-drive-off using the train ferry. During the war British servicemen recognised the great potential of landing ships and craft. The idea was simple; if you could drive tanks, guns and lorries directly onto a ship and then drive them off at the other end directly onto a beach, then theoretically you could use the same landing craft to carry out the same operation in the civilian commercial market, providing there were reasonable port facilities. From this idea grew the worldwide roll-on/roll-off ferry industry of today. In the period between the wars Lieutenant Colonel Frank Bustard formed the Atlantic Steam Navigation Company (ASN), with a view to cheap transatlantic travel; this never materialised, but during the war he observed trials on Brighton Sands of an LST in 1943 when its peacetime capabilities were obvious. In early 1946 the company approached the Admiralty with a request to purchase three of these vessels. The Admiralty were unwilling to sell, but after negotiations agreed to let the ASN have the use of three vessels on bareboat charter at a rate of £13 6s 8d per day. These vessels were LSTs 3519, 3534, and 3512. They were renamed Empire Baltic, , and , perpetuating the name of White Star Line ships in combination with the "Empire" ship naming of vessels in government service during the war. On the morning of 11 September 1946 the first voyage of the Atlantic Steam Navigation Company took place when Empire Baltic sailed from Tilbury to Rotterdam with a full load of 64 vehicles for the Dutch Government. The original three LSTs were joined in 1948 by another vessel, , renamed Empire Doric, after the ASN were able to convince commercial operators to support the new route between Preston and the Northern Ireland port of Larne. The first sailing of this new route was on 21 May 1948 by Empire Cedric. After the inaugural sailing Empire Cedric continued on the Northern Ireland service, offering initially a twice-weekly service. Empire Cedric was the first vessel of the ASN fleet to hold a passenger certificate, and was allowed to carry fifty passengers. Thus Empire Cedric became the first vessel in the world to operate as a commercial/passenger roll-on/roll-off ferry, and the ASN became the first commercial company to offer this type of service. employ RORO systems. The first RORO service crossing the English Channel began from Dover in 1953. In 1954, the British Transport Commission (BTC) took over the ASN under the Labour Governments nationalization policy. In 1955 another two LSTs where chartered into the existing fleet, and , bringing the fleet strength to seven. The Hamburg service was terminated in 1955, and a new service was opened between Antwerp and Tilbury. The fleet of seven ships was to be split up with the usual three ships based at Tilbury and the others maintaining the Preston to Northern Ireland service. During late 1956, the entire fleet of ASN were taken over for use in the Mediterranean during the Suez Crisis, and the drive-on/drive-off services were not re-established until January 1957. At this point ASN were made responsible for the management of twelve Admiralty LST(3)s brought out of reserve as a result of the Suez Crisis too late to see service. s Further developments on or about 19 May 1982 The first roll-on/roll-off vessel that was purpose-built to transport loaded semi trucks was Searoad of Hyannis, which began operation in 1956. While modest in capacity, it could transport three semi trailers between Hyannis in Massachusetts and Nantucket Island, even in ice conditions. In 1957, the United States military issued a contract to the Sun Shipbuilding and Dry Dock Company in Chester, Pennsylvania, for the construction of a new type of motorized vehicle carrier. The ship, , had a stern ramp as well as interior ramps, which allowed cars to drive directly from the dock, onto the ship, and into place. Loading and unloading was sped up dramatically. Comet also had an adjustable chocking system for locking cars onto the decks and a ventilation system to remove exhaust gases that accumulate during vehicle loading. During the 1982 Falklands War, was requisitioned as an emergency aircraft and helicopter transport for British Hawker Siddeley Harrier STOVL fighter planes; one Harrier was kept fueled, armed, and ready to VTOL launch for emergency air protection against long range Argentine aircraft. Atlantic Conveyor was sunk by Argentine Exocet missiles after offloading the Harriers to proper aircraft carriers, but the vehicles and helicopters still aboard were lost. After the war, a concept called the shipborne containerized air-defense system (SCADS) proposed a modular system to quickly convert a large RORO into an emergency aircraft carrier with ski jump, fueling systems, radar, defensive missiles, munitions, crew quarters, and work spaces. The entire system could be installed in about 48 hours on a container ship or RORO, when needed for operations up to a month unsupplied. The system could quickly be removed and stored again when the conflict was over. The Soviet Union flying Yakovlev Yak-38 fighter aircraft also tested operations using the civilian RORO ships Agostinio Neto and Nikolai Cherkasov. ==See also==