Reefer ship
A reefer ship is a refrigerated cargo ship typically used to transport perishable cargo, which require temperature-controlled handling, such as fruits, meat, vegetables, dairy products, and similar items. Description. "Types of reefers:" Reefer ships may be categorised into three types: A major use of refrigerated cargo hold type ships was for the transportation of bananas and frozen meat, but most of these ships have been partly replaced by refrigerated containers that have a refrigeration system attached to the rear end of the container. While on a ship these containers are plugged into an electrical outlet (typically 440  VAC) that ties into the ship's power generation. Refrigerated container ships are not limited by the number of refrigeration containers they can carry, unlike other container ships which may be limited in their number of refrigeration outlets or have insufficient generator capacity. Each reefer container unit is typically designed with a stand-alone electrical circuit and has its own breaker switch that allows it to be connected and disconnected as required. In principle each individual unit could be repaired while the ship was still underway. Refrigerated cargo is a key part of the income for some shipping companies. On  multi-purpose ships, refrigerated containers are mostly carried above deck, as they have to be checked for proper operation. Also, a major part of the refrigeration system (such as a compressor) may fail, which would have to be replaced or unplugged quickly in the event of a fire. Modern container vessels stow the reefer containers in cellguides with adjacent inspection walkways that enable reefer containers to be carried in the holds as well as on the deck. Modern refrigerated container vessels are designed to incorporate a water-cooling system for containers stowed under deck. This does not replace the refrigeration  system but facilitates cooling down of the external machinery. Containers stowed on the exposed upper deck are air-cooled, while those under deck are water-cooled. The water cooling design allows capacity loads of refrigerated containers under deck as it enables the dissipation of the high amount of heat they generate. This system draws fresh water from the ship's water supply, which in turn transfers the heat through heat exchangers to the abundantly available sea water. There are also refrigeration systems that have two compressors for very precise and low-temperature operations, such as transporting a container of blood  to a war zone. Cargoes of shrimp, asparagus, caviar and blood are considered among the most expensive refrigerated items. Bananas, fruit and meat have historically been the main cargo of refrigerated ships. History of ship refrigeration. In 1869, reefers were shipping beef carcasses frozen in a salt-ice mixture from Indianola, Texas, to New Orleans, Louisiana, to be served in hospitals, hotels, and restaurants. In 1874, shipping of frozen beef from America to London had already begun, which developed into an annual tonnage of around . The insulated cargo space was cooled by ice, which was loaded on departure. The success  of this method was limited by insulation, loading techniques, ice block size, distance and climate. The first attempt to ship refrigerated meat was made when the "Northam" sailed from Australia to the UK in 1876. The refrigeration machinery broke down en route and the cargo was lost. In 1877, the steamers "Frigorifique" and "Paraguay" carried frozen mutton from Argentina to France, proving the concept of refrigerated ships, if not the economics. In 1879, "Strathleven", equipped with compression refrigeration, sailed successfully from Sydney to the UK with 40 tons of frozen beef and mutton as a small part of her cargo . The clipper sailing ship , owned by the New Zealand and Australian Land Company (NZALC), was refitted in 1881 with a Bell-Coleman compression refrigeration machine. This steam-powered freezer unit worked by compressing air, then releasing it into the hold of the ship. The expanding air absorbed heat as it expanded, cooling the cargo in the hold. Using three tons of coal a day, this steam powered machine could chill the hold to below the surrounding air temperature, freezing the cargo in the temperate climate of southern New Zealand, and then maintaining it below freezing () through the tropics. "Dunedin"s most  visible sign of being an unusual ship was the funnel for the refrigeration plant placed between her fore and main masts (sometimes leading her to be mistaken for a steamship which had been common since the 1840s). In February 1882, "Dunedin" sailed from Port Chalmers New Zealand with 4,331 mutton, 598 lamb and 22 pig carcasses, 246 kegs of butter, and hare, pheasant, turkey, chicken and 2,226 sheep tongues and arrived in London after sailing 98 days with its cargo still frozen. After meeting all costs, the NZALC company made a £4,700 profit from the voyage. Soon after "Dunedin"s  successful voyage, an extensive frozen meat trade from New Zealand and Australia to the UK was developed with over 16 different refrigerated and passenger refrigerated ships built or refitted by 1900 in Scotland and Northern England shipyards for this trade. Within 5 years, 172 shipments of frozen meat were sent from New Zealand to the United Kingdom. Refrigerated shipping also led to a broader meat and dairy boom in Australia, New Zealand and Argentina. Frozen meat and dairy exports continued to form the backbone of New Zealand's. As of 2012, New Zealand has no refrigerated cargo ships. The Nelson  brothers, butchers in County Meath, Ireland, started shipping extensive live beef shipments to Liverpool, England. They successfully expanded their beef business until their imports from Ireland were insufficient to supply their rapidly growing business and Nelson decided to investigate the possibility of importing meat from Argentina. The first refrigerated ship they bought was "Spindrift" which they renamed in 1890 SS "Highland Scot". A vessel of 3,060 gross tons bought by James Nelson and Sons in 1889 and fitted with a somewhat primitive refrigerating plant operating on the cold air system became one of the pioneer vessels in the trade of  refrigerated meat and other perishable commodities. They hauled beef carcasses from Argentina to Britain. Their regularly scheduled shipments and ships developed into the Nelson Line that was formed in 1880 for the meat trade from Argentina to UK. Refrigeration made it possible to import meat from the United States, New Zealand, Argentina and Australia. All of their ships had a "Highland" first name. The Nelson Line began passenger service in 1910 between London, England and Buenos Aires and in 1913 came under control of the Royal Mail Steam Packet Company. In 1932, Royal Mail Group collapsed, Royal Mail Lines, Ltd.  was founded, and Nelson Lines merged into the new company. United Fruit Company reefer ships. The United Fruit Company has used some type of reefers, often combined with cruise ship passenger accommodations, since about 1889. Because of their cargo was mostly bananas, they were nicknamed the "Banana Fleet". Since bananas are relatively light and the normal shipping route was to Central America and then back to various U.S. ports, these ships were often built as combination cargo ships and what are now called cruise ships to pay for more of their operating expenses. After about 1910, they called these combination  cruise and cargo ships the "Great White Fleet". To avoid US shipping regulations and taxes they are registered in about six other countries, with very few now maintaining US registry. European associates with their own ships were often employed to ship fruit to Europe. United Brands was taken over by Chiquita Brands International in the 1980s and owns the largest fleet of banana boats in the world, but none of them now sails under the US flag. SS "Pastores" and SS "Calamares" were built in Ireland in 1912 and 1913 for the United Fruit Company as a combination cruise ship  and refrigerated cargo ship. The United Fruit Company's fleet of about 85 ships was one of the largest civilian fleets in the world. These ships normally carried up to 95 cruise ship passengers and a crew to ports in Central America and then would return to the United States with passengers and a cargo of refrigerated bananas and miscellaneous cargo. They were part of United Fruit's "Great White Fleet"—to minimize heat build-up the ships were all painted white. The renamed and were taken over by the United States Navy in World War I and used to take  troops and refrigerated supplies to and from Europe. After hostilities ceased they were returned to United Fruit Company in 1919. They were requisitioned again on 2 June 1941 from United Fruit for use in World War II. After hostilities ceased they were then returned again to United Fruit Company in 1946. Reefers in U.S. Navy service. World War I. In World War I, the US Navy contracted for 18 refrigerated ships for hauling provisions to the troops in Europe. They were launched 1918 and 1919 as the war was ending and were nearly all scrapped by 1933 in the Great  Depression as an economy move. Most were built in Baltimore Dry Dock in Baltimore, Maryland, Moore SB in Oakland, California and Standard SB Co. in Shooter's Island, New York. World War II. The s were six United Fruit passenger and refrigerated cargo liners built in 1931–1933 that the United States Maritime Commission requisitioned in 1941–1942. They were USS "Antigua", , , , and . "Antigua", although requisitioned, was never commissioned into the Navy. United States Maritime Commission Type R ship were Reefer ships. NOTE: also requisitioned from the United Fruit Co. was SS "Ulua"; which became . It was the last of the UFC  'reefer' ships to be taken over; which happened near the end of April 1943 in San Francisco. Other "reefers" converted for US Navy use were the Danish ships , and . In addition, the US Maritime Commission ordered 41 new refrigerated ships for the Navy. Because of the difficulty of building refrigerated ships only two were delivered in 1944. 26 were delivered in 1945 and the remainder in 1946–1948. Worldwide service. According to the CIA's "The World Factbook", there were about 38,000 registered merchant ships in the world in 2010, of which about 920 were designed as refrigerated cargo ships. Because  of the proliferation of self-contained refrigerated container systems on container ships, there are many more ships than those designed for only refrigerated cargo that are also carrying some refrigerated cargo. As of 2010, the countries with the largest numbers of reefer ships in their registries are the world's two most prominent flags of convenience: Panama with 212 and Liberia with 109.