Reefer ship

A reefer ship is a refrigerated cargo ship; a type of ship typically used to transport perishable commodities which require temperature-controlled transportation, such as fruit, meat, fish, vegetables, dairy products and other foods.

By 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. By 1874 they were shipping frozen beef from America to London, which developed into an annual tonnage of around 10,000 short tons (8,900 long tons; 9,100 t). 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 Le Frigorifique and Paraguay carried frozen mutton from Argentina to France, proving the concept of refrigerated ships, if not the economics. In 1879 the 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 Dunedin, 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 got cooler as it expanded, cooling the cargo in the hold. Using 3 tons of coal a day, this steam powered machine could chill the hold to 40 degF (22.2 degC) below the surrounding air temperature, freezing the cargo in the temperate climate of southern New Zealand, and then maintaining it below freezing (32 °F (0 °C)) through the tropics. The 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, the sailing ship Dunedin sailed from Port Chalmers New Zealand with 4331 mutton, 598 lamb and 22 pig carcasses, 246 kegs of butter, as well as hare, pheasant, turkey, chicken and 2226 sheep tongues and arrived in London UK after sailing 98 days with its cargo still frozen. After meeting all costs, The NZALC company made a £4700 profit from the voyage.

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