Dry-cargo ships are divided into the following classes: general cargo ships, bulk cargo ships (ore carriers, coal carriers, grain carriers), container's ships, timber carriers; refrigerators.
Tankers usually carry liquid cargoes such as oil products, spirits, wine, fresh water and the like. In some cases the tankers may carry grain and sugar in their tanks. Besides there are special vessels which do auxiliary service. They are tugs for towing ships, salvage vessels, icebreakers, dredgers, barges and lighters, fishing and whaling vessels.
Sea-going vessels are also classed according to the kind of propelling machinery into:
motorvessels, steamships, turbine-driven ships, electric-driven ships (turbine-electric ships and diesel-electric ships) and atomic- driven ships.
Let's consider one of typical vessels and its principal parameters. For example, a typical bulk-carrier usually carries grain, ore and the like bulk cargoes. The ship is divided by seven watertight bulkheads into eight compartments. Cargo handling is accomplished by grabs from 5-ton electric rotating cranes. The holds are closed with Mac-Gregor hatch covers. On board ship there are two lifeboats with manually-operated propeller drive. Each boat has a carrying capacity of 49 men. The living quarters are centrally-heated and air-conditioned. The engine develops 5400 h.p. at 115 r.p.m.
The main parameters are as follows (for example):
Length ... 139.5 m
Breadth ...18m
Depth ... 10,3 m
Hold capacity ... 12 000 cu. m.
Ore draught (8980 tons) ...8m
Coal draught (8630 tons) ... 7.82 m
Ballast draught:
Forward ... 3.4 m
Aft ... 5.61 m
Operating range ... 6 000 nautical miles
Displacement 4 200 tons
Deadweight... 12 800 tons
Speed .. . 14.3 knots
Crew ... 37
