Ocean Vessels: Passenger, Cargo and Other Ships | Geography

Ships that sail the high seas are varied in their structure and capacity, but fall into three main groups: 1. Passenger Ships 2. Cargo Ships 3. Other Ships for Special Tasks.

1. Passenger Ships:

Passenger liners, once operated on routes all over the world and were the most prestigious vessels afloat. They were practically floating hotels, with comfortable cabins, luxurious dining-halls, ballrooms, shops, banks, cinemas and swimming-pools. They could carry up to 2,000 passengers and crew. Liners are mostly of moderate size but some of the largest are up to 100 000 tonnes. Speeds of over 54 k.p h./30 knots (nautical miles) are maintained.

Sea-borne passenger transport on scheduled routes is no longer important. Liners now account for only about 1 per cent of ships. Air transport has virtually taken over from shipping in passenger transport be­cause of its speed but liners still play a role in tourism.

Cruise ships take holidaymakers from North America and Europe south to warmer climates in winter, visiting a number of countries. All passenger ships normally engaged on the North Atlantic route are now used for cruises in winter, and passengers cannot cross the Atlantic except by air during the winter months.

Ocean liners are specially constructed for carrying passengers and mail, but there are other vessels which carry both passengers and freight, and are described as cargo-liners. Besides the cabins for passengers, there are cargo-holds and facilities for loading and dis­charging goods. Such cargo-liners are usually smaller in size and do not travel as fast as passenger shipping.

For short journeys, e.g. crossing straits or narrow seas, as between Dover and Calais across the English Channel, or Harwich and Hook of Holland across the North Sea, packets or ferry-boats are used. They are usually equipped with roll-on-roll-off facilities for cars and other vehicles. Other types of passenger vessels include the mail boat (for express mail and passenger conveyance), the steam-yacht (for pleasure trips) and military transport carriers (for the deploy­ment of troops).

2. Cargo Ships:

Ships of all sizes and structures transport cargo but the tramps or cargo-steamers (between 2,000 and 20,000 tonnes) are the most numerous. As with other ships they have increased in size; the average size has nearly doubled in the last decade. Cargo ships travel more slowly than liners and have no regular schedules for their voyages, stopping at many ports to take on fresh cargoes or discharge them.

Many vessels carry the cargoes of a particular company but there are others which carry practically anything as long as there is a demand for their services. Because of their great flexibility and fuel economy (they travel much slower and have more cargo-space due to their box-like structure), their freight charges are the lowest.

Most of the world’s low-valued, bulky goods: coal, cotton, rubber, copra, grains, timber, etc., are carried by cargo vessels. Many vessels are owned by shipping companies that direct their ships using wireless communications, to points where there are goods to be picked up. Long voyages in ballast (i.e. without cargo) are to be avoided to reduce losses.

The cost of cargo transport is affected by several factors. When cargoes are plentiful and shipping scarce, freight rates naturally rise and shipping com­panies make good profits. On the other hand, a recession in world trade leads to the reduction in freight rates to be competitive. Another factor which affects costs is the ease of handling of cargoes.

Where containers, i.e. standard-sized units packed with goods, are used, handling may be much improved, especially since the goods do not need to be unloaded separately at the port. The whole container, including the goods, can be transferred to a rail wagon or lorry of special design, and taken on to its inland destina­tion.

When cargoes are varied and packed in crates of various sizes or in sacks, bales or irregular-shaped boxes, handling is difficult, time-consuming and cost­ly. Not all cargo ships are capable of handling con­tainers but the investment in special container ships with container handling facilities at ports is worth­while in the long run because of great gains in effi­ciency, and long-term cost reductions.

General cargo ships are being increasingly replaced by specialized industrial carriers, constructed for spe­cific cargoes only. There are, of course, many com­modities which do not lend themselves to such transport—and these continue to be carried by general cargo ships.

Many of the specialized ships now in use are owned not by shipping companies but by the producers of the commodities which they carry. By far the most important industrial carriers are oil tankers. These tankers, which include some of the largest vessels afloat (between 30,000 tonnes and 400,000 tonnes) have numerous compartments sepa­rated by bulkheads as a safety precaution.

Oil has been the largest single commodity in world trade for many years, and to cut costs tankers have been built on an increasingly large scale. They now make up almost half the world’s merchant shipping. Liquefied natural gas is also carried in highly specialized vessels.

Other special carriers include colliers for shipping coal; whalebacks or grain-ships for the conveyance of wheat (the grain is handled like a liquid in loading or discharging at ports); banana carriers with chambers at controlled temperatures and with good cruising speeds to ensure prompt delivery; and refrigerator ships for the transport of fruits, meat and dairy prod­ucts.

Plying along the coasts are various kinds of smaller coasters: steamers, junks, barges and cargo-boats that handle the local transport of goods. Their importance has declined because of competition from the faster and more convenient railways and trucks.

3. Other Ships for Special Tasks:

Apart from the commercial carriers, the world’s high seas and coastal waters are also served by many other ships that per­form special tasks either in making the seas more sailable or assisting merchant shipping.

Examples of such vessels include the dredgers that deepen the coastal waters and river ports; tugs which help to manoeuvre larger ships; lighters used for loading or unloading in shallow waters; ice-breakers that open up frozen waters; salvage-ships and lifeboats that recover wrecked vessels or rescue seamen; pilot-boats to aid navigation and lightships which replace light­houses in some areas; cable-laying ships which lay undersea cables in oceans; research-ships with built-in laboratories for marine research; fishing vessels and whalers and their factory ships; police launches and marine boats that guard the sea-coasts; and the fleets of military vessels such as cruisers, destroyers, gun­boats, submarines, torpedo boats, corvettes, moni­tors, battleships and aircraft carriers.