in length, has accommodations for 3,250 passengers, and a crew of 1,000.

The White Star Line has even larger vessels than the Cunard Company. In 1910 it launched the Olympic, which is 852 feet 5 inches long, and has a gross register tonnage of 46,359 tons. In 1914 this company launched the Britannic, which also was 852 feet 5 inches, but registered 47,500 tons gross. This vessel had nine decks, on six of which accommodation was provided for 2,600 passengers.

The Hamburg-American Line owns several vessels which are even larger than those of its British rivals. In 1912 it launched the Imperator, which registers 51,969 tons gross, and has a length of 882 feet 9 inches, 11 decks, accommodations for 4,000 passengers, and a crew of 1,100. In 1913 it launched the Vaterland, which registers 54,282 tons gross, is 907 feet 6 inches long, and is manned by a crew of 1,234 men; and in 1914 it launched the Bismarck, which is 912 feet long and registers 56,000 tons gross. The Bismarck is the largest vessel yet constructed. A composite view of the progress which has been made in ship construction during the past century may be had from the following drawing of the recent

Growth of Size of Ocean Vessels in One Hundred Years The smallest vessel in the group is the Dreadnaught, a clipper ship dating from the beginning of the nineteenth century. Then follow the Borussia, a side wheeler; the Britannia, Arizona, Oceanic, first greyhounds, and the Vaterland. exhibit of the United States War Department at the Panama Pacific Exposition.

1 Her sister ship, the Titanic, which was launched in 1911, struck an iceberg and sank April 14, 1912.

REFERENCES

CHAPTER III

THE CLASSIFICATION OF STEAMERS BY

STRUCTURE AND SERVICE

Steamships grouped by service, 35. Express liners, 35. Combination liners, 35. Cargo liners, 36. Cargo steamers or tramps, 36. Steamships grouped by deck arrangements, 36. Two-deck cargo vessels, 37. Three-deckers, 39. Spar-deck vessels, 39. Awningdeck vessels, 39. Shelter-deck vessels, 39. Four-deckers and larger vessels, 39. Shade-deck vessels, 41. Turret vessels, 42. Trunk steamers, 42. Whale-back steamers, 42. Self-trimming vessels, 43. Tank steamers, 43. Steam schooners, 44. References, 46. SEAGOING Steamships may be classified in various ways. They may be grouped according to the manner in which their power of propulsion is applied; according to the kind of engines with which they are equipped; according to the kind of material used in the construction of their hulls; and according to the manner in which they are equipped for the conduct of their services.

STEAMSHIPS GROUPED BY SERVICE

The last of these methods of classifying steamships practically results in grouping them according to their uses or the kind of service which they perform. It is a common practice, from this standpoint, to group ocean steamships as follows: (1) Mail and passenger steamships or "express liners," which have but a relatively small cargo space, and carry mainly passengers, mail, express goods and high-class freight; and (2) passenger and cargo steamships or "combination. liners," which have a relatively larger cargo space and, in addition to the passengers, mail, express goods and high-class freight on board, endeavor also to carry much bulky freight, such as grain, cotton, iron and steel goods and foodstuffs. The distinction between these two types of vessels is not always clear, but the two together comprise the world's deep

sea passenger carrying steamers, and, as compared with other vessels on a given route, are known for their speed, size, beauty, luxurious equipment and the regularity with which they operate on fixed routes and schedules. (3) Fast cargo steamships or "cargo liners" are vessels which carry cargo exclusively, but nevertheless operate over definite routes on fixed schedules. They are adapted to the carriage of the many different kinds of freight which move over their routes in less than ship-load lots, are frequently built for the particular trade in which they engage, and include many of the world's best built, fastest and most efficiently operated freighters. (4) Ordinary cargo steamers or "tramps" include the great number of freighters which, acting as common carriers, transport a large share of the world's low-grade bulky freightespecially that which moves in ship-load lots. "They are boats of full form, rarely exceeding 375 feet in length, of a speed varying from 8 to 10 knots and ready to go anywhere to pick up any sort of cargo." 1 (5) In addition to the passenger or general cargo carrying steamships mentioned above, there are numerous specialized steamships, i.e., vessels constructed and used largely for the transportation of some special kind of freight. Many of the steamers used to transport oil, iron ore, coal and lumber, for example, constitute distinct types of craft. Many of these vessels are owned and operated by large industrial concerns, directly in connection with their respective industries.2

STEAMSHIPS GROUPED BY DECK ARRANGEMENTS

Steamships may also be classified according to the number and arrangement of their decks and their above-deck or super

structures.

Small freight vessels have two decks, medium-sized freight and passenger ships have three decks, while larger freight vessels and 1 National Foreign Trade Council, Ocean Shipping, 10 (2d ed., March, 1917).

2 See pp. 152, 275.

those carrying both freight and passengers usually have four (or more) full decks, above which there may be one or more decks extending less than the full length of the vessel and inclosing successive tiers of superstructures. In vessels having more than one deck, the main deck is the second deck from the bottom of the vessel. When there are three decks they are designated lower, main (or middle), and upper deck. If there are four full decks, the fourth deck is generally called the shelter deck, above which there may be a bridge deck, and a promenade deck, or bridge, promenade, and boat decks. The decks above the shelter deck do not extend the full length of the hull.1

In practice one or more decks may be omitted in a vessel without affecting its classification as a two-, three-, or fourdecked vessel. Its classification depends upon whether or not the space between the decks actually constructed is sufficiently wide to come within the requirements of Lloyd's or other recognized marine underwriting associations, i.e., whether it has the equivalent of two, three or four, or other stated number of full-length decks.

Among the simplest of seagoing steamships are the relatively small two-decked cargo vessels which have two fulllength decks, a lower and main deck, above which the three. most usual superstructures—the forecastle, bridge, and poop -are placed. In many instances, however, the main deck from abaft the bridge to the stern is raised four or five feet, so as to increase the capacity of the after cargo hold and prevent the loaded vessel from trimming to the bow. Such a vessel is known as a "raised quarter-decker." The bridge, moreover, is often extended and brought nearer to the forecastle, thus creating a so-called "well" between the bridge and forecastle, which in case of heavy weather is awash. Vessels of this type are commonly known as "well-decked steamers." (See illustration, p. 38.) When the main deck forward of the bridge is raised so as to increase the freeboard and reduce the shipping of water, the vessel is called a "raised foredecker."

1 E. R. Johnson, Measurement of Vessels for the Panama Canal, 15.