Ocean Trade Routes

Abstract

HE statement that half of the shipping of the world is engaged regularly in the North Atlantic is received by most people with frank incredulity; yet in truth it is not far from the facts, as is shown by recent studies of the U. S. Department of Commerce. A map showing tracks for full-powered steam vessels is often interpreted as indicating the relative importance of the ocean trade routes of the world, and such maps are nearly always given in commercial geographies and books on shipping. The density of traffic over the main ocean tracks is something usually guessed at. A ship plying regularly between scheduled foreign ports is called a by the general public and by Kipling felicitously a lady. In equally picturesque phraseology the drab general-cargo vessel has come to be known as a tramp. The ocean-borne trade of the world is carried in these two kinds of vessels. Liners ply between terminals almost as regularly as railroad trains. Tramps,. in contrast, have no fixed routes or regular sailing schedules. They go from port to port wherever cargo offers. The demand for ship tonnage varies because of the seasonal nature of crops and the needs of commerce. Steamships in liner trades are operated by their corporate owners; tramp ships are operated by their owners or, most frequently, are offered for hire to anyone who desires to move a shipload of cargo at one time. The distinction between the tramp ship and the liner is chiefly in regularity of employment. Structurally each type merges into the other with respect both to speed and size. The liner furnishes service in times both of prosperity and depression. The tramp ship serves two general public purposes. It acts as a regulator of ocean freight rates at times and places where the demand for transportation exceeds the facilities offered by liners. It is the drudge of the seas, carrying the dirty and cumbersome cargoes which have great weight or bulk in proportion to value. The total weight of the ocean-borne cargoes carried in the world's foreign and colonial trades has never been exactly stated, because so many articles and standards enter into the computation and because the methods and periods, on which the returns of governments are based, vary. A committee of the British Board of Trade in I916-1917, after careful computations, estimated that the total volume of the world's sea-borne commerce in 1912 probably amounted to between