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[By Admiral C. S. Sperry, U. S. Navy.]

In discussing the proper development of commercial harbors and their facilities and the symmetrical development of the tributary internal waterway systems, it is advisable to consider, first, the development of the ocean carrier which is in progress and the conditions by which it is governed, recollecting that the same conditions do not govern the development of vessels navigating sheltered and narrow inland waters or rivers with strong currents and sharp bends. River boats and light-draft barges of great beam, singly or in tows, can navigate such waters more safely and economically than a vessel built on the lines of an ocean carrier.

The necessary characteristics of the most economical ocean carrier can not be better stated than by quoting from a paper on "Maritime commerce, past, present, future," by Elmer Lawrence Corthell, M. A. Dr. Sc., civil engineer, read before the American Association for the Advancement of Science, August, 1898:

Draft of water for the steamships of the present and future is the desideratum to which urgent attention should be called by all those who desire the continued development of commerce and the still further cheapening of transportation and a greater reduction in prices.

I can not state this important condition that confronts us any better than in the words of one of the leading naval architects of the world, Dr. Francis Elgar, the consulting naval architect of the Great Fairfield works on the Clyde, and the designer of the Campania and Lucania. In a paper entitled "Fast ocean steamships," read before the Institution of Naval Architects in 1893, not long after these ships were built, he used these words (the italics are our own):

"Deep draft of water. This is a most important element of speed at sea, and it is now strictly limited by the depth of water in the ports and docks used by the fast passenger steamers on both sides of the Atlantic. Twenty-seven feet is the extreme limit of depth to which a ship can load on either side. The Campania can not load an inch deeper than the Umbria, although she is 100 feet longer. If the underwater dimensions of Campania had been increased proportionately to those of Umbria her draft of water would have been 32 feet. This class of steamer is increasing in length and breadth, but the draft of water has to be kept the same. The result is that it is only a question of time, and not of a very long time with our present materials of construction and type of propulsive machinery, to find an absolute limit of speed imposed by the restriction of draft of water.

It is not only that the present limited draft of water will finally impose an absolute limit of speed, other conditions remaining the same, but it has already a very prejudicial effect in keeping down speed at the point actually reached. If the draft were not restricted, the form of section could not be improved by giving to it more rise of bilge and an easier curvature.

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"As the displacement is increased by increase of draft, the power required to drive a ton of displacement at a given speed becomes reduced. Hence increase of draft does not mean a proportionate increase of engine power, even when such increase is obtained merely by extra immersion without any improvement of form such as would otherwise be possible.

"The advantages of increased draft would be felt still more in a seaway than in smooth water, as the lower part of the hull would be less affected by the wave surface and better and more constant immersion could be given to the propellers.


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"The Atlantic trade is increasing at such a rapid rate that larger and swifter ships are certain to be soon called for. The depth of water has lately been somewhat increased at Liverpool; but much deeper harbors and docks will be required if further great increases of speed at sea are to be obtained without excessive difficulty and



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"The opinion of practical navigators and of commercial men handling large vessels is that the inability to provide the depth of channels and harbors necessary to increase the draft of large freight carriers is very detrimental to good navigation and economical transportation.

"As vessels increase in size they have to be built as flat as possible to allow them to enter the harbors, which injures their sea-going qualities and renders them more dangerous and unwieldly, as well as more liable to injury from their shape


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It appears from these statements that, as the displacement of an ocean carrier is augmented by increasing the draft and other dimensions symmetrically, the power required to drive a ton of displacement at a given speed is reduced, which lessens the necessary expenditure for coal and operating force per ton of cargo carried. A modern ocean carrier of 5,000 tons displacement requires 1,000 indicated horsepower to drive her at a speed of 10 knots, and a carrier of the same type symmetrically enlarged to 10,000 tons displacement requires only 1,587 horsepower to drive her at the same speed; that is, the cargo-carrying capacity is doubled at the same speed with an increase of little more than 50 per cent for fuel. The increased expense for labor is less than 1 per cent and the superiority of the large carrier in adverse weather is very marked. A small light-draft steamer in rough water is thrown about by every wave; her way is deadened by pitching into a heavy sea and her engines are always in danger of breaking down, owing to the racing of the propellor as her stern rises out of the water. Consider also that both the small ship and her cargo are liable to serious damage by heavy rolling and the shipping of water on her low decks, and the reason why the tonnage of the ocean carrier increases so steadily and keeps so close to the available depth of water at the harbor entrance is sufficiently apparent.

Lloyds Register of British Shipping shows that in 1893-94 there were only 87 steamers of and above 5,000 tons, while in 1908–9 there were 599, and during the same period the steamers of 3,000 tons and above 2,000 tons decreased in number from 1,277 in 1893-94 to 1,013 in 1908-9. The eagerness with which the size of steamers follows the available depth of water is shown by the fact that the White Star Line is now building the Olympic and Titanic, with a draft of 37 feet on a displacement of 60,000 tons, to take advantage of the new 40-foot channel into the port of New York.

The report of the Chief of Engineers, United States Army, 1907, states that the lowering of freight rates at Boston during the last 15 or 20 years has been about 50 per cent, and that the deepening of the harbor of Savannah has lowered the rates at that port from 30 to 50 per cent. A memorandum supplied by the Savannah Chamber of Commerce in November, 1909, states that the increase in the size of ships at that port, owing to the increase of the depth of the channel to. 22 feet at low water, has been 40 per cent in the last 10 years, and that during the same period marine insurance has fallen 25 per cent and freight rates 37 per cent.

The very great economy of the large ocean carrier sufficiently explains the activity with which such great ports as New York, Liverpool, London, Shanghai, and a host of lesser ports are being improved

the world over, while the great ship canals, Suez and Kiel, are being steadily deepened; but it is evident that long lines of canals, or even such rivers as the Amazon and the Yangtse, owing to the great labor involved, can not be improved commensurately, and therefore the most economical long-distance ocean carriers can never use them. Nor, conversely, can even the largest of the vessels using our inland waters, deepen and improve the waterways as we may, ever navigate the high seas economically or safely as compared to an ocean carrier of to-day of even moderate proportions.

Certain artificial waterways will always be used even though the size of vessels navigating them may be, to a certain extent, limited, and to this class belong the Suez and Panama Canals.

The Suez Canal, 87 miles in length, shortens the route for the vast commerce from northern and western Europe to Calcutta by 3,700 miles and to Hongkong by 3,300 miles, as compared to the routes by the Cape of Good Hope and the Straits of Sunda; and although vessels now using the canal are limited to a draft of 28 feet the canal is being deepened to take vessels drawing 31 feet, and even the greater economy of the larger freighter will not justify the expense of the longer voyage around the Cape. The same conditions make it certain that the Panama Canal, 49 miles long, with a designed depth of 41 feet, will be used by ocean carriers. The west coast of South America is in the same longitude as the Atlantic seaboard of the United States, and, with trifling deflections about Cuba, the course from New York to Callao is nearly a straight line. From New York to Callao via the Panama Canal the distance is 3,400 miles. From the entrance to the English Channel to Callao by the same route it is 6,500 miles. From the channel to Callao via the Straits of Magellan it is 10,100 miles. From New York to San Francisco via Panama the distance is 8,050 miles less than via the Straits of Magellan. The trade route for large carriers from Europe to Valparaiso may continue through the Straits of Magellan, because of the great ports of call on the east coast of South America, but the trade of the northern ports on the west coast will inevitably pass through the canal, and that short and cheap route for vessels of the largest class must develop a great trade between the east coast of the United States and the west coast of South America. The fertilizer nitrates and other products of the coast should come north in exchange for the lumber, manufactured cotton, and other goods and coal of the Atlantic States.

The considerations which force the use of the Suez and Panama Canals are manifest.

The Kaiser-Wilhelm, or Kiel Canal, connects the North Sea with the Baltic, and is 53 miles in length. The saving in distance for vessels bound from the English Channel to the Baltic is about 200 miles and the navigation of the narrow waters about Denmark is avoided. The canal can now take vessels of the largest class, but is being still further deepened in view of the increasing size of war vessels. The principal motives of the German Government in building the canal were undoubtedly military and strategic, the commercial aspect being incidental. The least depth of water encountered by vessels passing into the Baltic through the Great Belt, or route to the north and east of Denmark, is 36 feet.

The total number of steamers, barges, and sailing vessels carrying cargo, or in ballast, using the Kiel Canal, and their tonnage, are

given in the Great Canals of the World, Department of Commerce and Labor, 1895 to 1904, and in Statistiches Jahrbuch für das Deutsche Reich, edition of 1909, for remaining years, as follows:

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The Corinth Canal, connecting the Gulf of Corinth with the Gulf of Aegina, is less than 4 miles long and shortens the voyage from the Adriatic by 170 miles, and from the Mediterranean by 100 miles, but the Mediterranean Pilot, B. A., fourth edition, page 51, states: None of the foreign steamship companies navigating the Mediterranean now use the canal. It is mostly used by small Greek passenger steamers.

It can be navigated by vessels not drawing more than 23 feet 6 inches, but, owing to the troublesome winds and currents and the narrowness of the channel, the use of one or two tugs is necessary, even for steam vessels, to keep them from grounding. These drawbacks account for the little use made of the canal, and it is well to consider the general conditions under which large vessels navigate canals. If the draft of the vessel approaches very near to the limit fixed by the depth of the channel, the suction is so great, owing to the little water between the ship and the bottom of the canal, that the vessel will obey the helm very sluggishly and sometimes not at all, even if there is neither wind nor current, and an instant off the course in a narrow channel will put the vessel aground. The propellers are very likely to be damaged under such circumstances, which is a serious matter for the ship, and if the vessel continues aground for any length of time the traffic on the canal is tied up and the loss to all parties is very heavy. Such accidents add to the expense of operating the canal and must be considered in adjusting the tolls, and as they also add to the ship's expenses they must be considered in rates of freight and insurance.

In regard to such canals as the St. Marys, connecting Lake Superior with the chain of lakes to the east and south, it is obvious that, as there is no alternative, vessels must use them, and owing to the economy of large vessels many of them are of such size that for a portion of their route over connecting waters of the Great Lakes there is at times no more than 6 inches of water to spare-so narrow a margin is only possible in tideless waters with little seasonal variation in height, and the possibility of poor steering is contemplated and met by additional care because of the conomy of the larger vessel or barge.

The Welland Canal through Canadian territory takes vessels drawing not more than 14 feet, and with a length of 264 miles has 26 locks. It is the only available water route between Lakes Erie and Ontario; but the great body of the traffic on Lake Erie being destined for the middle and eastern United States naturally proceeds by rail or through the Erie Canal, thus lessening the traffic through the Welland Canal.

A canal from Chicago to Toledo, via Fort Wayne, would be about 250 miles in length, and the passage via the Straits of Mackinaw between the same points is about 700 miles, but it seems certain that large lake carriers would not use a canal between those points. The speed of a large carrier could not possibly exceed 5 knots, less than half the speed in open water, unless the depth were more than 3 feet greater than the draft of the vessel, and the power required to drive a large vessel in a canal is so greatly increased by the suction that there soon comes a point where the speed is practically constant, however great the power expended. Also, the danger of grounding in the case of a large carrier steering badly in shallow water and causing delays and blockade is very considerable. Any use of the canal except for local traffic by barges would probably be exceptional. The traffic in certain canals of no great length, which permít ocean carriers of more or less limited draft to reach important commercial centers, shows some increase, as in the case of the Manchester Canal, 35 miles in length, with a least depth of 28 feet, and the Bruges Canal, 7 miles in length, with a least depth of 26 feet. (Port of Manchester Official Sailing Ship List Guide, July, 1909, p. 90, and North Sea Pilot, B. A., 1909.)

The sea-borne traffic of the Manchester Canal in 1898 was 2,218,005 tons, and in 1905 it was 3,993,110 tons. (Royal Commission on Canals and Inland Navigations, Vol. IV, 1908, p. 80.)

At Bruges the number of vessels entering in 1900 was 101, tonnage 30,785 tons; in 1905 it was 151, tonnage 49,022 tons; and in 1908 it was 576, tonnage 321,067. (Tableau General du Commerce Etranger, Belgium, 1908, p. 692.)

The limit of the use of most canals by ocean carriers is speedily reached, but the particular conditions are local and various. In the North Sea and the English Channel the sea portion of the route rarely exceeds 12 hours, and the economy of the carrier of limited size making the continuous voyage lies in the fact that one handling is saved by proceeding direct to such a port as Bruges, but if the canal is long the delays of navigation, ordinary or due to casualties, are such that transshipment with proper terminals will be speedier and more economical.

The Seine has been so improved that Rouen is practically the seaport of Paris. The distance from the outer limit of the estuary of the Seine to Rouen is 71 miles, and vessels drawing 19 feet can ascend to that place at high-water neap tides, and vessels drawing 25 feet can ascend at high-water springs. The size of vessels frequenting the port is increasing. In 1905, 1,482 vessels, with a tonnage of 1,051,562 tons, entered the port. (Channel Pilot B. A., 1906.)


The navigation of the Yangtse is at all times difficult, and pilots who travel the river constantly are a necessity, as the changes are so frequent that charts can not be depended on. In summer when the river is high the banks are generally flooded and the strong current makes navigation dangerous. When the river has subsided the channels are completely changed, and shoals and bars have formed and new passages have been cut through where none existed.

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