This vessel is designed to carry torpedoes firing in line with the axes of the ship both fore and aft, and carries, also, torpedo tubes in the superstructure which may be trained to fire to either broadside. Of course, such a vessel as this should be fitted with wireless and sound-transmitting and detecting devices, and, to be effective, should have a speed of at least twenty-five knots, in which case she would be able to pursue and overtake any battle fleet that could be assembled from existing ships in any navy in the world. Undoubtedly such high-speed submarines will come into being within the next few years.
Congress, in 1914, appropriated money to build "fleet submarines," in which they expressed the desire to secure twenty-five knots. A certain amount of discretion, however, was left with the Navy Department, which would permit them to accept boats of not less than twenty knots. There is no difficulty in the way of making such vessels function satisfactorily when submerged, but up to date no internal-combustion engine has been produced suitable for such high-speed submarines, and steam has many disadvantages in a military submarine, which should be able to emerge and get under way at full speed after a long period of submergence.
The tactics of the fleet submarine would be to search for and destroy the enemy's warships or commerce carriers wherever they could be found. A seagoing submarine of such character would also carry rapid-fire guns of sufficient calibre to destroy surface merchantmen. Having sufficient speed to overhaul them, they would be able to capture the merchantmen and perhaps take them as prizes into their own ports, something which it is impossible for the commander of the small-sized submarines now in commission to do, as they have neither the speed to overhaul swift merchantmen nor guns of sufficient range and power to destroy them if they refuse to follow the instructions of the submarine commander. The only alternative, therefore, has been to destroy the merchantmen, and, in many cases, the crews and passengers of the merchant ships have been destroyed as well. This latter policy, however, is much to be regretted.
From a study of the submarine problem as it stands to-day, the one thing lacking to make the submarine sufficiently powerful to stop commerce on the high seas between countries at war is speed. We have seen from the foregoing that sufficient speed to accomplish this purpose means great additional cost, and, as the engine situation exists to-day, it may be considered that it is impossible. My own personal opinion is that we shall not see satisfactory twenty-knot submarines, let alone twenty-five-knot submarines, for a matter of several years. In the meantime the people of this country, now engaged in the gigantic conflict which is taking place across the water, are becoming much exercised as to the possibility of some condition arising which may bring about an attack upon our own country.
There is a method of preparing this country with a type of submarine which may be navigated, so to speak, at much greater speed than that called for by the 1914 Congress; namely, twenty-five knots. The boats would have the further advantage in that they would be much less expensive even than the fourteen-knot submarines now called for in the latest specifications for the coast-defence type. This new method calls for the construction of a moderate-size submarine, which, for the want of a better term to distinguish it, I have called an "amphibious submarine"; that is, a submarine which may be carried on land as well as on or under the water.
"AMPHIBIOUS" SUBMARINE
Making up a train to ship a Lake submarine across Siberia during the period of the Russian-Japanese war. Note the special trucks with sixteen wheels each, used to carry the load (about 130 tons). As the Trans-Siberian road had light rails, it was necessary to design these special trucks to distribute the weight so as to carry this heavy load. It is remarkable that several of these unheard-of weights should have been transported by vessel and rail a distance of over 10,000 miles each without accident or damage. Boats mounted on trucks especially designed to pass through tunnels could be transported from one port to another at railroad speed and be ready for immediate action in defending threatened sections of the country. The Germans have since made extensive use of this method of transporting submarines, giving them access to the Dardanelles and other points not easily accessible to their submarines by water.
These submarines would be much smaller than the present coast-defence type of submarine, and of a diameter that could pass through our tunnels and over our bridges. They could be of about two hundred and fifty tons submerged displacement. A railroad truck would be provided for each submarine, with a sufficient number of wheels to carry the load. The submarine itself would be constructed with proper scantlings to carry her entire load of machinery, batteries, fuel, and supplies without injury when mounted on her special trucks. Vessels of this type, which would have a surface speed of ten to twelve knots and a submerged speed of ten knots, would be readily constructed. They could carry as many as eight Whitehead torpedoes and have a radius of action on the surface of about two thousand miles at eight knots. Fitted with telescopic, or housing, conning towers and periscopes, nothing would need to be taken apart to ship these submarines from one section of the country to another at railroad speed. Fifty submarines of this type would probably be more efficient in time of need for protecting our thousands of miles of coast line than would many times the same number of fourteen-knot boats distributed over the same number of miles of coast line.
In the war game no one can tell where the enemy may decide to strike in force. An attack might be made in the vicinity of Boston, New York, Charleston, Pensacola, New Orleans, or Galveston on the eastern coast; it might be made at or in the vicinity of San Diego, Los Angeles, San Francisco, or Seattle on the western coast. There should be, of course, a certain number of the coast-defence type of submarines permanently stationed at these ports for their protection during war-time periods. But wars come suddenly, and the old saying that "the one who gets in the first blow has the advantage" is a true one. The history of recent wars shows that the declaration of war usually comes after the first blow has been struck. It is readily conceivable, therefore, that before we knew that we were going to become involved in war a fleet of battleships and transports stationed off our harbors, or off a suitable landing place on our extensive coast line, might be able to establish a shore base before we knew it or had time to get sufficient of our slow-going submarines at the danger point to prevent the landing of an invading force.