If we had one hundred submarines distributed over our Atlantic and Pacific coast lines, it would take weeks or months to mobilize many of them at the point of attack, for the reason that a submarine, when submerged, has such a small radius of action. The best in the service to-day have a radius of action of about one hundred miles at five knots, or eleven miles at ten and one-half knots, or twenty-four miles at eight knots. The enemy, with light, shallow-draft, high-speed picket boats, could probably make it very unsafe for a submarine to travel any considerable distance along the coast in the daytime, or even at night, in surface cruising condition. As it takes considerable time to charge the batteries to enable the boat to run in a submerged condition, should the enemy have control of the surface of the sea, the average submerged radius to-day of a submarine would probably be less than one hundred miles, unless it ran a grave risk of being captured while on the surface. The chances are, therefore, that if we had one hundred submarines distributed over our Atlantic and Pacific coast lines, not over ten or a dozen of them would be able to reach the point of attack in time to prevent the landing of an invading force with sufficient men, guns, and ammunition to do a great deal of harm in some of the thickly populated sections of the country.
AN AMPHIBIOUS SUBMARINE BEING HAULED OUT OF THE WATER
If, however, the country were provided with fifty "amphibious submarines" located at ten of our important Atlantic and Pacific ports, they could all be mobilized at an objective point within a week. If the government made arrangements with the railroads to run a track down under the water at each railroad coast terminal, or to run special tracks into the water at other suitable localities along the coast where there would be sufficient water to float a submarine, submarines could be rapidly mobilized to ward off a landing at any point.
To illustrate the point which I wish to make, assume that this country should become involved in war with nations lying both to the east and west of us. To get submarines from one coast to the other would require a long period of time. The "amphibious submarine," on the contrary, could in an hour's notice be run on to the tracks at New York and three days later be run into the water at San Francisco, with her crew, fuel, stores, and torpedoes all ready to go into action at once. A submarine could make a trip from Boston to New York in five hours, or from Boston to New Orleans in thirty-five hours. These boats could be built in quantities at a cost of about $300,000 (£61,500) each. Fifty of them could, therefore, be built at approximately the cost of one modern battleship.
There has been much talk recently about the so-called "baby" submarines—little one-or two-man boats. A large number of one-man submarines were built for the Russian Government previous to 1880 by Mons. Dzrewieckie, the well-known inventor of the Dzrewieckie type of torpedo launching apparatus. Mr. Holland, Goubet, and practically all inventors and builders of submarines commenced with "baby" submarines. One of the designs which I submitted to the United States Government in 1901 called for a one-man boat to be carried on the davits of a battleship or cruiser. A boat of that kind might have had a place a number of years ago when attacking vessels came near the shore. Such small craft must necessarily have a very limited range of action and very slow speed; they also would be unseaworthy. It would be impossible for a man to remain submerged in a vessel of this type for a considerable length of time, so that personally I can see very little use for them at present.
It has been well established that submarine boats should be divided into two classes: one a torpedo boat with as high surface and submerged speed as it is possible to attain with a large radius of action, capable, if possible, of exceeding battleship speed when on the surface, so that it may intercept a battle fleet on the high seas and submerge in its path of approach before being discovered; the second class should consist of smaller, slower-speed, mine-evading submarines, with torpedo and mining and countermining features. Such submarines are essentially defensive, but if they have sufficient radius of action to reach the enemy's harbors and to lie in wait off the entrance to such harbors, or to enter submerged the harbors themselves and there destroy the enemy craft, they have become potent offensive weapons of the raiding class. For a European power it is relatively easy to give such boats the radius necessary for them to invade an enemy's ports.
We have not pushed the consideration of the submarine of the second class, with its anti-mine features, because we have been kept busy trying profitably to meet the wishes of the various governments which demand constantly increasing speeds at a sacrifice of some characteristics which I personally regard very highly. Most government officials have been more attracted to vessels of the first class, as speed in all classes of vessels more than anything else seems to appeal to the imagination, but I think it may be the old story of the tortoise and the hare over again.
As regards the first class of submarines, the present submarine boats engaged in the continental war consist of vessels only a few of which have a surface speed exceeding twelve knots, or a submerged speed exceeding ten knots for one hour or eight knots for three hours. There may be a few in commission that exceed these speeds, but very few. Some are in course of construction that are expected to give a surface speed of seventeen and eighteen knots for forty hours and about eleven knots submerged for one hour, or a slower speed for a greater number of hours.
Governments are asking for bids for submarines of greater speed, and some have been designed which are expected to make twenty knots on the surface; but they are not in service as yet. One reason that higher surface speeds have not been reached is the difficulty of securing a perfectly satisfactory high-power, heavy-oil, internal-combustion engine, suitable for submarine boat work. As soon as a proven satisfactory heavy-oil engine is turned out by the engine builders, capable of delivering five thousand horsepower per shaft, submarine boats may be built capable of making up to twenty-five knots on the surface.