116 ON THE SUITABILITY OF CURRENT DESIGN OF SUBMARINES 
who will suffer most, since good-will and a common understanding between the sea- 
going navy and the industries which support it are essentials to success, and particu- 
larly necessary in a democratic nation. In fact, a basis for such a common under- 
standing is provided in the public hearings upon the naval appropriation bills, which 
give much information as to our policies and views. 
The purpose of this paper will, therefore, be first to examine the peculiar mili- 
tary characteristics of submarines in general and compare them with those of other 
types of combatant ships; second, to consider how these general characteristics 
will influence or control the employment of submarines in war; and, finally, what 
particular types of submarines seem best suited to American needs. 
Submarines are armed with torpedoes and with guns. Owing to the great per- 
centage of the displacement which is necessarily devoted to the heavy hulls and very 
heavy machinery installation, the speed of submarines is much less than that prac- 
ticable for surface craft of the same size. Consequently submarines, unlike torpedo- 
boats and other fast craft, cannot rely on their speed as a means of safety. For 
the submarine the chief means of defense is provided by her submersibility and con- 
sequent invisibility. Further, the great weight of storage batteries forbids giving 
submarines more than a small radius of action when submerged. The submarine 
obtains information only when able to see—at the surface. She can navigate 
freely and recharge her storage batteries only when running the oil engines at the 
surface. These are the chief peculiarities which affect the combatant powers of 
submarines. They affect alike those submarines which are armed with torpedoes 
and those of that other type, the fruit of the current war, which are designed as 
mine-layers. Bearing these peculiarities in mind, we may proceed to consider the 
general principles which these qualities require a captain to observe in the employ- 
ment of a submarine under his command. 
In regard to the torpedo, a pecularity exists which differentiates its use very 
much from that of the gun. The initial velocity of a projectile from a high-power 
gun is 3,000 feet per second. The speed of the fastest ship is not over 60 feet per 
second. As these two velocities are in the ratio of 50 to 1 a ship cannot escape 
from a projectile fired at her. The greatest velocity of an automobile torpedo sel- 
dom exceeds about 40 miles an hour, and this only for moderate ranges. By re- 
ducing the speed to 30 miles or less an hour the compressed air in the flask can drive 
the torpedo farther, but such speeds are of the same order of magnitude as those of 
the target ship. Consequently, the direction and speed in which the target ship is 
moving are most important elements in deciding when she is within range. Con- 
sider, for instance, a 30-knot torpedo capable of running 10,000 yards. If fired at 
a ship approaching at the rate of 20 knots there is a chance of hitting if fired at a 
distance of over 16,600 yards, whereas if the target is withdrawing at 20 knots, the 
torpedo will exhaust its motive power and stop before overtaking the target if fired 
from any range above 3,300 yards. 
When submerged the submarine itself also is limited both in speed and radius 
—12 miles at most at 10 or 12 knots, a hundred miles more or less at 5 or 6 knots. 
