78 THE TACTICAL RELATIONS BETWEEN DIFFERENT CLASSES 



threaten her present supremacy. England opposed the submarine till other powers made 

 it a success and then England was obliged to accept it. 



We may now come to defense by evasion or, less euphemistically, by flight 

 As we have seen, a ship's combatant power or battle endurance to live longer than her 

 enemy and accomplish her ultimate purposes is the product of her defensive by her offen- 

 sive strength. If either factor becomes very small, the other must become impracticably 

 great in order to give a probability of ultimate survival. Hence, if a type of ship sacrifices 

 defense by protection or by concealment, she must either secure herself by enormous 

 armament or she must get a reasonable measure of defense by her speed and consequent 

 ability to run away. 



As a principle of design, we may then take it that sacrifice of protection normally calls 

 for speeds superior to those of better protected types of ships. And so, taking battleships 

 as setting the standard speed for combatant ships, we find that all surface ships less thor- 

 oughly protected should be faster as their armor grows thinner, whereas to submarines, 

 whose defense lies in concealment, a submerged speed much less than battleship speed is all 

 that is necessary. 



OFFENSIVE STRENGTH. 



Next we may take up the subject of offense. The oldest form of attack now import- 

 ant is artillery fire, chiefly aimed at the upper works and crew, using explosive shell and, 

 recently, poison gas. With these latter may be classed deck bombs dropped by fliers. A 

 more recent form of attack is that of the torpedo directed against the underwater body of 

 the ship. 



The essential difference in the manner of employment of these two weapons is that the 

 velocity of the gun's projectile is such that, once within range of a gun, its projectile cannot 

 be avoided or parried by the target ship. The gun is the weapon best fitted for heavy "give 

 and take" and for the exercise of stem resolution to win by endurance to outlast the enemy. 



The torpedo, however, has a speed which at best is little greater than that of the fast- 

 est ships. It cannot overtake a ship unless the range is short, for it does not run far; it is 

 preferably fired to meet an advancing enemy. Hence the torpedo is eminently a weapon for 

 fast ships. Further, ships having a defensive element in their speed, if properly armed, 

 find in their speed also an offensive element as against slower ships, owing to their ability 

 either to gain desirable position or else force the enemy to maneuver disadvantageously 

 under gun fire. 



MOBILITY. 



We have already discussed speed as an element in attack and in defense from a tacti- 

 cal point of view. We must further consider it from a strategic point of view and the con- 

 sequent influence on design. 



Fuel endurance as a strategic factor must be increased as ships are expected to operate 

 in wider waters. The light cruisers operating against each other in the late war across the 

 North Sea were of from 3,000 to 5,000 tons and were quite effective. To operate equally 

 effectively across an ocean, the size of individual ships should be much larger. The Karlsruhe 

 and other German raiders in the broad ocean were much preoccupied by the question of 

 finding fuel. Some years ago this matter was the subject of marked divergence of views 

 between officers of the submarine flotilla and the Navy Department. 



