Page:The New International Encyclopædia 1st ed. v. 05.djvu/110

COAST DEFENSE. The outer mine line is derived by the intersection of the curves representing the limit ut aniior- piercing ranges of the guns on either side of the entrance, so that these torpedoes are under the efTective fire of all the guns in the harhor; the inner line is usually at the narrowest part of the entrance. The battle tactics of coast defense comprise de- fense against blockade, bombardment, and attack by sea. DEFENSE AGAINST BLOCKADE. The object of a blockade is the isolation of the port concerned in order to close all commercial commimication by way of the sea, and presup- 230ses the defeat of the enemy's fleet, which may also be shut up in the port. The observation of tne movements of a daring enemy thus shut in is one of the most difficult problems which fleets have to encounter, and liistory shows that it is almost impossible. "For example, in 1759, the French fleet succeeded in breaking through the blockade of Dunkirk without being observed by the English fleet consisting of 66 ships." "In 1805 Xelson was in continuous observation of the harbor of Toulon. In spite of this fact the I'rench fleet succeeded in running out, returning again because of injuries at sea. again leaving the harbor and joining the Spanish fleet, the com- bined fleets then sailing for the West Indies. Only after their return was Nelson enabled to seize them." The defender will naturally resist the blockade as long as jiossible and try to fit his fleet for active service again as promptly as he can. His first dut}', then, is to keep the blockading fleet as far out as possible, and this duty will fall to the coast artillery, which must be con- stantly prepared, the guns ready for immediate action, the stations and range-finders continually manned, and the search-lights constantly at work. The plentiful vise of electric light as a fighting agent is a passive factor, but one of very high value. His next duty is to inflict as much dam- age as possible on the tdoekading fleet, and this duty falls to the fleet stationed in the harbor, which must at all times be ready for action, and single torpedo-boats should be sent out iinder cover of darkness, to attempt the destruction of the enemy's ships. When the defeated fleet is ready for sea again the coast artillery will open a heavy fire on the enemy's ships, and. aided by their own artillery fire, the home fleet will en- deavor to break through. This will natiirally lead to a purely naval engagement, which need not be further considered here. DEFENSE AG.MNST BOMBARDMENT. Bombardments aim chiefly at the destruction of the naval establishments of a fort, such as the arsenals, docks, magazines, and ships of the fleet lying in the liarbor, but also secondarily at the destruction of cities and establishments other than those purely naval, in order to produce a de- ])ressing efTect on the people. Bombardments are applicable only under special circiimstances and not against every harbor; indeed, the latter must be a true roadstead. Biit even then the fortifica- tions and armament must be either weak or obso- lete. From this fact, and because of the limited supply of ammunition carried by ships, a bom- bardment will but rarely be justified. If it is at- tempted, however, the attacking fleet will set aside a small portion of its artillery to attack the coast artillery, reserving the greater part to attack the establishments lying within the harbor. 82 COAST DEFENSE. The defender will attempt to hold the opcii sea as long as possible with his fleet, but when driven in he will assemble his ships in rear of the outer obstructions, or at least attempt to hold that line with his torpedo-boats. The coast artillery will endeavor to keep the enemy as far as possible from the harhor. The object being to jirevent. if possible, a bonibardnient of the liarlior or city, all guns should take part, and when the enemy's fleet approaches the proper range, high-angle fire, with deck-piercing sliell, will be used. The gain- boats and coast defenders or monitors of the home fleet can materially assist the coast artillery by the fire of their guns, but they must be protected from the enemy's torpedo-boats by a number of destroyers. As in case of blockade, the guns must be kept constantly manned and ready for action, and at night the search-lights must be constantlj' at work. Should the enemy be forced to retire, the home fleet must advance to the attack. See Bombardment. defense against attack by sea. In attacking a hostile coast a fleet may either direct its elVorts against a fortified harbor, or at- tempt to take possession of unfortified coast re- gions. The problem for the defense, therefore, naturally resolves itself into the defense of fortified places, and the defense of unfortified coast regions. The phases of the attack by sea in the first case are, in order, the removal of the outer obstructions, the reconnaissance, the artil- lerj' duel, the removal of the inner obstructions, the forcing of the entrance, and, finally, land- ings to obtain full possession of the forts. The phases of the defense will correspond. Before endeavoring to ascertain the position of the guns of the defender, the attacking fleet will seek to destroy outer obstructions, in order to get possession of the outer bay, and, if the opportunity should otl'er, to force the passage. The torpedoes of the mine fields and the guns of the batteries on shore are com]ilemeiitary means of defense, each inadequate without the other. The obstructions are a passive means, but only become real obstacles when protected by the coast artillery: on the other hand, the latter alone, without the obstructions, cannot prevent the enemy from entering the harbor. The outer mine field is so important that there will be a serious struggle over it, for. once the attacking fleet passes over it, its further work is greatly sim- plified. The defender, therefore, must he constantly on the alert, especially at night, when the search- lights are continually in use lighting up the fore- ground beyond the mines. AW approaching ships are fired upon by the artillery, and since the enemy will probably not attempt to remove the mines with any but his smaller vessels, such as torpedo-boats (since the outer mine field is placed intentionally in the field of greatest effect of the guns on shore, both vertical and horizontal), rapid-fire guns should be used, because these small vessels move rajiidly, otTcr but a small target, and their work, by the lime their purpose is known on shore, can be done promptly. Moreover, since the attack may be directed on several points of the mine field at the same time, it is best to assign the rapid-fire batteries to particular sectors of the mine field to insure prompt action on all the enemy's vessels. The torpedo-boats of the de- fense remain close up to the mine fields in order to fight the enemy's torpedo-boats while they are