Observing and Firing the Guns

OBSERVING AND FIRING THE GUNS When the ranges were moderate it was the practice to use a single gun for ranging, before opening fire with the whole broad side. But no two guns can be built that will always shoot alike, and the differences between individual guns become accentuated at long ranges, owing to a variety of causes. This leads to a spread or "pattern" when a number of guns of the same size are fired at the same elevation. The "spread of the salvo," as it is called, can be reduced by making careful adjustments, but it can never he eliminated entirely, even if there are no errors in laying the guns. The spread can, however, with care and training of the per sonnel, be made an approximately constant quantity, and this quantity is known to the control officer of each individual ship. It is now the general practice to range with a salvo of several guns, usually half the broadside, and to continue firing alternate salvos, of an equal number of guns. The object of the control officer is, by using some form of bracketing system, to bring the mean point of impact of his salvos on to the target. This is termed a "straddle," that is, some shots over and some short, the maximum hitting effect being obtained.

Director Firing.

All modern navies have adopted some form of master sight or director, whereby all guns can be fired by a single layer. This system of firing has many advantages, chief amongst which are the elimination of smoke interference, the reduction of personal errors and the simplification of control.

In the British navy the director installation invented by Ad miral Sir Percy Scott is used. This consists of a director sight situated well away from the guns themselves and carried in a mounting which can be trained and elevated in the same manner as a gun mounting. The motion of the director mounting is transmitted electrically to the pointers of training and elevation receivers at the guns. On these receivers are mechanical pointers geared to the training and elevating gear of the turret or gun. The gun is moved in training and elevation so that the mechanical pointers are kept in line with the electric ones worked by the director mounting. The guns thus follow the motions of the director or master sight and are laid at the desired elevation and training. The gun range and deflection are set upon the director sight and the director telescope is laid upon the target in the same manner as a gunsight. The firing circuits of all guns are brought to a single trigger at the director sight so that all guns can be fired simultaneously by the director layer.

This brief description indicates the principle upon which the director is worked, but in practice there are many complications. Corrections have to be made for the relative positions and levels of the different gun mountings and for many other matters. The installation is intricate, but it has withstood the acid test of pro longed war service. In capital ships there are, as a rule, two di rector sights, one mounted aloft and one just above the level of the guns, which can be used alternatively for the main arma ment. A director is also fitted for use with the secondary arma ment.

Squadron Firing.

In the foregoing the gun control of a single ship only has been dealt with, but under modern battle conditions it often happens that more than one ship will engage the same target. When this occurs, unless there is some pre arranged organization, confusion will arise owing to the spotting officer taking the fall of the other ship's salvoes for his own. Therefore a pair of ships firing at the same target will generally fire a salvo or pair of salvoes alternately, each waiting upon the other. A squadron of four ships may fire together at the same target, the fire being controlled by the control officer of the leader, who orders the gun range at which each ship shall fire. He re ceives the results of observations of the fall of shell from his own and the other ship's spotting officers or from aircraft. Such practice necessitates high organization and an intimate in tercommunication between the control officers, which has been made possible by wireless telegraphy. The object of the squadron control officer is the same as that of the control officer of a single ship, that is, to bring the mean point of impact of the fire of the whole armament of the squadron as near the target as possible, for then only can he be sure that he is getting the maximum hitting effect. In view of the extreme ranges at which future actions at sea will be fought, it appears certain that fire tactics will tend to develop in the direction of concentrated fire by pairs of ships or by squadrons, aided by observation from the air.

(S. T. H. W.)