DETAILED DUTIES OF DESTROYER COMMANDER IN INDIRECT LAYING
1. TO LAY FOR ELEVATION WHEN GUNNER'S QUADRANT IS USED. a. The command QUADRANT (SO MUCH) indicates that the gunner's quadrant is to be used.
b. To set an elevation on the gunner's quadrant, for example, of 361.8 mils, the destroyer commander sets the upper edge of the head of the index arm opposite the 360 mark of the graduated arc on the quadrant frame; he then turns the micrometer index head until it reaches the correct decimal reading.
c. The announced elevation having been set on the gunner's quadrant, the piece is loaded, the breechblock is closed, and the destroyer commander places the quadrant on the leveling plates, with the words "line of fire" at the bottom and the arrow pointing towards the muzzle. The destroyer commander must be sure to use the arrow which appears on the same side of the quadrant as the scale he is using. He stands opposite the side of the quadrant and hold it firmly on the leveling plates parallel to the axis of the bore. It is important that he take the same position and hold the quadrant in the same manner for each subsequent setting, so that in each case he will view the quadrant bubble from the same angle.
d. The gunner operates the elevating handwheel until the quadrant bubble is centered, making sure that the last movement is in the direction in which it is most difficult to turn the handwheel. The destroyer commander warns the gunner when the bubble is approaching the center, in order that the final centering may be performed accurately.
2. TO MEASURE MINIMUM ELEVATION. a. Minimum elevation. The command is MEASURE THE MINIMUM ELEVATION. The destroyer commander, sighting along the lowest element of the bore, causes the gunner to operate the elevating mechanism until the line of sight is just clear of the crest. He then measures the quadrant elevation and, after reading the angle on the quadrant, reports it to the platoon commander thus: "Minimum elevation, No. (so-and-so), (so much)."
b. When the platoon commander announces the minimum quadrant elevation the destroyer commander records it in a notebook and causes the gunner to chalk it in a convenient place on the turret.
3. TO INDICATE TO THE GUNNER AIMING POINT, REFERENCE POINT, OR TARGET. Whenever an aiming point, a reference point, or a target has been designated by the platoon commander, the destroyer commander will make sure that he has properly identified the point in question. He will then indicate it to the gunner. If there is any possibility of misunderstanding, the destroyer commander will cause the turret to be turned until the gunner identifies the object.
4. TO FOLLOW FIRE COMMANDS. The destroyer commander will follow the fire commands mentally. He will be prepared to give any element of the last command to any member of the crew who has failed to hear it.
5. TO INDICATE WHEN PIECE IS READY TO FIRE. When the platoon commander can see arm signals of the destroyer commander, the destroyer commander will extend his right arm vertically as a signal that the piece is ready to fire. He gives the signal as soon as the gunner calls "Ready." When arm signals cannot be seen, the destroyer commander reports orally to the platoon commander, "No. (so-and-so) ready."
6. TO GIVE COMMAND TO FIRE. When the gunner can see arm signals made by the destroyer commander, the destroyer commander will give the command to fire by dropping his right arm sharply to his side. When his arm signals cannot be seen, he orally commands: NO. (SO-AND- SO) FIRE. The destroyer commander will not give the signal or command to fire until all the members of the crew are in their proper places.
7. TO REPORT ERRORS AND OTHER UNUSUAL INCIDENTS OF FIRE TO PLATOON COMMANDER. If for any reason the piece cannot be fired, the destroyer commander will promptly report that fact to the platoon commander, and the reason therefor; for example, "No. (so-and-so) out, misfire." Whenever it is discovered that the piece has been fired with an error in laying, the destroyer commander will report that fact at once; for example, "No. (so-and-so) fired with incorrect deflection." Whenever the gunner reports that the aiming stakes are out of alignment with the telescope, the destroyer commander will report that fact and request instructions. Likewise, he promptly reports other unusual incidents that affect the service of the piece.
8. TO RECORD BASIC DATA. The destroyer commander will record in a notebook data of a semipermanent nature. These include such data as minimum elevations; base deflections, including aiming points used; prearranged fires when prepared schedules are not furnished; safety limits in elevation and deflection; number of rounds fired, with the date and hour; and calibration corrections when appropriate.
9. TO KEEP THE GUN BOOK. The destroyer commander will enter in the gun book all data there required.
10. TO OBSERVE AND CHECK FUNCTIONING OF MATÉRIEL. The destroyer commander closely observes the functioning of all parts of the matériel during firing. Before the piece is fired, he verifies the fact that the recoil mechanism contains the proper amount of oil; thereafter he carefully observes the functioning of the recoil system. He promptly reports to the platoon commander any evidence of trouble.
11. TO ASSIGN DUTIES WHEN FIRING WITH REDUCED PERSONNEL. Whenever the personnel is reduced, the destroyer commander will make such redistribution of duties as will best facilitate the service of the piece.