Читать книгу The Gunner's Examiner - Harold E. Cloke - Страница 11

(a) Azimuth Instrument (pattern in use by the company for instruction), definition of angles, horizontal angles, vertical angle, angle measured by the instrument, leveling and orientation; focussing the telescope. Graduation of the instrument: Set up the instrument over a given point and orient it from sufficient data; direct the telescope successively on a series of points and read their azimuths with accuracy.

(b) The Plotting-room (for guns).

1. Plotting-board.—Point out the following: Primary and secondary stations, directing gun, displacement, gun-arm, travel-scale, azimuth-correction scale, tally dials, range-correction scale.

Lay off a distance of so many yards on the board; conversely, tell the distance in yards between two given points on the board.

The azimuths of a fixed target from the primary and secondary station being given, locate the corresponding point on the board, and give its azimuths and range, from the directing gun or directing point.

The azimuths of a fixed target from the primary and secondary stations being given, locate the corresponding point on the board and determine its range and azimuth from the directing gun or point.

2. Range Board.—Show how to make the range corrections for atmosphere, wind, tide, muzzle velocity, travel, and how this range correction is applied to the range-correction scale.

3. Deflection Board.—Show how to make deflection correction for wind, drift, and travel. Show how to make azimuth correction in Case 3 for wind, drift, travel, and how this correction is applied to azimuth correction scale.

What data are sent to the guns in Case 1, Case 2, and Case 3?

The plotting-room (for mortars).

1. Plotting-board.—Point out the following: Primary and secondary stations, directing point, gun-arm, gun-arm azimuth circle, displacement, powder zones, elevation, times of flight.

Lay off a distance of so many yards on the board; conversely tell the distance between two given points on the board.

The range and azimuth of a fixed point (from primary station) being given, locate the corresponding point on the board. Tell the zone, elevation for firing at this point, and its azimuth from the directing point. The azimuth of a fixed target from the primary and secondary stations being given, locate the corresponding point on the board and determine its range and azimuth from the directing point.

2. Show how a target is tracked, how to get travel, how the time of flight is used, how to get predicted point, how to get set-forward point. What is the predicted point used for? What is the set-forward point used for? What data are sent to the pit and what to the B. C. station? Show how range corrections are made.

3. Drift Device (for deflection board if issued).—Show how to make arbitrary and drift corrections.

(c) Aiming and Laying Guns or Mortars.

1. For Rapid-fire Guns.—Set and read the sight for given elevations and deflections; aim the gun at some object; show how elevating and traversing hand-wheels are used; explain the use of the deflection scale for firing right and firing left. What is Case 1?

2. For Mortars.—Use of the gunner's quadrant, setting and reading the instrument, when and how placed when used with mortars. With the data received from the plotting room lay the piece. What is Case 3?

3. For Heavy Guns.—(Heavy guns refer to 8-inch, 10-inch, and 12-inch rifles and other guns which are provided with a system of vertical and horizontal position finders.) Name the principal parts of the telescopic sight (one used for instruction purposes); show how it is used. Its readings for elevation and deflection, east count of its scales. Place it on the Hagood tripod mount, level it; set it for given elevation and deflection.

4. Use of Difference Chart.—An example like the following will be given: Range 4500 yards, azimuth 210. Put down the corrected range and azimuth.

Examination in the foregoing subject (c) to be confined to the authorized systems in use by the company during the year and to the complete equipment of the battery to which the company is assigned.

(d) Elementary Gunnery.—Axis of the bore; line of departure; line of sight; drift; muzzle velocity; quadrant elevation; sight elevation; angle of fall; jump; trajectory; time of flight.

(e) General Features of Warships.—General features of battleships (broad beam compared to length, low freeboard, general massive appearance, large turrets fore and aft, heavy guns, heavy armor, generally moderate speed).

Armored cruisers: (High freeboard, narrow beam compared to length, medium armor, medium turrets, medium guns, high speed).

Protected cruisers: (Fine lines, moderate size, no armor, medium guns usually with shields, protective deck).

Torpedo-boat destroyers: (High bow, generally great speed, light guns, no armor).

Torpedo boats: (Small size, high speed, no armor).

The following head will take the place of subject (b) in the examination of candidates for first-class gunners of organizations assigned exclusively to rapid-fire guns:

(b) Subcaliber Firing.—The 15-pounder gun and subcaliber attachment will be used. The target will be Target X, miniature target, page 25, Small-arms Firing Regulations, 1906, pasted on a screen of sufficient size to catch all the shots, preferably the screen used for small-arms Target A; range about 95 feet, where six minutes on the scale is equal to 2 inches at the target; method of scoring as prescribed for small-arms practice.

During the test one member of the board will be at the target and will personally superintend the marking.

The preliminary shots will be fired under direction of the examining board until three hits have been obtained with the same elevation and deflection. The center of impact of these three shots will be referred to the horizontal and vertical axes through the bulls'-eye of the target and its coordinates carefully measured. This center of impact will not be on the miniature target and may be changed by the board as often as they deem necessary during the examination. These measurements, with the elevation and deflection used, will be given to the candidate, who will be required to make corrections corresponding to the distance of the center of impact from the bull's-eye. Each candidate will fire five shots, the piece being thrown off the target between shots. Each shot will be marked as fired, the candidate making such changes in elevation and deflection as he may deem necessary before firing the next shot. The ratio of the candidates' score to the maximum score possible will determine the credit, the maximum credit being 20.

After this test the candidate will fire at the fixed subcaliber target anchored at about 500 yards, without knowing the exact distance, five rounds under service conditions in one minute and thirty seconds. Three sighting shots will be allowed each candidate preceding the latter test. Each hit on the material target counts 6.