INTRODUCTORY NOTES1. This chapter contains the arrangements to be made to engage a target at night. These arrangements can be applied to conditions of bad visibility such as fog or smoke.
2. The following are the occasions on which machine guns may be required to fire at night:-
- (a) When sections are in direct fire positions before darkness falls, with guns laid and aiming posts planted. In order to be able to fire on a fixed line during the night, aiming lamps must be put out (see Lesson 73).
- (b) When sections are required to occupy positions by night ready to fire on fixed lines. To lay the guns on their fixed lines, lights must be shown either from the place on which the fixed line is to fall or from a locality to be protected (see Lesson 107).
- (c) When a group is in an indirect position before darkness falls with guns on zero lines must be put out and fire control charts prepared (see lesson 80 and 118).
- (d) When a group is required to occupy a position by night to engage a target or series of targets, but the reconnaissance of the position can be carried out in daylight (see Lesson 108).
1. To teach how to obtain the necessary data and to prepare a position for engaging targets by night.
Class and instructors
2. Lecture – One officer instructor and not more than 30 in the class; Practice – Squads under squad instructors.
3. One 45-minute period, lecture; one 45-minute period, practice.
4. Lecture – Blackboard, chalk and director; Practice – Directors, gun flags, four zero posts and four direction pegs.
5. Draw the diagrams given on the following pages.
B – CONDUCT OF LESSONApproach
6. GIve the aim of the lesson (see para 1 above).
7. State that before darkness falls, all data to engage the various targets shall be obtained. This will include some or all of the following:-
- Angles of sight and ranges.
- Angular width of targets.
- Angles of switch from zero line to targets.
- Data affecting safety.
- Magnetic bearing of the zero line (this is required as a check to prevent a major error).
8. Explain the methods of recording data. An example is given in Fig 39 below.
Pegging the position
9. State that before dark the position must be pegged as follows:-
- (a) A gun position and zero line are selected. As the position will not be occupied until after dark, the zero line of each gun will have to be marked by zero posts and direction pegs.
- (b) Mount a director so that the hairline can just be laid on the zero line for the pivot gun; all drums and dials must be at zero. Swing the director through 180 degrees and get an assistant to plant a direction peg accurately in line with the hairline about 15 yards away. A zero post is planted in a similar manner about 30 yards away, and then the gun flag another 15 yards away.When engaging targets of less with than the gun frontage the procedure should be as given in Lesson 112.
- (c) Mount the director over the pivot gun flag, lay it through the zero line, with the direction dial set at 180 degrees, and put out the remaining gun flags. Using the deflection drums, swing the director on to each of the other gun flags and note the angle on paper.
- (d) Mount the director over each of the other gun flags in turn and with dials and drums at zero lay the hair line on the pivot gun flag and lock the head. Apply the angle measured previously to the director and get an assistant to plant out first a zero post and then a direction peg accurately in line with the hairline. The zero line for each gun will then be pegged as in Fig 40 below.
10. Sometimes a position may be selected on the front edge of cover which is in view of the enemy. To avoid exposing personnel in front of the cover, it will be necessary to place the direction pegs and zero posts in rear of gun flags (see Fig 41).
In this case, to peg the zero line for the pivot gun, the director should be mounted over the pivot gun flag and laid on the zero line with the deflection drums and dials at zero. It should then be swing through 180 degrees and the post and peg placed on this line. The angles to the remaining guns are then read off and pegs and posts placed out as before.
12. Revise the method of recording data.
13. Practise the squad in recording data from targets indicated by the instructor.
14. Explain and demonstrate pegging with pegs in front of the gun line.
15. Practise the squad.
16. Explain and demonstrate pegging with pegs in rear of the gun line.
17. Practise the squad.
18. Further practice as required.
19. Questions to and from the squad.
20. Sum up main main points.
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