1951: Chapter 8 – Instruments and Aiming

Lesson 35. – THE SIGHTS, AIMING AND LOADING

A INSTRUCTORS NOTES

Aim

1. To teach the soldier how to load and unload the gun correctly.

2. To teach the soldier how to adjust the tangent sight to the range ordered and to lay a correct aim.

3. To teach the use of the battle sight.

Class and instructors

4. Squads under squad instructors, seated on the right side of the gun.

Periods

5. One 45-minute period.

Stores

6. Gun, tripod, condenser can and tube, liner with belt and drill cartridges, landscape or natural targets.

Preparation

7. Gun mounted with the landscape target set up in front of the gun.

B CONDUCT OF LESSONPreliminaries

8. Safety precautions.

Approach

9. Give the aim of the lesson (see para 1).

10. Detail a No. 2, the instructor acting as No. 1, order “Take Post.”

Loading the gun

11. Explain and demonstrate that on the order “Load” the No. 2 will grasp the end of the belt with the right hand at the point where the tag joins the fabric, and push the tag through the feedblock as far as possible. The No. 2 must ensure that the belt is not twisted on entering the feedblock.

12. Exercise No. 2.

13. Explain and demonstrate that on the order “Load” the No. 1 will pull the crank-handle on to the roller with the right hand and advance the left hand to the left of the feedblock, ready to grasp the belt. When the No. 2 has passed the tag of the belt through the feedblock, the No. 1 will grasp it and pull it through the feedblock as far as possible; he must pull the belt gently and straight when doing so. He will release the crank handle and then repeat the movements.
Emphasize that while pulling the crank handle on to the roller the belt will be held not pulled. Stress the importance of pulling the belt gently and straightly; any snatching of the belt or pulling to the rear will result in faulty loading.

Unloading the gun

14. Tell the sqaud that on the order “Unload” the No. 2 will withdraw the belt from the feedblock when the No. 1 has pressed the pawls. He will then replace the belt in the liner.

15. Explain and demonstrate that on the order “Unload” the No. 1 will pull the crank handle on to the roller twice with the right hand, allowing it to fly forward each time, retaining correct holding with the left hand on the traversing handle. He will then press the top pawls of the feedblock down with the first and second fingers of the right hand, and lift the bottom pawls with the thumb of the right hand, taking care to keep the entrance of the feedblock clear. When the last round is clear of the feedblock, and while the belt is being withdrawn he will press the thumb-piece.

16. State that when if the order “Unload” is given, the tangent sight is raised the No. 1 will knock it down with his left hand.

Practice

17. Pratise the squad in loading and unloading the gun. Should any man show a tendency to slur in the loading motions, the instructor should make him load by numbers, counting aloud whilst he is doing so.

THE SIGHTS AND AIMINGApproach

18. State the aim of the lesson (see paras 2 and 3). Tell the squad that the sights are used in direct fire to obtain direction and elevation.

Adjusting the tangent sight

19. Point out that the sight is graduated form zero to 3,700 yards. The correct line on the graduated plate for any particular range is the one under the figures indicating that range. The sight can be set to 50-yard intervals by eye.

20. Demonstrate adjusting the sights, then practise the squad, each man making several adjustments.

Aiming with the tangent sight

21. State that the correct method of laying an aim with the machine gun is very similar to the rifle.

The rule of aiming is:–

Close either eye; look through the aperture at the target and select the point of aim, keeping the point of aim in the centre of the aperture. The sights must be upright, which is ensured by the correct mounting of the tripod.
Note.– The point of aim on a target when firing the machine gun, is the centre of the base, unless otherwise ordered by the Fire Controller.

Laying a correct aim

22. The instructor will now lay a correct aim on the landscape target and explain and demostrate that whilst laying an aim, direction is obtained by tapping the traversing handles and elevation by means of the elevating handwheel. Whenever either tapping or elevating the gun, the disengaged hand must retain correct holding.

Practise

23. Let each man in the squad view the correct aim and then, in turn, lay the gun himself. Should any faults be detected, the instructor must explain their effect, and see that they are remedied. If an man’s aim is incorrect the instructor must convince him that it is so and persevere until he can lay a correct aim.

24. Further practice shoudl then follow on natural targets.

Noting a point of aim

25. State that when allowing for wind it will often be necessary to note a point of aim to the right or left of a target. Lay an aim on a target, tap the gun off and ask the squad to describe where the gun is laid.

Battle sight

26. Point out the battle sight and tell the squad that this sight is used in emergency at ranges up to 600 yards.

Conclusion

27. Questions from the squad.

28. Further practice for backward men.

29. Sum up main points.

Lesson 36. – DIAL SIGHT

A INSTRUCTORS NOTESAim

1. To explain the parts of the dial sight and their working to the soldier.

Class and instructors

2. Squads under squad instructors. Squad seated in a semi-circle.

Periods

3. One 45-minute period.

Stores

4. Gun and tripod, wall diagram of dial sight and as many dial sights as possible.

B CONDUCT OF LESSONApproach

5. State the aim of the lesson (see para 1). Tell the squad that the dial sight is an instrument which is used to obtain and maintain direction and elevation in indirect fire or whenever the target cannot be seen from the gun position.

6. The class should have dial sights in their hands and follow the description and actions of the instructor.

Method of fixing to the gun

7. Demonstrate that the tapered bracket on the sight fits into the slot on the bracket on the gun. The sight is clamped tight by the fixing screw.

Elevation

8. State that elevation is placed on the dial sight by means of the range and angle of sight drums used in conjunction with the level bubble. Describe these drums. The main features to note are:–

(a) The range drum is graduated in 100s of yards up to 4,500 yards. Up to 400 yards one click represents 100 yards – over 400 yards one click represents 50 yards. Forward of the drum is a quick release lever which disconnects the clicker ring. This quick release should be used when initially setting the range drum, to avoid wear.

(b) The angle of sight drum is graduated in 5s of minutes to 10 degrees of elevation and depression. The drum is fitted with a friction clamp.

(c) The fitting for the spare level bubble.

9. Practise the squad in setting the drums.

Direction

10. Tell the squad that direction is placed on the sight by the dial and deflection drums. The main features to describe are:–

(a) The dial is marked in 10s of degrees from 0 to 180 degrees left and right. There is a quick release stud forward of the dial.

(b) The right and left deflection drums are marked in 10s of minutes from zero to ten degrees.

(c) The adjustable clicker lever and its arrows.

(d) The freewheeling and clicking of the deflection drums are controlled.

11. Practise the squad in setting the dial and deflection drums, and then replacing them at zero, by first putting the deflection drums at zero and then the dial.

Lensatic sight

12. State that the lensatic sight enables the No. 1 to lay an aim on a mark without altering the setting of the deflection drums or elevation drums. It is principally used for maintaining direction.

13. Describe the following points regarding the lensatic sight:–

(a) Point out that the tube may contain either a white triangle or a vertical white line.

(b) How the lensatic sight is adjusted vertically by the lensatic sight adjusting screw (marked cursor screw on Plate 3).

(c) How to zero the lensatic sight by means of the zero latch and how to free wheel it by means of the quick release.

(d) The operation of the fine adjustment worm.

14. Practise the squad in releasing and zeroing the lensatic sight.

Conclusion

15. Questions to and from the squad.

16. Sum up main points.

Lesson 37. – AIMING POST, AIMING LAMP, ZERO POST AND DIRECTION DIAL

A INSTRUCTORS NOTESAim

1. To familiarize the soldier with the instruments named above.

2. To teach the method of setting up the aiming post and lamp.

3. To teach the setting of the direction dial.

Class and instructors

4. Squads under squad instructors. Squad seated in a semi-circle facing the instructor.

Periods

5. One 45-minute period.

Stores

6. Aiming post, aiming lamp, zero post, gun and tripod.

B CONDUCT OF LESSONApproach

7. State the aims of the lesson (see paras 1, 2 and 3 above).

Aiming post

8. Describe the aiming post pointing out the adjustable arm, aiming mark, bracket for lamp and the supprting extension.

9. Demonstrate how to erect the aiming post vertically and lying on its side.

10. Practise the squad.

Aiming lamp

11. Describe the components of the lamp. Point out the coloured disc for toning down the light.

12. Show how to attach the lamp to the aiming post. The lamp is removed from the box and the cable passed through the slot in the side of the box. The lamp is secured to the extension above the aming mark, with the bracket uppermost, by tightening the wing nut. The box is then closed and placed close to the aiming post with the ring facing the guns.

13. Demonstrate how to secure the box. On soft ground, he hook is released from its securing strap and stamped into the ground. On hard ground, the securing chain is used to anchor the box to a post or other firm object, but never to the aiming post.

14. Show how the reel is removed from the box and the sqivel hook clipped through the switch ring. Demonstrate how to switch the light on and off by pulling on the line.

15. Practise the squad.

Zero post

16. Show the zero post to the squad and tell them that it is used in obtaining direction in indirect fire.

Direction dial

17. Point out that the direction dial is graduated from 0 to 180 degrees right and left. Show how the scale can be rotated round the socket and can be fixed in any position by the a clamping screw. Indicate the pointer to the squad.

18. State that the direction dial is used as a check in maintaining direction. No. 2 is responsible for setting it.

19. Practise the squad in setting the direction dial.

Conclusion

20. Questions to and from the squad.

21. Sum up main points.

Lesson 38. – AIMING WITH THE DIAL SIGHT BY DAY

A INSTRUCTORS NOTESAim

1. To teach the soldier to lay an aim with the dial sight by day.

Class and instructors

2. Squads under squad instructors. Squad seated in a semi-circle on the right of the gun.

Periods

3. One 45-minute period.

Stores

4. Two guns, tripods and dial sights, aiming post, aiming lamp, two zero posts, a direction peg and landscape or natural targets.

Preparation

5. The two guns should be mounted about 15 yards apart, with dial sights attached and all drums and dials set at zero. The aiming post shuld be placed centrally between and 15 yards out from the guns.

B CONDUCT OF LESSONApproach

6. State the aim of the lesson.

Aiming by day

7. Explain how to aim with the lensatic sight containing a triangle. The eye should be about three inches from the sight. By moving the head backwards or forwards, the white triangle can be made to fit the tube exactly. The tip of the triangle can now be aligned on the aiming mark.

8. Explain how to aim with the lensatic sight containing a line. The eye should be about three inches from the sight. By moving the head backwards or forwards, the vertical line can be made to touch the top and bottom fo the tube, and should be down the centre. The line can now be aligned on the aiming mark.

9. Demonstrate aims laid on the following types of aiming marks and practise the squad in each case:–

(a) Two zero posts, by having the sight set at zero, and moving the gun and tripod, until the lensatic sight and two zero posts are in line.

(b) The aiming post, by freewheeling the lensatic sight until it is aimed at the white disc.

(c) The aiming lamp, when fitted on the aiming post, by freewheeling the lensatic sight unti lit is aimed at the black aiming mark.

(d) The zero post, direction peg and lamp, by having the sight set at zero, and moving the gun and tripod, until the sight, the zero post and the lamp, which is held immediately behind the direction peg, are in line.

(e) The lensatic sight of another gun, by having a switch of about 90 degrees on the sight and tapping the gun until the lensatic sights are aimed at each other.

(f) Landscape or natural targets, by freewheeling the lensatic sight until it is aimed at the natural target.

Conclusion

10. Questions from the squad.

11. Further practice if necessary.

Lesson 39. – AIMING WITH THE DIAL SIGHT BY NIGHT

A INSTRUCTORS NOTESAim

1. To teach the soldier to lay an aim with the dial sight by night.

Class and instructors

2. Squads under squad instructors. Squad seated in a semi-circle on the right of the gun.

Periods

3. One 45-minute period, (day or night).

Stores

4. Gun, tripod, dial sight, aiming post, aiming lamp, zero post, direction peg and lamp, electric.

Preparation

5. The gun should be mounted and the dial sight attached with all drums and dials at zero. The aiming post should be placed out. The zero post and direction peg should be lined up ready for use, and the aiming lamp held behind the peg when required.

Ground

6. This lesson is best taught in a dark room or shed which can be illuminated when necessary to show faults. The room must have a floor suitable for planting the zero post and direction peg. If no such room is available, then the lesson must be taught outdoors by night.

B CONDUCT OF LESSONApproach

7. State the aim of the lesson (see para 1).

Aiming by night

8. Explain that the method of aiming with the dial sight by night is the same as by day, except that it may be necessary to assist the No. 1 by shining a torch at an angle into the front of the lensatic sight.

9. Demonstrate and practise the squad laying an aim on:–

(a) Zero post, direction peg and aiming lamp.

(b) Aiming lamp, when attached to the aiming post.

Conclusion

10. Questions from the squad.

11. Further practice at aiming at night is essential.

Lesson 40. – PARALLELING WITH THE DIAL SIGHT

A INSTRUCTORS NOTESAim

1. To teach the soldier how to handle the dial sight when the guns are being paralleled.

Class and instructors

2. Squads under squad instructors. Squad in a semi-circle around No. 2 gun.

Periods

3. One 45-minute period.

Stores

4. Two guns, tripods and dial sights and an aiming post.

Preparation

5. Guns mounted about 15 yards apart with dial sights attached. The aiming post should be planted 15 yards in front and centrally between the two guns.

B CONDUCT OF LESSONApproach

6. State the aim of the lesson. Tell the squad that the right hand gun represents No. 1 gun, the left hand gun No. 2 gun, and that Nos. 3 and 4 guns would be to the left again.

Zero lines

7. Explain that on the order “Zero Lines,” the No. 1 will ensure that all deflection drums and dials are at zero.

Paralleling

8. Describe and demonstrate the duties of the No. 1 and No. 2 on the order “No. 2 gun, Left ….. degrees …… minutes.” The No. 1 will set the dial and deflection drums as ordered. He will tap the gun, elevating or depressing the lensatic sight, until it is laid on the lensatic sight of No. 1 gun. The No.1 of No. 2 gun will then zero the deflection drums and dial again and by pressign the quick release, adjust the lensatic sight until it is laid on the aiming post. The No. 2 will then zero the direction dial.

9. Practise the squad in the duties of the No. 1 and No. 2.

Action on the order “Stop.”

10. State that on the order “Stop” or at any time when checking for direction, the gun will be tapped until direction is obtained on the aiming post.

11. Practise the squad.

Conclusion

12. Questions from the squad.

13. Further practice for backward men.

14. Sum up main points. Stress that, when once the guns are paralleled and the lensatic sight laid on the aiming post, the lensatic sight must never be moved for direction. To obtain direction, the gun must always be tapped.

Lesson 41. – ELEVATION WITH THE DIAL SIGHT

A INSTRUCTORS NOTESAim

1. To teach the soldier to place elevation on the gun by means of the dial sight.

Class and instructors

2. Squads under squad instructors. Squad setade on the left of the gun.

Periods

3. One 45-minute period.

Stores

4. Gun, tripod, dial sight and aiming post.

Preparation

5. The gun mounted with the dial sight attached and all drums and dials set at zero. The aiming post should be put out and the lensatic sight laid on to it.

B CONDUCT OF LESSONRevision

6. Revise briefly Lessons 40 and 36.

Approach

7. State the aim of the lesson (see para 1 above). Explain that it is assumed that the gun is now laid for direction.

Elevation

8. Tell the squad that orders in range will be given to the nearest 50 yards and orders in angle of sight to the nearest 5 minutes, eg, “All one nine fifty, plus two five minutes.” “All one eight hundred, minus one five minutes.”

9. Demonstrate that, on a range and angle of sight being ordered, the No. 1 will place them on the elevation drums, tighten the angle of sight drum clamping screw and level the bubble by means of the handwheel. Stress that when levelling the bubble, the No. 1 will retain his holding with his left hand. Finally, the lensatic sight will be readjusted for elevation on to the aiming post.

10. Practise the squad.

Action on order “Stop.”

11. Explain and demonstrate that on order “Stop” or when checking for elevation during firing the No. 1 will first tap the gun until direction is obtained on the aiming post and then check and if necessary correct:–

(a) Elevation drums.

(b) Level of the bubble.

(c) Alignment of the lensatic sight.

in that order.

Conclusion

13. Questions from the squad.

14. Further practice in elevation and direction with the dial sight.

15. Sum up main points. Emphasize that accuracy with the dial sight is essential if the guns are hit the target in indirect fire.

Lesson 42. – RECORDING THE QUADRANT ELEVATION AND MEASURING AN ANGLE OF SIGHT

A INSTRUCTORS NOTESAim

1. To teach the soldier to record the quadrant elevation of the gun.

2. To teach the soldier how to measure an angle of sight with the dial sight.

Class and instructors

3. Squads under squad instructors. Squad in a semi-circle on the left of the gun.

Periods

4. One 45-minute period.

Stores

5. Gun and tripod, dial sight and landscape or natural targets.

Preparation

6. Gun mounted with the other stores to hand.

B CONDUCT OF LESSONApproach

7. State the aim of the lesson (see paras 1 and 2).

Recording the QE

8. Tell the squad that in a direct fire position, the fire controller may want to record the quadrant elevation that is on the gun. Such occasions may occur are when darkness, fog or smoke are likely to obscure the target or when preparing to lay a fixed line.

9. Lay the gun on a target with a suitable range on the tangent sight. Demonstrate that, when he is ordered to record the QE, the No. 1 will first check his aim. He will then attach the dial sight, transfer the range on the tangent sight to the range drum and level the bubble by means of the angle of sight drum, and tighten the clamping screw. The two drums will now record the quadrant elevation of required to hit the target.

10. Practise the squad in recording the QE.

Measuring an angle of sight

11. Tell the squad that, in an indirect fire position, the section commander may order the No. 1 to measure the angle of sight to the crest. The section commander requires this in order to ascertain if the guns will clear the crest.

12. Demonstrate that the No. 1 will place the dial sight on the gun and, with the tangent sight set at zero, lay the gun by direct means on the point indicated. Then, with the range drum at zero, the No. 1 will level the bubble by means of the angle of sight drum and report the reading which is the angle of sight to the object.

13. Practise the squad in measuring angles of sight.

Conclusion

14. Questions from the squad.

15. Further practise as required.

16. Sum up main points.

Lesson 43. – THE DIRECTOR No. 9, MARK 1

A INSTRUCTORS NOTESAim

1. To teach the officer or NCO to set up and use the director.

Class and instructors

2. This lesson will only be taught to officers and NCOs. Squads should preferably be of not more than eight. The squad should be seated in a semi-circle.

Periods

3. Two 45-minute periods.

Stores

4. As many directors and stands as available.

B CONDUCT OF LESSONApproach

5. State the aim of the lesson (see para 1), and tell the squad that the director is an instrument used in indirect fire for measuring vertical and lateral angles.

The instrument

6. Point out that the instrument consists of a body and a telescope. The telescope has graticules marked in 10 minutes, measuring up to 5 degrees above and below the centre of a central vertical hair line. There is no focussing. (In a later pattern the angle of sight graticules measure up to 4 degrees only). On top of the telescope is the level bubble which is a fixture with the telescope, and the levelling screw. The action of the latter is to bring the bubble central by bringing the telescope level. Below the levelling screw and on top of the body is the director level by which it can be ensured the director is upright. At the bottom of the body is the dial which measures 0 to 180 degrees right and left, and which is normally set at zero. In front of the body are the deflection drums which enable the director to be turned about the dial. The angle of deflection is measured to 5 degrees on the dial, and in degrees and minutes by the appropriate deflection drum. Each deflection drum and dial has its own pointer. Between the deflection drums is a quick release, which, by being depressed, enables the director to be turned about the dial without the use of the deflection drums. Below the body is a socket, by which the director is attached to a pivot on the stand. When attached, the director complete can be turned about the pivot, or clamped in the required position by means of the clamping nut. Without altering the settings on the direction dial and deflection drums fine adjustments in direction can be made with the fine adjustment screw, below the right deflection drum. The two pointers alongside indicate when this is central, as it should be when the director is first set up.

7. Question the squad on the instrument.

The stand

8. Show that the legs are adjustable. Point out the pivot, the universal joint and its clamping screw. State that the protecting cap must always be screwed on when the director is not in use.

Setting up the director

9. Demonstrate how to set up the director. Undo the strap holding the legs together. By loosening the milled headed screws extend the legs as necessary and tighten up the screws. Splay out the legs and mount the stand, with pivot at convinient height and approximately upright. If necessary tighten butterfly nuts. Press the legs firmly into the ground. Remove pivot protector and attach director. Ensure that fine adjustment screw is central. Loosen the universal joint clamping screw and centralize director level bubble. Tighten universal joint clamping screw. Hang the case over the stand.

10. Practise the squad in setting up their directors.

To take an angle of sight (normal)

11. Explain and demonstrate that the telescope is aligned on to the target, and the clamping nut tightened. The bubble is then levelled. by looking through the telescope the angle of sight can be read form the graticules. Stress that the readings must be to the nearest five minutes and that the bubbles must be central.

12. Practise the squad on various targets.

To take an angle of sight of more than 5 degrees. (Or of more than 4 degrees on the later pattern director).

13. State that if the angle of sight is note than 5 degrees, the director is laid at a convinient point above or below the target and the angle of sight to this point noted. The vertical angle between this point and the target is then measured with the graticules by means of the levelling screw. The sum of the two angles will give the angle of sight to the target.

14. Practise the squad.

To measure a vertical angle

15. To measure the vertical angle between two objects. Using the levelling screw, put the zero graticule on one of the objects, and from the scale read the angular measurement to the second object.

16. Practise the squad.

To measure the lateral angle between two points

17. Demonstrate that the dial and deflection drum are set at zero, and the fine adjustment pointers opposite each other. The clamping nut is loosened and the director laid approximately at the first point. The dial and drums should still be at zero. The clamping nut is now tightened and the hair line brought accurately on to the first point by means of the fine adjustment screw. Then using the deflection drums, the hairline is swung on to the second point. The angle can now be read in degrees off the dial and in degrees and minutes off the appropriate deflection drum. Stress that readings must be as accurate as possible and that care must be taken not to read off the wrong deflection drum. State that before the director is returned to its case all drums must be set at zero and the fine adjustment screw centralized.

18. Practise the squad in measuring switches.

Conclusion

19. Questions from the squad.

20. Further practise as required.

21. Sum up main points in the use of the director.

Lesson 44. – THE RESECTOR PROTRACTOR
A INSTRUCTORS NOTESAim

1. To teach the officer or NCO to determine the position of the pivot gun on the map by means of the resector protractor.

Class and instructors

2. This lesson will be taught to officers and NCOs only. Squads should be of not more than eight.

Periods

3. Two 45-minute periods, partly indoors and partly outdoors. This lesson should be taught normally just before lesson 116.

Stores

4. One resector protractor, map and mapboard per student. One director for every two students.

Preparation

5. The instructor must select a suitable position for the pivot gun beforehand.

Equipment

6. The squad will require notebooks and sharp pencils.

B CONDUCT OF LESSONApproach

7. State the aim of the lesson (see para 1 above).

Resector protractor

8. Describe the instrument. The squad should follow the instructor’s description with their instruments. The resector protractor consists of:–

(a) A protractor graduated from left to right and from right to left in degrees, and containing roamers for scales of 1/20000, 1/25000, and 1/63360. It has three pin holes drilled in it.

(b) A fixed arm containing graduations in hundreds of yards for a scale of 1/25000, a scale of angles of sight in minutes and two pin holes. One edge of the arm is bevelled.

(c) A lower pivotting arm with graduations in hundreds of yards for a scale of 1/10000, a scale of angles of sight in minutes and two pin holes. The arm is continued on the opposite side of the pivot in the form of a tail. One edge of the arm is bevelled.

(d) An upper pivoting arm with two pinholes, one bevelled edge and a tail on the opposite side of the pivot. The arm has a scale of 1/63360.

(e) A clamping screw with pencil hole.

Obtaining data

9. Move the squad to the site selected for the pivot gun and erect the director over the spot. (G in Fig 3).

10. State that three objects on the ground, with well defined edges, and which can be identified on the map, should be selected.
For the best results these objects should be as far away as possible and spaced fairly equally around the point G. (In the diagram these points are refered to as A, B and C).

11. Explain and demonstrate that the director is then laid on A with its drums and dials set at zero. From A, the switches to B and C should be measured and noted, (angles X and Y in the diagram). The same ends of the objects should be used, ie, all right ends or all left ends.

12. Practise the squad.

fig3
Resecting the position

13. Move the squad indoors.

14. Explain and demonstrate how to resect a position:–

(a) Take the resector and with all arms closed, hold it so that they are pointing away and release the clamping screw.

(b) Move the lower pivotting arm in an ant-clockwise direction and using the inner scale of the protractor, set the bevelled edge at the angle X.

(c) Move the upper pivotting arm in a clock-wise direction using the hairline on the tail and the outer scale, set the arm at the angle Y. Taking care that the arms do not move, tighten the clamping screw.

(d) Lay out the map on a flat surface, removing all creases and folds. A small pencilled cicle around each of the objects A, B and C will assist identification.

fig4

(e) The bevelled edge of the fixed arm should be laid on the left edge of A and then by moving the protractor around get the bevelled edges of the two pivoting arms over the left ends of B and C respectively as in Fig 4 above. Care must be taken that the eye is immediately above the bevelled edges when the resector is set.

(f) A sharp pencil through the hole in the clamping screw marks the position of No. 1 gun. The resector is removed and the mark circled in pencil.

(g) The accurate map references can be measured with a romer.

15. Practise the squad in resecting a position using the data obtained outdoors.

16. If time allows, practise the squad in the complete process of resecting a new pivot gun position.

Conclusion

17. Questions from the squad.

18. Sum up main points.

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