1951: Chapter 17 – Direct Fire – The Vickers Machine Gun

INTRODUCTORY NOTES

1. The direct fire unit is the section, because:-

(a) Two guns are required to give the necessary volume at the most usual machine gun ranges.
(b) In the evemt of the stoppage of one gun, sustained fire can be maintained by the other.
(c) It can be easily concealed and it not too vulnerable.

2. The requirements of fire control necessitate the two guns being under the command of a fire controller, who is supplied with a rangetaker to enable him to determine the range and to observe the fire.

3. In order to avoid casualties, the two guns of the section in action should be as far apart as possible, provided that the section commander is able to control the two guns by voice.

4. At distances beyond 2000 yards, the volume of fire produced by a section cannot always be relied upon to give results proportionate to the expenditure of ammunition, and the fire of two sections may have to be directed onto the same target from their respective positions.

LESSON 97 – FIRE ORDERS, DIRECT
A – INSTRUCTOR’S NOTES

Aim

1. To teach the sequence and layout of a direct fire order.

Class and instructors

2. One officer instructor and not more than 30 in the class.

Periods

3. One 45-minute period, lecture.

Stores

4. Blackboard and chalk.

Preparation

5. Write the sequence of a fire order on the blackboard.

B – CONDUCT OF LESSON

Approach

6. Give the aim of the lesson (see para 1 above).

7. State that the following is the procedure for engaging a target by a section:-

(a) The section commander by means of a fire order gives a range and indicates a point of aim on the target for both guns.
(b) Each firer sets his tangent sight at the range ordered, and by tapping the gun and by use of the handwheel, directs the line of sight on to the point ordered.

Issuing fire orders

8. Tell the class that fire orders are given in sequence as in para 9 below, and that sequence must not be departed from. Rigid adherence to the sequence will ensure that errors and emissions are detected immediately, and that the gun numbers, knowing what to expect, will act more quickly.

The orders must be given loudly and clearly, the section commander facing towards the guns. He must make up his mind what is the correct order to give before embarking on it. Long and unnecessary pauses, during which is is coming to a decision as to the next part of the order, can result only in inaccuracies and slovenly drill.

THE BEST FIRE ORDER IS THAT WHICH GETS BULLETS ONTO THE TARGET IN THE SHORTEST POSSIBLE TIME.

Sequence

9. Point out the sequence of a fire order:-

Designation.
Range (including wind allowance, if necessary).
Indication of the target.
Method of fire.
Lay.
Side wind allowance.
Rate of fire.
Order to fire.

10. Explain that when giving out the order, pauses should be made as under, until it is seen that the gun numbers are ready for the next part of the order:-

After method of fire

To enable the guns to be laid

After the range	To allow time to set the sights.
At various stages during the indication	Time must be given for points to be recognized. When degree method of indication is used, a pause must be made to enable the angles to be measured.
After wind allowance	To allow time to pick up an aiming mark.

Explanation of headings in fire order

11. Explain each heading of the fire order as under:-

(a) Range
- (i) Ranges when ordered to the guns will be given to the nearest 50 yards and according to the examples in Lesson 52, para 12.
- (ii) For the first target the section commander will usually obtain the range from the rangetaker but, where the situation demands if, he should not hesitate to estimate the range. For subsequent targets, to save time, tangers can be key ranged.
- (iii) When the range is ordered to the guns, it will be preceded by the word “All,” eg “All – one two hundred”.
- (iv) If the wind is sufficiently high to warrant a correction to elevation, the range will be corrected before being given out.
(b) Indication.- The section commander will indicate the target as laid down in Lesson 66. Reference points and degrees should be used only when they are necessary in order to indicate the target clearly.
(c) Method of fire.- This is dependent on whether the target has width, depth or neither. It may take any of the following forms:-
- (i) “Right and left-two taps “Lay”Both guns are laid on the target. When “Fire” is ordered, they are fired and tapped TWO TAPS right and left of the target. No. 1 gun starts tapping to the right first and No. 2 gun to the left.
- (ii) “Traversing lay”Both guns are laid on the centre of the target. When “Fire” is ordered each gun traverses its own half of the target.
- (iii) “Half way up – Right and Left – Two taps “Lay”Both guns are laid halfway up the depth of the target. When “Fire” is ordered each gun acts as in sub-para 1.
(d) Side wind.- The section commander will calculate the effect of the side wind to the nearest tap (Lesson 95).
It will be ordered to the guns in the following form:-“Wind – Right (or left) “Taps”. Nos. 1 tap their guns across by the number of taps ordered, pick up an aiming mark and report “On”. If the allowance is one degree or more, it should be ordered in degrees. Nos. 1 by means of a hand angle will pick up an aiming mark. If no correction is needed, this headed is omitted from the order.
(e) Rates of fire.- If no order is given, normal is implied. If it is desired to fire rapid, the order will be given before the order to “Fire”.
(f) The order to fire.- This will normally be given by the order “Fire”.

Orders during a shoot

12. State that the following orders may be given out during a shoot:-

(a) “Stop” This order is normally given by a signal.
(b) Ranging correction. These may be for:-
- (i) Direction.- The section commander converts the necessary correction into taps or degrees (if more than three taps) and orders it to one or both guns as required. Nos. 1 note the new aiming point.Examples:-“All, right two taps”
  “No 1 gun, left one degree”
- (ii) Elevation.- The section commander decides on a new range or the correction required and gives it out.Examples:-All, one four hundred”
  “All, down fifty”
  “No 1, up fifty”
- (c) “Go on” This order may be given verbally or by signal.

Conclusion

13. Questions to and from class.

14. Opportunity can be taken during Lessons 98 to 101 to practise the correct issue of fire orders.

15. Sum up main points.

LESSON 98 – POINT TARGETS
A – INSTRUCTOR’S NOTES

Aim

1. To teach the method of engaging a point target by direct fire.

Class and instructors

2. Lecture – One officer instructor and not more than 30 in the class; Practice – Squads under squad instructors.

Periods

3. One 45-minute period, lecture and demonstration; one 45-minute period, practice.

Stores

4. Lecture – Blackboard, and chalk, and landscape target; Practice – Director, gun, tripod, portable blackboard. Class require range tables.

Preparation

5. Select suitable targets on the landscape target. Prepare black board with diagrams as given in Fig 20.

6. Practice – Gun and tripod mounted ten yards to a flank of the director.

B – CONDUCT OF LESSON

Approach

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

8. Tell the class that a point target is a target that appears to the naked eye to have no width or depth, although in actual fact it must have both.

For example, a target may well be an enemy machine gun detachment covering a width of perhaps five yards. To the gun numbers all that may be visible may be the top of a steel helmet. The width of the beaten zone might not cover the actual width of the target.

Similarly, a point target may be visible to the section commander using his glasses, but presents to the gun numbers no clearly defined point on which to lay. The section commander can indicate the target using the clock ray and degree measurement from an auxiliary reference point, but it is unlikely that the guns will be laid very accurately.

Method of fire

9. State that to ensure that such types of targets are effectively engaged, one extra tap right and left will always be given. This will be in addition to the tap to cover errors in direction.

The rule is, therefore, point targets will always be engaged at all ranges with “RIGHT AND LEFT TWO TAPS.”

Lifts

10. Explain that errors in elevation will be overcome by the combined sight rule. Nos. 1 tapping right and left at each elevation.

Illustrate on the blackboard a section engaging a point target at 1200 yards (key ranging). (See Fig 20).

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Illustration

11. Illustrate the engagement of the following types of targets by a section:-

Point target below 1400 yards.

Point target between 1450 and 2000 yards.

The following examples of fire orders may be of assistance to the instructor:-

Reference points are as shown in Plate 21.

Target “A” – point target – 900 yards (rangefinder).

“All, nine hundred.
Right of arc – group of four large trees – left tree.
Right and Left – Two taps. Lay.
Rapid fire.”

Target “B” – Point target – 1650 yards (key ranging).

“All, one six fifty.
Poplar – right 3 o’clock – bush in hedgerow.
Right and Left – Two taps. Lay.
Wind, right one tap.
Fire”

“Stop.
All, down fifty.
Go on.”

“Stop.
All, up one hundred.
Go on.”

“Stop.
All, down one fifty.
Go on.”

“Stop.
All, up two hundred.
Go on.”

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Practice

12. Revise the lesson by questions.

13. Detail two gun numbers.

14. Lay the director on a simple target and left the remainder of the squad view.

15. The squad should work out the fire order individually and the instructor should then select a fire controller. The fire controller should then give out his fire order, the two gun numbers complying.

16. Discuss the fire order.

17. Proceed as above with other targets.

Conclusion

18. Questions from squad.

19. Sum up main points and discuss progress made.

LESSON 99.- TRAVERSING TARGETS
A – INSTRUCTOR’s NOTES

Aim

1. To teach the method of engaging a traversing target by direct fire.

Class and instructors

2. Lecture.- One officer instructor and not more than 30 in the class. Practise squads under squad instructors.

Periods

3. One 45-minute period, lecture; one 45-minute period, practice.

Stores

4. Lecture – Blackboard, chalk, two guns; Practice – Director, gun, tripod, portable blackboard. Class require range tables.

Preparation

5. Select suitable targets on the landscape target. Prepare blackboard with diagrams as given in Fig 22.

6. Practice – Gun and tripod mounted 10 yards to a flank of the director. The instructor should select targets before the lesson starts.

B – CONDUCT OF LESSON

Approach

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

8. Tell the class that a traversing target is a target that appears to the naked eye to have width, eg, a group of bushes, or a hedgerow.

A traversing target may well have a different angle of sight to each end, eg, a hedgerow running up the side of a hill. But so long as it has no greater difference than 50 yards in the range to each end, it is a traversing target.

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9. State that a section should not engage a target more than 100 yards wide. If a target exceeds this width, it must be split up and engaged as separate targets.

Method of fire

10. Explain that the method of engaging a traversing target is as follows:-

On the order “Traversing lay”, both guns are laid in the centre of the target. On the order “Fire” both guns fire at the centre.

Each gun is then tapped one tap outwards, the line of sight relayed and fired again. This process is continued until the guns reach the end of the target. They are then tapped one tap outside of the ends to cover errors in direction and then traversed back to the centre. To ensure the overlap of the beaten zones at the centre, each gun is tapped one tap over the centre (see Fig 22). The line of sight is re-aligned onto the target after each tap.

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Lifts

11. Tell the class that errors in elevation will be overcome by the combined sight rule, gun numbers traversing their own half of the target at each elevation.

Obscuration

12. State that when engaging a target that is likely to become obscured, the section commander will order Nos. 1 to lay their guns a quarter way in from each end of the target, and order “Pick up aiming mark”. The section commander will measure the width of the target with his binoculars, divide it by four and bring it to the nearest tap, adding one tap for overlap. Guns can then engage each half of the target by tapping right and left the number of taps ordered.

Example:-

Target = 2 deg 40 min wide

2 deg 40 min divide 4 = 40 min = 3 taps (to the nearest).

Add one tap for overlap

“Right and left 4 taps”

Demonstration

13. Demonstrate the engagement of the following types of targets, by a section:-

Traversing target at all ranges.

Traversing target with a different angle of sight to each end.

The following examples of fire orders may be of assistance to the instructor:-

Reference points are as shown in Plate 22.

Target “C” – traversing target – 900 yards (rangefinder).

“All, nine hundred.
Poplar, – 6 o’clock – right end of house – left limit.
Right 3 o’clock – 2 degrees – bush – right limit.
Traversing lay.
Fire.”

Target “D” 1350 yards (estimated).

“All, one three fifty.
Haystack – left 11 o’clock – group of bushes at corner of field.
Traversing lay.
Fire.”

“Stop.
All, down fifty.
Go on.”

“Stop.
All, up one hundred.
Go on.”

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Practice

14. Revise the lecture by questions.

15. Detail two gun numbers.

16. Lay the director on a simple target and let the remainder of the squad view.

17. The squad should work out the fire order individually and the instructor should then select a fire controller. The fire controller should then give out his fire order, the two gun numbers complying.

18. Discuss the fire order.

19. Proceed as above with other targets.

Conclusion

20. Questions from squad.

21. Sum up main points and discuss progress made.

LESSON 100.- DEPTH TARGETS
A – INSTRUCTOR’S NOTES

Aim

1. To teach the method of engaging a depth target by direct fire.

Class and instructors

2. Lecture – One officer instructor and not more than 30 in the class; Practice – Squads under squad instructors.

Periods

3. One 45-minute period, lecture and demonstration; one 45-minute period, practice.

Stores

4. Lecture – Blackboard, chalk, landscape target; Practice – Directors, gun, tripod, portable blackboard. Class require range tables.

Preparation

5. Select suitable targets on the landscape target. Prepare blackboard with diagrams given in Figs 23 and 24.

6. Practice – Gun and tripod mounted ten yards to a flank of the director. The instructor should select targets before the lesson begins.

B – CONDUCT OF LESSON

Approach

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

8. Tell the class that a depth target is a target that has a difference in the range to each end of more than 50 yards. A section should not engage a target with a greater depth than 200 yards. If a target exceeds this depth, it must be split up and be engaged as separate targets.

9. State that a depth target can take two forms, it can either have no appreciable width or it can have width. In other words, as regards direction, it can appear to be a point target or a traversing target. For direction, then, a depth target should be treated as laid down in Lesson 98 and Lesson 99.

Method of engaging

10. Explain that the method of engaging a depth target is as follows:-

The section commander will indicate the limits of the target and order

“Halfway up. Right and Left. Two taps. Lay.”

If the target is more than 30 minutes wide the order will be “Traversing Lay,” as Right and Left two taps will not cover the width of the target and allow for errors in direction.

The section commander will then apply sufficient lifts in the form “All down fifty – All up one hundred etc.” to cover the depth of the target, the guns being tapped or traversed at each elevation.

On a target with no appreciable width, the line of sight will be maintained on the centre of the target throughout. On a target with width, the line of sight will be re-aligned as the guns traverse across their own half of the target.

11. Illustrate the engagement of the two types of target on the blackboard (see Figs 23 and 24).

12. State that if the difference in range between the ends of a target is 150 yards, then the range 50 yards short of the far end should be used as the opening elevation. In this case, to cover the depth of the target, two elevations below the opening elevation will be required and only one above.

Example:-

Target 1000 yards far end, 850 yards near end.

Order	Range
“All, 950.”	950
“All, down 50.”	900
“All, up 100.”	1000
“All, down 150.”	850

13. Point out that when a target is on a forward slope, there will be a difference in the angle of sight between the centre of the target and its ends. In such a case, the beaten zones may not reach to the ends of the target. To ensure that they do so, the section commander should order additional elevations at his discretion.

Errors in elevation

14. Errors in elevation will be overcome by the combined sight rule. If additional elevations are required by the combined sight rule, the section commander should order them when he has covered the depth of his target. The mean of the ranges to the near and far ends should be used as the basis for determining the number of extra elevations required by the combined sight rule.

15. Illustrate the engagement of the following types of targets by a section:-

Depth target – no width.

Depth target – with width.

Depth target – 150 yards difference in range to each end.

The following examples of fire orders may be of assistance to the instructor:-

Reference points are as shown in Plate 23.

Target “E” – Depth target – no width; Far end – 897 yards; Near end – 708 yards.

“All, eight hundred.
Poplar, right 4 o’clock, T-shaped junction of hedgerows – Far end.
6 o’clock, end of hedgerow – Near end.
Halfway up, right and left – two taps. Lay.
Wind, left one tap.
Fire.”

“Stop.
All, down fifty.
Go on.”

“Stop.
All, up one hundred.
Go on.”

“Stop.
All, down one fifty.
Go on.”

“Stop.
All, up two hundred.
Go on.”

Target “F” – Depth target – with width; Far end – 1300 yards (estimated); Near end – 1200 yards (estimated).

“All, one two fifty.
Poplar, left 8 o’clock, junction of hedgerow – Far end.
Left 8 o’clock, another junction – near end.
Traversing Lay.
Fire.”

Depth of target

“Stop.
All, down fifty.
Go on.”

“Stop.
All, up one hundred.
Go on.”

Combined sight rule.

“Stop.
All, down one fifty.”

“Stop.
All, up two hundred.
Go on.”

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Practice

16. Revise the lesson by questions.

17. Detail two gun numbers.

18. Lay the director on a simple target and let the remainder of the squad view.

19. The squad should work out the fire order individually and the instructor should then select a fire controller. The fire controller should then give out his fire order, the two gun numbers complying.

20. Discuss the fire order.

21. Proceed as above with other targets.

Conclusion

22. Questions from squad.

23. Sum up main points and discuss progress made.

LESSON 101.- MOVING TARGET
A – INSTRUCTOR’S NOTES

Aim

1. To teach the method of engaging moving targets by direct fire.

Class and instructors

2. Lecture – One officer instructor and not more than 30 in the class; Practice – Squads under squad instructors.

Periods

3. One 45-minute period, lecture and demonstration; one 45-minute period, practice.

Stores

4. Lecture – Blackboard, chalk, landscape target; Practice – Director, gun, tripod, portable blackboard. Class require range tables. MT vehicle and driver.

Preparation

5. Select suitable targets on landscape target. To represent moving targets, prepare a landscape target as under (see Fig 25 below).

Practice

6. Gun and tripod mounted to a flank of the director. The instructor should decide and arrange the route, speed and timings of the vehicle acting as target beforehand.

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B – CONDUCT OF LESSON

Approach

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

8. State that there are two methods of engaging a moving target:-

(a) Engaging an area through which the target is likely to pass. This method is suitable for fleeting targets, such as infantry making use of ground, and unarmoured vehicles. It is carried out by selecting areas through which the target is likely to pass, and giving an anticipatory order based on the estimation of the speed and direction of the target.
(b) Swinging traverse.- This is a suitable method of engaging moving targets at close range, when other methods would be too slow, or it may be used when the target is particularly suited to this method of engagement, eg, a line of infantry.

Fire control

9. Tell the class that:-

(a) Fire orders must be short and simple, otherwise the opportunity of engaging the target may be lost.
(b) The section commander will maintain control until, owing to the closeness of the range or other factors, greater fire effect may be expected from gun control. He must change to gun control before unit fire control breaks down.
(c) When engaging a moving target, whether by a section or gun control, attention must be directed continually to:-
(i) The changing line of sight, both horizontally and vertically.
(ii) Alterations in range.
(iii) The amount which the fire has to be directed in front of the target. This depends upon the speed and direction of the target.

10. Explain that the appropriate angle in minutes through which the target will travel during the time of flight of the bullets can be determined by multiplying the target speed in miles per hour by the factor 5 at all ranges.

For targets moving obliquely across the line of fire, a proportion of this allowance should be given.

Guns are not tapped right and left, nor is the combined sight rule applied.

Demonstration

11. Demonstrate the engagement of a moving target by a section.

12. The following examples of fire orders may be of use to the instructor:-

Target – A lorry moving from right to left at ten mph.

The allowance will be 10 mph x 5 = 50 minutes.

“All, one four hundred.
Left of arc – house – right 3 o’clock – hedge junction.
Lay.
Wind, left one tap.
Await my order.”

The section commander picks up a point 50 minutes to the right of the hedge junction. When the target reaches this point, he gives the order to fire.

Target – Enemy advancing across field, range 400 yards.

“All, battle sight.
Enemy advancing across field.
Swinging traverse.
Fire.”

Practice