Slide 1

Unclassified

Suppression and the Efficiency of
Infantry Soldiers
Dr. Eylam Gofer, Ben Levav, Yohay Gerafi


Slide 2

Unclassified

Background
 Combat models tend to focus on:
 The battlefield
 The weapons
 Both factors are physical and quantifiable
 The soldier is less emphasized

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Slide 3

Unclassified

Background cont.
 Soldiers are expected to perform different tasks on
Fear
the battlefield and operate various weapons

results
from
the
 They are also affected by:
obvious threat to
• Physiological factors
one’s life
• Psychological factors
Subjective and
• Human-weapons system interface
varied between
• …
soldiers
 Most of these influences are subjective
therefore
Is theand
basis
to the
vary from one soldier to the other

phenomenon called
suppression
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Slide 4

Unclassified

Suppression - Definition
 Time-limited degradation of combat
efficiency of a unit or an individual
subjected to enemy fire

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Slide 5

Unclassified

Quantitative Approach
 “Macro” approach: Marshall, Wigram, and
Rowland
 Mainly define degradation measures to combat
efficiency
 We tried to use a “Micro” approach that
focuses on the soldiers activities in combat and
how they are affected by suppression

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Slide 6

Unclassified

Objective
 Describing, Quantifying and Analyzing Fire
Suppression Effect on Infantry Soldiers in
Combat

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Slide 7

Unclassified

Method
General
Suppression Model

Soldier advancing

Soldier in a “foxhole”
or behind a temporary
cover

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Slide 8

Unclassified

1st

3rd

2nd

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Slide 9

Unclassified

Down Hill
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Slide 10

Unclassified

Scanning
The Field
of Fire

Target
Acquisition

Aiming

Firing

“BDA”

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Slide 11

Unclassified

t1

t2

t3

t4

t5

 Soldier Activity Cycle:
 Length: Tw  t1  t 2  t3  t 4  t5
Fire
Nominal
Rate Fire
in Training
Rate
 Rate: w  1 / Tw
Scanning
Target
The Field
Combat condition
degradationAiming
Acquisition
of Fire
[Rowland, 1986]

0.66
0.1 (shots/sec)
(shots/sec)
Firing

“BDA”

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Slide 12

Unclassified

Down Hill
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Slide 13

Unclassified

Effect of Suppression
Scanning
The Field
of Fire

Target
Acquisition

Indirect
Fire

Aiming

Suppressing
Event

 Suppressing events:
 Time between events: Ts
 Rate: s  1 / Ts
 Duration of suppression:

Firing

“BDA”

Direct
Fire

t
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Slide 14

Unclassified

Suppression Duration
 Approximate duration: Seconds
 Not deterministic, variance sources:
• Between soldiers
• Between events, for the same soldier
• Between the weapons or ammunition that
cause the suppression - mainly caliber
 Therefore we regard t as a random variable
t~Gamma(,1/|cal)
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Slide 15

Unclassified

Direct Fire Gamma Distributions
0.06
'5.0 ‫קליע‬
12.7 mm (50
cal.)
7.62 mm ‫ מ"מ‬26.7 ‫קליע‬
5.56 mm ‫ מ"מ‬65.5 ‫קליע‬

0.05

‫הצפיפות‬
Density

0.04

0.03

0.02

0.01

80

76

72

68

64

60

56

52

48

44

40

36

32

28

24

20

16

12

8

4

0

0

Suppression
Duration
)‫(שניות‬
‫מתחמושת קליעית‬
‫(הדיכוי‬Seconds)
‫משך‬
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Slide 16

Unclassified

General Model
The Soldier
Activity Cycle
Length - Tw
Rate - w=1/ Tw

Suppression
Model

The Soldier
Suppressed Activity
Rate - ’w
Degradation rate

Suppressing Event
Length - Ts
Rate - s=1/ Ts
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Slide 17

Unclassified

Results
 Simulation:
 On-going soldier activity cycle
 A sequence of suppressing events - each
with a random duration
 “Disturbing” the soldier activity cycle
 Measuring the activity rate with the
disturbance

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Slide 18

Unclassified

Direct Fire - Fire Rate Under
Suppression
0.090

‫ מ"מ‬5.56

5.56 mm

(shots/sec)
Foxhole
Rate From
Fire)‫לשנייה‬
‫קצ ה ש‬
‫הנו ית‬
‫מהעמדה (כדו י‬

0.080

‫ מ"מ‬7.62
0.070

7.62 mm

0.060

12.7 mm (50 cal.)

‫מ"מ‬

2.7

0.050

0.040

0.030

0.020

0.010

0.000
0

0.05

0.1

0.15

0.2

0.25

)‫לשנייה‬
‫ ( כדו‬Enemy
‫כלפי העמדה‬
‫קצ ה ש הנו ית‬
Fire‫ י‬Rate
(shots/sec)

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Slide 19

Unclassified

Direct Fire - Degradation Rate (%)
100%
90%

‫ההנחתה קצ‬
) ( ‫ה ש מהעמדה‬Rate
(%)
Degradation

80%
70%

60%
50%

‫ מ"מ‬5.56
5.56 mm
‫ מ"מ‬7.62
7.62 mm
12.7 mm
(502.7
cal.)
‫מ"מ‬

40%
30%

20%
10%
0%
0

0.02

0.04

0.06

0.08

0.1

0.12

)‫לשנייה‬
‫ ( כדו‬Enemy
‫כלפי העמדה‬
‫קצ ה ש הנו ית‬
Fire ‫י‬Rate
(shots/sec)

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Slide 20

Unclassified

Indirect Artillery Fire
 Direct fire is usually more accurate due to
range and system accuracy - It is reasonable to
assume the majority of the shots fired will hit
the vicinity of the post close surrounding,
therefore suppressing the soldier in it
 Indirect fire is statistical - Not every round will
cause suppression

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Slide 21

Unclassified

Probability of Suppression
 [Mueller & Pietsch, 1978] - empirical study
 Ammunition calibers examined: 155mm, 81mm
 The main result: formulation of the probability of
suppression when the ammunition caliber (D) and
impact distance (r) are given: P(suppression|r,D)
 We have transformed that into P(suppression|R,D)
 R - the distance of the position from the aiming
point (assuming artillery fire CEP is 30 meters)
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Slide 22

Unclassified

81 mm

Probability of Suppression

155 mm





P(suppression | R)  0.89  exp  8 10 5  R 2  0.02

Distance of the Artillery Aiming Point from the Post (meters)

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Slide 23

Unclassified

Suppression Duration
 [Mueller & Pietsch, 1978] give a rather low
empirically-based estimate
 This, we assume, is due to the absence of real
danger to the subjects during the experiment
 Again, based on [Rowland, 1986], it is
reasonable to assume figures are about ten
times larger

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Slide 24

Unclassified

Indirect Fire - Fire Rate Under
Suppression
Position Fire Rate
(shots/minute)

Time Between
rounds (seconds)

Position Distance From Aiming Point (meters)
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Slide 25

Unclassified

Concluding Remarks
 The suppression model is one of the building
blocks of the methodology for comparing
force configurations based on operational
efficiency
 The mathematical results can be, and already
have been, incorporated in different models,
modules and combat simulators

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Slide 26

Unclassified

Thank you!
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