Tactile and Visual Identification of the XM106 Bursting 

Smoke Grenade: Limited User Evaluation 

by Clifford C. Swiecicki, Elizabeth S. Redden, and Christian B. Carstens 

ARL-TR-5416 December 2010 

Approved for public release; distribution is unlimited. 
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Army Research Laboratory 

Aberdeen Proving Ground, MD 21005-5425 

ARL-TR-5416 December 2010 

Tactile and Visual Identification of the XM106 Bursting 

Smoke Grenade: Limited User Evaluation 

Clifford C. Swiecicki, Elizabeth S. Redden, and Christian B. Carstens 

Human Research and Engineering Directorate, ARL 

Approved for public release; distribution is unlimited. 
ii

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PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 

1. REPORT DATE (DD-MM-YYYY)

December 2010 

2. REPORT TYPE 

Final 

3. DATES COVERED (From - To) 

17–25 September 2009 

4. TITLE AND SUBTITLE 

Tactile and Visual Identification of the XM106 Bursting Smoke Grenade: Limited 

User Evaluation 

5a. CONTRACT NUMBER 

5b. GRANT NUMBER 

5c. PROGRAM ELEMENT NUMBER 

6. AUTHOR(S) 

Clifford C. Swiecicki, Elizabeth S. Redden, and Christian B. Carstens 

5d. PROJECT NUMBER 

ARL-20098-09040 

5e. TASK NUMBER 

5f. WORK UNIT NUMBER 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 

U.S. Army Research Laboratory 

ATTN: RDRL-HRM-DW 

Aberdeen Proving Ground, MD 21005-5425 

8. PERFORMING ORGANIZATION 

 REPORT NUMBER 

ARL-TR-5416 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 

PM Smoke - JPM R&PI 

ATTN: SFAE-CBD-NBC-R 

Aberdeen Proving Ground, MD 21010-5424 

10. SPONSOR/MONITOR’S ACRONYM(S) 

11. SPONSOR/MONITOR'S REPORT 

 NUMBER(S) 

12. DISTRIBUTION/AVAILABILITY STATEMENT 

Approved for public release; distribution is unlimited. 

13. SUPPLEMENTARY NOTES 

14. ABSTRACT 

This experiment evaluated the tactile and visual identification of the XM106 bursting smoke grenade in a variety of situations 

representing the typical handwear and eyewear configurations of dismounted Warfighters. Thirty-six test Soldiers participated 

in the evaluation from 17 to 25 September 2009. After being trained on the visual and tactile features of the XM106 bursting 

smoke grenade and the M83 smoke grenade (with and without a “pull safe” device), each Soldier completed tactile and visual 

identification performance trial exercises. Tactile identification trials had Soldiers identify grenades by touch alone, using bare 

hands; contact gloves; nuclear, biological, and chemical (NBC) gloves; and cold weather gloves. Visual identification trials 

had Soldiers identify grenades using normal vision, the Enhanced Night Vision Goggles, the AN/PVS-14 night vision goggles, 

the NBC protective mask, and the ballistic laser eye protection system with tinted lens. Performance trials included 

identification under a cognitive load (while operating a robot) and identification while under a physical load (individual 

movement techniques). The XM106 was also evaluated through the use of Soldier questionnaires and observations from 

representatives of the U.S. Army Research Laboratory, Human Research and Engineering Directorate. Findings indicated that 

the XM106 bursting smoke grenade could be readily distinguished from the M83 smoke grenade under all handwear and 

eyewear conditions. 

15. SUBJECT TERMS

XM106, smoke grenade, tactile/visual identification 

16. SECURITY CLASSIFICATION OF: 

17. LIMITATION 

OF ABSTRACT 

UU 

18. NUMBER 

OF PAGES 

44 

19a. NAME OF RESPONSIBLE PERSON

Clifford C. Swiecicki 

a. REPORT 

Unclassified

b. ABSTRACT 

Unclassified

c. THIS PAGE 

Unclassified

19b. TELEPHONE NUMBER (Include area code) 

706-545-9140 

Standard Form 298 (Rev. 8/98) 

Prescribed by ANSI Std. Z39.18 
iii

Contents 

List of Figures v

List of Tables vi

1. Introduction 1

1.1 Differentiation Between Grenades ..................................................................................1

1.2 Overview of Experiment .................................................................................................2

1.3 Objectives ........................................................................................................................2

1.3.1 Handwear Compatibility .....................................................................................2

1.3.2 Eyewear Compatibility ........................................................................................3

1.3.3 Physical Load ......................................................................................................3

1.3.4 Cognitive Load ....................................................................................................3

2. Method 3

2.1 Participants ......................................................................................................................3

2.2 Apparatus.........................................................................................................................3

2.2.1 XM106 Grenade, Hand, and Smoke: Visual Restricted Terrain ..........................3

2.2.2 M83 White Smoke Hand Grenade ........................................................................5

2.3 Instruments ......................................................................................................................5

2.4 Procedures .......................................................................................................................6

2.4.1 Overview of Activities ........................................................................................6

2.4.2 Soldier Orientation ..............................................................................................6

2.4.3 Medical Status .....................................................................................................6

2.4.4 Demographics ......................................................................................................6

2.4.5 Training ...............................................................................................................7

2.4.6 Tactile Differentiation Using Gloves and Bare Hands ........................................7

2.4.7 Visual Differentiation Using Normal Vision, Night Vision Goggles, NBC 

Mask, and Tinted Eye Protection ..................................................................................11

2.4.8 Differentiation While Experiencing a Cognitive Load .....................................16

2.4.9 Differentiation After Physical Exertion ............................................................17

3. Results 18

3.1 Demographics ................................................................................................................18
iv

3.2 Training .........................................................................................................................18

3.3 Tactile Differentiation Using Gloves and Bare Hands ..................................................18

3.4 Visual Differentiation Using Normal Vision, Night Vision Goggles, NBC Mask, 

and Tinted Eye Protection ......................................................................................................20

3.5 Differentiation While Experiencing a Cognitive Load .................................................20

3.6 Differentiation After Physical Exertion ........................................................................20

4. Conclusions 21

5. Recommendations 22

Appendix A. Demographics 23

Appendix B. XM106 Training and End of Experiment Questionnaire 27

Distribution List 34
v

List of Figures 

Figure 1. XM106 bursting smoke grenade. ....................................................................................4

Figure 2. Fielded version of the M83 smoke grenade without pull-safe device. ............................5
vi

List of Tables 

Table 1. Order of grenades requested from the box barehanded. ...................................................7

Table 2. Order of grenades requested from the box using Nomex gloves. .....................................8

Table 3. Order of grenades requested from the box using NBC gloves. ........................................8

Table 4. Order of grenades requested from the box using cold weather gloves. ............................9

Table 5. Order of grenades presented one by one using cold weather gloves. ...............................9

Table 6. Order of grenades presented one by one using NBC gloves. .........................................10

Table 7. Order of grenades presented one by one using Nomex gloves. ......................................10

Table 8. Order of grenades presented one by one using bare hands. ............................................11

Table 9. Order of grenades requested when normal vision is used. .............................................11

Table 10. Order of grenades requested when ENVG are worn. ...................................................12

Table 11. Order of grenades requested when AN/PVS-14s are worn. .........................................12

Table 12. Order of grenades requested when tinted eye protection is worn. ................................13

Table 13. Order of grenades requested when the NBC mask is worn. .........................................13

Table 14. Order of grenades presented one by one when NBC mask is worn. ............................14

Table 15. Order of grenades presented one by one when tinted eye protection is worn. .............14

Table 16. Order of grenades presented one by one when AN/PVS-14s are worn. .......................15

Table 17. Order of grenades presented one by one when ENVG are worn. .................................15

Table 18. Order of grenades presented one by one when normal vision is used. .........................16

Table 19. Order of grenades presented one by one when Soldier is operating a robot. ...............16

Table 20. Order of grenades requested after completion of the 3- to 5-s rushes. .........................17

Table 21. Order of grenades presented one by one after completion of the MOUT IMT. ...........18

Table 22. Tactile differentiation using gloves and bare hands results. .........................................19

Table 23. Grenade identification errors for Soldiers using bare hands. ........................................19

Table 24. Grenade identification errors for Soldiers using Nomex gloves. ..................................19

Table 25. Grenade identification errors for Soldiers using NBC gloves. ......................................19

Table 26. Grenade identification errors for Soldiers using cold weather gloves. .........................19

Table 27. Visual differentiation using normal vision and eyewear results. ..................................20

Table 28. Visual differentiation for Soldiers during a cognitive load. .........................................20

Table 29. Grenade identification errors for Soldiers experiencing a cognitive load. ...................20

Table 30. Tactile differentiation after physical exertion. ..............................................................21

Table 31. Grenade identification errors after physical exertion. ..................................................21
1

1. Introduction 

Hand grenades have been effective weapons in the arsenals of fighting forces for hundreds of 

years. Skennerton1

 dates the first use of the grenade to be sometime during the 15th century. 

Hand grenades were widely used in World Wars I and II, the Korean War, and the Vietnam 

War.1˗3 Over time, their major role changed from that of an offensive weapon to a defensive 

weapon (e.g., production of smoke to obscure vision). Although hand grenades appear to be 

simple to use, safe, and effective, operation can be difficult. Without proper training, the hand 

grenade can be more lethal to the person employing it than to the enemy. 

There are basically two types of smoke grenades: emission smoke grenades (those from which 

smoke escapes rather slowly from emission holes and that create heat which can harm the user) 

and bursting grenades (those from which smoke is spread by explosive action and that create an 

explosion which can harm the user). Incorrect use of either can cause injury or fatality; however, 

bursting grenades are much more dangerous to users, as they must throw the grenade quickly 

before it explodes. Thus it is particularly important to easily distinguish a bursting smoke 

grenade and one from which smoke is slowly emitted. 

1.1 Differentiation Between Grenades 

Differentiation of rounds of ammunition and types of grenades has been a topic of study for 

many years. Tactile markings, color coding, iconic drawings, shapes, etc., have been considered 

to help with the differentiation of ammunition and grenades. In the late 1960s, the Engineering 

Sciences Laboratory Information Report no. 2544

 was prepared by the Human Factors Section of 

Picatinny Arsenal, which investigated the problem of differentiating hand grenades with a delay 

fuze from those with an impact fuze. It discussed the advantages and disadvantages of six 

different approaches to solving the differentiation problem. The approaches included color 

coding, a pictorial display on the grenade body, an embossed safety lever, a dual safety, a 

knurled plastic tab or cap fitted to the grenade body and secured by the fuze, and user training. 

The recommendation from the report was that a knurled plastic cap placed upon the upper half of 

the grenade body offered the best means of differentiating dissimilarly fuzed grenades. 

Engineering Sciences Laboratory Information Report no. 255,5 a follow-on to the previous 

report, provided the results from a field study of the grenade with the knurled plastic cap and a 

 1

Skennerton, E. D. An Introduction to British Grenades; Margate: Dural, Austrailia, 1988. 

2Canfield, B. N. U.S. Infantry Weapons of the First World War; Andrew Mowbray, Inc.: Lincoln, RI, 2000. 

3Canfield, B. N. U.S. Infantry Weapons of World War II; Andrew Mowbray, Inc.: Lincoln, RI, 1996. 

4Human Factors Section, Picatinny Arsenal. Differentiating Hand Grenades Fuzed With a Delay Fuze From Those Fuzed 

With an Impact Fuze; Report no. 254; Engineering Sciences Laboratory Information: Picatinny Arsenal, NJ, 1966. 

5

Human Factors Section, Picatinny Arsenal. Effectiveness of a Knurled Plastic Cap as a Grenade Coding Device; Report 

no. 255; Engineering Sciences Laboratory Information: Picatinny Arsenal, NJ, 1966. 
2

standard M26 delay fuzed grenade. Blindfolded subjects had to differentiate between the two 

types of grenades solely by the sense of touch with bare hands and while wearing Arctic gloves. 

Correct differentiation was achieved over 97% of the time, which demonstrated that a knurled 

plastic cap was an effective aid in differentiating grenades with different functions. 

1.2 Overview of Experiment 

This study was an investigation of Soldiers’ ability to differentiate between the XM106 and two 

versions of the M83 smoke grenade rounds. Several smoke grenades are currently fielded; they 

are all very similar in terms of physical characteristics. The M83 was chosen as a representative 

of currently fielded smoke grenades. Many of the XM106 physical characteristics are similar to 

these other smoke grenades as well. However, the XM106 is a bursting grenade and needs to be 

thrown immediately after the pin is pulled, otherwise the Warfighter incurs the risk of injury or 

compromise to the mission. Therefore, it is important that the Warfighter be able to distinguish 

the XM106 from other smoke grenades. Currently, the most distinguishing feature of the 

XM106 is the “pull-safe” device on top, which is not a feature of the M83. However, the pullsafe device is envisioned to be placed on other smoke grenades in the future. Therefore, it is 

important to include an M83 with this device added in the experiment to ensure that Soldiers will 

be able to differentiate between the M83 and the XM106 in the future. 

The experiment took place at Fort Benning, GA. Thirty-six Soldiers from the Officer Candidate 

School (OCS) and Warrior Training Center (WTC) participated in the study. After training on 

the characteristics of the grenades, each Soldier completed exercises in which they had to 

differentiate between the grenade types. The presentations were counterbalanced, and the design 

of the XM106 was evaluated based on objective performance data, data collector observations, 

and information from Soldier questionnaires. 

1.3 Objectives 

The primary objectives of this experiment were to evaluate the capability of Soldiers to 

distinguish between the current M83 and the XM106 and between the M83 with “pull-safe 

(w/PS)” device (envisioned for the future) and the XM106. Trials were conducted to evaluate 

the Soldiers’ ability to correctly identify grenades under various environmental clothing 

conditions. The major goals were as follows: 

1.3.1 Handwear Compatibility 

• Assess the impact of various handwear on the Soldiers’ ability to correctly distinguish the 

XM106 from the two versions of the M83 smoke grenades using their bare hands or while 

wearing contact gloves; nuclear, biological, and chemical (NBC) gloves; and cold weather 

gloves. 

• Soldiers’ overall ratings of identification tasks. 
3

1.3.2 Eyewear Compatibility 

• Assess the impact of various eyewear on the Soldiers’ ability to correctly identify or 

distinguish the XM106 from the two versions of the M83 smoke grenades using their 

normal vision or while wearing the Enhanced Night Vision Goggles (ENVG), AN/PVS-14, 

NBC protective mask, and ballistic laser eye protection system (BLEPS). 

• Soldiers’ overall ratings of identification tasks. 

1.3.3 Physical Load 

• Assess the impact of a physical load on the Soldiers’ ability to correctly identify or 

distinguish between the XM106 and the two versions of the M83 smoke grenades using 

their bare hands and normal vision. 

• Soldiers’ overall ratings of identification tasks. 

1.3.4 Cognitive Load 

• Assess the impact of a cognitive load on the Soldiers’ ability to correctly identify or 

distinguish between the XM106 and the two versions of the M83 smoke grenades using 

their bare hands and normal vision. 

• Soldiers’ overall ratings of identification tasks. 

2. Method 

2.1 Participants 

Thirty-six Soldiers were recruited from the OCS and WTC to participate in the study. Although 

the OCS and WTC were officially requested for troops, it was made clear that Soldier 

participation in the experiment was voluntary. OCS Soldiers included those with prior service as 

well as those who entered directly from college.

2.2 Apparatus 

2.2.1 XM106 Grenade, Hand, and Smoke: Visual Restricted Terrain 

The XM106 (figure 1) answers the need for rapid obscuration in urban operations and restricted 

terrain. The grenade weighs 18.8 oz and is 2.5 inches in diameter and 5.55 inches long. The 

XM106 contains titanium dioxide, a nontoxic, noncombustible fill, and is explosively dispersed 

to form a dense, obscurant cloud within 1–2 s after employment. The XM106 uses 8 g of 

potassium perchlorate, aluminum, and pentaerythritol with nitrocellulose binder burster mix, 
4

Figure 1. XM106 bursting smoke grenade. 

which is initiated by the M201A1 MOD3 fuze. Although it is safer and less toxic than current 

smoke grenades, its short fuze and the burster composition make it dangerous to untrained 

Soldiers. The cloud formed by the XM106 is a particulate, rather than a toxic burning smoke 

generated by the AN M8 grenade. The XM106 obscures the visual and near-IR spectra. In an 

outdoor environment, the XM106 provides 5–9 s of effective obscuration (weather dependent). 

For long-lasting smoke (outdoor only), the M8 or M83 could be employed in conjunction with 

the XM106. Inside of a building, the XM106 provides 1.5–2 min of effective obscuration (it 

visually obscures a 12- × 12- × 12-ft room). 

The XM106 will be employed in three mission areas: 

• Detection Avoidance. The Warfighter will employ the XM106 in uncertain situations, 

(e.g., suspected ambush sites in restricted terrain) to degrade threat detection, observation, 

and engagement capabilities by the aided (image intensifiers and viewers) and unaided eye, 

and electro-optical devices associated with various weapon systems and equipment. 

• Breaking Contact. The Warfighter will employ the XM106 to rapidly break line-of-sight 

contact with threat forces when unexpected detection, observation, or engagement has 

occurred. 

• Assault Position. The Warfighter will employ the XM106 to cover dismounted maneuver 

prior to or during an assault on a threat position. 
5

The XM106 grenade features a pull-safe device to prevent premature or inadvertent functioning 

of the grenade (the M83 currently does not have this device). Inert variants of the XM106 and 

M83 smoke grenades will be used in the study. The XM106 has similar physical characteristics 

to the M83. Its color is a lighter green than the forest green of the M83 with a brown band, and 

has a smooth top as compared to the indention on the top of the M83 grenade. 

2.2.2 M83 White Smoke Hand Grenade 

The M83 smoke hand grenade (figure 2) is used for screening the activities of small units and for 

ground-to-air signaling. The body is a cylinder of thin sheet metal, 2.5 inches in diameter, which 

is filled with 11 oz of terephthalic acid. The fuze is an M201A1. The grenade weighs 16 oz and 

is 2.5 inches in diameter and 5.7 in long. It currently has no safety clip, but one is planned for 

the future. The M83 produces a stream of white smoke for 25 to 70 s. The grenade has a forest 

green body with light green markings, a blue band, and a white top. The fuze is an M201A1. 

Figure 2. Fielded version of the M83 

smoke grenade without 

pull-safe device. 

2.3 Instruments 

The questionnaires were designed to elicit Soldiers’ opinions about their performance and 

experiences with each of the grenade types. The questionnaires asked the Soldiers to rate the 

distinguishing characteristics on a seven-point semantic differential scale ranging from 

“extremely good/easy to differentiate” to “extremely bad/difficult to differentiate.” 

Questionnaires were administered to each Soldier at the end of the experiment day. 

Questionnaires were also used to gather information concerning demographic data, experience, 

and physical characteristics that might affect the participant’s ability to differentiate between 

grenades. 
6

2.4 Procedures 

2.4.1 Overview of Activities 

Six Soldiers a day participated in this experiment. They were first trained on the distinguishing 

characteristics of the three grenade types—the M83, the M83 with pull-safe device, and the 

XM106. After training, the Soldiers completed a series of exercises designed to evaluate the 

distinguishable visual and tactile characteristics of the grenades. These exercises included:

• Tactile differentiation using various gloves and bare hands.

• Visual differentiation using normal vision, night-vision goggles, and while wearing an 

NBC mask, and while wearing tinted eye protection.

• Differentiation while experiencing a cognitive load.

• Differentiation after physical exertion. 

Differentiation exercises included exercises in which all three grenade types were available, and 

the Soldier had to choose the type requested. There were also exercises in which one of the 

grenade types was presented, and the Soldier must determine which type it was without the 

ability to make comparisons (i.e., compare which is the lighter color of green or which has the 

larger indentation). Soldiers were allowed to review the grenade characteristics during the time 

between each session. 

2.4.2 Soldier Orientation 

The experiment Soldiers reported in groups of six for one day each, 0800–1700 daily. Soldiers 

were issued a meals-ready-to-eat lunch by their unit. After they arrived, the experiment Soldiers 

received a roster number, which was used to identify them throughout the evaluation. The 

Soldiers were given an orientation on the purpose of the study and their participation. They were 

briefed on the objectives and procedures, as well as on the grenades. Any questions the Soldiers 

had concerning the experiment were answered. They were also told how the results will be used 

and the benefits the military can expect from this investigation. 

2.4.3 Medical Status 

After arriving at the experiment site, the Soldiers were asked to complete the medical status form 

shown in appendix A. If any of them had a medical profile or history that would jeopardize them 

if they participated in the study, they were excluded from the experiment. 

2.4.4 Demographics 

Demographic data was taken for each Soldier. Data concerning their physical characteristics and 

experience, especially their knowledge of grenades, was included in the demographic data sheet. 
7

2.4.5 Training 

No specialized experience was required from the requested Soldiers. Representatives from the 

Human Research and Engineering Directorate trained the Soldiers on the use of the grenades and 

their features. Training questions were included in the postiteration questionnaire so that 

Soldiers would have the opportunity to comment on the adequacy of training and provide 

suggestions for improvement of the training course. 

2.4.6 Tactile Differentiation Using Gloves and Bare Hands 

Soldiers stood and reached for the requested grenade from a box that contained two of each of 

the grenades with an opaque cover placed on a table in front of them. (See tables 1–4 for the 

order of grenades requested by handwear condition, with A representing the baseline M83 with 

current pull pin, B representing the M83 with the pull-safe pull ring configuration, and C 

representing the XM106 with the pull-safe pull ring configuration.) They were requested to 

quickly withdraw the requested grenade without looking at it and hand it to the data collector. 

The grenade was then returned to the box so the Soldier had six grenades to choose from. The 

position of the grenades inside the box was changed after each attempt. Data collectors recorded 

the number of correct grenades chosen and which grenade was chosen if incorrect. 

Table 1. Order of grenades requested from the box barehanded. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 C A B B C A 

2, 17, 32 B C A A B C 

3, 18, 33 B A A B C C 

4, 19, 34 A C C A B B 

5, 20, 35 C B B C A A 

6, 21, 36 A B C C A B 

7, 22 C B B A C A 

8, 23 A C A C B B 

9, 24 B A A C B C 

10, 25 B A B A C C 

11, 26 C B C B A A 

12, 27 A C C B A B 

13, 28 B C A A B C 

14, 29 B A A B C C 

15, 30 A C C A B B 
8

Table 2. Order of grenades requested from the box using Nomex gloves.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 C A B B C A 

2, 17, 32 B C A A B C 

3, 18, 33 B A A B C C 

4, 19, 34 A C C A B B 

5, 20, 35 C B B C A A 

6, 21, 36 A B C C A B 

7, 22 C B B A C A 

8, 23 A C A C B B 

9, 24 B A A C B C 

10, 25 B A B A C C 

11, 26 C B C B A A 

12, 27 A C C B A B 

13, 28 C A B B C A 

14, 29 C B B C A A 

15, 30 A C C B A B 

Table 3. Order of grenades requested from the box using NBC gloves. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B A A C B C 

2, 17, 32 B C A A B C 

3, 18, 33 A C C A B B 

4, 19, 34 B A A B C C 

5, 20, 35 A C C A B B 

6, 21, 36 B C A A B C 

7, 22 B A B A C C 

8, 23 C B C B A A 

9, 24 C A B B C A 

10, 25 C B B C A A 

11, 26 A B C C A B 

12, 27 A C C B A B 

13, 28 A C A C B B 

14, 29 C B B A C A 

15, 30 B A A B C C 
9

Table 4. Order of grenades requested from the box using cold weather gloves.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 A B C C A B 

2, 17, 32 A C C B A B 

3, 18, 33 C A B B C A 

4, 19, 34 C B C B A A 

5, 20, 35 B A A C B C 

6, 21, 36 C B B C A A 

7, 22 A C C A B B 

8, 23 C B B C A A 

9, 24 B A B A C C 

10, 25 C A B B C A 

11, 26 A C C B A B 

12, 27 B C A A B C 

13, 28 A C A C B B 

14, 29 C B B A C A 

15, 30 B A A B C C 

Tables 5–8 present the order in which the grenades were presented to the Soldiers one by one for 

them to identify. Soldiers identified the grenade type without looking at it. Soldiers were 

instructed to either keep their eyes closed or turn their hat around to cover their eyes during the 

trials. Data collectors recorded the number of correct grenades chosen and which grenade was 

chosen if incorrect.

Table 5. Order of grenades presented one by one using cold weather gloves. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 C B B A C A 

2, 17, 32 A B C C A B 

3, 18, 33 C B C B A A 

4, 19, 34 A C C A B B 

5, 20, 35 C B B C A A 

6, 21, 36 B C A A B C 

7, 22 B C A A B C 

8, 23 B A A C B C 

9, 24 A C C B A B 

10, 25 B A A B C C 

11, 26 B A B A C C 

12, 27 C A B B C A 

13, 28 B A A B C C 

14, 29 A C A C B B 

15, 30 A C C A B B 
10

Table 6. Order of grenades presented one by one using NBC gloves. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 A C C B A B 

2, 17, 32 A B C C A B 

3, 18, 33 C B B A C A 

4, 19, 34 C B B C A A 

5, 20, 35 A C A C B B 

6, 21, 36 C B C B A A 

7, 22 B C A A B C 

8, 23 C B B C A A 

9, 24 C A B B C A 

10, 25 B A A C B C 

11, 26 C A B B C A 

12, 27 A C C B A B 

13, 28 B A A B C C 

14, 29 A C C A B B 

15, 30 B A B A C C 

Table 7. Order of grenades presented one by one using Nomex gloves. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 A C C A B B 

2, 17, 32 B C A A B C 

3, 18, 33 B A A C B C 

4, 19, 34 C B C B A A 

5, 20, 35 A B C C A B 

6, 21, 36 B A B A C C 

7, 22 C B B C A A 

8, 23 B A A B C C 

9, 24 A C A C B B 

10, 25 C B B A C A 

11, 26 B C A A B C 

12, 27 A C C B A B 

13, 28 B A A B C C 

14, 29 A C C A B B 

15, 30 C A B B C A 
11

Table 8. Order of grenades presented one by one using bare hands.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 C B B C A A 

2, 17, 32 B C A A B C 

3, 18, 33 A C C A B B 

4, 19, 34 B A A B C C 

5, 20, 35 C B B A C A 

6, 21, 36 C A B B C A 

7, 22 C B B C A A 

8, 23 B A A C B C 

9, 24 C B C B A A 

10, 25 A C A C B B 

11, 26 A C C B A B 

12, 27 B A B A C C 

13, 28 A B C C A B 

14, 29 C A B B C A 

15, 30 A C C B A B 

2.4.7 Visual Differentiation Using Normal Vision, Night Vision Goggles, NBC Mask, and 

Tinted Eye Protection 

Soldiers were positioned in front of a table, presented with the grenade types in a box that 

contained two of each type grenade, and asked to quickly hand the data collector the requested 

grenade in the order presented in tables 9–13. Data collectors recorded the number of correct 

grenades chosen and which grenade was chosen if incorrect. 

Table 9. Order of grenades requested when normal vision is used. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B A A B C C 

2, 17, 32 B A B A C C 

3, 18, 33 C B B C A A 

4, 19, 34 A C C B A B 

5, 20, 35 B A A B C C 

6, 21, 36 A C C A B B 

7, 22 A B C C A B 

8, 23 C A B B C A 

9, 24 A C C A B B 

10, 25 C B C B A A 

11, 26 B A A C B C 

12, 27 B C A A B C 

13, 28 C B B A C A 

14, 29 B C A A B C 

15, 30 A C A C B B 
12

Table 10. Order of grenades requested when ENVG are worn.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 A B C C A B 

2, 17, 32 C A B B C A 

3, 18, 33 C B B A C A 

4, 19, 34 B A A C B C 

5, 20, 35 B A B A C C 

6, 21, 36 B A A B C C 

7, 22 C A B B C A 

8, 23 A C C B A B 

9, 24 C B B C A A 

10, 25 A C C A B B 

11, 26 C B B C A A 

12, 27 A C C B A B 

13, 28 B C A A B C 

14, 29 C B C B A A 

15, 30 A C A C B B 

Table 11. Order of grenades requested when AN/PVS-14s are worn.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 A C A C B B 

2, 17, 32 B A A C B C 

3, 18, 33 A C C B A B 

4, 19, 34 B C A A B C 

5, 20, 35 A C C A B B 

6, 21, 36 C B B A C A 

7, 22 B A A B C C 

8, 23 B A B A C C 

9, 24 A B C C A B 

10, 25 B C A A B C 

11, 26 B A A B C C 

12, 27 C B C B A A 

13, 28 C B B C A A 

14, 29 C A B B C A 

15, 30 A C C A B B 
13

Table 12. Order of grenades requested when tinted eye protection is worn.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B A A B C C 

2, 17, 32 A C C B A B 

3, 18, 33 B A B A C C 

4, 19, 34 B C A A B C 

5, 20, 35 A C C B A B 

6, 21, 36 A C A C B B 

7, 22 C B C B A A 

8, 23 C A B B C A 

9, 24 C B B C A A 

10, 25 B A A C B C 

11, 26 A B C C A B 

12, 27 A C C A B B 

13, 28 C A B B C A 

14, 29 C B B C A A 

15, 30 C B B A C A 

Table 13. Order of grenades requested when the NBC mask is worn.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 A C C A B B 

2, 17, 32 A C C B A B 

3, 18, 33 B C A A B C 

4, 19, 34 B A B A C C 

5, 20, 35 B C A A B C 

6, 21, 36 C B C B A A 

7, 22 B A A B C C 

8, 23 B A A B C C 

9, 24 C B B A C A 

10, 25 B A A C B C 

11, 26 A C C A B B 

12, 27 A C A C B B 

13, 28 C B B C A A 

14, 29 A B C C A B 

15, 30 C A B B C A 

Tables 14–18 present the order in which the grenades were presented to the Soldiers one by one 

for them to identify. Data collectors recorded the number of correct grenades chosen and which 

grenade was chosen if incorrect.
14

Table 14. Order of grenades presented one by one when NBC mask is worn. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 C B B C A A 

2, 17, 32 B C A A B C 

3, 18, 33 C B C B A A 

4, 19, 34 B A B A C C 

5, 20, 35 A C C A B B 

6, 21, 36 B A A B C C 

7, 22 C A B B C A 

8, 23 C B B C A A 

9, 24 A C A C B B 

10, 25 A B C C A B 

11, 26 A C C B A B 

12, 27 C B B A C A 

13, 28 B A A C B C 

14, 29 A C C B A B 

15, 30 C A B B C A 

Table 15. Order of grenades presented one by one when tinted eye protection is worn.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 A B C C A B 

2, 17, 32 A C C A B B 

3, 18, 33 B A A B C C 

4, 19, 34 A C A C B B 

5, 20, 35 C A B B C A 

6, 21, 36 C B B A C A 

7, 22 B C A A B C 

8, 23 C B C B A A 

9, 24 B A A B C C 

10, 25 C B B C A A 

11, 26 B A A C B C 

12, 27 B A B A C C 

13, 28 A C C B A B 

14, 29 B C A A B C 

15, 30 A C C A B B 
15

Table 16. Order of grenades presented one by one when AN/PVS-14s are worn.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B A A B C C 

2, 17, 32 C B B C A A 

3, 18, 33 A C C B A B 

4, 19, 34 C A B B C A 

5, 20, 35 C B C B A A 

6, 21, 36 B A B A C C 

7, 22 A C A C B B 

8, 23 C A B B C A 

9, 24 A C C B A B 

10, 25 A C C A B B 

11, 26 B A A C B C 

12, 27 C B B C A A 

13, 28 B C A A B C 

14, 29 A B C C A B 

15, 30 C B B A C A 

Table 17. Order of grenades presented one by one when ENVG are worn.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B A A B C C 

2, 17, 32 C B B C A A 

3, 18, 33 B C A A B C 

4, 19, 34 A C C B A B 

5, 20, 35 A C C A B B 

6, 21, 36 B A A B C C 

7, 22 C A B B C A 

8, 23 A C C A B B 

9, 24 C B B A C A 

10, 25 B A A C B C 

11, 26 A C A C B B 

12, 27 C B C B A A 

13, 28 B A B A C C 

14, 29 A B C C A B 

15, 30 B C A A B C 
16

Table 18. Order of grenades presented one by one when normal vision is used.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B C A A B C 

2, 17, 32 A C C B A B 

3, 18, 33 A C C B A B 

4, 19, 34 C A B B C A 

5, 20, 35 A B C C A B 

6, 21, 36 C B C B A A 

7, 22 C B B C A A 

8, 23 B A B A C C 

9, 24 B A A C B C 

10, 25 C B B A C A 

11, 26 A C A C B B 

12, 27 A C C A B B 

13, 28 C A B B C A 

14, 29 B A A B C C 

15, 30 C B B C A A 

2.4.8 Differentiation While Experiencing a Cognitive Load 

While operating a robot performing a reconnaissance mission, Soldiers were requested to 

identify the grenade type which was handed to them by the data collector. The order of 

presentation of the grenades can be found in table 19. Data collectors recorded the number of 

correct grenades chosen and identified which grenade was chosen if incorrect.

Table 19. Order of grenades presented one by one when Soldier is operating a robot. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B A A C B C 

2, 17, 32 C A B B C A 

3, 18, 33 B A B A C C 

4, 19, 34 B A A B C C 

5, 20, 35 C B B C A A 

6, 21, 36 C B B C A A 

7, 22 A C C B A B 

8, 23 A B C C A B 

9, 24 C B B A C A 

10, 25 C A B B C A 

11, 26 C B C B A A 

12, 27 A C A C B B 

13, 28 A C C B A B 

14, 29 B C A A B C 

15, 30 A C C A B B 
17

2.4.9 Differentiation After Physical Exertion 

Soldiers conducted a series of 3- to 5-s rushes with a kneeling firing position assumed after each 

of the three rushes. Immediately following the completion of this course, Soldiers were asked to 

hand the data collector the requested grenade from a box inside a trash bag containing six 

different grenades (two of each type) using tactile identification. The order of grenades 

requested can be found in table 20. Data collectors recorded the number of correct grenades 

chosen and which grenade was chosen if incorrect. 

Table 20. Order of grenades requested after completion of the 3- to 5-s rushes. 

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 C B B A C A 

2, 17, 32 A C C A B B 

3, 18, 33 B A B A C C 

4, 19, 34 C B C B A A 

5, 20, 35 A B C C A B 

6, 21, 36 A C C B A B 

7, 22 B C A A B C 

8, 23 B A A B C C 

9, 24 A C A C B B 

10, 25 B A A B C C 

11, 26 B C A A B C 

12, 27 C A B B C A 

13, 28 B A A C B C 

14, 29 A C C A B B 

15, 30 C B B C A A 

After completing the first part of the grenade identification trial, the Soldiers completed a course 

that required them to execute a variety of individual movements and to assume a variety of 

positions while maneuvering through, under, and around urban obstacles, such as doorways, 

stairs, and rooms. They were required to perform these military operations in urban terrain 

(MOUT) individual maneuver techniques (IMTs) as quickly as possible. They proceeded 

through two rooms, ascended a flight of stairs, exited the building to an upper deck, assumed a 

standing firing position, reentered the building, descended the stairs, proceeded through the two 

rooms, and conducted another grenade identification trial while under the physical load created 

by these maneuvers. The order of the grenades that was handed to them can be found in table 

21. Data collectors recorded the number of correct grenades chosen and identified which 

grenade was chosen if incorrect.
18

Table 21. Order of grenades presented one by one after completion of the MOUT IMT.

Roster 

Iteration 

1 2 3 4 5 6 

1, 16, 31 B A A C B C 

2, 17, 32 A B C C A B 

3, 18, 33 C A B B C A 

4, 19, 34 B A B A C C 

5, 20, 35 A C C B A B 

6, 21, 36 B A A B C C 

7, 22 A C C A B B 

8, 23 C A B B C A 

9, 24 A C C B A B 

10, 25 C B B C A A 

11, 26 A C A C B B 

12, 27 C B B A C A 

13, 28 C B C B A A 

14, 29 C B B C A A 

15, 30 B C A A B C 

3. Results 

3.1 Demographics 

The Soldiers ranged in rank from E4 to E6. The participants’ military occupational specialties 

included infantry, ranger, medic, and combat engineer. Their ages ranged from 21 to 47 years. 

The average time in the military was 65 months. One Soldier was red/green color blind and four 

wore prescription lenses. 

Details of the Soldiers’ responses to the demographics questionnaire can be found in appendix A. 

3.2 Training 

Soldiers rated the training as very good. In addition, after training, they reported expectations 

that the XM106 grenade would be easy to distinguish because of its smooth, flat top compared to 

the ring or indentation around the top of the M83 grenades. Soldiers, overall, felt that the task of 

distinguishing between grenades would be fairly easy to perform under most conditions. 

Details of the Soldiers’ responses to the training questionnaire can be found in appendix A. 

3.3 Tactile Differentiation Using Gloves and Bare Hands 

The results for the two tasks performed by the Soldiers (choosing the specified grenade from the 

box and identifying the grenade presented to them) are shown by each handwear condition in 

table 22. 
19

Table 22. Tactile differentiation using gloves and bare hands results. 

Handwear Soldier Picks Correct Grenade 

(%) 

Soldier Identifies Grenade 

Presented 

(%) 

None (bare hands) 99.1 99.1 

Nomex gloves 98.6 99.1 

NBC gloves 99.1 99.1 

Cold weather gloves 100 99.1 

The errors made for each condition are shown in tables 23–26. The first bold column represents 

the grenade that was supposed to be picked or identified, and the rows represent which errors, by 

grenade type, were made. 

Table 23. Grenade identification errors for Soldiers using bare hands. 

Bare Hands

Soldier Picks Grenades Soldier Identifies Grenades 

M83 M83 w/PS XM106 M83 M83 w/PS XM106 

M83 — — 0 — — 0 

M83 w/PS — — 2 — — 0 

XM106 0 0 — 0 2 — 

Table 24. Grenade identification errors for Soldiers using Nomex gloves. 

Nomex 

Gloves 

Soldier Picks Grenades Soldier Identifies Grenades 

M83 M83 w/PS XM106 M83 M83 w/PS XM106 

M83 — — 0 — — 0 

M83 w/PS — — 2 — — 0 

XM106 0 1 — 0 2 — 

Table 25. Grenade identification errors for Soldiers using NBC gloves. 

NBC Gloves 

Soldier Picks Grenades Soldier Identifies Grenades 

M83 M83 w/PS XM106 M83 M83 w/PS XM106 

M83 — — 0 — — 0 

M83 w/PS — — 2 — — 2 

XM106 0 0 — 0 0 — 

Table 26. Grenade identification errors for Soldiers using cold weather gloves. 

Cold 

Weather 

Gloves 

Soldier Picks Grenades Soldier Identifies Grenades 

M83 M83 w/PS XM106 M83 M83 w/PS XM106 

M83 — — 0 — — 0 

M83 w/PS — — 0 — — 0 

XM106 0 0 — 1 1 — 
20

For each of the handwear conditions, the Soldiers made the errors shown in tables 23–26 for 

either picking the grenades from the box or identifying the grenade presented to them.

3.4 Visual Differentiation Using Normal Vision, Night Vision Goggles, NBC Mask, and 

Tinted Eye Protection 

The results for the two tasks performed by the Soldiers (choosing the specified grenade from the 

box and identifying the grenade presented to them) are shown by each eyewear condition in 

table 27. 

Table 27. Visual differentiation using normal vision and eyewear results. 

Eyewear Soldier Picks Grenade 

(%) 

Soldier Identifies Grenade Presented 

(%) 

None (normal vision) 100 100 

ENVG 100 100 

AN/PVS-14 100 100 

BLEPS 100 100 

NBC mask 100 100 

3.5 Differentiation While Experiencing a Cognitive Load 

The result for the task performed by the Soldiers (identifying the grenade presented to them) is 

shown in tables 28 and 29. 

Table 28. Visual differentiation for 

Soldiers during a cognitive 

load. 

Soldier Identifies Grenade 

Presented 

91.7% 

Table 29. Grenade identification errors for Soldiers experiencing a 

cognitive load.

Bare Hands Soldier Identifies Grenades 

M83 or M83 w/PS 

XM106 5 

3.6 Differentiation After Physical Exertion 

The results for the two tasks performed by the Soldiers (choosing the specified grenade from the 

box and identifying the grenade presented to them) are shown by each handwear condition in 

table 30. 
21

Table 30. Tactile differentiation after physical exertion. 

Soldier Picks Grenade Soldier Identifies Grenade Presented 

95.8% 98.1% 

After physical exertion, the Soldiers made the errors shown in table 31 for either picking the 

grenades from the box or identifying the grenade presented to them. 

Table 31. Grenade identification errors after physical exertion.

Bare Hands 

Soldier Picks Grenades Soldier Identifies Grenades 

M83 M83 w/PS XM106 M83 M83 w/PS XM106 

M83 — — 0 — — 0 

M83 w/PS — — 7 — — 1 

XM106 0 2 — 0 3 — 

For the total discriminations between the prototype and baseline grenades, the mean percent 

correct after exertion was 96.4%. The percent correct without prior exertion (bare hands, 

unaided vision) was 99.3%. A paired samples t-test indicates that the difference between the 

means was statistically significant, t(35) = 3.05, p = 0.004, Cohen’s d = 0.618. 

4. Conclusions 

Soldiers identified the XM106 from the M83 grenades easily and effectively in most cases. 

Soldiers made slightly more errors with handwear than they did with eyewear, indicating that 

visual identification of the grenades was easier than tactile identification. Although the 

identification rate with handwear seems acceptable, it is still a safety problem if the Soldier does 

not visually confirm the grenade selection prior to employment. There were slightly more errors 

after physical exertion when Soldiers were differentiating between the M83 w/PS and the 

XM106. The percent of incorrect grenade identifications for the XM106 grenade during the 

cognitive load trials was higher than trials without the additional cognitive load. This may be 

due to the fact that grenade identification was a secondary task during the operation of the robot 

and of less concern to the Soldier than operating the robot. Soldiers were allowed to use visual 

identification during cognitive trials and both visual and tactile identification during physical 

exertion trials, so it is evident that degradation does occur under these loads even when Soldiers 

could see the devices.
22

5. Recommendations 

While tactile and visual identification of the XM106 is high when it is the only task being 

performed, Soldiers are more likely to be under cognitive and physical loads when they have to 

identify a grenade in combat. Training should emphasize the physical differences (tactile and 

visual) between the XM106 and M83 smoke grenades as well as the safety and importance of 

being able to differentiate the XM106 from the other smoke grenades to ensure safe employment 

of the XM106. During combat, all attempts should be made to provide each Soldier only one 

type of smoke grenade so that misidentification does not occur.
23

Appendix A. Demographics

 

This appendix appears in its original form, without editorial change. 
24

MOS RANK DUTY POSITION

 

09S – 14 68W – 1 E4 – 10 Air Aslt Instructor – 1 Pathfinder Instructor - 1 

11B – 8 68X – 1 E5 – 19 Crew Chief – 1 Ranger Instructor – 2 

12B – 1 74D – 1 E6 – 3 Driver – 1 Support – 1 

15T – 1 88M – 2 OCS – 3 Instructor – 1 Team leader – 4 

31B – 1 OCS – 1 NR – 1 Medic – 1 Training – 1 

68D – 1 NR – 4 OCS – 7 Cbrn NCO – 1 

 Combat Engr - 1 NCOIC – 1 

 NR – 12 

AGE 

28 years (mean)

 

1. How long have you served in the military? 54 months (mean) 

2. How long have you had an infantry-related job? 79 months (mean) 

3. How long have you been a fire team leader? 21 months (mean) 

4. How long have you been a squad leader? 38 months (mean) 

5. How long have you been deployed overseas? 21 months (mean) 

6. How long have you been deployed in a combat area? 14 months (mean) 

7. With which hand do you most often write? 32 Right 4 Left 

8. With which hand do you most often fire a weapon? 33 Right 3 Left 

9. Do you wear prescription lenses? 29 Yes 7 No 

10. If yes, which do you wear most often? 3 Glasses 3 Contacts 1 NR 

11. Which is your dominant eye? 28 Right 7 Left 1 Both 

12. Do you have any vision related problem? 4 Yes 31 No 1 NR 

If so, what? Red/green color blind (1), farsighted (1), near-sighted (1), astigmatism (1) 

13. Have you ever used a robotic system? 1 Yes 28 No 7 NR 

If so, what type? Davinci (1) 

14. Please describe the conditions under which you used the robotic system. 

Surgical (1) 

15. Using the scale below, please rate your skill level for each of the following activities. 
25

None Beginner Intermediate Expert 

1 2 3 4 

ACTIVITY MEAN RESPONSE 

Operating ground unmanned vehicles 1.21 

Operating aerial vehicles 1.07 

Target detection and identification 1.44 

Playing commercial video games 2.68 

Training with Army video simulations 2.11 
26

INTENTIONALLY LEFT BLANK. 
27

Appendix B. XM106 Training and End of Experiment Questionnaire 

 

This appendix appears in its original form, without editorial change. 
28

1. Using the scale below, please rate the training that you received on how to 

distinguish between the grenades. 

1 2 3 4 5 6 7 

Extremely bad Very bad Bad Neutral Good Very 

good 

Extremely good 

MEAN RESPONSE 

6.06 

Comments Responses

Great training! 1 

Robot training was great – the instructor was very good. Grenade 

training was also good. 

1 

Excellent training to do, especially with lower enlisted and junior officers. 1 

Very good training. I feel the different stations helped to prove that with 

all types of situations, i.e., vision and touch, were covered thoroughly 

and all smoke grenades could be determined correctly. 

1 

The training was really good and helped distinguish the difference 

between the smoke grenades. 

1 

Really good training on training the differences between grenades by 

touch. 

1 

Identification of grenades was very detailed and in depth. 1 

Feel comfortable distinguishing M83 and XM106 grenades. 1 

Simple instructions on differences and how to look and feel for them. 1 

Quick easy tips and distinction between each type was clear. 1 

Training on grenades was simple because the differences in 

distinguishing aren’t too different from one another. We still had time to 

orient ourselves to the grenades. 

1 

Explained well and in detail – good job. 1 

I was given very clear and concise and effective instruction on the 

distinguishing characteristics of the grenades. 

1 

Good and clear instructions on how to determine differences. 1 

Easy and understandable instructions. 1 

The training was brief and to the point. He quickly demonstrated the 

differences and repeated it a couple of times in order to ensure we 

remembered. It was kept simple so that only pertinent information was 

given. 

1 

The trainer was thorough in his explanations of the experiment as well as 

the expectations of us. 

2 

The initial training was detailed, though short. Getting the answers out 

quickly was slightly tough because I got tongue-tied. 

1 

It gets very repetitive but it helps because it becomes muscle memory of 

how to distinguish between the different grenades. 

1 

Tests seemed pertinent to what we will face in the field. Cold weather 

gloves are in need of change – hard to determine by touch with them. 

1 
29

Comments Responses

I would go after the lower enlisted with not that much time in service to 

take these tests just because they haven’t figured the military out yet. 

1 

There should be more difference between M83 and m83 with confidence 

clip. 

1 

2. What were the easiest and hardest features of the grenades to distinguish between? 

Comments Responses

EASIEST 

It all seemed easy to me. 1 

M83 had the lip on top, whereas the XM106 was smooth and the 

confidence clip was easy to distinguish because of using the spoon you 

could “feel” the clip on the top. 

1 

Indentations/ridge on top. 3 

The grooves on the tops of the grenades. 2 

Ridges on the top and bottom. 1 

XM106. 2 

The easiest feature between the M83 and XM106 is the ridges on the top 

of the canister and the color of the canister. The clip was easily 

distinguishable on the M83 with it. 

1 

Ridges on top of grenades for distinguishing between XM106 and M83 

with or without confidence clip. 

2 

Using night vision, the XM106 was still easy to pick out. 1 

The smooth top of the XM106 was very easy to recognize by touch. 

Even with gloves on it was easy. 

2 

The smooth top on the XM106 and the shine of its top, the texture, the 

smooth corners of the top and color made it very easy to distinguish 

from both M83s. Plus the M83s had a different feel to them. 

1 

The easiest to identify was the XM106. It had the smooth surface which 

was different from the others. 

4 

The XM106 is flat on the top of the body and on the thumb clip it has a 

clip. 

1 

The easiest feature to distinguish between grenades was the flatness on 

top of the XM106 compared to the M83. 

5 

Between the XM106 and the other two, the flat surface versus the ridged 

surface. 

1 

M83 – pins rattle. M83 with confidence clip – clip was easy to identify. 1 

The M83 with confidence clip was easy as well. 1 

The M83 has a ridge on the top of the body. The M83 with clip has the 

same features as the M83 but on the thumb release there is a safety 

clip. 

1 

The easiest was the grooved top on the M83 and M83 with confidence 

clip. 

1 

Colors of grenades. Feel of grenades without gloves, XM106 feels 

smoother than the M83s. 

1 
30

Comments Responses

Color between the XM106 and M83s by sight. Top indentation between 

the same by feel. 

1 

Color and indentation on top edge. 2 

The color difference between the M83 and XM106. 1 

Plain eye sight was the easiest. 1 

Smooth top, color, confidence clip, and Nomex gloves. 1 

Knowing what to look and feel for. 1 

Using your own senses to identify grenades – bare hands and normal 

vision. 

1 

Telling the difference barehanded. 1 

Comments Responses

HARDEST 

Nothing at all/ nothing hard. 5 

Safety clip. 3 

The confidence clip on the M83. 3 

Clip was sometimes hard to distinguish with gloves. 2 

The hardest feature to distinguish was the confidence clip on the M83, 

but still that was not very difficult. 

1 

Distinguishing between M83 with confidence clip and M83 without due to 

the clip’s size but overall, not difficult at all. 

5 

The hardest was in a rush situation, without looking, if the Soldier did not 

feel the top and only looked for confidence clip, a mistake could be 

made between the XM106 and M83. 

1 

Trying to use the PVS-14 night vision and distinguishing between an M83 

and M83 with confidence clip because of the blurred vision. I would 

have to resort to touching them. 

1 

Telling the difference between the two M83s with the cold weather 

gloves. 

2 

It was harder to tell which grenade was the M83 and which had the 

confidence clip when using gloves, although it was figured out after a 

few additional seconds. 

1 

The M83 with night vision. 1 

Using the MOPP gloves to identify between the M83 and M83 with 

confidence clip. 

2 

M83 with and without confidence clip – if the pin was horizontal it would 

feel like a confidence clip when you slide your thumb over it. 

1 

Seeing the confidence clip on the M83, distinguishing between the two by 

sight due to the same color and small variation. 

1 

Little harder to distinguish M83 and M83 with clip visually in low light 

conditions. 

1 

The hardest was to distinguish between the M83 and M83 with 

confidence clip, especially with the different gloves on. 

1 

The hardest was to distinguish with thick gloves on whether there was a 

confidence clip present or not. 

1 

Wearing the cold weather gloves. 2 
31

Comments Responses

When using cold weather gloves it is hard to feel. When using night 

vision goggles, make sure to focus them first. 

1 

NBC gloves – the rubber gets caught on the safety clip. 1 

General comments. 

Comments Responses

It was an overall awesome experience. It’s nice to know our equipment 

gets this much attention and goes through such rigorous testing. 

1 

Overall, Soldiers should have little if any difficulty differentiating between 

the grenades. 

1 

Overall it was good. 1 

Good experiment; enjoyed it thoroughly. 1 

Overall, easily distinguished between XM106 and M83. 2 

Pretty thorough testing between differences. 1 

Pretty easy. 1 

None were really all that difficult but at first touch/glance. 1 

The training in different settings (i.e., protective mask, night vision, etc.) 

was effective. 

1 

The trainer moving the canisters in the box was effective from learning 

where you dropped them. 

1 

Even though there’s differences between smoke grenades, the design 

and training was very helpful in distinguishing the difference. 

1 

Even with all of the gloves, if I immediately grabbed with any finger on top 

or slid it up the side to the top, I could feel the ridge and smooth edges 

and easily distinguish between them. 

1 

Cadre and training were good. 1 

Although a simple task, the training is necessary even though it’s nearly 

impossible to mistake the XM106. 

1 

XM106 was faster. 1 

Best distinguishing features of the XM106 was the color and the flat top. 1 

The ridge on top of the two M83s was surprisingly easy to feel even with 

gloves. 

1 

The different gloves slowed down the process of identification but 

ultimately I was still able to correctly identify. 

1 

Only complaint was cold weather gloves were too bulky for touch 

identification. 

1 

You need to constantly rearrange the grenades in the boxes since once I 

knew where they were, I knew where to grab. 

1 

Next time use a black garbage bag because you can see through the 

orange one before you start the task. 

1 

The M83 and M83 with confidence clip are a little hard to tell apart with 

thick gloves, while the XM106 is not. 

1 

The night vision that we used when on a normal setting is very blurred 

when up close trying to tell what grenades you are looking at. 

Night vision was a little blurry, hard to distinguish M83 and M83 with 1 
32

Comments Responses

confidence clip. 

The night vision goggles helped me easily find the XM106 by vision alone 

but I had to also use touch when possible to properly and quickly 

identify the M83 and M83 with confidence clip. 

1 

I wear excessively large glasses so the sunglasses did not fit very tough 

to see the confidence clip or not on the M83 with such precise focus on 

the night vision goggles. And the mask was uncomfortable. 

Distinguishing confidence clip can be tricky. 1 

I really had to double and triple check to make sure I was grabbing the 

right grenade with regards to the M83 and M83 with confidence clip. 

1 

3. What are your overall comments on your ability to distinguish between the 

grenades? 

Comments Responses

Excellent training. 1 

Very good training. 1 

Night vision was pretty easy as well. 1 

I feel like I am thoroughly trained and ready to tell the difference between 

all three smoke grenades in any situation. 

3 

For me it was actually very easy. It might change in combat due to a 

higher stress level. 

1 

It is easy, plus there is always at least one thing that will identify the 

difference between the grenades. 

1 

Distinguishing the grenades was not difficult. 8 

Can identify all three now. 1 

Thought it was very easy no matter what you wore. 1 

Rather easy to learn and do. 1 

Easy if you know what to look and feel for. 1 

They are very easy to distinguish, but I believe if we are able to throw a 

live one to see the smoke effect, it would greatly impact training. 

1 

The XM106 smooth top and the color was a very good indicator of what it 

was. The confidence clip on the M83 grenades was a difference there 

as well. 

1 

I believe in combat I would be able to tell the difference and would rather 

use the XM106 if it produced the smoke quicker. 

1 

The XM106 was very easily distinguishable from the other two. The M83 

and M83 with confidence clip were easy to distinguish visually and took 

a few more seconds to verify when using touch. Overall, the grenades 

were all pretty easy to distinguish because of their different features. 

1 

With a little bit of time and muscle memory, it became easier to 

distinguish between the two. 

1 

It was fairly easy to tell which grenades were which, especially with the 

XM106. 

1 

It wasn’t even a challenge to distinguish between the XM106 and M83 1 
33

Comments Responses

with confidence clip because of the feel and other factors. The XM106 

was actually easier to spot using night vision because it shined on top. 

Was able to identify most, if not all, grenades successfully. 1 

I think I had a good concept overall. Once you learn the characteristics 

of the grenades, there should be no doubt of which one to choose. 

1 

No problem when not using gloves. 1 

Being able to use both hands was helpful in addition to no time 

constraints. 

1 

Awkward at first, but repetition is the key. 1 

Fairly simple to tell the difference between the three. The only problem 

may be discerning the M83 from the M83 with safety clip. 

1 

When testing for recognition, use a black non-see through trash bag and 

maybe a large ammunition box so you have to search for the grenades 

not just pick up one out of the ones you just put down. 

1 

Naming them so similarly – it’s tough to get the names squared away so 

quickly, but overall, the grenades were pretty distinct. The colors of the 

two M83s is toughest. 

1 

Only trouble spot was locating clip through night vision when outside 

focal range. 

1 

Difficult at times with gloves on and 1 

The NBC gloves and the Nomex gloves were too thick to determine the 

correct grenade clip. 

1 
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