Jump to content

M18 smoke grenade

From Wikipedia, the free encyclopedia
M18
M18 Colored Smoke Grenade with "violet" or purple smoke filling.
TypeSmoke grenade
Place of originUnited States
Service history
In service1942-present
Used byUnited States
Australia
Iraq
New Zealand
South Vietnam
Ukraine
WarsWorld War II
Vietnam War
Korean War
Iraq War
War in Afghanistan
Russo-Ukrainian War
Production history
Designed1942
ManufacturerPine Bluff Arsenal
Unit cost$109.02 (avg. cost in 2025)
Produced1942-present
No. built3,800,000+
VariantsG940 (Green)
G945 (Yellow)
G950 (Red)
G955 (Violet)
Specifications
Mass19 oz (540 g)
Length5.75 in (146 mm)
Diameter2.50 in (64 mm)
FillingSmoke Mix, colored
Filling weight11.4 oz (320 g)
Detonation
mechanism
Pyrotechnic M201A1 Pull-ring delay Igniter (1.0–2.3 seconds)

The M18 Colored Smoke Grenade is a U.S. Army grenade used as a ground-to-ground or ground-to-air signaling device, a target or landing zone marking device, or a screening device for unit maneuvering. It entered service in 1942 and has been the primary colored smoke grenade for the U.S. Army since.

History

[edit]

The M18 was developed in 1942 during World War II and was completed in November of that year. It was designed to replace the M16 smoke grenade, which did not burn as long or as vividly. It was designated standard issue in the fall of 1943. Both were produced at the same time as the M16 production lines were already setup when the M18 was adopted.[citation needed]

The M16 was available in red, orange, yellow, green, blue, violet, and black. The M18 initially were going to be produced in the same colors, including white, but it was decided to limit it to four colors (red, yellow, green and violet) for simplicity. The M16 was declared limited standard in 1944 but was still available when it was declared obsolete in the early 1990s.[citation needed]

During the Vietnam War, the M18 was mainly used by troops for signaling to helicopters and other aircraft. Red typically meant danger, while violet and yellow were used to mark pickup zones and friendly force locations. Green was rarely used due to it being difficult to spot.[1][2][3] However, color coding and usage varied by squad.

In 1971, a non submersible version of the M18 was under testing as the M18 provided poor signal when used in areas partially or fully covered in water. This made the standard M18 ineffective in such areas in Vietnam. This version of the M18 had a silicon ballute which acted as a parachute and flotation device. It was produced by Northrup Carolina, a subsidiary of Northrup Grumman at the time.[4][5]

By June 2019 the Pine Bluff Arsenal has produced 3,888,502 M18 grenades since its introduction.[6]

In 2022, the US supplied Ukraine with an undisclosed amount of M18 smoke grenades as part of a military aid package.[7][8]

Design

[edit]

The early M18 has a 5.75" x 2.50" steel cylindrical outer casing with a M200A1 or M200A2 pull-ring fuze assembly and four emission holes on the top that were covered by tape. On the bottom is an additional hole for smoke to release when ignited.[9][10]

Diagram and cross section of the M18 Colored Smoke Grenade (Yellow smoke filling depicted).

The body contains a primer, and starter/ignition mixture. Below that is a pyrotechnic delay column surrounded by donut shaped smoke filler mixture that varied in composition depending on the color used.[11] Including filling, the M18 weighed 19 oz.

The M18 was light gray, with yellow text painted stating the color. It came shipped in a metal tube used to protect it from moisture. The M18 came in four variations: G940 (Green), G945 (Yellow), G950 (Red), and G955 (Violet).[12]

Two yellow M18's cut open revealing the inside. The one on the right has starter patches between dye layers.

Later M18 versions came with an M201A1 pull-ring fuze assembly in an olive drab body with the top painted indicating the color and white text with a band towards the bottom.[13] One version removed the bottom emission hole, keeping the four on the top, while the most recent version removed the top emission holes and had one on the bottom.[12][14] Instead of a metal tube a wax/cardboard tube was used for shipping.

In 2006 wafer starter patches were added inside the body between the donut shaped pucks of dye which improved burn times.[15]

Non-submersible Variant

[edit]

The non submersible M18 was the same size as the standard M18 and looked almost identical on the outside. The body contains a chimney design vent hole under the fuze in the middle. Surrounding the chimney is a folded silicone fiberglass ballute that is attached to a bulkhead plate. 8 vent holes on the top of the bulkhead are used to inflate the ballute when the grenade is ignited. Below the bulkhead is a starter/ignition mixture, inflation mixture, and smoke mixture.[16]

When ignited and thrown, the top of the grenade with the pull-ring fuze assembly detached while the ballute inflated. The grenade would then glide towards the ground upright, and could float in water.[16]

It was found these versions of the M18 had a lower smoke volume but burning time was almost double the standard M18 with 90 seconds minimum.[16]

Usage

[edit]

The M18 is used by holding it in one hand with the safety lever pressed against the canister. The safety pin/ring is then removed and the M18 can be thrown. As the safety lever is released, it is forced away from the body by a striker spring. The striker rotates on it's own and strikes the percussion primer. The fuze delay then starts the ignition process. The tape covering the bottom emission hole is blown off and smoke is released. After ignition, the M18 produced a cloud of colored smoke for 50 to 90 seconds.[10] The M18 could be thrown up to 35 meters by the average soldier.[12]

If the fuze was non-functional, the M18 could still be used. This was done by removing the tape covering the hole on the bottom, removing the fuze assembly, and igniting the starter mixture with an open flame.[9]

With the M18 there is a danger of starting a fire if it is used in a dry foliage area as the tube gets very hot during the burning process. Expended smoke grenade canisters remain hot for some time after burning out and should not be picked up bare-handed.

Chemistry

[edit]

The smoke from an M18 is produced by volatilizing and condensing a colored dye mixture. The heat produced by the starter mixture volatilizes the dye which is then condensed by the air forming a colored smoke cloud.[17] A cooling agent is added to the smoke mixture to help prevent excessive decomposition of the dye while burning time can be regulated by adjusting the amount of oxidant and combustible materials.[18]

In the original M18 chemical components, sulfur was used for the starter mixture with sodium bicarbonate as a coolant. Smoke mixture was dependent on the color of smoke being produced.[18]

The formula for the M18 was later changed in the late 90s due to health and environmental concerns. The new M18 used sugar for the starter mixture and magnesium carbonate as coolant.[17][18] The smoke mixtures were also changed, using different dyes.

New yellow and green M18 were made with relative ease, while red and violet were more challenging to produce. Early attempts failed due to insufficient flaming/smoke production of the mixtures. Additionally the new red formula produced a pink smoke rather than the intended red. Several attempts were made to correct it but were unsuccessful.[19]

The smoke produced by an M18 is harmful if inhaled, even with the new less toxic smoke mixtures. In enclosed spaces the grenade displaces oxygen due to the burning process and can cause respiratory or oxygen deprivation.

The new dye mixtures are produced by Nation Ford Chemical in South Carolina.[20][21]

Old/New Mixture Comparison Table

[edit]
Component Green Yellow Red Violet
Old New Old New Old New Old New
Vat Yellow 4 4.0% 14.0%
Solvent Yellow 33 12.6% 42.0%
Disperse Red 9 40.0% 8.4%
Solvent Red 1 34.2%
Disperse Red 11 6.8% 38.0%
Solvent Green 3 28.0% 29.4%
Benzanthrone 8.0% 24.5%
1,4-Diamino-2,3-dihydroanthraquinone 33.6%
Sulfur 10.4% 8.5% 9.0% 9.0%
Sodium Biocarbonate 22.6% 33.0% 25.0% 24.0% 5.1%
Potassium Chlorate 27.0% 25.0% 20.0% 24.1% 26.0% 17.7% 25.0% 23.5%
Magnesium Carbonate 15.5% 17.5% 9.6% 10.2%
Terephthalic Acid 14.0% 7.6%
Sugar 17.5% 16.4% 17.7% 15.5%
Stearic Acid 0.5% 0.5%
Table Sources:
  • [22] - Toxicity of Military Smokes and Obscurants: Volume 3
  • [19] - Demonstration of the Replacement of the Dyes and Sulfur in the M18 Red and Violet Smoke Grenades

Manufacturing

[edit]

The Pine Bluff Arsenal in Arkansas is the only manufacturer of the M18 today.[23] It has been assembled there since it's introduction in 1942.[24] Majority of M18's were produced by Pine Bluff. This is denoted on an M18 by a "PB" before the lot number marked on the outside. The various components of the M18 are made by different manufacturers contracted yearly in the United States. As of 2024 the body and lid are made by Tool Masters, Inc. in Tuscumbia, Alabama. The fuze assembly is made by Day & Zimmermann in Texarkana, Texas. The smoke mixture dyes are produced by Nation Ford Chemical in South Carolina.[25][21][26]

During the Vietnam War, the M18 was also manufactured by Martin Electronics, Inc. ("MEI") in Florida and Talley Industries, Inc. ("TAC") in Arizona.[27][28][29]

Unit Costs/Year

[edit]
M18 Cost Per Unit
Year Green Yellow Red Violet
2025 $104.53 $106.03 $113.10 $112.42
2024 $101.83 $103.39 $115.44 $114.87
2023 $118.75 $118.75 - $120.15
2022 $110.57 $117.97 - -
2021 - - $88.04 $154.68
2020 $90.53 $91.72 - $99.68
2019 $81.21 $82.30 - $90.38
2018 $68.24 $71.67 - $74.02
2017 $64.84 $68.22 - $70.79
2016 $57.45 $60.81 - $63.34
2015 $49.89 $53.05 $56.06 $55.25
2014 $44.93 $47.82 $50.25 $49.71
2013 $60.26 $61.80 $122.80 $74.68
2012 $54.73 $57.73 - $70.54
2011 $58 $59 $72 $65
2010 $59 $59 $85 $64
2009 $49 $64 $62 $59
2008 $41 $62 $67 $61
2007 $55 $52 $55 $56
2006 $54 $51 $54 $53
2005 $45 $39.89 $53 $58
2004 - - $39.44 -
2003 $32.00 $30.06 $29.10 $27.73
2002 $25.17 $25.48 - $31.92
2001 $27.05 $26.61 - -
2000 - $27.13 - -
1999 $47.30 $33.27 - $37.61
1998 - $31.89 - $31.90
Table Sources:

Users

[edit]
[edit]
  • Smoke billowing from a red M18.
    Smoke billowing from a red M18.
  • Smoke billowing from a green M18.
    Smoke billowing from a green M18.
  • Smoke billowing from a yellow M18.
    Smoke billowing from a yellow M18.
  • Violet M18 used to identify landing zone (Vietnam 1967)
    Violet M18 used to identify landing zone (Vietnam 1967)
  • U.S. Army radio operator with multiple M18 grenades (Vietnam 1966)
    U.S. Army radio operator with multiple M18 grenades (Vietnam 1966)
  • Green M18 used for cover during training exercise (Hawaii 2010)
    Green M18 used for cover during training exercise (Hawaii 2010)
  • U.S. Army Paratrooper with yellow M18 visible (Iraq 2004)
    U.S. Army Paratrooper with yellow M18 visible (Iraq 2004)
  • U.S. Army radio operator with M18 grenades (Vietnam 1968)
    U.S. Army radio operator with M18 grenades (Vietnam 1968)

Media use

[edit]

See also

[edit]
[edit]

References

[edit]
  1. ^ "Purple Haze: Smoke Grenades in Vietnam". HistoryNet. 18 May 2022. Retrieved 31 March 2025.
  2. ^ Rottman, Gordon (2015). THE HAND GRENADE (PDF). Osprey Publishing. p. 56. ISBN 9781472807342.
  3. ^ Rottman, Gordon (2017). Vietnam War US & Allied Combat Equipments. Elite 216. Osprey Publishing. ISBN 978-1-4728-1905-5.
  4. ^ Renfroe, Donald (18 Feb 1972). Development of a Floating Smoke Grenade Air and Surface to Surface (PDF). General Testing Laboratories, Inc.
  5. ^ "U.S. GRENADE, HAND, SMOKE, NONSUBMERSIBLE". ORDATA. 27 Feb 2009. Archived from the original on 27 February 2009. Retrieved 30 March 2025.
  6. ^ Selby, Rachel (16 July 2019). "Pine Bluff Arsenal provides ammunition, CBRND readiness for nation's military". U.S. Army. Archived from the original on 30 March 2025. Retrieved 29 March 2025.
  7. ^ a b Trinko, Myroslav (8 November 2022). "The Ukrainian Armed Forces use the legendary American M18 smoke grenades". gagaget. Retrieved 29 March 2025.
  8. ^ Basic Identification of Ammunition in Ukraine (PDF). Vol. 5. Ukraine EOD. 10 October 2023. Retrieved 29 March 2025.
  9. ^ a b "CHAPTER 1 - FUNDAMENTALS OF GRENADES". Army Training Information System. Archived from the original on 12 March 2000. Retrieved 29 March 2025.
  10. ^ a b "Hand Grenade". Brookside Press.
  11. ^ Cooke, Gary (22 April 2007). "Hand Grenades". Gary's U.S. Infantry Weapons Reference Guide. Archived from the original on 6 March 2025. Retrieved 29 March 2025.
  12. ^ a b c GRENADES AND PYROTECHNIC SIGNALS (PDF). U.S. Army. 2021. pp. 3–42, 3–43. Retrieved 30 March 2025.[dead link]
  13. ^ "M16-M18 Coloured Smoke". Grenades, mines and boobytraps. Archived from the original on 3 November 2007. Retrieved 29 March 2025.
  14. ^ Cooke, Gary (22 April 2007). "Hand Grenades". Gary's U.S. Infantry Weapons Reference Guide. Archived from the original on 6 March 2025. Retrieved 29 March 2025.
  15. ^ Newton, Rachel (12 May 2009). "Pine Bluff Arsenal reaches major production milestone". U.S. Army. Archived from the original on 30 March 2025. Retrieved 29 March 2025.
  16. ^ a b c Renfroe, Donald (18 Feb 1972). Development of a Floating Smoke Grenade Air and Surface to Surface (PDF). General Testing Laboratories, Inc.
  17. ^ a b Taylor, Keith (3 May 2007). "Sugar-based Smoke in Colored Grenades Protects Soldiers, Environment". U.S. Army. Retrieved 29 March 2025.
  18. ^ a b c "Combustion Chemistry". Toxicity of Military Smokes and Obscurants: Volume 3 (3rd ed.). National Academies Press. 1999.
  19. ^ a b Demonstration of the Replacement of the Dyes and Sulfur in the M18 Red and Violet Smoke Grenades (PDF). U.S. Department of Defense. January 2007. pp. 2, 5, 18, 25.
  20. ^ PEO AMMUNITION PORTFOLIO BOOK (PDF). JPEO. 27 Feb 2017. p. 77. Archived from the original (PDF) on 30 March 2025. Retrieved 29 March 2025.
  21. ^ a b Gaines, Jenny. "Nation Ford Chemical Supports Troops by Making Colorants for Smoke Grenades". socma. Archived from the original on 31 March 2025. Retrieved 31 March 2025.
  22. ^ "TABLE 1-1". Toxicity of Military Smokes and Obscurants: Volume 3 (3rd ed.). National Academies Press. 1999.
  23. ^ "M18 Colored Smoke Grenade". The Coolest Thing Made in Arkansas. Archived from the original on 31 March 2025. Retrieved 30 March 2025.
  24. ^ Selby, Rachel (16 July 2019). "Pine Bluff Arsenal provides ammunition, CBRND readiness for nation's military". U.S. Army. Archived from the original on 30 March 2025. Retrieved 29 March 2025.
  25. ^ PEO AMMUNITION PORTFOLIO BOOK (PDF). JPEO. 27 Feb 2017. p. 77. Archived from the original (PDF) on 30 March 2025. Retrieved 29 March 2025.
  26. ^ Department of Defense Fiscal Year (FY) 2025 Budget Estimates - Army Justification Book Volume 1 of 1 Procurement of Ammunition, Army (PDF). U.S. Army. March 2024. p. 31. Retrieved 31 March 2025.
  27. ^ MEI Product Guide (PDF). Martin Electronics, Inc. 2006. Retrieved 31 March 2025.
  28. ^ B-171121, B-171123, MAR 26, 1971. U.S. Army. 26 March 1971. Retrieved 31 March 2025.
  29. ^ "American Manufacturers". Archived from the original on 31 March 2025. Retrieved 31 March 2025.
  30. ^ Lyles, Kevin (25 May 2004). Vietnam ANZACs: Australian & New Zealand Troops in Vietnam 1962-72. Osprey Publishing. ISBN 9781841767024.
  31. ^ Gordon L. Rottman (26 Jan 2017). Vietnam War US & Allied Combat Equipments. Osprey Publishing. p. 44. ISBN 9781472819055.
  32. ^ Rottman, Gordon (2017). Vietnam War US & Allied Combat Equipments. Elite 216. Osprey Publishing. ISBN 978-1-4728-1905-5.
  33. ^ "An Iraqi Security Forces student throws a smoke grenade". NARA & DVIDS Public Domain Archive. 31 May 2019. Retrieved 31 March 2025.
  34. ^ IRAQ TRAIN AND EQUIP FUND (ITEF) (PDF). United States Department of Defense. 2016. p. 10. Archived from the original (PDF) on 31 March 2025. Retrieved 31 March 2025.
  35. ^ "New Zealand Army". Twitter. 18 August 2020. Retrieved 5 April 2025.
  36. ^ Rottman, Gordon (2017). Vietnam War US & Allied Combat Equipments. Elite 216. Osprey Publishing. ISBN 978-1-4728-1905-5.
Retrieved from "https://en.wikipedia.org/w/index.php?title=M18_smoke_grenade&oldid=1285660673"