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The M17 series of protective masks were a series of field protective respirators designed for the United States military in the early 1960s and used through the middle 1990s when it was officially phased out with the introduction of the new M40 series protective mask.

Background Edit

After WWII, and with the cold war between the US and the USSR looming, it was clear to war planners that any future war would quickly escalate from conventional to chemical and biological war. With the proliferation of the G-series and relatively new V-series nerve agents, the US military decided to design a new mask to meet the challenges of this lethal style of war. It was assumed that the M9 was too bulky and obsolete to be effective on the modern battlefield (although M9 series masks would be used for special purposes well through the mid-1990s). New design requirements were drawn up for a compact design that did not have external filter canisters or hose-connected filter elements. The internal filter pouch solution was selected to meet this form factor and also eliminated the requirement to have different designs for left and right handed service members. A voice diaphragm was also a design requirement to aid in battlefield speech communications in a contaminated environment.[1] After about a decade of testing and development, a mask began production in 1959 as the ABC-M17 (Atomic, Biological, Chemical) with the same standard of protection as the M9 series, although with a downside of a shorter filter lifespan and filtering capacity.

PrototypesEdit

In the 1950s, the U.S. Army experimented with a variety of masks testing various filter technologies; many concepts that were tested were ultimately dropped. The E13-series masks tested these various configurations. The E13R4 mask had integral cheek-mounted filters and was considered superior since the mask did not require a separate filter connected by a hose and accommodated left and right-handed soldiers without modification. The final mask, adopted as the M17, was a slightly modified E13R10.[2] Experimentation with the design continued throughout the operational life of the mask. One such variant was the XM27[3] created in 1966. This experimental design was basically an M17 made entirely of clear silicone rubber instead of the black butyl rubber formulation of the basic M17 model. While more comfortable for the wearer, the design was rejected since the silicon rubber would discolor from clear to amber as it aged and there was the concern of penetration of liquid persistent chemical warfare agents such as VX. This prototype was scrapped and the XM27 is considered by collectors as one of the rarest gas masks known to exist.[4]
M17

Earlier prototype model, possibly first design idea.

ABC-M17 Edit

In 1960, the US Army issued service members the ABC-M17 protective masks for the first time. The mask received generally positive reviews but some service members complained about the difficulty of filter changing. This first version of the M17 did not incorporate a drinking tube or resuscitation system, instead only featuring a voice diaphragm. As newer models of the M17 was introduced, the old ABC-M17s migrated to law enforcement agencies where the advanced features of later models were not as important for simple crowd control with tear gases.

IMG 20170705 141215271

The ABC-M17 was used by civilian law enforcement agencies for crowd control operations when protection from tear gas was required. This specimen is from the Texas Ranger Museum in Waco, Texas.

USA-0004(007)

Final design ABC-M17 Picture by: Johannes Möller

M17A1Edit

Eight years after the introduction of the ABC-M17 the US Army decided to update the mask design. In 1966, Army research rolled out the M17A1, officially dropping the ABC prefix from the name of the mask. The new mask came new features; the addition of the drinking system and the addition of the resuscitation system.

The drinking system designed for the M17A1 is believed to be the first in the world, followed shortly thereafter by British and German designs. The drinking system, standard on US protective masks today, incorporates a hose pre-attached to the mask, instead of unscrewing and screwing multiple connections together (all the while exposing the water and human body to possible contamination). The M17A1 incorporates a quick couple connector that greatly reduces the risk of contamination when used with the compatible M1 Water Canteen Cap.

One of the oddest (and most ill thought out) ideas of the M17A1 was the resuscitation tube provided to soldiers with the mask. Designed with intent to allow a masked soldier to provide artificial respiration to an unmasked casualty, the resuscitation tube was a noble idea gone wrong. The problem with it being the exposure of both soldiers to contamination, the soldier giving aid ran the risk of encountering resistance from the airway of the casualty, pushing air back into his mask and breaking the seal on it. The casualty would remain unmasked and would continue absorbing the contaminated environment. It was for this reason that the resuscitation system was dropped on the M17A2.

M17A2Edit

M17 Gas Mask

US soldiers wearing M17A2 masks, fitted with the M6A2 protective hood during the Gulf War.

During the early 1980s, the US government began fielding the latest and what would be the final variation of the M17 mask; the M17A2. This version of the M17 mask would not feature the resuscitation tube of the M17A1 and would be used by US forces deployed around the world. A variety of items, depending upon the mission, were issued with the mask and stored in the mask carrier such as a waterproof bag that would protect the mask's filters from water damage during immersion. The M17A2 also has the exterior tilt (rotary) lever for the drinking tube. The purpose of this tilt lever was to allow the user to position the inner drinking tube into one's mouth from the exterior of the mask. Once the user was done drinking, the lever would be manually tilted back and the tube would move up and away from the user's mouth. This feature was discarded on later respirators like the MCU-2/P gas mask and this meant that users with pronounced lips would have the tube contact the edge of their lips even if there was no desire to drink and this became a distraction to some. The M17A2 would use common M17 accessories such as neutral gray outserts and the characteristic olive drab NBC hood.

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US Army Soldiers in a defensive position prior to the Gulf War wearing the M17A2 protective mask in anticipation of chemical warfare.

M17A2s were made by MSA although it is possible that other companies did manufacture the M17. Manufacturer stamps on the M17A2 can be found in two locations, one is near the right eyepiece with the manufacturer's name and year of manufacture and the second (almost hidden) mark is on the right side of the inner end of the nose cup assembly facing the internal filter compartment. Other markings include "M17 C2" just on the top of the right side.

Although the M17A2 was phased out and replaced by the M40 series protective masks, the extra-small version of the M17A2 was retained and issued to servicemembers with particularly small faces that could not be properly fitted with an M40 series mask. The extra-small masks were issued on a case-by-case basis directly from Rock Island Arsenal and the service member would retain that mask throughout his or her career. This purpose for the extra-small M17A2 was eventually phased out when the extra small M45 was fielded as part of the Land Warrior program.

Filter Elements Edit

The M17 series protective mask took a slightly curved, triangular filter elements often referred to as "pork-chop-shaped." The filter elements came in white airtight, vacuum packed paper bags with labels indicating the filter nomenclature. The filter elements were designated M13 and were improved over time to the M13A1 and M13A2. The different generations of filter elements could be identified by the color of the connector ring:

Filter Element Connector Ring Color
M13 Black
M13A1 Black or Gold
M13A2 Green

All generations of the filter elements were intended for full combat use and were effective against all known chemical warfare agents, however as each generation was introduced, the previous generation was designated as only sufficient for training with tear gas (CS) or another confidence source such as amyl acetate (banana oil) or camphor.[5] The filters were not designed to filter out vapors generated from fuel, paints or solvents and the exposure to these hazardous materials would ruin the filter's ability to filter out chemical warfare agents.[6] The filters could filter out radioactive particles to keep those particles out of the wearer's respiratory system but concentrated those particles in the filter media close to the face. This could pose a danger to the wearer if gamma emitting particles are trapped in the filter media or could expose the operator to beta or alpha emitting particles during filter changes.

The filter elements were composed of lightweight gas-aerosol filter material that fit into cheek pouches of the mask.[2] The filter media contained ASC Whetlerite activated charcoal that contained chromium VI (hexavalent chromium) specifically added to defeat hydrogen cyanide (AC) and cyanogen chloride (CK), both blood agents.[2] The chromium VI additive is a known carcinogen, but the filters are considered safe for use as long as the filters are in good repair. However, the filters should be treated as hazardous waste when disposed of due to the chromium VI content.[5] The filter elements could only be changed in a clean environment from the inside of the mask. The filter elements were notoriously difficult to change, often taking 15 to 20 minutes to complete the task.

Maintenance Issues Edit

Although the M17 series protective masks earned a reputation as being a reliable and robust mask that could stand up to difficult field environments, the series was vulnerable to faults unique to the design.

Drinking Lever Edit

The innovative drinking system of the M17A1 and M17A2 operated with a small lever on the outlet valve assembly.  That lever became a source of maintenance problems due to service members over-torquing the lever and cracking the metal of the voice diaphragm and outlet valve assembly. It was believed that the drink tube was missing or poorly adjusted in the affected masks causing service members to over-torque the lever in frustration. The 1987 version of the technical manual addressed this problem by adding that fault to the inspection regime for the mask.[7]

Permanent Set Edit

The rubber formulation of the M17 series mask was vulnerable to "permanent set."  That is when the rubber of the mask retains a memory of a position when stored in that position for a long period of time.  For example, when the mask is stored folded in the mask carrier for an extended period of time.  This condition may result in a compromised seal which rendered the mask unusable.[7]

Copper Poisoning Edit

The black lacquered brass hardware of the head harness system of the mask often became scratched and worn with normal training and use of the mask. This allowed copper ions to migrate into the rubber around the hardware of the mask making the rubber weak and brittle.  This "copper poisoning" of the rubber was easily prevented by making sure the black lacquer on the brass hardware was in good repair and scratches or worn spots were covered with fresh black lacquer.[7]

Torn Buttonholes Edit

The filter element pouches on the mask were closed with a series of plastic dumb bell-shaped buttons and buttonholes in the rubber of the face blank and nose cup assemblies.  A common fault of the mask was the tearing of these buttonholes--often due to the frustration of the service member while trying to replace the filter elements.  These button closures were critical to the proper airflow through the mask and torn buttonholes were considered a deadlining fault.  The task of changing the filter elements could be made easier by lubricating the plastic lugs with water or more commonly, saliva before attempting to button the closure flaps.[7]

Eye Lens Yellowing Edit

The polycarbonate formulation of both the eye lenses and eye lens outserts were prone to yellow over time due to exposure to UV light, excessive heat and atmospheric pollutants such as ozone. With normal use, this process is slow enough not to affect the mask during its operational life, however, masks on the secondary market and "new-old stock" eye lens outserts can show significant yellowing. The yellowing is uniform across the lens and is sometimes mistaken for purposely colored lenses, however, no yellow colored eye lenses or outserts were made for the M17 series mask. The final stage of the polycarbonate eye lens degradation is severe yellowing, crazing, and embrittlement of the lens material.

Accessories Edit

M1 Water Canteen Cap Edit

This canteen cap has a special fitting that allowed a service member to drink water from a standard one or two-quart canteen safely in a contaminated environment. The cap connects with the drink tube connector on the M17A1, M17A2 and subsequent US protective mask models such as the M40 series, however, the M50 series opted for a different canteen connector type that is not compatible with the M1 cap. The cap did not work with the older style canteens due to a threading mismatch but works with all modern one and two-quart canteens.[8] The cap had a protective cover attached with a strap of plastic, but the plastic was susceptible to fatigue and quickly broke, losing the protective cover and rendering the cap unserviceable. Later designs incorporated a two-part strain relief system that had greater success at retaining the protective cover.

M4 Winterization KitEdit

This kit was an olive drab canvas cover that goes over the inlet valves. It was designed to protect the valve disks from freezing in environments below freezing, usually at below 20 degrees Fahrenheit (-30 Celsius). The kit also prevents frost accumulation on the inlet valve caps. Use of the kit increases the breathing resistance for the wearer of the mask.[9]

M1 Resuscitation HoseEdit

This apparatus was made specifically for the M17A1 and attached over the exhale valve allowing a masked soldier to perform mouth-to-mouth resuscitation on an unmasked soldier.[10] The hose assembly was difficult to use and often broke the seal on the wearer exposing the service member to chemical warfare agents.

ABC-M6A2 Field Protective Mask Hood Edit

This was the standard Nuclear, Biological Chemical (NBC) hood for the M17 series protective mask. The hood attaches to the M17 series mask and protects the wearer's head and neck from chemical agent vapors or liquid droplets, biting insects, and radioactive dust particles.[11] The hood had a plastic fastener for the neck strap similar to the M4 hood for the M9A1 mask. The M6A2 was an updated variant; the difference being that the A2 had a different fastener type for the neck strap and a zipper that made the mask and hood combination easier to don and doff. The hood could be worn in one of two configurations; summer and winter. The summer configuration had the hood pulled up over the outlet valve forcing clean, filtered air under the hood. This theoretically overpressurized the hood to make the infiltration of chemical warfare agent vapors less likely. However, in reality, the moisture content of the exhaled air condensed on the inside of the hood and eventually saturated the chemical protective overgarment rendering the garment less effective and increased the heat load on the wearer. The winter configuration had the hood under the outlet valve allowing the exhaled air to escape to the atmosphere. This prevented the build-up of ice from the moisture-laden, exhaled air under the hood in freezing temperatures.

Neutral Gray Eyelens OutsertsEdit

For use in high illumination areas and were essentially sunglasses for the protective mask. The outserts were not a basic issue item supplied with the mask and had to be ordered separately when missions in sunny areas were anticipated. The lenses attenuated the light but did not change the color of the light since accurate color vision was required to read the M256A2 chemical agent detector kit tickets.

Green Laser Protection Eyelens OutsertsEdit

For use at night or in low light conditions. These outserts provide protection from ruby and neodymium type lasers. They are made of polycarbonate and offer ballistic and impact protection.[12]

Brown Laser Protection InsertsEdit

These inserts were used for day use only. The inserts offer protection against ruby, neodymium, and double neodymium lasers. The inserts snap into place behind the mask's lenses. Because of this, the inserts do not offer ballistic protection.

Optical Inserts Edit

For servicemembers that require corrective lenses, two types of optical inserts were developed for the M17 series mask. The first consisted of a wire frame that fit into the perimeter of the eye lenses and suspended the corrective lenses roughly at eye level inside the mask. The second type attached to the area where the nose cup assembly met the face blank with a set of prongs. The frame type optical inserts were considered safer since that type was more difficult to dislodge during the donning procedure.[13]

M13 Individual Decontaminating And Re-Impregnating KitEdit

This individual decontamination kit contains a small pad[14][15] and diatomaceous earth powder for decontaminating skin. The kit also contained larger bags containing calcium hypochlorite powder for decontaminating clothing and equipment or for re-impregnating clothing. A cutter (packaged with a small pad) was included for cutting out liquid contamination spots from clothing.[16]

M258 Series Personal Decontamination KitEdit

This individual decontamination kit replaced the M13 series kits first with the M258 and subsequently, the M258A1 kit. The kit contains six foil-packaged decontamination towelettes/wipes in an olive-drab plastic case that fits in a pouch in the rear of the M-17 mask carrier.[7] Each wipe was labeled either "1" or "2." To decontaminate skin, you would crush the ampules and fold the wipe to distribute the decontamination solution. Next, open the towelette and wipe away from the body for one minute with packet number one followed by two minutes with packet number two.

M8 Chemical Agent Detector PaperEdit

Consists of a book of perforated sheets of chemically treated, dye-impregnated paper. A color comparison bar chart is printed inside the front cover. Chemicals in the paper cause specific color changes when paper contacts liquid nerve or blister agents.[7]

M1A1 Waterproof Bag Edit

The M1A1 waterproof bag was a heavy-duty vinyl bag supplied with rubber bands that was designed to accommodate the M17 series mask with attached hood. The bag was used in operations where the mask was likely to get wet; e.g. river crossing operations. The bag was stored folded in a pouch inside the main compartment of the mask carrier. Keeping the mask dry was critical to the correct operation of the mask. If the filter elements become saturated with water, the breathing resistance would dramatically increase and the protective qualities of the filter elements would be compromised.[9]

Mark I Nerve Agent Antidote Kit (NAAK) Edit

The mark I nerve agent antidote kit consists of four separate components: the atropine autoinjector, the pralidoxime chloride autoinjector, the plastic clip, and the foam envelop (carrying case). The kit was normally only issued when the threat of nerve agent attack was anticipated. The autoinjectors were filled with pre-measured nerve agent antidotes with an automatic, spring-loaded needle injection system. Three kits were normally carried in a pouch inside the main compartment of the mask carrier along with the waterproof bag. The NAAKs had to be protected from freezing as the expanding ice inside the kit damaged the automatic injection system.

M17 Mask Carrier Edit

The mask carrier for the M17 series mask was a heavy cotton canvass, olive drab colored bag with nylon webbing and brass fasteners. The mask carrier had nylon stiffeners sewn into the sides of the pouch to add to the structural integrity of the bag. The carrier had a large pouch that would contain the mask with a small pouch inside the main compartment designed to accommodate three Nerve Agent Antidote Kits (NAAK) and the waterproof bag. The carrier also had a small snapped pouch on the rear to accommodate the M13 and later the M258 personal decontamination kits. The carrier was always worn on the left side of the body in the hip or shoulder carrying configurations. The mask was stored in the carrier with eye lenses facing the opening of the carrier and the hood stored inside out to facilitate the rapid donning of the mask. The carrier had the nomenclature of the mask and often the Chemical Corps insignia stenciled on the side of the carrier.

Foreign Copies Edit

The M17 series mask design was copied in at least four countries. These include:

M10 (Czechoslovakia) Edit

Main article: M10

Similar to the ABC-M17. Made of a light grey rubber, has a different exhale valve cover and system. Its filters inlet disks thread on, as opposed to snapping on like the original M17 series mask.

M10M (Czechoslovakia) Edit

Main article: M10

Identical to the M10 but it includes a drinking tube system similar to the M17a1 and M17a2. The diaphragm and exhale valve assembly on this model are also completely made out of grey plastic, as opposed the rubber that covers the assembly on the M10 Model.

PDE-1 (Bulgaria) Edit

Main article: Bulgarian PDE-1

The same as the M10 mentioned above, but made of black rubber, as well as a rubber five-point head harness. It has more significance, due to the fact it was the only clone which featured a peripheral seal.

MP-4 (Poland) Edit

Main article: MP-4

Another direct clone, they usually varied in different colors. Older models appear to be made of an olive-colored rubber, with olive drab straps. While newer models are made of a gray rubber, with blue straps. The eye lenses are also slightly farther apart compared to the original M17.

Gallery Edit

ReferencesEdit

  1. Edgewood Chemical Biological Center 85th Anniversary Flyer [1]
  2. 2.0 2.1 2.2 The History of Military Mask Filters
  3. XM 27 Article[2]
  4. Facebook Post.
  5. 5.0 5.1 [3]SB-3-30-2 Chemical - Biological Canisters and Filter Elements: Serviceability Lists Manual
  6. Field Manual 3-8, Chemical Reference Handbook, Page 64
  7. 7.0 7.1 7.2 7.3 7.4 7.5 [4] TM 3-4240-279-10 (M-17A2 User Technical Manual)
  8. PS Magazine Issue 207
  9. 9.0 9.1 [5]Treating Chemical and Biological Agent Casualties Lesson 1: Chemical Agents and Protection From Chemical Agents
  10. https://youtu.be/TW4XO0L-UFk?t=937
  11. FM 34/FMFM 11-9, NBC Protection
  12. http://imgur.com/a/RLKgk
  13. Field Management of Chemical Casualties Handbook (3rd Ed. ), page 200
  14. https://youtu.be/TW4XO0L-UFk?t=238
  15. http://imgur.com/a/XX3D2
  16. https://youtu.be/TW4XO0L-UFk?t=404