Monday, 18 June 2018

American Projectiles and Explosives - Anti-Personnel and Trip Mines





American Projectiles and Explosives



Anti-Personnel Mines



M2, M2A1, M2A2, M2A3, M2A3B1, M2A3B2, M2A4, and M2A4B2


M2A1
Overall Height: 6.5 inches
Case diameter: 2.5 inches
Base diameter: 5.25 inches
Weight of shell: 3 pounds
Weight of explosive: 0.4 pounds
Material: Steel
Lethal range: 60 feet


General: The M2 is a "bounding" anti-personnel mine, usually activated by a combination firing device.  The M2 has undergone several structural modifications to make it watertight.  The mine consists of an explosive shell contained in an upright thin-walled steel tube which is riveted to the base plate.  A cavity in the base plate contains the propelling charge, which consists of 20 grains of black powder in a small bag.  The tube containing the shell is sealed at the top by a metal cap.  A 1/4-inch pipe nipple threaded to the base plate serves as a connection for the firing mechanism.  Attached to the pipe nipple is a coupling into which is fitted the primer and igniter assembly.  The primer is protected during shipment by a hexagonal cap.


Modifications: The Mine M2 has been modified inthat the thin-walled steel tube is silver-soldered to the base (M2A1), or stamped (M2A3), instead of being riveted (M2).  The Mine M2A3B1 is a modification in which the tube, base, and nipple are cast in one piece.  The mine was approved but not issued, being too heavy.  The Mine M2A3B2 is a combination of the M2A3 and the M2A3B1, in that the base is cast but the tube and nipple are stamped to the base.  In the M2A4, which has two propellant bags, the tube and nipple are welded to the base, while, in the M2A4B2, the tube and nipple are welded to a base which is cast.  The M2A2 was a field modification thought to involve the use of a canvas bag.


Operation: The mine is similar to a small mortar.  When the fuze is actuated, the primer sets off the igniter.  The flash from the igniter sets off the propelling charge in the base plate.  The propelling charge projects the shell into the air and at the same time ignites the delay fuse in the base of the shell.  When the shell is at a height of approximately six feet above the base plate, the delay fuse fires a tetryl booster, which detonates the main charge.  The effective lethal range of the shell is 60 feet.


Color: The mine and firing device are dull olive drab in color except for the base flange, which is yellow.


Remarks: Each mine is packed in a corrugated paper carton with firing device, attached igniter, and four spools of wire.  Markings of "Olive Drab" or "Sand Color" on outside of container refer to the color of the wire.







M3



Body length: 5.4 inches
Body height: 3.5 inches
Body width: 3.5 inches
Weight: 9.6 pounds
Flaked TNT explosive: 0.9 pounds
Material: Cast iron
Lethal range: 30 feet
Color: Olive drab


Components: The mine consists of a rectangular cast-iron body containing high explosive, with fuze wells on two opposite sides and one end.  The filling hole on the other end is closed by a disc.  The mine is activated by the Fuze M7A1.


Remarks: On the surface, the lethal range for the mine is 30 feet.  If the mine is buried only deep enough to be camouflaged, the effective range is reduced to approximately 10 feet.

Exposure to moisture will not affect the operation of the mine; however, it is not water-proof and should not be planted where it will be immersed in water for more than a few days.






Practice Mine M8


The Practice Mine M8 is similar in appearance and operation to the M2A3.  Obsolete bodies of Mines M2 and M2A1B1 are utilized.  This mine does not contain a propelling charge in the base, as does the standard H.E. mine.  The propelling charge for projecting the cardboard projectile into the air is contained in the igniter charge on the base of the fuze.  The projectile contains a 12-gauge shotgun charge loaded with black powder to simulate the action of a live mine.  The primer and igniter, which has a delay of approximately five seconds, is activated by the M10 Combination Mine Fuze.  This fuze is a three-pronged firing device similar to the Combination Mine Fuze M6.





Trip Flares for Mine Fields




M48


General: Trip flares are used as a warning device in forwards edges of mine fields.  They can replace or supplement anti-personnel mines, especially when the field is being hastily prepared.  The flares give warning of approaching patrols entering the mine field and illuminate the area so that effective fire can be directed at intruders.


M48: This is a mortar-type parachute flare similar in appearance to the M2 series of anti-personnel mine.  The flare, weighing a total of five pounds, has a metal case which is painted olive drab.  In operation, the functioning of the igniter sets off the propelling charge, which projects the canister into the air and ignites the delay fuse in its base.  When the canister is 300 to 500 feet in the air, the delay fuse sets off the propelling charge in its base, which forces the flare and parachute out of the canister and sets off the ignition charge at the base of the flare.

The parachute unfolds, and the ignition charge ignites the flare, which burns for 20 seconds.  It illuminates effectively a circle of 300 yards radius.



M49


M49: This is a candle flare for use above the ground.  The flare, weighing a total of 1.4 pounds, has a laminated paper body with metal fittings which are painted olive drab.  Functioning of the flare is similar to that of the Fragmentation Hand Grenade Mk II.  The flare is installed with a taut trip wire which holds the trigger in an armed (vertical) position against the pressure of the trigger spring.  An additional pull of two to nine pounds on the trip wire pivots the trigger against the pressure of the spring, or release of the tension in the trip wire allows the spring to pivot the trigger in the opposite direction, either of which will release the cocked lever.  The pressure of the striker throws the lever off, and the released striker fires the percussion cap.  The flame from the cap ignites the black powder, which blows out the top and ignites the illuminant composition.  The flare produces a brilliant white light for approximately one minute.

The M49 can also be installed with a loose trip wire by having the trigger horizontal and attaching a trip wire to the safety pin.  A subsequent pull on the wire would withdraw the safety pin and permit the flare to fire.





Firecracker


Mk 2 Mod 0

General: The firecracker is used as a practice charge for booby traps and firing devices.  It produces a loud report accompanied by a bright flash and a considerable quantity of smoke, yet it is designed to reduce the hazard from flying particles such as are attendant upon the use of a standard potassium perchorate firecracker or flash salute.  The Firecracker Mk 2 Mod 0 contains no high explosive.  It is coated with a waterproofing material, yet it should be stored in a dry place.


Installation: The nipple of the coupling base of any standard firing device is pushed through the wax-filled hold int he hollowed end of the firecracker and rotated clockwise until at least two threads of the coupling base are inside the hollowed end.




Next Time: Explosive Bombs - Modified Series, and "M" Series (Part 1)

Monday, 11 June 2018

American Projectiles and Explosives - Anti-Tank Mines (Part 2)





American Projectiles and Explosives




Anti-Tank Mines




M6



Diameter: 12.5 inches
Height: 3.25 inches
Total weight: 20 pounds
TNT filler weight: 12 pounds
Material: Steel
Color: Olive drab

Components: The mine consists of a loaded mine body, fuze, and pressure-plate plug.  The steel body is cylindrical, with a carrying handle attached to the bottom.  Assembled to the mine body is a round pressure plate, 7 and 1/2 inches in diameter, containing the reversible pressure-plate plug which covers the fuze well.  The pressure plate is supported internally by circular Belleville springs and sealed against moisture by a rubber diaphragm.  In addition to the primary fuze well, supplementary fuze wells are located on the side and on the bottom of the mine for use in anti-lifting or booby-trap purposes.


Remarks: For booby traps or anti-removal devices, after the main fuze is installed, any standard firing device may be attached to the supplementary fuze wells by using the Activator M1.  This activator is a plastic adapter approximately 2 inches long, which contains a tetryl booster charge.

This fuze myst not be used with the Anti-Tank Mine M7.





M7A1



Length: 7 inches
Width: 4.5 inches
Height: 2.5 inches
Total weight: 4.5 pounds
Tetryl filler weight: 3.25 pounds
Material: Steel
Color: Olive drab

Components: This mine can be used as either an anti-tank or an anti-personnel mine.  The body is a rectangular steel container filled with high explosive.  The fuze well is located in the center of the top surface, and at one end is an activator well that will accommodate any standard firing device with a Corps of Engineers' blasting cap.  The pressure plate is shaped to the contour of the mine body and is slotted so that it may be guided by rivets in the sides of the mine body, into position over the fuze.  A small circular pad on the underside of the pressure plate bears against the head of the fuze.


Remarks: For a booby trap or anti-personnel mine, any standard firing device may be attached to the side fuze well.





Improvised Mines





Bangalore Torpedo

No picture available

Special torpedo caps are furnished with each box of ten bangalores, to adapt the bangalore torpedo for use on an anti-tank mine.  Pull-firing detonators are furnished separately.  To assemble the bangalores for use as an anti-tank mine, insert detonators in two torpedo caps; place a safety pin through the torpedo-cap ears and the detonator loop of each; and snap a torpedo cap onto each end of the torpedo, so that the detonator fits into the cap well.  Lay the torpedo on the ground across a wooden block and drive eight-inch spikes on drift pins into the ground as close to the ends as possible.  Pass the detonator wire through each detonator loop, and attach the wire to the spike.  Make sure there is no tension on the detonator wire.  Withdraw the safety pin.  The mine is now armed and ready for use.



2.36-inch A/T Rocket

No picture available

The A/T Rocket M6 may be employed by placing the rocket, nose-up in its container, in a hole about two feet deep, either ina  roadbed or horizontally on the side of a cut or bank.  It can be set to fire electrically by arranging a circuit containing the rocket, a battery, and an improvised circuit closer.  Connections to the rocket are made on the ignition wires: one from the brass ring on the nose, the other from the fins.  Ordinary field telephone wire will serve; the battery and connections should be protected from water if necessary.

The container cap is removed and the other end knocked out.  The container is thus a guide for the rocket.  A hole is punched in the container cap, through which the electric firing-device wire (or trip-wire) are run.  When connections have been made, the container cap is slid in place over the fins to protect the contacts from fouling.  The rocket safety pin is removed; the container tube is slid over the rocket and joined to the cap; and the assembly is placed in the hole.  Loose dirt and leaves are then placed over all of the rocket except the nose; the nose is concealed by covering with leaves or light bunches of grass.  Care must be taken not to bump the nose, as the rocket is completely armed when the safety pin is removed.







Practice Mines


  General: Practice mines are used in training.  These mines can be identified by their blue color and white markings.


M1: The Practice Mine M1 consists of three components: an empty mine body, a spider, and a fuze.  The parts are similar in construction to the high-explosive mine, except that the body has five one-inch holes equally spaced around the side.  The explosive filling consists of a caliber .32 blank cartridge in the fuze, 100 grains of red phosphorus, and 60 grains of black powder.


M1B1: The Practice Mine M1B1 is made of sheet metal and resembles the service mine, except that the filling hole is in the bottom of the mine body.  The body is sand-filled to weight before it is issued for use in practice.  Four sections are cut out of the top of the body near the fuze well, to permit the passage of smoke.


T8E1: The Practice Mine T8E1 simulates the standard Mine M6.  It uses the Practice Fuze T20, which simulates the M600, but gives a puff of smoke instead of detonating the mine.  Four sections cut out of the top of the body near the fuze well permit the passage of smoke.


M10: The Practice Mine M10 simulates the standard Mine M7A1.  It is loaded with 3.4 pounds of inert filler, consisting of Santo wax M, 50%, plaster of paris, 12%, and powdered red iron oxide, 38%.  It uses the Practice Fuze T20.  Four sections cut out of the top fo the body permit the passage of smoke. 






Next Time: Anti-Personnel and Trip Mines

Monday, 4 June 2018

American Projectiles and Explosives - Tree Suspension Device and Anti-Tank Mines (Part 1)





American Projectiles and Explosives




Tree Suspension Device




M18


General: The Tree Suspension Device M18 for smoke grenades is designed to provide a quick and simplified means for suspending standard burning-type smoke hand grenades from trees and foliage to permit emission of smoke above forests and foliage, where it is more readily visible to air observer.  It must be used with the Chemical Grenade Projection Adapter M2 assembled to any of the following hand grenades: AN-M8, M16, or M18.


Description: The device has a small cardboard tube into which is loosely packed about a ten-foot length of heavy rayon line.  Attached to each end of this line are two light metal cables, one for fastening to the body of the grenade and the other for fastening to the stabilizer of the Adapter M2.  It also has a heavier metal set-back ring to replace the set-back band issued with the chemical grenade projection adapter.  This heavier set-back ring retains the grenade safety lever in a safe position after removal of the fuze safety pin, releases the safety lever by set-back action upon being fired, and separates the grenade from the adapter by set-back action against the clips of the adapter, upon being fired.


Assembly: The device is assembled for use by slipping the double loop of cable over the grenade body under the safety lever.  The set-back ring is slipped over the bottom of the grenade so that it holds the safety lever in place, and the set-back band issued with the grenade is discarded.  The grenade is assembled to the adapter, and the single loop of cable is slipped over the adapter fins and secured to the stabilizer tube.  The rifle or carbine is prepared for firing in the usual manner, using positions 3 or 4, at an angle of elevation of 50 or 70 degrees and, normally with the butt of the gun supported by soft earts or other resilient material to avoid the possibility of cracking the stock.


Operation: Upon firing, the entire assembly is projected forward, and the set-back ring strikes the clips sharply, separating the grenade from the adapter.  Because of the construction of the adapter, it tends to slow down as soon as it is separated from the grenade.  In doing so, pulls the rayon line from the cardboard tube.  The grenade then flies through the air, with the adapter trailing at the end of the cord.  Upon reaching a tree, the cord and adapter become entangled on branches or foliage, suspending the smoking grenade.






Land Mines




Introduction



Mine Types: There are two common types of land mines: anti-tank and anti-personnel.  Anti-tank mines, designed to immobilize track or wheeled vehicles, vary in the amount of explosive they contain, the normal charge being 6 to 12 pounds.  They are used in mine fields or road blocks.  Anti-personnel mines are used primarily to produce casualties to personnel, and, secondarily, to give local security and warning.  The explosive charge varies from 1/4 to 4 pounds.  Other, less common, mines are classified in the general categories of improvised, dummy, and practice.


Firing Devices: Firing devices are classified in accordance with the method of their initiation; that is, pressure, pull, tension-release, or pressure-release.  The initiating action causes the device to function by chemical reaction, friction, percussion, or the closing of an electrical circuit.

Anti-tank mines generally have a main fuze which is employed as the primary initiating device; however, some anti-tank mines have supplementary activator wells on the side and bottom for booby trapping.


Marking: Mines can be identified by their color and markings.  Land mines are generally painted lusterless olive drab with a yellow base and black markings, while practice mines are painted blue with white markings and dummy mines are black.


Army and Navy Types: The Navy does not design land mines, but it has produced three firing devices for use with demolition charges - the Firing Devices Mk 1, Mk 3, and Mk 15.  The Navy also produced the practice firecracker.





Anti-Tank Mines




M1A1 (Obsolete)


Diameter: 8 inches
Height (with spider): 4 inches
Height of body: 2.75 inches
Total weight: 10.6 pounds
Cast TNT weight: 6 pounds
Material: Steel
Fuzing: M1A1, M1A2

Components: The metallic Anti-Tank Mine M1A1 has three main components: loaded body, fuze, and spider.  The spider fits over the fuze to increase the effective size of its head.  The steel body is a squat cylindrical container of light steel filled with high explosive.  A carrying ring is attached to its side.  The flanged rim around the top is notched for attaching the spider.  In the center of the top is the cavity for the fuze and booster; the booster fits into the cavity and locks into place.  The spider is a ring with two cross members pressed from a single sheet of metal.  Hooks on the spider engage the flange on the mine body, and the center hub of the spider rests on the striker head of the fuze.  When the mine is packed, the spider is placed over the bottom of the steel body to save space.


Arming: The safety fork is not removed until after the mine is laid; and, after removal, the fork is left beside the mine, attached to its cord, never between the body and the spider.  Before the mine is taken up, the safety fork is replaced.


Color: The bottom and 3/4-inch of the side are painted yellow; the rest of the mine is painted olive drab.


Remarks: The M1, the original model, is no longer being manufactured or issued.  The principal difference is that, in the Mine M1, the booster is an integral part of the fuze; in the Mine M1A1 the booster is a separate part and issued assembled in the fuze cup of the mine.

Protective bag covers made of moisture-resistant, mildew-proof fabric are provided with this mine to prevent foreign matter from working between the mine body and the spider.  The cover is cylindrical in shape, 8.75 inches in diameter, 9 inches high, and open at one end.  The Mine M1A1 is being replaced by the M6.





M4 (Obsolete)


Diameter: 8 inches
Height (with spider): 4 inches
Total weight: 10.6 pounds
Cast TNT weight: 6 pounds
Material: Steel

Components: The metallic Anti-Tank Mine M4 is identical to the M1A1 type except for the booster, the fuze, and the activator wells.  The M4 has one activator well on the bottom and one on the side.  Since the booster, after loading, becomes an integral part of the mine, and since the M1A1 and M4 boosters and fuzes are not interchangeable, it is especially important that the Mines M1A1 and M4 and their respective fuzes be kept separate.  However, the two mines are assembled, armed, and employed in the same manner.  The advantage of the Mine M4 is that the internal construction of the M4 fuze makes it safe to re-use, because it is not made more sensitive by repeated light blows.


Booster: The M4 booster is identical with M1A1 booster, except that it has a flat top with a crossed scar to insure rupture of the booster shell by the detonator, while the M1A1 booster has a cavity int he top to receive the protruding primer and detonator of the M1A1 fuze.


Arming: The safety fork is removed from the fuze by pressure of the thumbs on the prongs.


Color: The bottom and 3/4-inch on the side are painted yellow; the rest of the mine is painted olive drab.


Remarks: The Mine M4 is being replaced by the M6.

The M4 also has a protective cover bag.





M5


Diameter: 10 inches
Height: 5.5 inches
Total weight: 14.5 pounds
Weight of filler: 5.6 pounds
Type of filler: TNT or Tetrytol
Material: Pottery and impregnated felt

Components: The cylindrical mine body consists of a ceramic bowl containing the high explosive, with a ceramic plate which acts as the spider.  These components are separated by a cushion of rubber or similar material and enclosed in asphalt-impregnated felt and tarred paper.  There is a threaded opening in the top of the mine for assembly of the fuze and a bakelite plug in the bottom, which may be removed for the attachment of an anti-removal device.


Color: The mine is painted olive drab and marked in yellow


Remarks: This is a non-metallic mine in order that it may not be detected by an electro-magnetic mine detector.

An anti-lifting device may be attached by removing the rubber plug in the bottom of the mine; however, use of a metal device tends to defeat the purpose of designing the mine and fuze with no metal parts.

This mine is considered a substitute standard item by the Army Ordnance Department.






Next Time: Anti-Tank Mines (Part 2)

Monday, 28 May 2018

American Projectiles and Explosives - Rifle Grenades (Part 2)





American Projectiles and Explosives




Rifle Grenades (Listing)




Anti-Tank M9 and M9A1


Length: 11.24 inches
Diameter: 2.25 inches
Color: Olive drab
Weight: 1.23 pounds
TNT filling: 4 ounces


Description: Anti-Tank Grenade M9A1 consists of a body, a stabilizer assembly, and a fin.  The body is cylindrical, the two pieces joined in the middle with rounded ends.  The stabilizer is a hollow tube which screws into the base of the body and fits over the launcher; it also carries a shroud fin assembly which aids in stabilizing the flight of the grenade.  The body is made of cast steel.

The impact fuze, which consists of a striker held away from a detonator by a creep spring and a safety pin, is assembled integrally with the stabilizer assembly.  The safety pin projects through the fuze body and clamps around the stabilizer tube.  When the pin is withdrawn, a drop of two feet, nose-first, to a hard surface will cause the fuze to function.

This grenade is designed primarily for use against tanks and other armoured or resistant targets.  It must strike within 20 degrees or normal to be sure to function.  However, the velocity of the grenade itself is not a critical factor, as it incorporates the hollow-charge principle.  The danger radius to the rear of the explosion is 50 yards.


Operation: The grenade is fired from a rifle by means of a special launcher attachment.  A special cartridge is used for propulsion.  The grenade must be placed on the launcher before the safety pin is withdrawn.  The safety pin is removed before firing.  When the grenade is fired, set-back holds the striker away from the detonator.  On impact, the striker overcomes the creep spring and hits the detonator.


Remarks: The M9 is an earlier model.  It has the same tail assembly, but the head is acorn-shaped and is equipped with a point detonating fuze.  It is slightly less sensitive than the M9A1.  The safety pin of the M9 is located in the base of the grenade body instead of in the stabilizer tube.  Its pull ring is secured to the body with adhesive tape.







Fragmentation M17


Length: 9.775 inches
Diameter: 2.25 inches
Color: Olive drab
Weight: 1.47 pounds
E.C. powder filling: 0.77 ounces


Description: This grenade consists of a fragmentation-type body similar to the Hand Grenade Mk IIA1 assembled to a fuze and stabilizer assembly similar to that for the anti-tank and practice rifle grenades.  The stabilizer and fuze assembly threads into the grenade body.

The fuze is a simple impact type.  The striker is held away from the detonator by a safety pin and a creep spring.  The safety pin projects through the fuze body and clamps around the stabilizer tube.  When the pin is withdrawn, a drop of two feet, nose-first, to a hard surface will cause the fuze to explode the grenade.  Detonation will not occur upon impact with water, mud, or soft sand.  This grenade is designed primarily for use against personnel.


Operation: The grenade must be placed on the launcher before the safety pin is withdrawn.  The safety pin is removed before firing.  When the grenade is fired, set-back holds the striker away from the detonator.  On impact, the striker overcomes the creep spring and hits the detonator.


Remarks: The Fragmentation Grenade M17 is no longer in production; however, large quantities were issued.






Smoke M19, M19A1, M20, and T6E1


Length: 10.72 inches
Diameter: 2 inches
Color: Blue grey
Filling: Smoke mixture


Description: In outward appearance, this grenade is similar to the Anti-Tank Grenade M9A1, except that the body is in one piece and does not have the joining rib.  The body is cylindrical, with rounded ends.  The stabilizer is a hollow tube which screws into the base of the body and fits over the launcher.

The impact fuze of the Anti-Tank Grenade M9A1 has been modified so that a long detonator which extends into the body of the grenade acts as a burster when the fuze operates.  The fuze is an impact type, with the striker held off the detonator pin by a safety pin and a creep spring.  The safety pin projects through the fuze body and clamps around the stabilizer tube.

The explosion of the burster tube breaks the grenade and scatters burning white phosphorus over an area of 25 square yards.  The burning phosphorous gives off a dense white smoke.  The particles are of incendiary nature and make an excellent anti-personnel weapon.


Remarks: The M20 adn T6E1 are rifle smoke grenades with a filling that emits white smoke.  The T6E1 is 1/4 inch longer than the M20.  Both are identical in construction and operation to the M19A1.  The M10 is filled with 10.8 ounces of H.C. smoke mixture and is used exclusively for screening purposes.  The fuze functions on impact and ignites the smoke mixture.  The smoke mixture burns for approximately one minute, giving off a dense white non-toxic smoke through the emission holes in the base of the grenade body.






Smoke M22


Length: 10.72 inches
Diameter: 2 inches
Color: Blue grey
Filling: Smoke mixture


Description: This grenade is similar to the Smoke Grenades M20 and T6E1.  In outward appearance, it is similar to the Anti-Tank Grenade M9A1, except that it does not have the joining rib.  The nose of the body has a small circular opening which is closed with a light metal cover.  The stabilizer contains the Fuze M9A1 Type.

The body is filled through the nose.  After filling, a tool is inserted longitudinally through this nose opening, and the filling is packed against the sides of the body, leaving a central channel.  Then, this channel is coated with an igniting composition.  The smoke-emission holes are through the base shoulder of the grenade body.

Four colors are issued: red, green, violent, and yellow.

The primary use of the grenade is for signaling.


Operation: The igniter ignites the igniting mixture, which initiates the burning of the smoke mixture.  Smoke is emitted through the emission holes for one to one and one-half minutes.





Practice M11A2 and M11A3


Length: 11.18 inches
Diameter: 2.25 inches
Color: Black


Description: This grenade simulates the Anti-Tank Grenade M9A1.  The grenade is so constructed that the fin and the ogive assemblies, which are most liable to damage in use, may be replaced and the grenade used repeatedly.  It is for training in marksmanship.






Ground Signals

There are a number of smoke and flare pyrotechnic signals in containers launched from rifle-grenade launchers.  They are used in signaling and for simulation of air bursts of artillery, etc.






Projection Adapters





M1A1

Description: This adapter consists of a stabilizer and fin assembly to which are attached three spring-steel fingers.  It is designed to project the standard fragmentation hand grenade by means of the rifle or carbine.  The Hand Grenade Mk II is assembled to the adapter with the fingers engaging the grooves in the grenade body.  When the grenade is assembled to the adapter, the safety lever of the grenade is inserted in the arming clip.  The safety lever is held in place by the arming clip until the grenade is fired.  On set-back, the clip lags and so is removed from over the safety lever, which is then thrown off by the rotating striker.  The striker hits the primer, igniting the 4.5 second delay, after which the grenade explodes.

When the grenade is assembled to the adapter and the safety pin removed, the lever bends outward, on account of pressure from the striker.  If the lever is struck on its outer surfaces, near the striker, while in this condition, it is possible that the lever may spring loose from the fuze and release the striker, allowing the fuze to function.  Care should be exercised, once the safety pin is removed, to prevent the lever from being struck.



M2

Description: This adapter consists of a stabilizer and fin assembly and a metal set-back band.  To the stabilizer are attached four short spring-steel clips.  It is designed to project the following grenades: CN-DM-M6; CN-M7; H.C., AN-M8; AN-M14; M16; and M18.

The grenades are assembled to the adapter with the clips holding over the ridge at the base of the grenade.  The set-back band contains a short spring and fits around the grenade, over the safety lever.  It holds the safety lever in a safe position after removal of the fuze safety pin.  When the grenade is fired, set-back causes the band to slide off the safety lever toward the base of the grenade.  This permits the safety lever to spring outward and the striker to ignite the fuze.  The fuze ignites the grenade in approximately one to one and a half seconds.





Next Time: Tree Suspension Device and Anti-Tank Mines (Part 1)

Monday, 21 May 2018

American Projectiles and Explosives - Rifle Grenades (Part 1)





American Projectiles and Explosives




Rifle Grenades






General

Resembling rockets in their shape because of the tube and stabilizing fin on their after end, rifle grenades are designed for about the same tactical purposes as are hand grenades.  Rifle grenades have much greater range, however, and, because of their being launched at greater initial velocities, the forces of set-back and creep are employed in the design of their fuzes.


Launchers

The launcher, on which the grenade is placed for firing, is an extension to the barrel of the rifle or carbine.  A special device, integral with the launcher, attaches it securely to the muzzle of the weapon.  US launchers are all of the spigot type; that is, the stabilizer assembly of the grenade fits over the launcher.



Classification of launchers

M1 - US rifles, caliber .30 M1903, M1903A, and M1903A3

M2 - US rifle, caliber .30 M1917

M7 - US rifle, caliber .30, M1, M1A3


The launcher M7 is secured to the Rifle M1 by a latch which clamps behind the bayonet lug.  A valve screw, issued with the launcher, is substituted for the gas-cylinder lock screw.  A stud on the launcher protrudes into the valve screw when the launcher is attached, opening the valve and providing for enough gas release to avoid damage to recoiling parts.  The valve remains open as long as the launcher is attached to the rifle.  The launcher has six gradations for different ranges.  The range of the grenade is dependent upon the position of the stabilizer assembly on the launcher.  A grenade-retainer spring, slightly larger in diameter than the launcher, holds the grenade at the position on the launcher for the selected range.

The Launcher M8 is similar to the Launcher M7, except that it is secured to the carbine by a simple clamp and wing nut.

If necessity demands, ball cartridges may be fired, even thought the launcher is attached, assuming, of course, that no grenade is on the launcher.



Rifle grenade cartridges


Rifle caliber, .30 M3: This cartridge is used in US rifle M1, M1903, M1903A1, M1903A3, and M1917.  It is loaded in the standard caliber .30 case.  The load consists of five grains of black powder and approximately 49 grains of a progressive-burning smokeless powder; the exact amount is adjusted to give the Anti-Tank Rifle Grenade M9A1 a velocity of 165 feet per second at five feet.


Carbine caliber, .30 M6: This cartridge is used in the US carbine M1, M1A1, and M1A3.  It is loaded in the standard carbine cartridge case with approximately 21 grains of special powder adjusted to give the Anti-Tank Grenade M9A1 a velocity of 145 feet per second at 5 feet.


Auxiliary Grenade Cartridge M7: This cartridge, designed to give additional range when used in firing grenades from rifles and carbines, is a caliber .45 case drawn piece loaded with 20 grains of powder and sealed with a paper wad.  It is placed in the end of a launcher, a rim on the base of the case holding the cartridge in place.  It funcitons only in combination with the standard Grenade Cartridge M3 or M6 and fits the Launchers M1, M2, M7, and M8.  When using this cartridge, the rifle or carbine will not be fired from the shoulder.



Next Time: Rifle Grenades (Part 2)

Monday, 14 May 2018

American Projectiles and Explosives - Hand Grenades (Part 2)





American Projectiles and Explosives




Grenades






Illuminating Mk I


Overall length: 4.4 inches
Diameter: 2.1 inches
Weight: 9.5 ounces
Delay: 7 seconds
Burning time: 25 seconds
Intensity: 50,000 candlepower


Description: This grenade is approximately the same size and shape as the fragmentation hand grenade.  It consists of two sheet-steel cups joined together by a force fit, and sealed with Petman cement.  The lower half contains the illuminating compound and a charge of black powder, which, when ignited by the fuze, blows the grenade apart and ignites the pyrotechnic.  The upper half contains the fuze assembly, which is similar in appearance and in operation to that of the fragmentation hand grenade.


Operation: For hand launching, the grenade is held in one hand with the safety lever against the palm.  The safety pin is removed with the other hand.  When the grenade is thrown, the safety lever is released, and the striker, driven by its spring, forces the lever off, swings around its pivot, and strikes the primer.  The flame from the primer ignites a delay train which burns through to the charge of black powder.  The black powder charge bursts the case and ignites the pyrotechnic.

For rifle launching, assemble the grenade int he Adapter M1, insert the safety lever into the arming clip, and force the grenade into place between the claws, so that the claws engage the raised portion of the grenade where the upper and lower halves are formed together.  When the grenade is fired, set-back will cause the arming clip to come off of the safety lever, and the striker will throw the lever off and hit the primer to activate the grenade.






Incendiary AN-M14

No picture available

Overall length: 5 inches
Diameter: 2.5 inches
Color: Blue grey

Filling: Thermate, thermite, and nitrates
Fuze: M200A1
Delay: 2 seconds


Description: This grenade has a cylindrical body made of tin plate.  A clamp of flat steel strapping and a nail are packed in the container with each grenade.  These are used to hold the grenade in position, as it has a tendency to move upon ignition.  The Fuze M200A1 threads into the top of this grenade.


Operation: The igniter ignites the thermite, which ignites the thermate.  The grenade burns with such intense heat that it will melt its way through steel.






Riot - CN Gas - M25




Diameter: 2.9 inches
Filling: Micropulverized chloracetophenome (CN)
Weight of filling: 3 and 1/3 ounces
Delay: 2 seconds


Description: The Riot Grenade M25 is made of phenolic plastic.  It is spherical in shape and is formed from halves cemented together.  Inside the sleeves, integral with the halves, form the casing for the firing components.  These sleeves telescope; the lower is cemented into the upper.  The channel thus formed through the center of the grenade receives the firing mechanism.  A plastic closure plug in the base of the lower sleeve has an integral firing pin on the inner side.  A filling closure plug is located 1/2 inch from the firing-pin closure plug.

The fuze assembly contains a primer, a two-second delay element, and a detonator.  A slider holds the fuze assembly cemented inside its lower end, and a hole in the upper end receives the safety pin.  Two safety balls fit under a projection on the slider and hold it in the unarmed position until released into the grooves when the arming sleeve is expelled.  The firing spring fits over the slider and is compressed between the projections on the slider and the upper end of the lower sleeve.  The arming spring is compressed inside the arming sleeve, which in turn rests int he channel of the upper sleeve, extending 5/16 inch beyond the grenade body.  Holes through the arming sleeve provide for the entry of the safety pin.


Operation: When the safety pin is withdrawn, the arming sleeve is expelled by the compressed arming spring; this permits the two safety balls to recede into the grooves, releasing the slider, which is driven against the firing pin, activating the primer.  The fuze provides a two-second delay before detonation.  With shattering of the plastic body, the micropulverized CN is dispersed in a cloud.






Improvised frangible types (Obsolete)


Igniters: M1, M2, or M3

Filling:
-Gasoline and alcohol
-Thickened gasoline
-Smoke
-Hydrocyanic acid
-Gasoline and napalm



Description: These are improvised grenades made by simply filling a glass bottle with one of these chemical agents.  They may or may not have an igniter, depending upon the filling that is used.  If the filling is smoke or hydrocyanic acid, no igniter is required; but if the filling is one of the others mentioned above, an igniter is necessary.


Igniter M1: This is a plastic cylinder containing a chemical powder.  It is used with grenades containing a mixture of gasoline and alcohol.  When the glass container breaks against the target, the powder and liquid come in contact and ignite spontaneously.


Igniter M2: This is a paper cartridge, filled with powder, assembled to a pull-wire igniter.  This igniter is taped to a frangible grenade filled with thickened gasoline.  To operate the igniter, pull the wire, lighting the powder.


Ingiter M3: This is a simple fuze consisting of a spring-loaded firing pin and a blank cartridge contained in a cylinder, and a metal clamp to hold the cylinder against the frangible grenade.  The clamp has a conical projection which, when the clamp is tightened around the safety pin which passes through the cylinder, also restrains the firing pin.  When the grenade is used, the safety pin is removed and the grenade is thrown so as to smash against the target.  When the bottle breaks, the tension on the clamp is released and the firing pin, driven by its spring, pushes the cone aside and strikes the primer of the cartridge.  The flash from the cartridge ignites the grenade filler.  This igniter is used with the napalm grenade.


Remarks: These frangible grenades are considered obsolete.





Practice Mk II and Mk IA1 - Fuze M206



Length: 4.58 inches
Diameter: 2.25 inches
Weight: 1.28 pounds
Color: Light blue

Fuze: M206
Delay: 4 to 4.8 seconds


Mk II: This grenade consists of a fragmentation body with a filling hole in the base, an Igniting Fuze M206 or M10A3, a small charge of black powder, and a cork plug in the filling hole.  Extra fuzes, charges, and plugs are supplied separately, so that the grenade body can be re-used.


Operation: When set off by the delay element, the igniter fires the small black-powder charge, which goes off with a loud report and blows the cork plug out of the filling hole.


Mk IA1: This grenade consists of an iron body and simulated fuze, all cast in one piece to resemble a Fragmentation Grenade Mk IIA1.  The simulated fuze has a removable safety pin and ring.  There is a hole in the bottom of the grenade body.  There is no charge in either the grenade or the fuze.  It is painted black, with a white band at the top.





Next Time: Rifle Grenades (Part 1)

Monday, 7 May 2018

American Projectiles and Explosives - Hand Grenades (Part 1)





American Projectiles and Explosives




Grenades




General

The design of hand grenades has been confined by several limiting technicalities, as follows: the grenade must be small and light; its range is short; there is no set-back or creep force of significance in the throwing operation; and the grenade must be rugged and safe enough to be carries on the bodies of troops.

Hence, despite the many tactical purposes, anti-tank, anti-personnel, screening, etc, hand grenades are generally of the same shape, size, and fuze action.





Fragmentation Mk II, Mk IIA1; also Fuze M204


Overall length: 4.5 inches
Diameter: 2.25 inches
Color: Olive drab
Weight: 1.4 pounds
Filling: Flaked and granular TNT
Weight of filling: 1.75 ounces

Fuze: M204
Delay: 4 to 5 seconds


Description: The Fragmentation Grenade Mk II has a serrated cast-iron body of the familiar "pineapple" design.  The grooves run both horizontally and vertically to assist in the formation of uniform fragments of effective size.

This grenade is issued loaded and fuze with Igniting Fuze M204.  This Fuze M204 produces no noise other than that of the impact of the striker on the primer, and emits no smoke or sparks during its burning.  The fuze consists of a body, striker, safety lever, and safety pin.  The body of the fuze is cylindrical in shape and is threaded for assembly to the grenade.  It contains the primer, a delay element sufficient to give an average delay of 4.5 seconds, and a detonator of PETN.  At the top of the body, one side is extended and slotted to form a point of fulcrum for the attachment of the safety lever.  The striker is retained by the safety lever.  The lever is hooked under the lip of the fuze body, extends across the head of the fuze and over the striker, and curves downward in an arc that conform to the shape of the grenade body.  The lever is held in position for shipping and handling by a split safety pin which passes through the safety lever, through the fuze body, and over the striker to protrude on the other side, where the pin is spread so that a pull of between 20 and 30 pounds is required to withdraw it.


Operation: When the safety pin is withdrawn preparatory to throwing, the lever is held in place by the hand holding the grenade.  When the grenade is thrown, the lever is released.  The striker, driven by its spring, throws off the lever and rotates about its pivot to impinge on the primer.  The primer ignites the delay element, which takes from 4 to 5 seconds to burn through to a relay element which flashes through a flash channel to ignite the detonator.  Explosion of the PETN detonator, detonates the main charge of the grenade.

The grenade can be thrown about 35 yards.  Effective fragmentation covers an area of 30-yard radius, but fragments may travel as far as 200 yards.


Earlier models: This grenade replaces an earlier model, the Mk IIA1, which was identical to the Mk II except for the fuze and the filling, the Mk  IIA1 being issued with the Fuze M10A3.  The only external difference is that the safety lever fits over rather than under the lip of the fuze body.  The Fragmentation Grenade Mk II is filled with 3/4 ounce of E.C. powder.







Offensive Mk IIIA1 and Mk IIIA2; also Fuzes M6 and M206A1


Overall length: 5.35 inches
Diameter: 2.125 inches
Color: Black
Weight: 0.84 pounds

Fuze: M206A1
Delay: 4.5 seconds


Description: The Offensive Grenade Mk IIIA2 consists of a cylindrical pressed-fiber body and a charge of pressed TNT.  The head contains a threaded fuze hole which is sealed by a water-proof paper disc.

It is fuzed with Detonating Fuze M206A1, which has a delay varying between 4.3 and 4.8 seconds.  The fuze consists of a threaded metal body which contains the primer, delay element, and detonator, and to which a spring-drive striker is attached.  The striker is restrained by the safety lever, which hooks over the lip of the body and passes across the head of the body, over the striker, and down the side of the grenade.  The lever is held in place during shipping and handling by a split safety pin which passes through the safety lever, through the fuze body, and over the striker, to protrude on the other side, where it is spread so that a pull of between 10 and 30 pounds is required to withdraw it.  This fuze is distinguished from igniting fuzes by the red sealing compound, instead of green, used to seal the detonator into the fuze.


Operation: When the safety pin is removed preparatory to throwing, the lever is held in place by the hand holding the grenade.  When the grenade is thrown, the lever is released.  The striker, driven by its spring, throws off the lever and rotates about its pivot to impinge on the primer.  The primer ignites the delay element, which takes about 4.5 seconds to burn through to the detonator.

The explosion of the detonator sets off the main charge, producing a blast effect.  This blast is not effective against personnel except at very short ranges or in enclosed spaces.


Earlier models: The Offensive Grenade Mk IIIA1 differs from the Mk IIIA2 in that the ends of the grenade body are of sheet metal and the grenade weighs 0.875 pounds fuzed.  The Mk III had metal ends and contained only 0.27 pounds of TNT.  It was shipped with a wooden plug in the fuze well.  The M6A1, M6A2, and M6A3 models of this fuze may be encountered.  These modifications have been declared unsafe for use and should be destroyed.


Remarks: The Hand Grenade Mk IIIA2 has been taken out of production, but large quantities of them still exist.






Smoke (W.P.) M15; also Fuzes M6A3, M10A3, and M200A1



No picture available

Overall length: 5 inches
Diameter: 2.5 inches
Color: Blue grey
Filling: White Phosphorus

Fuze: M6A3
Delay: 4.5 seconds


Description: This grenade is of the bursting type and contains white phosphorus in a sealed cylindrical container.  The body corners are rounded.  It is fuzed with the Detonating Fuze M6A3, which has a delay varying between 4.3 seconds and 4.8 seconds.  The fuze consists of a threaded metal body which contains the primer, delay element, and detonator, and to which a spring-driven striker is attached.  The striker is restrained by the safety lever, which hooks over the lip of the body and passes across the head of the body, over the striker, and down the side of the grenade.  The lever is held in place during shipping and handling by a split safety pin which passes through the safety lever, through the fuze body, and over the striker, to protrude on the other side, where it is spread so that a pull of between 10 and 30 pounds is required to withdraw it.  This fuze is distinguished from igniting fuzes by the red sealing compound, instead of green, used to aid in sealing the detonator into the fuze.  It differs from the Detonating Fuze M10A3 in that the safety lever is straight, while that of the M10A3 is curved.  It differs from the Detonating Fuze M200A1 int hat the length of the body is approximately four inches, as compared with a body length of two inches for the M200A1.  The detonator consists of a seven-grain primer charge and a 13.5-grain tetryl charge.


Operation: When the safety pin is removed preparatory to throwing, the lever is held in place by the hand holding the grenade.  When the grenade is thrown, the lever is released.  The striker, driven by its spring, throws off the lever and rotates about its pivot to impinge on the primer.  The primer ignites the delay element, which takes about 4.5 seconds to burn through to the detonator.

When ignited by the delay element, the detonator bursts the case and scatters the phosphorus over an area about 25 yards in diameter.  The phosphorus ignites spontaneously, and the scattered pieces will burn for about 30 seconds.






Gas CN-DM-M6, CN-M7, and CN-M7A1; also Fuze M201A1


Overall length: 5 inches
Diameter: 2.5 inches
Color: Blue grey

Filling:
-M6: Cloracetophenome, Diphenylamine, Chloraisine, burning mixture
-M7: Cloracetophenome, burning mixture

Fuze: M201A1
Delay: 2 seconds


Description: These grenades are of the burning type; they do not explode.  They have a cylindrical body made of tin plate.  The M7A1 has a half-inch gas port in the bottom and four ports in the head, covered by small squares of adhesive tape.  A center hole is placed through the CN mixture.  At the top of the hole is the starter mixture.  The M6 and M7 have three lines of six gas ports in the body and four ports in the head, covered by small squares of adhesive tape.

The Fuze M201A1 threads into the top of these grenades.  It is essentially the same as the Igniting Fuze M10A3 used in the fragmentation hand grenade.  However, there is only a two-second delay element, an igniter, and no detonator.  This results in a fuze with a much shorter body.  At the top of the body, one side is extended to form a lip for the attachment of the safety lever; the other side forms a hinge to carry the spring-loaded striker.  The striker is restrained by the safety lever.  The lever is hooked over the lip of the fuze body and extends across the head of the fuze, over the striker, and down the side of the grenade.  The lever is held in position for shipping and handling by a split safety pin which passes through the safety lever, through the body, and over the striker, to protrude on the other side, where it is spread so that a pull of between 20 and 30 pounds is required to withdraw it.


Operation: When the safety pin is removed preparatory to throwing, the lever is held in place by the hand holding the grenade.  When the grenade is thrown, the lever is released.  The striker, driven by its spring, throws off the lever and rotates about its pivot to impinge on the primer.  The primer ignites the delay element, which takes about 2 seconds to burn through to the igniter.  The igniter ignites the starter mixture, which creates enough heat to vaporize the chemical ingredients.  The pieces of adhesive tape covering the gas ports are blown or burned off and gas is emitted  The gas generation reaches full volume three seconds after the safety lever is released, and gas is emitted for from 20 to 60 seconds.  The M7A1 has an average burning time of 45 seconds.


Remarks: The M7A1 is an improved model of the M7, which is now substitute standard.  The tendency of the M7 to flame or explode upon ignition has been eliminated in the M7A1, which also produces more than double the concentration of CN smoke and vapor.





Smoke, White, H.C., AN-M8, and Colored, M18 and M16; also Fuze M201


No picture available

Length: 5 inches
Diameter: 2.5 inches
Color: Blue grey

Filling:
-AN-M8: Hexachlorethane-zinc
-M18: Colored smoke mixture

Fuze: M201
Delay: 2 seconds


Description: These grenades have four ports in the head.  These are covered by small squares of adhesive tape.  The Grenades M18 produce seven colors of smoke: red, orange, blue, green, black, violet, and yellow.  The M16 is a limited standard colored-smoke grenade and differs from the M18 in that it produces smoke for 2.5 minutes, while the M18 produces smoke for one minute, and the AN-M8 produces a white smoke for three minutes.

The Fuze M201 threads into the top of these grenades.  It is essentially the same as the M10A3 used in the fragmentation hand grenades.  However, there is only a two-second delay element, an igniter, and no detonator.  This results in a fuze with a much shorter body.  At the top of the body, one side is extended to form a lip for the attachment of the safety lever; the other side forms a hinge to carry the spring-loaded striker.  The striker is restrained by the safety lever.  The lever is hooked over the lip of the fuze body and extends across the head of the fuze, over the striker, and down the side of the grenade.  The lever is held in position for shipping and handling by a split safety pin which passes through the safety lever, through the fuze body, and over the striker, to protrude on the other side, where it is spread so that a pull of between 20 and 30 pounds is required to withdraw it.


Operation: The igniter ignites the starter mixture, which initiates the smoke mixture.  The pieces of adhesive tape covering the gas ports are blown or burned off and gas is emitted for approximately 3.5 minutes.

The volume of smoke generated by a grenade is generally too small for screening purposes.  Although these grenades may be used to patch gaps in a larger screen, the authorization is for signals.


Remarks: The presence of moisture will cause these grenades to ignite spontaneously.  If a fire should occur in such munitions, an attempt should be made to remove and segregate the burning items.  Neither water nor the usual chemical extinguishers should be used in an attempt to extinguish such fires.

The Smoke Grenade M16 is designated as a substitute standard item.







Smoke, Red, AN-M3, also Modified Fuze M201


Length: 5.5 inches
Diameter: 3 inches
Color: Blue grey
Filling: Red smoke mixture

Fuze: Modified M201
Delay: 2 seconds


Description: This grenade differs from the other smoke grenades in that the body is assembled in a cylindrical outer container.  This container has eight smoke-emission ports in its top.  It also has three light metal flaps welded to the side, which may be bent outward at right angles to furnish bearing for supporting the grenade in snow, mud, or other soft surface.  With the outer container, this grenade is slightly larger than the ordinary smoke grenade.

The Fuze M201 has been modified by shortening the safety lever so that it does not protrude down the side of the grenade.  At the top of the body, one side is extended to form a lip for the attachment of the safety lever; the other side forms a hinge to carry the spring-loaded striker.


Remarks: This grenade is used for signaling, especially in snow.




Next Time: Hand Grenades (Part 2)