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)

Monday, 30 April 2018

American Projectiles and Explosives - Submarine Pyrotechnics





American Projectiles and Explosives




Shipboard Pyrotechnics



Submarine Items





Submarine Float Signal Mk 1 Mod 1 and Mk 2 Mod 0



Length: 18.75 inches
Diameter: 3 inches
Delay: 27 seconds
Burning time: 15 seconds

Color: Black, Yellow, Green, or Red


Use: These float signals are used to mark the position of a submerged submarine, and for other marking purposes.


Description: The firing mechanism consists of a firing pin, firing-pin spring, firing-pin lever, and tripping lever or lug.  The ignition system consists of a primer, time fuse, quick match, and a starter mixture.  The aluminum signal contains a smoke pot, smoke mixture, smoke pot cover, and central tube.  The signal has a nose cap and release valve.


Operation: The signal is fired from a submerged submarine, through a tube, using compressed air as a propellant.  As the signal is leaving the ejector, a tripping lever is raised by contact with a lug in the gun, cocking and releasing the firing-pin lever, which fires the primer.  The primer ignites the time fuse, which burns for 27 seconds.  The signal is buoyant and rises to the surface within the 27 seconds of fuse delay.  The time fuse ignites a piece of quick match, which, in turn, initiates the starter composition.  The starter composition sets off the smoke mixture.


Remarks: The maximum launching depth is 162 feet.

The Submarine Float Signal Mk 2 Mod 0 is similar to the Mk 1 Mod 1, except for a fixed delay of 54 to 59 seconds, a maximum launching depth of 285 feet, and sturdier construction.





Submarine Emergency Identification Signal Mk 2 Mods 1 and 2; also Submarine Emergency Signal, Star, Mk 3 Mods 0 and 1


Length: 18 inches
Diameter: 3 inches
Burning time: 25 seconds
Delay: 27 seconds

Color of star: Red, Yellow, or Green


Use: These signals are used for submarine emergency identification, whether submerged or surfaced.


Description: The signal consists of a cylindrical aluminum case containing the grenade-type Pyrotechnic Candle Mk 3.  The bottom end contains two delay elements.  A single-star candle is attached to a parachute by an asbestos cord.


Operation: The shell is projected from the standard submarine emergency identification signal ejector, using compressed air as the propellant.  The shell is fired by a lug at its base which projects beyond the side of the shell and rides in a groove in the ejector tube.  As the shell is forced through the tube, the extended lug reaches the end of the groove just before the base of the shell passes the muzzle door.  The tripping lever is pulled back, thereby cocking and releasing the firing pin lever and firing pin.  The firing pin strikes the primer, and the flash from the primer ignites a time fuse.  The time fuse burns while the signal is rising to the surface.  The delay ignites the grenade-ejection charge, which ejects the signal to a distance of approximately 250 feet.  At the summit of the trajectory, the delay train flashes into the signal-ejection charge and causes the parachute-suspended star to be ejected.


Remarks: The Mk 2 Mod 2 is obsolescent, being replaced by the Mk 3 Mods 0 and 1.  The Mk 3 Mod 0 has a slightly different method of expelling the inner grenade.  The maximum launching depth is 160 feet.

The Mk 3 Mod 1 is similar tot he Mk 2 Mod 1, except for the following:
-A delay of 54 to 59 seconds,
-A maximum launching depth of 285 feet, and
-A sturdier construction to withstand pressures at a lower depth






Pistol Rocket Signal Mk 1, Comet; Mk 3, Shower; and Chameleon




Length: 14 inches
Diameter: 1.5 inches
Burning time: 1 seconds
Intensity: 60,000 candlepower

Color of single star: Red, Yellow, or Green


Use: These signals are used for emergency identification by surfaced submarines.


Description: The upper section or signal chamber contains a pyrotechnic composition and powder-ejection charge.  The rocket motor, which is riveted to the signal chamber, contains one gram of black powder above a felt washer and 58 grams of black powder, which is the rocket element.  Four spring-loaded hinged vanes, four inches long and one inch wide, are attached to the rocket tube and fold and fit into the rocket chamber.  The rocket chamber is an aluminum container with a Primer Mk 5 in its base.  This unit receives the rocket motor.


Operation: The signal is fired from the submarine rocket pistol or the Pyrotechnic Pistol AN-M8.  Release of the trigger fires the primer, which ignites the one-gram auxiliary propelling charge.  This black-powder charge propels the signal chamber and attached rocket motor to about 30 feet from the pistol muzzle.  At this point the 58-gram charge of black powder, which is the rocket element, takes effect and propels the signal to a height of approximately 650 feet.  The rocket element ignites the expelling charge at the zenith of its trajectory.  The expelling charge ignites the star and simultaneously ejects it.  The single star falls freely, and burns out just before hitting the water.


Remarks: This signal replaces the chameleon-type submarine rocket signal.

The Rocket Pistol Signal Mk 8 Mod 0 (Shower) is similar to this signal, except that a burst shower is produced instead of a single star.

The Rocket Pistol Signal, Chameleon, is similar to this signal, except that a variety of colors is obtained.






Submarine Emergency Identification Flares Mk 10 Mods 0-2, Mk 11 Mods 0-2, and Mk 12 Mods 0-2


Length: 9.75 inches
Diameter: 2 inches
Weight: 3.2 pounds


Use: These signals are used by surfaced submarines to identify themselves.


Description: The flare case consists of a seamless steel tube, one end of which is closed by a steel closure disc.  The firing mechanism, which extends along the side of the flare body, is attached tot he base casting, which carries the closure disc and primer.  The firing mechanism is enclosed in a brass housing which contains the following: (1) a brass shaft held in place by a cotter pin, (2) a firing pin attached to the brass shaft by a sear join, (3) a spring surrounding the firing pin, and (4) a lanyard attached to the brass shaft.  The flare case contains the following: (1) a black-powder charge, (2) a starter composition, (3) a pyrotechnic charge, and (4) a steel cup riveted to the case, closing one end.  Two clamps are welded to the flare body for mounting on the bracket, fixed to the submarine bridge.





Operation: Mount the flare so that the firing mechanism points toward the deck.  A vertical pull on the lanyard forces the brass shaft up, compressing the firing-pin spring.  The sear joint between the shaft and firing pin is broken when the shaft is pulled approximately 0.5 inches.  The firing pin strikes the primer, which ignites a small charge of black powder.  The flash from the black powder ignites the starter composition, which, in turn, ignites the pyrotechnic candle.  The flare burns in four increments of 10 seconds duration and intervening blackout increments of five seconds.



Remarks: Flares that have been submerged below periscope depth should be thrown overboard at the first opportunity.

 The possibility of detonation in any of the flares, and particularly in those with green pyrotechnics, should never be lost sign of.  For this reason, personnel in the vicinity of the flares should be adequately shielded prior to firing.

Submarine Emergency Identification Flares Mk 10 and Mods are similar to the Flares Mk 11 and Mods and Mk 12 and Mods, except that these burn with only one uninterrupted color - Mod 0, red; Mod 1, green; and Mod 2, yellow.





False Target Shell Mk 1 Mod 0


Length: 18 inches
Diameter: 3 inches
Delay: 27 seconds
Persistence of echo: 4 to 18 minutes


Use: This shell is used to confuse and disrupt enemy underwater echo ranging.


Description: The external appearance is similar tot he Submarine Emergency Signal Mk 2 Mod 2.  The shell holds six metal cups 2.75 inches in diameter and 1.875 inches in depth, filled with a lithium hydride paraffin mixture.  The base of the shell contains a primer, time fuse and 20-gram charge of smokeless powder.  Attached tot he base is a firing mechanism which is used with the standard emergency identification signal ejector.


Operation: The shell is projected from the standard emergency identification signal ejector, using 200 pounds per square inch air pressure if possible.  The shell is fired by a lug at its base which projects beyond the side of the shell and rides in a groove in the ejection tube.  As the shell is forced through the tube, the extended lug reaches the end of the groove just before the base of the shell passes the muzzle door.  The tripping lever is pulled back, thereby cocking and releasing the firing pin lever and firing pin.  The firing pin strikes the primer, and the flash from the primer ignites a length of time fuse coiled in the base of the shell.  The time fuse burns for 27 seconds, and then ignites the 20-gram charge of smokeless powder, which ejects the six cups of lithium hydride.  When the lithium hydride touches the water, a chemical reaction occurs which yields fine hydrogen bubbles.  The hydrogen bubbles return an echo of the same order and magnitude as that returned by a submarine.


Remarks: False target shells should be segregated from pyrotechnics and other ammunition components, and should be kept in a dry atmosphere.

When visibility is such that surface disturbance may be a hazard, false target shells should not be released from depths less than 150 feet, because small bubbles or a surfaced canister may result.









False Target Can Mk 2 Mod 0


Length: 19.3 inches
Diameter: 3 inches


Use: False Target Can Mk 2 Mod 0 has the same use as False Target Shell Mk 1 Mod 0.


Description: Generally similar tot he False Target Shell Mk 1 Mod 0, this can is a tube of sheet steel sealed at both ends, containing nine metal cups filled with a lithium hydride composition.  These cups can be released individually at any desired rate when used with the new hydraulic-type air-operated signal ejector.  The cups are separated by aluminum discs, and a one-inch metal spacer separates the end caps of the outer tube from the top and bottom inner cups.  Tear strips are provided at either end to open the can.


Operation: The tear strips, the end caps, the spacers on either end, and the corrugate paper disc at the top end are removed, with the can in a horizontal position to prevent dropping one of the cups.  Insert one end into the breech of the ejector about one inch.  Put a rammer int he other end of the can and push the cups toward the muzzle of the ejector, until the spring detent near the top of the barrel drops behind the last cup.  Remove the empty tube.  Place the firing valve on "Vent". Close the breech door and flood the barrel from the sea through the flood line, allowing air to escape through the vent line.  When no air escapes the vent or firing valve, close these valves and open the muzzle door.

Make the pressure in the volume tank 50 pounds greater than sea pressure, and through the firing valve into the "Fire" position.





Signal (Pepper) Mk 14 Mods 0-2 (Production Suspended)

No picture available
  
Length: 27.5 inches
Diameter: 3 inches
Weight: 19 pounds (approximately)


General: The Signal (Pepper) Mk 14 is an expendable explosive noisemaker for underwater use.  It consists of a series of aluminum discs, each of which has sixteen small explosive charges around its periphery.  Each disc contains a gas-less fuse train which ignites the charges at one-half second intervals and then communicates the ignition to the succeeding discs.  Approximately five minutes of noise can be produced.  Parachute suspension is used to retard the sinking rate.  A firing device ignites two delay-fuse trains.  The initial delay train ignites the first of the explosive discs, and the secondary delay train fires a small black-powder charge which ejects the parachute.  The Signal (Pepper) Mk 14 is supplies as Mods 0, 1, and 2, having 30-second, 2-minute, and 6-minute initial delays respectively.  Mods 0, 1, and 2 are identical, except that one explosive disc in Mod 1, and two in Mod 2, have been replaced by initial time-delay discs.  The effective firing time is the same in all three Mods, for practical consideration.

Tests on the initial production of this device show that about 75% of the units may be expected to operate to completion.  It is recommended that, wherever possible, two or more units be fired in quick succession to insure functioning.


Description: The signal consists of the following components: firing device, initial time delay, secondary time delay, a stack of explosive-loaded discs, a center connecting tube and end discs to support the explosive stack, a parachute knock-off charge, parachute assembly, and packing container.

The firing device is identical in operation to the firing device used on the Submarine Emergency Identification Signals.  It consists of a support, firing lever, tripping lever, safety pin, and safety cotter pin.  When the safety cotter pin is pulled, it allows the safety pin to be forced back by its spring, releasing the tripping lever.  On ejection, the tripping lever is forced back by the end of the tripping groove.  The tripping lever lifts the firing lever against the firing spring and then releases it to fire the primer. The primer ignites both the initial and the secondary time delays.

The initial time delay is a pyrotechnic fuse train from the primer tot he first of the explosive capsules.  It has the approximate times as follows:

-Mod 0: 30 sceonds
-Mod 1: 2 minutes
-Mod 2: 6 minutes

The secondary time delay is a pyrotechnic fuse train from the primer to the parachute knock-off charge.  It is approximately five seconds for all three Mods, starting from the time of ejection.

The explosive stack consists of a series of aluminum discs three inches in diameter and one-half inch thick.  Each disc has sixteen small explosive-loaded capsules inserted radially around the periphery.  The capsules are connected by an internal ring fuse train which is timed to fire the charges at the rate of two shots per second.  The number of explosive discs in the stack varies with each Mod as follows:

-Mod 0: 37
-Mod 1: 36
-Mod 2: 35

A center connecting rod and end discs support the explosive stack.  The secondary delay and parachute-ejection charge are located int he center tube.  The parachute assembly, chute packed in a can which is split open by the ejection charge, is screwed onto the end opposite the firing device.


Ejection: The signal may be ejected from either the hand or the new hydraulic air-operated ejector at any depth.




Next Time: Hand Grenades (Part 1)

Monday, 23 April 2018

American Projectiles and Explosives - Shipboard Pyrotechnics





American Projectiles and Explosives




Shipboard Pyrotechnics



Surface Vessel Items





Distress Smoke Hand Signal AN-Mk 1 Mods 0 and 1




Length: 3.875 inches
Diameter: 1.625 inches
Weight: 0.37 pounds


Description: The signal is encased in a metal cylindrical body, one end of which is closed by a soldered cap and pull ring.  The case can be held comfortably and safely in the bare hand during the burning period.  The signal contains a pyrotechnic smoke mixture and is watertight.


Operation: The sealing tape around the end of the cylinder is torn off and the paper cap is removed.  The pull ring is brought down over the rim of the can and pressed down, using the ring as a lever to break the seal.  The cylinder is pointed away from the face; and a quick pull is exerted on the pull ring, which comes out of the can, thereby igniting the smoke mixture.  The signal should be held at arm's length at an angle of about 30 degrees, so that drippings will not fall on the hand.


Remarks: This signal is to replace the White Smoke Grenade, H.C., AN-M8, for emergency kits in life rafts and aircraft.





Signal, Distress - Day and Night - Mk 13 Mod 0




Length: 5.12 inches
Diameter: 1.62 inches
Weight: 6.4 ounces


General: Adapted for both day and night use, Hand Signal Mk 13 contains both the orange smoke canister for daylight and a flare pellet, for darkness.  Like the Smoke Signal AN-Mk 1 in appearance and operation, the Signal Mk 13 is small and is easily stowed in life-vest pockets, flight suits, or life rafts.


Description: The metal outer case is closed at both ends by a soldered cap to which is attached a pull ring.  Removing the soldered cap pulls a brass wire attached to its bottom through a cup coated with a friction igniting compound.  Depending on whether the "day" or "night" ring is pulled, the two ends of the case being distinctly so marked, the smoke mixture or the flare is ignited.  Smoke emission time is 18 to 20 seconds.  The average candlepower of the flare is 3,000 candles.  Paper cups cover the pull rings on each end of the signal.


Operation: After the paper cup is removed from desired end, a quick pull is given on the ring.  If the soldered cap fails to come off, bring the pull ring down over the side of the can, and use the ring as a lever to break the seal.  Hold the signal at arm's length and 30 degrees elevation while burning.  After one end is used, the signal should be doused in water to cool the metal parts.  It should then be retained for possible use of the other end.  Each end is insulated and waterproofed from the other.


Remarks: Both ends of the Signal Mk 13 should never be ignited at the same time.






Navy Red Light Mk 1 and Navy Blue Light Mk 1 Mod 1




Length: 12 inches
Diameter: 1.25 inches

Burning time (Blue): 1 to 1.5 minutes
Burning Time (Red): 2.5 to 3 minutes


Description: The flare consists of a paper tube filled with a pyrotechnic composition and attached to a wooden handle.  The top of each flare contains a button of ignition material.  A friction striker is provided with each signal.


Operation: The flare is ignited by scraping the top of the inside cap against the forward end of the pyrotechnic mixture.  Hold the flare in an inclined position while burning, to prevent drippings from burning the hand.







Ship's Emergency Identification Signals Mks 1-4


General: The body of each of these signals varies in length according to its design.  Each signal consists of a pressure-retaining disc and disc-locking nut, a primer, a four-gram smokeless-powder propelling charge, a copper obturating cup, a delay train, an ejection charge of approximately 1.1 grams of black powder, and a signal of pyrotechnic composition.  All signal cups except the shower signals have a parachute for mid-air suspension.


Operation: The signal is fired from Signal Projector Mk 1 or Mk 1 Mod 1.  The signal is placed in the projector primer-first, where it rests against the retaining pin.  A pull on the lanyard removes the firing pin and allows the signal to descend against the firing pin with sufficient force to close the valve and fire the primer.  The primer ignites the delay train and propelling charge simultaneously.  The gases from the propelling charge expand the obturating cup until it is secured tightly in the bore of the projector.  Increased pressure ruptures the pressure-retaining disc, and the gases then escape through the openings in the retaining-disc locking nut into the projector bore.  The gases propel the signal approximately 600 feet.  The ignited delay train burns until the signal reaches approximately the zenith of its trajectory, and then ignites the ejection charge.  The ejection charge ejects and ignites the signal pyrotechnics through a quick match and first fire composition




Mk 1 (Star)

Length: 5.124 inches
Diameter: 2.49 inches
Color: Red, white, green, or yellow
Burning time: 25 ±5 seconds

The closing cup is embossed for night identification.  The star is parachute suspended.




Mk 2 (Shower)

Length: 6.374 inches
Diameter: 2.5 inches
Color: Red, white, or green
Burning time: 5 seconds

This signal is designed to give two distinct bursts, one with a short delay and one with a long delay.  The closing cup is embossed for night identification.




Mk 3 (Smoke)

Length: 9.124 inches
Diameter: 2.49 inches
Color: Red, black, green, or yellow
Burning time: 25 ±5 seconds

The closing cup is embossed for night identification.  The star is parachute suspended.


Mk 4 (Chameleon)

Length: 5.124 inches
Diameter: 2.49 inches

Color Combinations:
Red-green-white
White-red-green
Green-white-red


Burning time for each color: 9 seconds
Delay between colors: 1 second

The signal is parachute suspended and designed to change color while burning.  Otherwise, the signal is similar to the Signal Mk 1.






Float Flare Mk 15 Mods 0 and 1


Length: 37.2 inches
Diameter: 6.5 inches
Weight: 26 pounds
Burning time: 5 minutes
Intensity: 100,000 candlepower
Delay before ignition: 5 minutes


Use: Float Flare Mk 15 Type is used by PT boats in illuminating enemy ships.


Description: The flare consists of a wooden body housing a pyrotechnic column and having a metallic base to provide flotation stability.  The top of the flare is closed by a cone-shaped adapter which contains a bouchon grenade-firing mechanism attached to a celluloid disc.  Enclosed is a 3.5-foot length of time fuse.  The starter composition is attached tot he flash end of the time fuse.  The illuminant composition is next to the starter composition.


Operation: The flare is held horizontally, with the right hand firmly grasping the bouchon lever and the left hand supporting the nose cap.  The safety key is pulled and the flare is tossed overboard.  When the bouchon lever is released, the firing pin is forced by the firing-pin spring to impinge upon the primer.  the primer ignites the time fuse.  The time fuse flashes into a booster bag of starter composition, which, in turn, ignites the flare.


Remarks: It is recommended that one man hold the flare while a second man pulls the safety ring.

 Mod 1 is like the Mod 0, except that it has a mechanical clockwork timing device, for settings from one to 30 minutes, instead of the time-fuse device.






Rocket, White, Marine Type, Mk 1 Mod 0


Length: 12 inches
Diameter: 1.5 inches
Weight: 2 pounds
Burning time: 5 seconds


Use: This is a merchant marine rocket issued by the Navy


Description: This rocket signal consists of the rocket body, star pellets, propelling charge, clay heading, and closing cap.


Operation: The rocket is fired by the Pyrotechnic Pistol AN-M8 and reaches a height of 250 feet.  At the height of its trajectory, the rocket bursts.  The falling particles burn for five seconds.


Remarks: This signal will be replaced by the Rocket Pistol Signal Mk 3 Mod 0 (Shower).





Next Time: Submarine Pyrotechnics

Monday, 16 April 2018

American Projectiles and Explosives - Ground Pyrotechnics (Part 3)





American Projectiles and Explosives




Ground Pyrotechnics



Flares


Parachute Trip Flare M48




Diameter of flare tube: 2.5 inches
Height of trajectory: 300-500 feet
Burning time: 20 seconds
Intensity: 100,000 candlepower
Effective Illumination: Circle of 800 yards radius

Color: White to Yellowish


Use: The flare is used to give warning of enemy marauders or infiltrating hostile troops; also, for illumination or signaling.


Description: The flare consists of a 1/4-inch pipe and a steel tube approximately 2.5 inches in inside diameter, which are attached to a base plate that contains a 75-grain propelling charge.  The steel tube contains a delay fuse, an expelling charge, a candle, and a parachute assembly.  The 0.25-inch pipe and the firing mechanism are joined by a coupling, and the pipe is threaded to the base plate.  The firing train is composed of a primer, an igniter, and a relay charge.  The firing mechanism contains the pressure cap, pull ring and pin, safety screw, safety cotter pin, and spring-loaded firing pin.


Operation: A 20- to 30-pound pressure on the pressure cap or a tension of four to six pounds on the pull pin releases the firing pin and fires the primer.  The primer initiates the igniter, which, in turn, starts the relay charge.  The relay charge sets off the propelling charge, which projects the illuminating shell through the large steel tube to a height of 300 to 500 feet.  The propelling charge ignites a three-second delay fuse in the shell.  The delay fuze ignites an expelling charge which expels a parachute-supported candle from the shell.






Trip Flare M49


Length: 3.8 inches
Diameter: 2.5 inches
Burning time: 1 minute
Intensity: 40,000 candlepower

Color: White to Yellowish


Use: The Trip Flare M49 has the same uses as the Parachute Trip Flare M48


Description: The flare has a grenade-shaped cylindrical body, with a nose fuze that protrudes 0.875-inch from the head end.  A mounting bracket and a spring-loaded trigger mechanism are mounted on a metal base cap.  The upper arm of the trigger is attached to a trip wire, and the lower arm of the trigger restrains the safety lever after the removal of the safety pin.


Operation: A pull on the trip wire rotates the upper trigger arm away from the fuze lever.  If the trip wire is cut, the upper trigger arm, which is restraining the fuze lever, rotates away from the fuze lever but in an opposite direction from above.  A grenade-type fuze is used, but is has no delay element.  The fuze ignites the flare simultaneously.





Trip Wire Flare Mk 1 Mod 0


Length of tube: 5.5 inches
Diameter of tube: 2.5 inches
Weight: 3.5 pounds
Burning time: 65 seconds
Candlepower: 100,000
Effective illumination: Area 500 feet in diameter


Use: The purpose of the flare is to reveal the approach of enemy troops.


Description: The flare case is a steel tube approximately 5.5 inches long and 2.5 inches in diameter.  Fixed to one end is a pull-type, spring-actuated firing mechanism to which the trip wire is attached.  Enclosed in the tube are the primer, black-powder charge, impregnated muslin disc, and pyrotechnic composition.  Two 40-foot lengths of wire are available, making it possible to have two trip wires running in opposite directions.  A web belt secures the flare to a tree.


Operation: A tug of three pounds or more on the trip wire draws the plunger and firing pin away from the primer and compresses a spring which surrounds the firing pin.  As the plunger is pulled away from the firing mechanism, its notched end disengages from that of the firing pin, which is then forced against the primer by the compressed firing-pin spring.  The primer ignites 0.3 grams of black powder.  The black powder ignites the impregnated muslin disc, and in turn the pyrotechnic composition.  The resultant gas pressure blows out the closure disc from the head, and the flame from the burning candle illuminates the surrounding area.  White smoke given off by the flare does no interfere with the effectiveness of the illumination.


Remarks: To prevent self illumination, the flare should be mounted about 125 yards before friendly positions.  While mounting the flare, personnel should wear steel helmets, and heads should be kept below and away from the top of the flare.





Ground Flare M81-M83

No picture available

Length (w/o spike): 7.75 inches
Diameter: 1.75 inches
Weight: 0.88 pounds
Burning time: 2 minutes

Color and Intensity:
-M81: Red - 20,000 candlepower
-M82: Yellow - 25,000 candlepower
-M83: Green - 35,000 candlepower


Use: The flare indicates, to cooperating air elements, a line of position or direction.  It is also used for troop-recognition purposes.


Description: The flare consists of a paper cylinder containing a pyrotechnic composition.  It has a wooden base block with a 20-penny spike through it, and a match head covered by a removable metal cap, under which lies a wooden disc.  A plastic film seals the metal cup to the flare body.  The outer head of the wooden disc has the scratching surface required to ignite the match composition.


Operation: The flare is stuck in the ground with the spike as a support.  The plastic seal is pulled off and the wooden disc scratched against the match composition, which ignites the flare.


Remarks: These ground flares are not procured by the Navy at present.




Target Rocket Flare Mk 1 Mod 0


Weight: 3 pounds


Use: The Target Rocket Flare Mk 1 Mod 0 is used with the 3.25-inch Rocket Targets Mk 10 and Mk 11.


Description: A pyrotechnic candle, secured into a wooden body, is housed in a steel tube.  An electric squib is located over the starter composition of the candle.  A steel cup shields the ignition end of the flare, and squib leads are coiled inside the nose cap.


Operation: Tear off the adhesive strip and remove the cover.  Place the flare over the nose of the rocket, and uncoil the squib leads.  Fasten the alligator clips to the cotter pins of the leads, and fire.





Airport Flare M13 (Obsolete)

No picture available

  Length: 23.1 inches
Diameter: 1.75 inches
Intensity: 40,000 candlepower
Burning time: 3 minutes


Use: Airport Flare M13 is used to provide illumination for airplane landing at emergency fields, and to illuminate targets and objectives.  A further use is to prevent infiltration or surprise by enemy troops.


Description: The flare consists of a cylinder; the top cover sealed with a strip of adhesive tape, and a seven-inch hollow chip-board tube mounted to one end of the cylinder.


Operation: Remove the adhesive tape and slip the hollow tube over a rod stuck in the ground.  Pull on the lanyard attached to the ignition wire to fire the flare.


Remarks: This flare is not procured by the Navy.






Airport Flare M76

No picture available

  Length: 32 inches
Diameter: 6 inches
Intensity: 800,000 candlepower
Burning time: 6.5 minutes


Use: Airport Flare M76 is used to indicate the end of a runway in a fog.


Description: This flare consists of a cylinder containing a candle similar to, but larger than, the candle of the Flare AN-M26.  The cylinder is fitted with a socket base arrangement into which four channel-shaped legs may be inserted to hold the flare upright on the runway.


Operation: The flare may be initiated by the use of the electric squib or by pull on the release fork which allows the spring-loaded firing pin to strike the primer.  The primer acts directly to ignite the first fire composition.


Remarks: Airport Flare M76 is not procured by the Navy.






High-Altitude Parachute Mortar-Fired Flare Mk 20 Mod 0

No picture available

  Length: 10.75 inches
Diameter: 2.5 inches
Weight: 5 pounds
Height of trajectory: 1,000 feet
Intensity: 85,000 candlepower
Color: White
Burning time: 60 seconds
Rate of fall after ignition: 16 feet/second


Use: This high-altitude flare is used to illuminate seaplane landing areas at night, and to illuminate an island base when low ceilings do not permit proper visibility from normal flying levels. 


Flare: The flare consists of a cylindrical steel tube body with a copper cup welded to the closed tube body with a copper cup welded to the closed end of the tube.   The body contains an expelling charge, a pyrotechnic candle, and a silk parachute.  The copper cup contains a fuse assembly, a propelling charge, 25 grams of a combination smokeless powder and black powder, and a standard shotgun primer.


Mortar: The mortar consists of a steel tube 36 inches long and 2.8 inches in diameter.  The tube is screwed into a steel base plate 0.75 inches thick and 12 inches square.  The base plate is provided with a central stud into which is pressed a hardened steel firing pin.


Operation: Remove the closing cap from the end of the mortar.  Attach a 30-foot lanyard to the brass release pin and insert the pin in the two holes drilled transversely about six inches from the end of the mortar.  Insert the flare into the mortar so that it rests on the release pin, with the copper end down.  Fire the flare by pulling the lanyard, thus removing the release pin.  The flare falls to the bottom of the mortar, firing the primer.  The primer sets off the propelling charge and ignites the delay fuse.  the expanding gases force the copper cup away from the flare and fill the bore of the mortar.  The flare is propelled 1,000 feet into the air, at which time the delay fuse ignites the expelling charge.  The pyrotechnic candle and parachute are expelled, the expelling charge igniting the candle.


Remarks: A suitable barrier should be erected to shield personnel firing the flare.  In case of a misfire, wait at least three minutes before disassembling the mortar.  Clean mortar tube after firing.







Next Time: Shipboard Pyrotechnics