Imperial Japanese Explosives - Land Mines and Grenades (Part 4)

Imperial Japanese Explosives

  

  

Type 99 Hand Grenade
 

Overall length: 3 and 1/2 inches
Maximum diameter: 1 and 5/8 inches

Total weight: 0.8 pounds
Filling: Cast picric acid
Delay: 4-5 seconds

Color and markings: Body is black with white label pasted around it.  The top of the grenade is painted red; fuze cover, red; fuze, brass. 

Description: The cast steel body has smooth surfaces.  There is a shoulder projecting 1/16 inch from each end of the body.  The inside of the body is finished with lacquer to keep the filler from reacting with the steel case.  The filler is also wrapped in heavy paper.

A light metal flash deflector is fitted in the top of the grenade.  This deflector is 3/8 inch wide and 7/8 inch in diameter.  Two 1/8 inch holes are punched in the outer periphery and match the spanner holes in the fuze body.  This positions the gas vents in the fuze 90 degrees from the holes in the flash deflector.  The flash deflector reduces the possibility of the flash from the cap burning the hand of the thrower and the possibility of the flash being seen by the enemy at night.

The fuze is similar to that used in the Type 91 and Type 97 grenades with a few improvements.  On the old type the striker may turn or spring clear of the grenade when the safety wire is pulled.  In this fuze, a screw in the fuze body projects through a slot in the striker cover and keeps the cover in place.  The slot allows the cover to move down when the striker is struck on a hard object.  Also, the striker and inertia weight are machined together and the striker protrudes so that it does not have to be threaded down to arm the grenade.  In other respects, the fuzes are identical.

Operation: The safety pin is withdrawn and the head of the fuze is truck on some hard object.  This forces the striker down into the primer igniting the delay.

Remarks: A Type 99 grenade has been encountered with a machined, waterproof, metal fuze cover.  The only difference between this variation and the standard grenade is the fact that the flash guard is externally threaded to receive the waterproof fuze cover.

  

  

Type 4 Pottery Hand Grenade

  

Height (base to top of neck): 4 inches
Diameter: 3 inches
Body (material): Terra Cotta
Thickness of case: 7/16 inch

Total weight of grenade: 16 ounces
Filling: Type 88 explosive
Delay: 4-5 seconds

Color and markings: Light brown

Description: Except for the neck at the top, the grenade is spherical, consisting of two hemispheres baked together.  The pottery body is light brown in color, lightly glazed inside and out.  The grenade is encased in a straw-coloured rubber sack which serves as waterproofing and permits the thrower to take a better grip.

The ignition system consists of a match composition, a 4 or 5 second delay element, a lead azide initiator, and a tetryl booster.  All but the match composition are encased in a rubber tub which is lacquered into the neck of the grenade.  The upper portion of the delay element is surrounded by a wooden collar, the top of which is covered with the match composition.

A wooden scratch block is seated on top of the neck of the grenade.  It is held in place by a small rubber sack which snaps around the neck of the grenade.  This sack serves a second purpose in waterproofing the ignition system.

A cloth band tied around the neck is probably used for carrying.

Operation: The small rubber sack is removed from the top and the scratch block is struck on the protruding match composition, igniting the delay element.  The grenade is thrown and explodes after a 4 or 5 second delay.

Remarks: This grenade appears to be made of the same type pottery as the Type 3 pottery land mine, and like the land mine, uses Type 88 explosive.  For these reasons it may be assumed to be a Navy weapon.

The color of the grenade may vary from white to dark brown, and the exterior may be glazed or unglazed.

Type 23 Hand Grenade

Overall length: 3 and 3/4 inches
Maximum diameter: 2 inches

Total weight of grenade: 1 pound
Filling: Granular TNT
Weight of filling: 39.5 grams
Delay: 5 and 1/2 seconds

Color and markings: Black

Description: The body, unlike the Type 91 or Type 97, has no longitudinal serrations, but does have five transverse depressions.  On one side, fitted top and bottom, are two rings which could be used for carrying or for anchoring.  The lead cover is screwed on to the top of the grenade and is grooved to provide a grip for easy removal.  The thumb cover release holds the cover on and must be depressed before the cover can be removed.

When this is depressed, the cover can be unscrewed in one and one-half turns, thus exposing the firing string which is attached to a friction igniter.

Operation: The thumb cover release must be depressed, and then the cover must be removed.  When the firing string is pulled, it draws a sanded string through a match composition.  The ignition of the match composition will ignite the black powder delay train.

Type 98 Stick Grenade
  

Overall length: 7 and 3/4 inches
Maximum diameter: 1 and 5/16 inches

Total Weight: 1 pound, 3 ounces
Filling: Cast picric acid
Weight of filling: 3 ounces
Delay: 4-5 seconds

Color: Black body; Unpainted handle

Description: The body is cylindrical in shape and is made of cast steel 1/4-inch thick.  The handle is turned from soft wood and slips into the steel body where it is held by three screws.  This joint is sealed with a coating of tar.  The screw cap at the pull end of the handle is of light, tin-plated steel.

The fuze consists of a friction ignition composition with a sanded string running through it.  This string extends up the hollow handle and is connected to a pull ring which is exposed by removing the screw cap at the top of the handle.

Operation: The screw cap is removed from the top of the handle.  The ring inside the handle is then pulled.  This draws the sanded string through the ignition composition igniting the 4 or 5 second delay.  The delay train detonates a cap which detonates the main charge.

This grenade has more fragmentation effect than the German high explosive stick grenade.

Type 3 Conical Antitank Hand Grenade

 
Small Grenade
Length of grenade: 5 and 7/8 inches
Length of tail: 14 inches
Diameter at base: 4 inches
Length of fuze: 1 and 7/8 inches
Length of cone: 2 and 3/8 inches
Diameter of cone: 2 inches
Cone angle, apex: 38 degrees
Total weight: 0.84 kg
Thickness of cone: 3 mm
Material of cone: Aluminum

Large Grenade
Length of grenade: 6 and 3/4 inches
Length of tail: 14 inches
Diameter at base: 4 and 3/8 inches
Length of fuze: 1 and 7/8 inches
Length of cone: 3 and 3/4 inches
Diameter of cone: 2 and 3/8 inches
Cone angle, apex: 30 degrees
Total weight: 1.25 kg
Thickness of cone: 3 mm
Material of cone: Steel
  

Description:  This grenade is manufactured in two sizes.  The basic principles of construction are the same in both sizes, but variations occur in weights, measurements and the explosive charge.  The grenade consists of a cone-shaped explosive charge, a metal cone, and a wooden base all contained in a silk bag.  A fuze is inserted and a tail attached to the apex of the charge.

The explosive charge is cast in the form of a truncated cone.  A metal cone is inserted in the base and in the upper end is a well which receives the gaine of the fuze.  Surrounding the gaine is a cast ring pellet.  In the large size grenade the explosive is Type 94, and in the small size grenade it is Pentolite (50/50 TNT and PETN).  A thin layer of waxed paper surrounds the charge.

At the bottom of the explosive charge is a wooden base which is flat on the top and rounded on the bottom.  The hole in the base has a slightly smaller diameter than the hole in the cone.

Covering the charge and base is a silk bag either white or olive drab in color.  When the grenade is assembled, a drawstring closes the bottom.  A metal ring is inserted over the top of the bag.  Inside the top of the explosive charge is fitted an adapter ring which is threaded to receive the fuze.  Four screws hold the parts together.

Tied around the top of the grenade is a tail made of hemp to provide stability in flight and to make the grenade strike the tank base first.  The fuze is constructed in two parts which are threaded together.  The lower body has external threads for screwing into the adapter ring and internal threads for receiving the gaine.  The striker is held in position by a safety pin and creep spring.  The under side of the upper body and the top of the striker are curved so that if the grenade strikes at a slight angle the striker will be cammed down.
  

Operation: Before the grenade is thrown the safety pin is pulled out.  On impact the firing pine overcomes the spring and moves down to pierce the primer.  The fuze is not "all-ways action", but will probably function on a slight angle of impact.

A second small grenade has been recovered which is identical to the previously described small grenade in measurements and type of construction but differs in the following details.  The silk bag which covers the charge of the second grenade is made of bright yellow finished silk.  The main explosive charge is picric acid with a small RDX booster.  The adapter ring is bakelite instead of metal, while a straw tail is used in place of hemp.

The fuze of the second grenade has a black finish, a single safety pin, and a gaine which is crimped to the fuze body, but otherwise is similar in construction and operation to the fuze of the first grenade.

Sling Hand Grenade
  

Overall length: 5 and 7/8 inches
Maximum diameter: 1 and 13/16 inches

Total Weight: 1 pound, 3 ounces
Filling: TNT
Weight of filling: 1 ounce
Delay: 4 or 5 seconds

Color: Black

Description: The sling grenade consists of a steel grenade body, wooden base plug, reinforcing cloth, scratch type friction ignited fuze, wooden fuze seat, wooden spacing ring, and a metal protective cap.

The rough, cast steel, cylindrical grenade body has a hollow projection on its forward end into which the wooden fuze seat and fuze are fitted and secured with glue.  The after end of the body opens directly into the TNT filled explosive cavity of the grenade.  This opening is closed by the wooden base plug, which is glued in place.  The throwing line is attached to the after end of the wooden base plug.

A strip of reinforcing cloth is wrapped around the base plug and the after end of the grenade body in order to help prevent the two sections from pulling apart when a line is used to throw the grenade.  The cloth is lashed securely in place by light line, which is tied around the annular groove in the grenade body and the cylindrical after section of the base plug.

A light, sheet metal cap is sealed over the nose of the grenade with waterproof paper tape.  The wooden spacing ring prevents contact between the fuze and the protective cap.  A flat surface on the side of the ring is coated with the abrasive compound used to ignite the fuze.

The fuze for the sling grenade is made in two sections: a long brass detonator tube and a short igniter head.  This tube is pierced by a single gas port and is crimped to the detonator tube.

Operation: The abrasive on the spacing ring is rubbed against the match head of the fuze to ignite the match composition which initiates the firing train.  The grenade is then thrown by hand or by means of the line attached to the ring in its base.  The delay is from 4 to 5 seconds.




1/2kg Incendiary Hand or Mortar Grenade
  

Overall length: 5.6 inches
Maximum diameter: 2 inches
Body material: Brass

Weight: 1.1 pounds
Filling: White Phosphorus
Delay: 4 or 5 seconds

Description:  This grenade may be thrown by hand or projected with the 50mm grenade discharger, Model 89.  The incendiary filling is contained in a brass body which may have a propelling charge on the base.  The fuze is identical to the one used in the Type 91 and Type 97 fragmentation hand grenades.

The steel propellant container is 1 and 1/4 inches long, 1.02 inches in diameter, and has six perforations in its walls.  It is screwed into the base of the body.  A perforated plug screws into the base of this container and in a cavity in this is a percussion cap.  Two flash holes head through the percussion cap holder to a small quantity of black powder.  A perforated steel disc covers the plug and inside the propellant container proper is a copper cup containing flakes of nitrocellulose propellant powder.

Operation: The firing pin must first be threaded down into the inertia weight.  The safety pin must then be withdrawn.  If the grenade is to be thrown by hand, it is necessary to strike the inertia weight on some hard object thus driving the firing pin into the primer to ignite the delay train.

If the grenade is to be fired from the grenade discharger, or knee mortar as it is sometimes called, the grenade with propellant container is dropped base first into the discharger.  When the trigger mechanism of the discharger is operated, its firing pin strikes the percussion cap igniting the propelling charge which propels the grenade.  Force of setback causes the firing pin in the grenade fuze to compress the creep spring and hit the primer to ignite the delay train.

Next Time: More Imperial Japanese Grenades, and Sabotage Devices

Imperial Japanese Explosives - Land Mines and Grenades (Part 2)

Imperial Japanese Explosives

  

  

Type 3 (a) Antivehicular and Antipersonnel Land Mine
 

Diameter: 8.6 inches

Height (w/o fuze): 4.13 inches
Height (fuzed): 6.2 inches
Length of fuze: 2.5 inches

Material of mine wall: Terra cotta
Thickness of wall: 7/16 inch

Explosive fillin: Type 88 explosive.  Captured document states bursting charge might also be either ammonium nitrate (50%), TNT (50%); or ammonium nitrate (90%), dinitronaphthalene (10%)

Weight of explosive: 4 pounds, 8 ounces

Total weight of mine: 11 pounds, 6 ounces

  

Color and markings: Brown


Description: The mine is circular with a slightly concave top and a moderately convex base.  The mine case is made of earth-colored terra cotta.

The outer surface has a thin dull glaze while the inner surface is covered with a thin coat of lacquer.  A rubber fuze seat is sealed in place in a hole in the center of the top of the mine.  The explosive filler is contained in a light rubber bag inside the mine.

The fuze body, cover, plunger, and striker support are made of bakelite.  The springs, percussion hammer, striker, and the release fork are the only metal parts in the mine and with the exception of the release fork, all are contained inside the fuze.
 

Employment: May be used as an antivehicular or antipersonnel mine.
 

Operation: The mine is place in the desired location and the safety pin is withdrawn.  The fuze may then be rigged to fire either by pull or pressure.

The percussion hammer located within the fuze is held in place by a release fork to which a trip wire may be attached.  When the wire is pulled (22-pound pull required), the fork releases the hammer which is forced downward by the hammer spring.  The hammer hits the striker forcing it through its bakelite holder into the percussion cap.

When pressure of 20-25 pounds is applied directly on the head of the fuze the plunger spring and hammer spring are compressed causing the hammer head to exert pressure on the hammer release fork.  When the plunger is further depressed a groove in its inner surface comes down to the level of the hammer release fork.  The pressure of the hammer head cams out the fork.  The hammer is released and hits the striker which in turn pierces the detonator.

Remarks:  A larger model of this mine exists, and differs from it only in size.  The larger version has a diameter of approximately 10 and 1/2 inches.

  

  

Type 3 (b) Antivehicular and Antipersonnel Land Mine

Diameter: 7 and 1/8 inches

Height (w/o fuze): 5 inches
Height (fuzed): 7.5 inches

Material of mine wall: Wood
Thickness of wall: 9/16 inch

Explosive fillin: Type 88 explosive.  Captured document states bursting charge might also be either ammonium nitrate (50%), TNT (50%); or ammonium nitrate (90%), dinitronaphthalene (10%)

Weight of explosive: 4 pounds, 8 ounces

Total weight of mine: 6 pounds, 4 ounces (w/o fuze)

  

Color and markings: Unpainted wood

   

Description: The mine is simply a wooden box with dovetailed sides to which top and bottom closing pieces have been fastened by screws and nails respectively.  It is a standard mine manufactured to standard specifications and employing the Type 88 explosive charge and its rubber container, the threaded rubber fuze seat, and the same type fuze used in the Type 3 (a) land mine.

The threaded rubber fuze seat is nailed to the bottom side of the top closing piece beneath a hole provided to allow insertion of the fuze.

Employment: May be used as either antivehicular or antipersonnel mine.

Operation: Same as Type 3 (a) land mine.

Beehive Antipersonnel Land Mine

    

Diameter at base: 8 inches

Height (w/o fuze): 4.5 inches
Total weight: 17 pounds (approximate)
Thickness of mine wall: 3/8 inch

Explosive filling: TNT
Weight of explosive: 5 pounds (approximate)

 

Color and markings: Black
  

Description: The mine is hemispherical in shape and its surface is uniformly serrated.

The central hole in the top of the mine is internally threaded to receive one of two fuze adapters.  The first adapter takes either the plastic fuze used in the Type 3 (a) ceramic and Type 3 (b) wooden land mines, or the Type 88 instantaneous artillery fuze from which the centrifugal detents have been removed.  The second adapter is constructed to take the fuze employed in the Type 93 tapemeasure mine.

Both the serrations of the mine case and the thickness of the wall (3/8 inch) indicate that this mine was to be used as an antipersonnel weapon.

Employment: Antipersonnel mine

Operation: The operations of the Type 93 land mine fuze and the Type 3 (a) ceramic land mine fuze are discussed under their respective mines.

The Type 88 artillery projectile fuze from which the centrifugal detents have been removed is fired by pressure on the firing pin head.  Pressure on the firing pin head compresses the anticreep spring and the firing pin is forced into the primer.

5kg Hemispherical Antitank Land Mine

 The 5kg hemispherical A/TK mine is a weapon designed to help overcome the shortage of A/TK weapons and armored vehicles which the Japanese forces experienced during the war.  It is a suicide weapon, intended to be placed against an armored vehicle either by hand or by means of a pole or lines.

The mine is hemispherical in shape, black in color, with the fuze mounted opposite the flat face.  It is equipped with a straight projection to which a pole may be lashed, and with four eyelets to which lines may be attached.

The mine is detonated by the same fuze as that used in the Type 99 magnetic A/TK mine.  No specimens of this mine were found outside of the Japanese homeland, very few of them having been produced.

    

Bangalore Torpedo and Igniter

  

Dimensions: See Drawing
Total weight of torpedo: 10 pounds

Weight of filling: 3 pounds
Type of filling: TNT (36.4%), Cyclonite (63.6%)


Color and markings:
-Torpedo tube: Brown with red band onboard of externally threaded end, white triangle near midepoint of tube, and eleven inches inboard of red band on opposite side from white triangle is (see below)

  

Description:  The igniter system consists of two pull igniters screwed into an igniter holder which fits into the igniter locking collar.  The rings of the igniters are connected by lines to the lanyard holder.  The igniters are simple match composition pull igniters with a black powder delay of 8 seconds, an initiant, and a base charge of tetryl.  When shipping, the steel nose cap is threaded onto the igniter as shown in drawing.

The torpedo proper is a steel tube with shoulders welded to both ends.  One end is internally threaded to take the igniter locking collar and the other end is threaded externally to take the pointed nose cover.  When shipped the tube has a cap screwed over one end and a male plug threaded into the other.

Employment: The Bangalore torpedo is used by the Japanese to demolish barbed wired entanglements.  It can also be used as a booby trap, actuated by pull.

Operation: The caps are removed from the ends of the tube, the pointed nose cover is screwed onto one end, and the igniter locking collar into the other end.  The torpedo is now ready for use.  When the torpedo is placed the safety pin is removed and the firing lanyard is pulled sharply.  Personnel can take cover in the 8 seconds delay period.

The pulling of the firing lanyard pulls the match composition through the abrasive.  The flash starts the black powder which after 8 seconds delay fires the initiant and tetryl base charge and the torpedo charge.




Pressure and Traction Land Mine
  

Overall length: 12.5 inches
Overall width: 9.5 inches
Overall height: 7 inches

Weight of filling: 2 pounds
Type of explosive: Three blocks picric acid or TNT detonator of igniter inserted in center block.



Description: The mine consists of a wooden box, the lid of which is held in place against the internal flanges on the top by four stout springs (one in each corner).  A wooden block is secured by two bolts to the underside of the lid and serves to operate the pull igniter by pressure exerted on the cover.

The explosive charge is in a separate container with the igniter and detonator inserted in the center block.  A pull wire extends from the igniter over to the wire rod directly under the wooden block attached to the underside of the lid.

To this wire rod are attached a trip wire which passes out through the cover to be secured to a tree or other suitable object and an antilifting wire attachment which passes through a hole in the base of the box and is secured to a peg.  The igniter contains ignition composition and a pellet of powdered glass in red cement.

Employment: Used as an antitank or antipersonnel mine.

Operation: The mine will function by either of three methods:
-Pressure exerted on the lid,
-Tension exerted on the trip wire; or
-By lifting the mine to operate the antilifting device.

In all instances the wire rod is moved which pulls the wire leading to the igniter.




Friction-Fuzed Land Mine
  

Overall length: 13 inches
Overall width: 3 inches
Overall height: 2.37 inches

Weight of filling: 3.5 pounds

Type of explosive: Five blocks picric acid or TNT detonator of igniter inserted in end block.

Description: The mine consists of a wooden box, the sides of which are 0.59 inch thick.  A wooden partition block inserted 4.25 inches from the unfilled end of the box serves to hold the five blocks of explosive in place and also to secure the igniter in position.  To the igniter is attached a trip wire which extends out through the end of the box and is secured to a tree or other suitable object.

A safety device, the exact nature of which is unknown but reported to consist of a bottle cap, is incorporated on the outside of the box at a point of egress of the trip wire.  The antilifting device consists of a wire attachment which passes through the base of the box and is secured to a peg driven in the ground.

Employment: The mine is buried 1 to 2 inches below the surface and used as either an antitank or antipersonnel mine.

Operation: The mine can function by either a tension exerted on the trip wire or by lifting the mine to operate the antilifting device.  In both instances the pull igniter is fired which in turn detonates the explosive charge.




Improvised Land Mine
  

Dimensions: A box 5 and 5/8 by 4 and 1/4 by 3 and 1/4 inches
Material: Tin
Color: Silver
 
Description: The mine consists of a rectangular box with a cover securely fastened by friction tape.  Two holes are roughly punched in the cover through which a grenade fuze or detonator projects.  The grenade fuze projects approximately 3/4 inch, projection of detonator is unknown.

Contained in the box are one Japanese Type 91 hand grenade and twelve blocks of 1/3 aluminum powder and 2/3 RDX.  Each block is 1 and 1/2 inch by 3/4 inch and wrapped in waxed paper.  Color is black.  The grenade and blocks, 1/3 aluminum powder and 2/3 RDX, are firmly held in place by waxed paper.

Employment: Can be used as an antitank mine when fuzed with the armed grenade.  With a pull or tension detonator it can be used as an antipersonnel mine or booby trap.

Operation:
-As an antitank mine: Safety pin on fuze is removed.  When it is hit by a sharp blow the striker breaks a shear wire and penetrates the primer.  After a delay of 4 to 5 seconds the bursting charge explodes setting off the charge.

-As an antipersonnel mine or booby trap: A pull igniter with detonator is inserted into the charge.  When the trip wire is pulled, the flash will fire the detonator which in turn sets off the explosive and hand grenade.

Next Time: More Imperial Japanese Land Mines, and Grenades

Imperial Japanese Navy Explosives - Bombs (Part 8)

Imperial Japanese Navy Explosives

Type 0 Model 1, Type 0 Model 2, and Cardboard Type Sea Markers

  

Fuzes: None
  

Type 0 Model 1

Overall Length: 12 and 1/2 inches

Length of body: 7 and 1/2 inches

Diameter of body: 3 inches

Thickness of wall: 1/64 inches

Material of wall: Sheet Steel


Cardboard type

Overall Length: 12 and 1/2 inches

Length of body: 7 and 1/2 inches

Diameter of body: 3 inches

Thickness of wall: 1/16 inches

Material of wall: Cardboard

  
 

Type of suspension: Dropped by hand

Suspension lug: None


Type 0 Model 1
Length of tail: 5 inches
Width of tail: 4 and 1/4 inches
Width of tail fins: 1 and 7/8 inches
Dimensions of tail struts: None

 Material of tail: Light tin

Cardboard type

Length of tail: 5 inches
Width of tail: 3 inches
Width of tail fins: 1 and 1/4 inches

Dimensions of tail struts: None

Material of tail: Cardboard
  

Type of filling: Aluminum powder, containing 6.5% zinc.  1 ounce covers 118 square feet.
No explosive

Type 0 Model 1

Weight of filling: 0.7 pound

Total weight of bomb: 3.5 pounds
Charge/weight ratio: 20%

Cardboard type

Weight of filling: 1 pound

Total weight of bomb: 3.5 pounds
Charge/weight ratio: 20%

 

Color and markings: Aluminum color.  Japanese inscription printer on a paper label which is glued to the body of the marker. (Instructions for operation of marker.)
 

Construction of body:
-Type 0: A sheet steel cylindrical body is fastened to the steel nosepiece by four punch marks.  The tail cone and body are joined by a thin disk of light wood secured by four tacks in each component.

-Cardboard type: A hollow-steel nosepiece is secured to a paper body by a strip of adhesive tape.  The body is reinforced by cardboard strips.  A cardboard tail cone is fastened to the body by adhesive tape.  Four cardboard fins are glued to the tail cone.

Situated in the hollow section of the steel nosepiece is a wooden cylinder 1 and 7/16 inches in diameter.  Fastened to this cylinder is a small wooden disk the same diameter as the inside of the body.  Located between this nose disk and the wooden disk in the tail is a connecting wooden pin 4 and 3/4 inches long.


Operation:
-Type 0: On impact with the water, the plug in the nose is forced up into the body, forcing the tail portion to be freed from the body, thereby scattering the aluminum powder.

-Cardboard type: On impact with water the container breaks up and releases the aluminum powder.

Remarks: Type 0 Model 2 is similar in construction to Model 1.  It is painted yellow overall and contains a filling of dark green powder which produces a green slick on the water.

  

  

Type 3 No.6 Target Marker Bomb
 

 
Fuzes: A-1 or A-3 series

Overall Length: 42 and 1/4 inches

Length of body: 21 inches

Diameter of body: 9 and 1/2 inches

Thickness of wall: 1/8 inches

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug

Length of tail: 21 and 1/4 inches
Width of tail: 13 and 1/4 inches
Width of tail fins: 6 inches

Dimensions of tail struts:
-Length: 9 and 1/4 inches
-Width: 1 and 1/2 inches
-Thickness: 1/16 inch

Material of tail: Steel
  

Type of filling: The filling consists of 152 phosphorus-filled steel pellets contained in three cylindrical steel canisters.  Each canister is filled with pellets and the space not occupied by the pellets is filled with white phosphorus.  The canisters are covered with a heavy wax coating.  There is a charge of Type 98 explosive in the nosepiece of the bomb.
  

Weight of canisters:
-Canister One: 68 pellets - 56 pounds
-Canister Two: 56 pellets - 37.5 pounds
-Canister Three: 28 pellets - 13 pounds
  

Dimensions of canisters (Length x Diameter):
-Canister One: 7 inches by 8 and 1/4 inches
-Canister Two: 5 and 3/4 inches x 8 and 1/4 inches
-Canister Three: 3 inches x 8 and 1/4 inches

Dimensions of pellets:
-Length: 2 and 1/2 inches
-Diameter: 1 and 1/2 inches

Weight of filling: 107 pounds
Total weight of bomb: 155 pounds
Charge/weight ratio: 69%
  

Color and markings: The bomb is grey overall with a red band on the nose and red tail struts.  Four longitudinal grooves are painted red.
 

Construction of body: A cast-steel nosepiece is attached to a longitudinally welded steel body by a continuous weld.  The nosepiece contains a gaine well surrounded by an explosive charge which in turn is surrounded by a wooden filler plug.  The body has 4 external longitudinal grooves 90 degrees removed from each other.  The tail cone is welded to a collar which fits into the body and is held there by a single row of 16 screws.
 

Construction of tail: The tail cone is constructed of 1/8-inch steel and is welded longitudinally.  Four steel fins are welded to the cone and are braced by a single set of box-type struts.

  

  

 

Type 2 2kg Target Indicator

    

Fuzes: None
Overall Length: 17 inches

Length of body: 11 and 3/16 inches

Diameter of body: 3 inches

Thickness of wall: 3/16 inches

Material of wall: Bakelite
   

Type of suspension: Horizontal

Suspension lug: A steel suspension ring is attached to a steel band by a soldered tin strip.  The steel band fits tightly around the bomb body.

Length of tail: 4 and 7/8 inches

Width of tail: 5 inches
Width of tail fins: 1 and 9/16 inches
  

Dimensions of tail struts:
-Length: 3 and 1/8 inches
-Width: 7/16 inch

Material of tail: Sheet Tin
  

Type of filling: F.M. (titanium tetrachloride)

Weight of filling: 1 pound, 7 and 3/4 ounces

Total weight of bomb: 3 pounds, 14 ounces
Charge/weight ratio: 37%
  

Color and markings: Black body and tail.  No other color or markings present.
  

Construction of body: The bomb body is of molded bakelite construction with an opening in the after end only.  This opening is threaded to receive a bakelite stopper, the union being sealed by a black rubber washer.  The stopper is threaded internally to receive a bakelite tube which extends nearly the complete length of the bomb body.  The after end of the stopper is a slightly tapered tube and a rubber tube is cemented over it.

Cemented into the after end of the rubber tube is a glass tube through which the bomb is filled.  When the bomb is approximately two-thirds filled with liquid F.M. the glass tube is heated and sealed off.  A small wire is attached to the glass tube at the point of sealing.  Each of the cemented unions is reinforced with a wire wrapping.

A ballistic cap is glued to the nose of the bomb.  The cap is made of heavy paper and is filled with fine iron fillings to make the bomb nose heavy.

Construction of tail: The tail fins are made of sheet tin.  Pairs of adjacent fins are stamped from the same piece of metal and soldered to the forward end after circular struts.  The edges of the fins are strengthened by having a one-eight-inch turn-back.  The after circular strut (width: 1 inch; diameter: 1 and 7/8 inches) is similarly strengthened.

The forward circular strut (width: 9/16 inch; diameter: 1 and 1/16 inches) is of lighter gage tin and is secured to the fins by soldering except for one free end which is secured by a bolt and nut after the fins are assembled to the bomb.  To insure positive seating of the fins, a rubber insert extends half-way around the inside of the forward circular strut.  A single set of box-type struts (length: 3 and 1/8 inches; width: 7/16 inch) is located at the after extremities of the fins.

Operation: The bomb is released from the plane and the case fractures on contact with the target.  The smoke mixture is dispersed.

2kg Window Bomb

  

Fuzes: Pull igniter

Overall Length: 37 inches

Length of body: 37 inches

Diameter of body: 1 and 3/4 inches

Thickness of wall: 1/32 inches

Material of wall: Sheet Steel
 

Type of suspension: None, hand thrown

Suspension lug: None

Length: 12 inches
Width of tail: 2 and 7/8 inches
Width of tail fins: 9/16 inches

 

Dimensions of tail struts:
-Length: 2 inches
-Width: 3/8 inch
-Thickness: 1/32 inch

Material of tail: Sheet Steel

Type of filling: 250 paper strips, cylinder containing iron pyrite

Weight of filling:
-Paper strips: 10 ounces
-Iron pyrite and cylinder: 20 ounces

Total weight of bomb: 4 pounds, 7 ounces
 

Color and markings: Grey overall.  Two yellow labels.  One gives instructions for use, the other the following: "Silver paper scattering bomb, manufactured October 1944, Navy Air Force Arsenal"
  

Description:  Bomb consist of a nosepiece, body, and end cap.  Nosepiece is made of wood and has a hole in the center to accommodate the string attached to the pull igniter. End of nosepiece is sealed with a paper disk which is removed when the bomb is to be used.  Nosepiece is secured to the body by six nails.  Body is of light sheet metal construction, soldered longitudinally.  After end is closed by an end cap of similar metal and held in place by a sealing tape.

Filling of the bomb case consists of 250 metal coated paper strips and an inner cylinder which contains the delay element and ejection charge.  Inner cylinder is in the front end of the case.  It is of light sheet metal construction and soldered longitudinally.  A metal disk closes the nose end and another metal disk is soldered in place 1 and 5/8 inches from the tail end.  Space between the two disks is filled with iron pyrite to make the bomb nose heavy. 

Each disk has a 1/2-inch hole in the center through which a metal tube is inserted.  This houses a standard type pull igniter such as is used in the 5 kilogram parachute flare.  An 11 inch length of safety fuse is crimped into the after end of the igniter is led to an annular bag containing smokeless powder.

The 250 paper strips are just after of the inner cylinder.  Two L-shaped metal strips placed back to back hold 125 strips each.  Four heavy cardboard strips surround the paper strips to insure their smooth ejection.  The paper strips are covered on one side only by a metal foil.

Operation: The cotton tab on the nose is pulled, exposing the pull igniter cord.  This cord is pulled and the striker hits a flash cap which ignites the safety fuse.  The bomb is thrown from the plane.  The safety fuse burns for 40 seconds and sets off the smokeless powder which ejects the paper strips.

"Baka" Piloted Rocket Bomb

Bomb Data
Overall length: 19 feet, 10 inches
Wingspread: 16 feet, 5 inches


Description: The "Baka" bomb is a suicide weapon designed to be controlled by a human pilot.  It is carried beneath the fuselage of a bomber and released near its target.  Three rocket motors provide propulsion after release from the mother plane.  The entire explosive content of the Baka bomb is contained in the warhead in the nose.


Warhead Data
  

Fuzes: A-3(g), B-9(a), B-10(a), two of each.
Overall Length: 68 and 1/2 inches

Diameter: 23 and 1/2 inches

Thickness of wall: 1 and 1/4 inches

Material of wall: Steel

Suspension: The warhead is secured to the fuselage of the "Baka" bomb by four brackets welded to the base plate.

  

Type of filling: Trinitroanisol

Weight of filling: 1,135 pounds

Total weight of warhead: 2,645 pounds
  

Color and markings:  Grey overall.  Green band around nose, a brown band adjacent to it.
 

Description: The warhead is of one-piece machined steel construction.  It has parallel sides and an ogival nose.  The nose fuze pocket is 8 and 1/2 inches deep.  The after end of the warhead is closed by a base plate.  Four tail fuze pockets are grouped around a central threaded hole in a slightly raised portion of the base plate.  The center hole accommodates an arming device which the pilot operates to arm the four tail fuzes simultaneously.
    

Type 3 and Model 10 Bomb Launching Devices

Type 3

Overall Length: 40 and 1/2 inches

Maximum Diameter: 7 and 7/8 inches

Model 10

Overall Length: 33 inches

Maximum Diameter: 7 and 7/8 inches

Description: Both motors are designed as propulsion units for 60-kilogram ordinary or land-use bombs.  The motors are used to propel these bombs from crude V-shaped wooden troughs for land bombardment.  The motors are interchangeable and may be used on either the 60kg ordinary or land-use bomb.

Type 3

Weight of complete round: 92 pounds

Weight of propellant: 25 pounds
Length of propellant stick: 18 and 1/8 inches
Depth of propellant stick: 3 and 5/16 inches
Weight of ignition charge: 2 ounces

Model 10

Weight of complete round: 52 pounds

Weight of propellant: 13 pounds
Length of propellant stick: 10 and 1/4 inches
Depth of propellant stick: 3 and 5/16 inches
Weight of ignition charge: 2 ounces

Propellant: The propellant charge consists of three sticks of 343 D.T.2 and 343 special D.T.2 (code designation) for the Model 10 and Type 3, respectively.  The chemical analysis of 343 D.T.2 is 65% nitrocellulose, 30% nitroglycerine, 3% ethyl centralite, and 2% sodium chloride.  The chemical analysis of 343 special D.T.2 is not known but probably involves a small variation of 343 D.T.2.  The complete Japanese designation for 343 D.T.2 is Type 93 Mk 2 propellant.

Ignition: The propellant is ignited by an electrical squib.  Current is supplied by a hand generator.

Launcher: A crude V-shaped wooden trough mounted on a bipod forward and a steel base plate aft.  The angle of elevation can be varied.

Remarks: The variation in the size of the two motors is possible a means of varying the range.

Next Time: Imperial Japanese Land Mines

Imperial Japanese Navy Explosives - Bombs (Part 6)

 
Imperial Japanese Navy Explosives



 

Type 3 No.25 Mk 31 Bomb Model 1
 

Fuzes: Type 3 electric firing device B-3(a)

Overall Length: 62 inches

Length of body: 30 and 3/8 inches

Diameter of body: 11 and 3/4 inches

Thickness of wall: 1/2 inches

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy type suspension lug
 
Length of tail: 32 inches
Width of tail: 16 and 1/8 inches
Width of tail fins: 7 and 1/8 inches

Dimensions of tail struts:
-Length: 17 and 1/4 inches
-Width: 3 and 3/8 inches
-Thickness: 1/8 inch

Material of tail: Steel
 

Type of filling: Type 98 explosive, cast

Weight of filling: 175 pounds

Total weight of bomb: 378 pounds

Charge/weight ratio: 33%
 

Color and markings: Gray overall.  Green tail struts.  No color bands on nose.
 

Construction of body: The bomb consists of a nosepiece, barrel, and tail assembly.

The nose of the bomb is blunt.  A flat metal plate is fitted into the forward end of the barrel and welded there.  The plate is drilled centrally and a gaine pocket is welded in the hole.  A flange 3 and 7/8 inches long, and 7/32-inch thick and of the same outer diameter as the barrel is welded to the forward end of the barrel.  The flange is pierced by four 1/2-inch holes just aft of the forward end.

The barrel is of tubular steel construction.  The tail cone is held by 1 row of 18 plug welds and a continuous weld to a coupling ring which fits inside the barrel.  The ring is held in the barrel by 2 rows of screws numbering 40 in all.  There is a standard tail fuze pocket at the apex of the tail cone.

Construction of tail: Four Navy type fins are spot-welded to the tail cone.  The fins are braced by a single set of box-type struts.
 
Operation: The Type 3 electric firing device is an influence fuze, operated by a photo-electric cell, which is activated by reflection of a beam of light projected from the fuze, and reflected from the target.  Aerial burst at an altitude of 7 meters or above was desired by the designers.  Fifty percent accuracy was considered to have been attained.

Type 3 No.80 Mk 31 Bomb Model 1
 

 
Fuzes: Type 3 electric firing device B-3(b)

Overall Length: 113 inches

Length of body: 72 inches

Diameter of body: 18 inches

Thickness of wall: 9/16 inches

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Two guide studs on the bomb body position the steel suspension band.
 
Length of tail: 41 inches
Width of tail: 25 inches
Width of tail fins: 10 and 1/2 inches

Dimensions of tail struts:
-Length: 17 and 1/4 inches
-Width: 3 and 3/8 inches
-Thickness: 1/8 inch

Material of tail: Steel
 

Type of filling: Type 98 explosive cast in paper-wrapped blocks

Weight of filling: 922 pounds

Total weight of bomb: 1,584 pounds

Charge/weight ratio: 58%
 

Color and markings: Gray overall.  Green tail struts.  No color bands on nose.
 

Construction of body: The bomb consists of a nosepiece, barrel, and tail assembly.

The slightly tapered longitudinally welded nosepiece is closed at its forward end by a flat plate which has an 11 and 3/8-inch diameter.  The plate is drilled centrally and this nose pocket can only accommodate a Navy gaine.  

 

A metal flange is welded to this plate. It is 5 and 1/4 inches long by 7/32-inch thick and has an 11 and 3/8-inch inner diameter.  It is pierced by four 1/2-inch holes 3/4-inch aft of the forward end.  The nose section is attached to the barrel by a continuous circumferential weld and 17 plug welds.  There is a second circumferential weld at the point where the nose section begins to taper.

 

The barrel is of tubular-steel construction.  The tail cone is attached by 30 plug welds to a coupling ring which fits inside the barrel.  The coupling ring is held in the barrel by 2 rows of screws numbering 34 in all.  There is a standard tail fuze pocket at the apex of the tail cone.

 

Four Navy type tail fins are welded to the tail cone.  The fins are braced by a single set of box-type struts.

   

Remarks: The Type 3 electric firing device is an influence fuze, operated by a photo-electric cell, which is activated by reflection of a beam of light projected from the fuze, and reflected from the target.  Aerial burst at an altitude of 7 meters or above was desired by the designers.  Fifty percent accuracy was considered to have been attained.

Type 5 No.25 Mk 33 Bomb
Please make sure to read the last line of this entry

  
This bomb is designed to detonate upon approach to the earth.  It is a combination of a number of mechanical and electrical devices, all of which must operate if the bomb is to function properly.

 

Proximity detonation is to be initiated through the action of an all-ways action electrical fuze contained in a plummet which falls ahead of the bomb in flight.  An atmospheric fuze functions at the tail to open a set of four drogue plates at the tail, and release the nose plummet.   A type 15 Model 2 tail fuze is provided to detonate the bomb in case of failure of either of the other fuzes.

 

The nose section contains a 20-kilogram spherical plummet housing an all-ways action electrical fuze, connected by 20 meters of silk-clad copper cable to a Type 3 electric gaine projecting into the main explosive charge of the bomb.  The plummet is held in place in the nose of the bomb by two hinged latches held in the closed position by two steel wedges controlled, through wires, by the action of the tail drogue plates.

 

The barrel of the bomb is standard in construction, bu added provision for fragmentation has been made by the addition of a layer of cylindrical steel pellets just under the case of the bomb.

 

The tail cone is standard with the Type 15 Model 2 tail fuze (B-3(a)) in place at its apex.  The tail fin assembly is unique.  It is designed to perform the function of slowing the fall of the bomb.  It consists of a standard set of fins to which are hinged four rectangular drogue plates.  These plates are hinged at their after end so that they may lie either flat against the fins or may be extended to serve as retarding plates.  They are held in position flat against the fin surfaces by four pins which are in turn held in place by a blowout plug.

 

The blowout plug is operated by an atmospheric fuze welded in place at the tail on the longitudinal axis of the bomb.  The tail drogue plates operate the release mechanism for the nose plummet through two wires which run forward through eyelets on the outside of the barrel of the bomb.

 

When the bomb is dropped, the aneroid in the atmospheric tail fuze operates at the preset altitude, firing a squib electrically, which blows out the blowout plug at the tail, allowing the drogue release pins to move, releasing the drogue plates.  The plates assume an angle of 90 degrees with the fin surfaces, and act to slow the fall of the bomb.  

  

Through the action of the plummet release wires, the plummet is release, and falls to the end of its cable.  The all-ways action fuze in the plummet is armed by air travel, and operates through its cable and gaine to fire the main charge of the bomb upon striking the target. The Type 15 Model 2 tail fuze operates in case of failure of the all-ways action nose fuze.

 

Both atmospheric tail fuze and the all-ways action nose fuze carry their own electrical supply for firing in the form of self-contained batteries.  

  

The data on this bomb is the result of incomplete investigation, and must not be considered as specific, accurate information.

 

 

 

1-kg Practice Bomb Modification 2 and Modification 3

  

Fuzes: A-5(a)

Overall Length: 10 and 1/4 inches

Length of body: 2 and 3/4 inches

Diameter of body: 3 inches

Thickness of wall: 1/8 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: A rectangular hinged steel lug on a plate riveted to the body with four rivets.
 

Length of tail: 7 and 1/2 inches

Width of tail: 1 and 1/4 inches
Width of tail fins: 3 and 1/2 inches
 

Dimensions of tail struts: None

Material of tail: Sheet steel
 

Type of filling: Picric burster and a red or white phosphorus main charge.

Weight of filling: 3 ounces (approximately)

Total weight of bomb: 2 pounds 3 ounces

Charge/weight ratio: 9%
 

Color and markings: White rubber nose, black body, white tail cone and fins.  Brass band just aft of rubber nose.
 

Construction of body: A hemispherical rubber nosepiece is attached by screws to the forward end of the one-piece, cast-iron body.  The bomb fuze is contained in the nose and body.  A burster charge is attached to the after end of the fuze and extends into the tail cone which is held to the bomb body by five screws.
 
The burster charge is surrounded by cotton wadding which is contained in a central tube.  The remaining space in the tail cone is filled with red or white phosphorus.

A safety plunger is depressed when the bomb is loaded in the bomb rack.  A screw type safety pin is removed when the bomb is in the bomb rack.
 

Construction of tail: Four fins are welded to the sheet metal tail cone.  There are no tail struts.

No.3 Practice Bomb Model 1

 

 

Fuzes: B-6(a)

Overall Length: 33 and 3/8 inches

Length of body: 16 and 15/16 inches

Diameter of body: 7 inches

Thickness of wall: 1/4 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: 2 Normal Navy type lugs 180 degrees apart
 

Length of tail: 17 and 1/4 inches

Width of tail: 9 and 1/2 inches
Width of tail fins: 4 inches
Thickness of tail fins: 1/16 inch
 

Dimensions of tail struts:

-Length: 6 and 7/8 inches
-Width: 1 and 3/16 inches

-Thickness: 1/16 inch

Material of tail: Steel 
  

Type of filling: Concrete in nose and body.  Titanium tetrachloride and picric burster charge in tail cone.
Total weight of bomb: 68 pounds
 

Color and markings: The body forward of the suspension lugs is black.  Aft of lugs, the bomb is white.  Two red lines 90 degrees on either side of the suspension lugs run the length of the body and tail cone.  New color markings will be found.
 

Construction of body: The nose and body are constructed in one piece of machined steel.  The sheet steel tain cone is attached to the after end of the body by screws.  The nose and body are concrete filled.  A wooden block fills the lower part of the tail cone and a conical steel tank containing a spotting charge of titanium tetrachloride and a picric burster fits into the apex of the cone.

Four slots in the tail cone allow the smoke to escape when the burster charge ruptures the metal container.
 

Construction of tail: Four steel fins are welded tot he tail cone and are braced by a single set of box-type struts.

Type 99 No.3 Practice Bomb

 

Fuzes: B-6(a)

Overall Length: 35 and 3/4 inches

Length of body: 19 and 1/2 inches

Diameter of body: 7 inches

Thickness of wall: 1/4 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy type suspension lug
 

Length of tail: 16 and 1/4 inches

Width of tail: 9 and 1/2 inches
Width of tail fins: 4 inches
 

Dimensions of tail struts:

-Length: 6 and 7/8 inches
-Width: 1 and 3/16 inches

-Thickness: 1/16 inch

Material of tail: Steel 

  

Type of filling: The nose is filled with fine gravel held in place by a steel separating plate.  The body contains 15 glass disks 6 and 1/2 inches in diameter and 3/4-inch thick.  A spotting charge of titanium tetrachloride and a picric burster are contained in a tank in the apex of the tail cone.  A wooden block fills the remainder of the cone.
 
Total weight of bomb: 72 pounds
 

Color and markings: The forward half of the bomb is painted black and has a green band around the nose.  The after half, including the tail cone, fins, and struts, is painted white.
 

Construction of body: The bomb is of three-piece construction.  A steel nosepiece is attached to a tubular-steel body by screws.  A tail cone is attached to a collar by screws.  The collar fits into the after end of the body and is held there by screws.

Four slots in the tail cone allow the smoke to escape when the burster charge ruptures the metal container.
 

Construction of tail: Four steel fins are welded tot he tail cone and are braced by a single set of box-type struts.

 

Remarks: The purpose of the glass disk filling in practice bombs is to lessen the damage to the target ship while still preserving the correct trajectory and ballistics of the bomb.

Type 96 Landing Flare
  

Fuze: Pull Igniter

Overall Length: 16 and 3/8 inches

Length of body: 16 and 3/8 inches

Diameter of body: 5 and 1/8 inches
 

Thickness of wall:
-Nosepiece: 1/8-inch
-Body: 1/32-inch

Material of wall: Brass nose, sheet steel body
 

Type of suspension: Hand thrown

Suspension lug: None
 

Length of tail: 6 and 3/4 inches

Width of tail: 5 and 1/4 inches
Width of tail fins: 1 and 5/8 inches
 

Dimensions of tail struts: None

Material of tail: Sheet Steel 

 
Type of filling: Illuminant
Weight of filling: 1 pound
Total weight of bomb: 6 pounds

Color and markings: Gray overall

Description: A brass nosepiece, ogival in shape is brazed to a conical body.  A brass plug screws into the nose of the flare.  It is threaded internally to hold a central tube containing the pull igniter, delay train, and illuminant.  The after end of the flare is closed by a lead cap.

Four fins are soldered to the after end of the body.

Operation: The igniter cord is pulled firing the primer which ignites the delay train.  This in turn ignites the quick match which fires the illuminant.  The heat melts the lead cap and the flame escapes through this hole.

The flare burns for 3 to 5 minutes.



 

 Landing Flare
 

 

Fuze: Pull Igniter

Overall Length: 22 and 9/16 inches

Length of body: 15 and 1/16 inches

Diameter of body: 6 and 1/4 inches

Thickness of wall: 1/32 inch

Material of wall: Sheet steel
 

Type of suspension: Launched by hand

Suspension lug: Two handles held flush against the case by springs are riveted to the body.
 

Length of tail: 7 and 1/8 inches

Width of tail: 10 inches
Width of tail fins: 2 and 1/4 inches
 

Dimensions of tail struts: None

Material of tail: Steel 
 
Type of filling: Illuminant
Weight of filling: 5 and 1/8 pounds
Total weight of bomb: 13 pounds (approximately)
Charge/weight ratio: 39%

Color and markings: Gray.  Label just below carrying handles reads "Manufacturing Date - September 1940. Naval Aerial Factory Illuminating Flare Bomb."

Construction of body: Consists of three distinct parts: Nose, Body, and Tail.  The nose is a solid metal weight which is hemispherical in shape.  It is welded to the body.  The body is of sheet-metal construction and conical in shape.  It is welded to the nose and secured to the tail portion by eight small screws.  On the exterior of the body is a tear strip which covers a small water inlet hole.  

 

Inside the body is a long central tube which extends the full length of the flare.  This tube contains the illuminating composition.  It is held in place by a large wooden spacer disk situated at the junction of the body and the tail with another wooden spacer at the junction of the body and the nose.  Spacers are held in place by small screws, six at the nose and eight at the tail.

Construction of tail: Constructed of light sheet metal with 4 fins soldered to it.  A metal cap is soldered over the end of the tail and fits around the central cylinder.  There is a small air outlet in the cap.  A percussion igniter is inserted through a hole in the cap and soldered into position. 

 

Over the end of the central cylinder is a lead cap which is soldered to the end cap.  This lead cap has a central disk of the same metal but much thinner.  The central cylinder is surrounded by an asbestos liner covered by a metal sheath.  This extends down to the wooden spacer, also covered by a metal disk.

Operation: Before dropped, remove tear strip and safety wire and pull the igniter cord.  When catch has been pulled out approximately 3/4-inch, the spring-loaded striker is released.  The striker then impinges on the primer.

A 10-inch safety fuze is ignited by the flash from the cap and, after burning for 35 seconds, the safety fuze ignites a coil of black powder.  The resultant heat melts the lead cap, allowing flash to escape.  The illumminant burns rapidly with brilliant greenish-white flame which lasts approximately 1 minute and 20 seconds.

  

Next Time: More IJN flares