Imperial Japanese Navy Explosives - Bombs (Part 7)

Imperial Japanese Navy Explosives

5kg Parachute Flare Model 2 Modification 1

 

Fuzes: Pull igniter

Overall Length: 25 and 1/8 inches

Diameter: 3 and 1/8 inches

Material of wall: Light sheet steel
  

Type of suspension: None

Suspension lug: Thrown by hand from plane

 

Type of filling: Illuminant

Weight of filling: 5 pounds 8 ounces

Total weight of flare: 10 pounds 3/4 ounce

Composition of illuminant:
-Barium nitrate: 55.5%
-Aluminum, powdered: 11%
-Magnesium, powdered: 18%
-Wax: 9.1%
 

Color and markings: Body is grey overall.  Two labels give description and instruction for use.
 

Construction: The flare case is cylindrical and of light sheet steel construction.  It contains an illuminating candle unit and a parachute, and is closed at both ends by metal caps.  The cap on the parachute end may be removed by pulling a tear strip.

The illuminating candle unit container is cylindrical in shape and is made of corrugated sheet tin.  A copper tube extends the length of the unit and the illuminant is cast around it.  A wooden plug is fitted into the top of the flare and is held there by a metal cap and several screws.

The fuze is inserted in a hole in the plug and fits down into the copper tube.  Four black powder impregnated strips are attached to the fuze and extend down the copper tube to the base of the illuminant.  Similar black powder strips are cast in the bottom of the flare.  A wooden ring in the base of the candle unit holds it away from the bottom of the flare containers.

The fuze used is of the pull igniter type.  A tin cylinder fits over the end of the fuze and extends up through the parachute to the end cap.  The pull cord attached to the catch on the fuze is led up through the tin cylinder to the end cap.

The parachute is made of silk and is attached to the candle unit by a length of wire rope.  The wire rope is spliced and the two ends are attached to two eyes fastened to the wooden plug in the end of the illuminant container.

Operation: The tear strip is pulled and the end cap removed.  Then the igniter cord is pulled and the flare is thrown from the plane.  The striker in the fuze hits the primer which ignites the powder train.  This burns slowly down to the black powder strings cast in the base of the illuminant, igniting the illuminant.  The expanding gases expel the candle unit and the parachute from the container.  The unit burns for approximately 1 minute and 30 seconds giving off a brilliant white flame.

 

 

 

Type 0 Parachute Flares Model 1 and Model 1 Modification 1
 

 
Fuzes: D-3(a), D-4(a)

Overall Length: 42 and 1/2 inches

Length of body: 39 and 1/2 inches

Diameter of body: 6 and 3/4 inches

Thickness of wall: 3/64 inches

Material of wall: Sheet Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug

Length of tail: 14 and 3/4 inches
Width of tail fins: 1 and 13/16 inches

Dimensions of tail struts: None

Material of tail: Sheet Steel
 

Type of filling: Illuminant (silver-grey in appearance)

Weight of filling: 66 pounds

Total weight of bomb:
-Model 1: 84 pounds
-Model 1 Modification 1: 88 pounds
 

Color and markings:
-Model 1: Grey overall with 1/4-inch red stripe just below the end piece
-Model 1 Modification 1: Grey overall with a 1/4-inch red stripe just above the end piece and a 1/2-inch white stripe around the body.
 

Construction: The flare consists of three main elements: (1) the flare case, (2) the illuminating candle unit, (3) the parachute.

1. The flare case consists of three sections: a nosepiece, body, and end cap.  The nosepiece is soldered securely to the body, and the hemi-spherical end cap is held in position by spot soldering in four places.  Four tail fins are welded to the after two-fifths of the body.  A steel ring 1 inch wide fits around the body at its junction with the tail cone.  It is attached to the fins and serves to brace them as well as to retard the velocity of the flare's free fall.  The nose is threaded to receive the fuze.

2.  The illuminant is contained in a cardboard canister which is covered by sheet brass 0.025 inch thick.  The after end is closed by a steel plate held by screws to the cylinder.  A 1/4-inch wire rope 65 inches long from which the candle unit is suspended is attached to this steel plate by means of a shackle.  The forward end of the container is open and fits against a wooden block in the nosepiece.  The illuminant at the opened end contains in its center an ignition charge 3 inches in diameter and 1/4-inch thick.

Length of illuminant container: 26 inches
Length of illuminant: 24 and 1/2 inches
Diameter of illuminant: 5 and 1/2 inches

3.  Model 1: A single silk parachute is housed in the after end of the body.  It is surrounded by a layer of cardboard to insure smooth ejection.
 
Model 1 Modification 1: A small guide parachute and a larger parachute are housed in the after end of the body.  They are surrounded by a layer of cardboard to insure smooth injection.
 

Operation: Shortly after being released from the plane the aerial burst fuze operates.  The resultant flash from the magazine ignites the ignition charge which in turn ignites the illuminant.  The expanding gases force the end cap off and eject the parachute and illuminating candle unit.  The flare sheds a bright white light and burns for 3 minutes and 40 seconds.

 

 

 

Type 0 Parachute Flares Model 2 and Model 3 Modification 1

   
Fuzes: D-3(a), D-4(a)

Model 2

Overall Length: 38 and 1/2 inches

Length of body: 35 and 1/2 inches

Diameter of body: 6 and 3/4 inches

Thickness of wall: 3/64 inches

Material of wall: Sheet Steel

Model 3 Modification 1

Overall Length: 42 and 1/2 inches

Length of body: 39 and 1/2 inches

Diameter of body: 6 and 3/4 inches

Thickness of wall: 3/64 inches

Material of wall: Sheet Steel

  
 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug

Model 2
Length of tail: 13 and 1/2 inches

 

Model 3 Modification 1

Length of tail: 15 inches

 

 

Dimensions of tail struts: None

Material of tail: Sheet Steel
 

Type of filling: Illuminant

Weight of filling: 66 pounds

Total weight of bomb:
-Model 2: 84 pounds
-Model 3 Modification 1: 88 pounds
 

Color and markings:
-Model 2: Grey overall with 1/4-inch red stripe just below the end piece
-Model 3 Modification 1: Grey overall with a black stripe around the nose and a 1/4-inch red stripe above the end piece.
 

Construction: The flare consists of three main elements: (1) the flare case, (2) the illuminating candle unit, (3) the parachute.

1. The flare case consists of three sections: a nosepiece, body, and end cap. The nosepiece is soldered securely to the body, and the hemi-spherical end cap is held in position by spot soldering in four places.  Four tail fins are welded to the after two-fifths of the body. A steel ring 1 inch wide fits around the body at its junction with the tail cone. It is attached to the fins and serves to brace them as well as to retard the velocity of the flare's free fall.   The nose is threaded to receive the fuze.

2. The illuminant is contained in a cardboard canister which is covered by sheet brass 0.025 inch thick. The after end is closed by a steel plate held by screws to the cylinder. A 1/4-inch wire rope 65 inches long from which the candle unit is suspended is attached to this steel plate by means of a shackle. The forward end of the container is open and fits against a wooden block in the nosepiece. The illuminant at the opened end contains in its center an ignition charge 3 inches in diameter and 1/4-inch thick.

Length of illuminant container: 26 inches
Length of illuminant: 24 and 1/2 inches
Diameter of illuminant: 5 and 1/2 inches

3. Model 2: A single silk parachute is housed in the after end of the body. It is surrounded by a layer of cardboard to insure smooth ejection.

Model 3 Modification 1: A small guide parachute and a larger parachute are housed in the after end of the body. They are surrounded by a layer of cardboard to insure smooth injection.

Operation: Shortly after being released from the plane the aerial burst fuze operates. The resultant flash from the magazine ignites the ignition charge which in turn ignites the illuminant. The expanding gases force the end cap off and eject the parachute and illuminating candle unit. The flare sheds a bright white light and burns for 3 minutes and 40 seconds.

Experimental Model 11 Parachute Flares

 

Fuzes: D-3(a), D-4(a)

Model 11 Conical

Overall Length: 45 inches

Length of body: 43 and 1/2 inches

Diameter of body: 9 and 1/4 inches

Thickness of wall: 3/64 inches

Material of wall: Sheet Steel

Model 11 Ogival

Overall Length: 46 and 1/2 inches

Length of body: 43 and 1/2 inches

Diameter of body: 9 and 1/4 inches

Thickness of wall: 3/64 inches

Material of wall: Sheet Steel

 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug

Length of tail fins: 13 and 3/4 inches

 

Dimensions of tail struts: None

Material of tail: Sheet Steel

Type of filling: Illuminant

Weight of filling: 68 pounds

Total weight of bomb:
-Model 11 Conical: 106 pounds
-Model 11 Ogival: 110 pounds
 

Color and markings: Grey overall with 1/4-inch red stripe above the end piece
 

Construction: The flare consists of three main elements: (1) the flare case, (2) the illuminating candle unit, (3) the parachute.

1. The flare case consists of three sections: a nosepiece, body, and end cap. The nosepiece is soldered securely to the body, and the hemi-spherical end cap is held in position by spot soldering in four places. Four tail fins are welded to the after two-fifths of the body. A steel ring 1 inch wide fits around the body at its junction with the tail cone. It is attached to the fins and serves to brace them as well as to retard the velocity of the flare's free fall. The nose is threaded to receive the fuze.

2. The illuminant is contained in a cardboard canister which is covered by sheet brass 0.025 inch thick. The after end is closed by a steel plate held by screws to the cylinder. A 1/4-inch wire rope 65 inches long from which the candle unit is suspended is attached to this steel plate by means of a shackle. The forward end of the container is open and fits against a wooden block in the nosepiece. The illuminant at the opened end contains in its center an ignition charge 3 inches in diameter and 1/4-inch thick.

Length of illuminant container: 25 and 3/4 inches
Length of illuminant: 23 and 3/4 inches
Diameter of illuminant: 7 and 3/4 inches

3.  A small guide parachute and a larger parachute are housed in the after end of the body. They are surrounded by a layer of cardboard to insure smooth injection.

Operation: Shortly after being released from the plane the aerial burst fuze operates. The resultant flash from the magazine ignites the ignition charge which in turn ignites the illuminant. The expanding gases force the end cap off and eject the parachute and illuminating candle unit. The flare sheds a bright white light and burns for 4 minutes and 40 seconds.

Type 94 and Experimental Type Modification 1 Float Lights

 

Fuzes: None

Type 94

Overall Length: 11 and 7/16 inches

Length of body: 11 and 7/16 inches

Diameter of body: 2 and 13/16 inches

Thickness of wall: 3/64 inches

Material of wall: Tin Plate

Experimental type, Modification 1

Overall Length: 21 and 3/4 inches

Length of body: 21 and 3/4 inches

Diameter of body: 4 and 3/4 inches

Thickness of wall: 3/64 inches

Material of wall: Tin Plate

Type of suspension: None

Suspension lug: None

Type 94

Length of tail: 2 and 3/4 inches

Width of tail: 3 inches
Width of tail fins: 1 and 3/4 inches
Dimensions of tail struts: None
Material of tail: Tin Plate

Experimental type, Modification 1

Length of tail: 7 inches

Width of tail: 5 inches
Width of tail fins: 2 and 3/8 inches 

Dimensions of tail struts: 5 inches x 3/8 inch x 1/32 inch

Material of tail: Tin Plate
  

Type of filling: Calcium carbide and Calcium phosphide

Total weight of bomb:
-Type 94: 2.2 pounds
-Experimental type, Modification 1: 6.6 pounds

Charge/weight ratio:
-Type 94: 23%
-Experimental type, Modification 1: 33%
  

Color and markings:
-Type 94: Grey with red pull rings.  One paper label
-Experimental type, Modification 1: Chrome yellow.  Red pull rings.  Two paper labels.
 

Construction of body:  In both types the body is constructed of tin plate rolled into a cylinder with soldered lapped joints.  The hemispherical nosepiece and conical tail piece are soldered to the body.  The nosepiece houses a lead weight. 
  
The calcium carbide is contained in the forward part of the body, the calcium phosphide in the after part.  Two metal tear strips cover water inlet holes in the nose and tail.
  

Construction of tail: Four steel fins are soldered to the body and tail cone.  There are no struts on the Type 94.  The fins on the experimental type are braced by a single set of box-type struts.

Operation: The tear strips are removed before dropping.  On impact with the water, the water enters the holes formerly covered by the tear strips.  Water reacts with calcium phosphide to generate phosphine and calcium carbide to generate acetylene gas. 

On contact with the air phosphine ignites spontaneously and the resultant flame is fed by the acetylene which acts as the main source of fuel.

Type 94 Model 2 and Type 0 Model 1 Float Lights

 

Fuzes: None

Type 94 Model 2

Overall Length: 10 inches

Length of body: 10 inches

Diameter of body: 2 and 13/32 inches

Thickness of wall: 3/64 inches

Material of wall: Tin Plate

Type 0 Model 1

Overall Length: 13 and 13/16 inches

Length of body: 13 and 13/16 inches

Diameter of body: 2 and 7/8 inches

Thickness of wall: 3/64 inches

Material of wall: Tin Plate

Type of suspension: None

Suspension lug: None

Type 94 Model 2

Length of tail: 3 and 1/4 inches

Width of tail fins: 1 inches
Dimensions of tail struts: None
Material of tail: Tin Plate

Type 0 Model 1

Length of tail: 4 and 1/8 inches

Width of tail fins: 1 and 5/8 inches

Dimensions of tail struts: 3 and 1/8 inches x 1/4 inch x 1/32 inch

Material of tail: Tin Plate

Type of filling: Calcium carbide and Calcium phosphide
 

Color and markings: Grey overall with two labels posted on body.
 

Construction of body: In both types the body is constructed of tin plate rolled into a cylinder with soldered lapped joints. The ogival nosepiece and conical tail piece are soldered to the body. The nosepiece houses a lead weight.

The calcium carbide is contained in the forward part of the body, the calcium phosphide in the after part. Two metal tear strips cover water inlet holes in the nose and tail.
 

Construction of tail:
-Type 94 Model 2: Three tail fins are soldered to the tail cone.  There are no struts.

-Type 0 Model 1: Four tail fins are soldered to the body and tail cone and are braced by a single set of box-type struts.

Operation: The tear strips are removed before dropping. On impact with the water, the water enters the holes formerly covered by the tear strips. Water reacts with calcium phosphide to generate phosphine and calcium carbide to generate acetylene gas.

On contact with the air phosphine ignites spontaneously and the resultant flame is fed by the acetylene which acts as the main source of fuel.

Remarks: The Type 0 Model 1 float light has a deflector on the exterior of the nosepiece which prevents it from penetrating too deeply into the water.

2kg Smoke Float

  

 

Fuze: Pull Igniter

Overall Length: 18 and 1/8 inches

Diameter of body: 4 and 3/4 inches

Type of suspension: Thrown by hand

Total weight: 4 and 3/4 pounds

Color and markings: White except for yellow nose

Description: A cast-brass nosepiece weighted with lead is soldered to a conical body of 22 gage sheet metal.  A smoke candle unit screws into the nose.  An emission tube, supported by three metal disks, passes lengthwise through the center of the body and has a cork plug in the tail end.  Three rounded tail fins are soldered around the after end of the body.

The smoke candle unit consists of a casing of light alloy containing a smoke-producing composition.  A quick match wich and a length of safety fuse connects the candle with the igniter.  The igniter casing contains a release pin, a spring-loaded striker and primer pressed into a plug which screws into the end of the casing.

Operation: The safety pin is removed and the release pin is withdrawn by pulling on the pull ring.  The striker spring is compressed until the release pin is free of the casing and then the striker is released.  It strikes the primer thus igniting the safety fuse and quick match wick which ignites the smoke composition (after a short delay) which produces a yellow smoke.

Remarks: This smoke float will also be found with a black nose and white body.  When so painted, it contains a black smoke unit.



43kg Smoke Float

 

Fuze: D-3(a) (with vane cups)

Overall Length: 51 inches

Length of body: 35 and 1/2 inches

Diameter of body: 11 and 1/4 inches

Thickness of wall: 1/32 inch

Material of wall: Sheet steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug
 

Length of tail: 15 inches

Width of tail: 13 and 1/2 inches
Width of tail fins: 2 and 3/4 inches

Dimensions of tail struts: None

Material of tail: Sheet Steel

Type of filling: Smoke composition
Weight of filling: 42 pounds (including container)
Total weight of bomb: 94 pounds
 

Color and markings: Gray overall with a 1/4-inch red stripe forward of the end cap.

 

Description: The float consists of five sections: a weighted nose, a conical body, a boat-tailed attachment, an after piece and an end cap.  All parts are soldered solidly together with the exception of the end cap which is held on by four spot solders.  Four fins are soldered to the after piece and boat-tailed attachment.  The fuze pocket is located in the side of the after piece and has an extended opening.

The smoke composition is contained in a tin cylinder running from the nosepiece to a steel ring in the boat-tailed attachment.  A pull igniter, delay train, and quickmatch composition are contained within the smoke unit.

The parachute of light weight white silk is packed compactly in the after piece.  The parachute is secured to a 1/4-inch wire rope which is attached to a shackle on a wooden block.  At the junction of the parachute shrouds and wire rope is a chock absorber 3/8-inch bungee rubber strands.  On the opposite side of the block are two 1/4-inch wire ropes which lead through a second wooden block to a steel ring at the after end of the boat-tailed attachment.

Lashed securely to one of the 1/4-inch cables is a 1/16-inch cable leading to a pull igniter in the smoke container.  A second 1/16-inch cable leads from the shackle on the after wooden block to a small wooden disk contained in the second block.  Around this is a black powder ejection charge.  A third 1/16-inch cable leads from the shackle to a contact on the body at the top of the container.

Operation: When the aerial burst fuze functions, the ejection charge is ignited.  The end cap is torn off and the parachute ejected.  As the parachute is blown out, the pull igniter is actuated and the delay train initiated.

The parachute checks the fall of the flare sufficiently to prevent smashing of the case on impact with the water.  The smoke composition burns from 5 to 8 minutes giving off a grey-black smoke that is heavier than air.

Next Time: IJN Markers, a "Window" bomb, and the Baka Bomb

Soviet Satellite Country Ammunition - Czechoslovakia (Part 2)

 
 
 
 
 
Examination of Czechoslovakian Ammunition Production/Inventory

 

Author's Note: The Czech M48 is mentioned quite a few times in the manual, referring to the CZ52, as well as mentions of a Czech 7.62mm submachine gun - the CZ model 25.  The M48 was the nomenclature of the round, not the pistol.  The semi-automatic rifle is the Vz.52, and the light machine gun is named the same - Vz.52.

 

 

 

7.62mm Ball Pistol Cartridge, (Model 48?)
(Czechoslovakian Nomenclature Unknown)

 
This cartridge is interchangeable with the Soviet 7.62mm pistol ammunition.  It is used in Czech 7.62mm submachineguns and the new Czech 7.62mm automatic pistol M48.  Specimens of the cartridge tested in the United States have considerably higher velocity, and propellent charges about 20% heavier, in comparison to the standard Soviet 7.62mm Type P pistol cartridges thus far encountered.

The power of the Czech cartridge would seem to indicate that it was designed mainly for use in submachineguns; however, so far as can be determined at present, it can be safely fired from any existing 7.62mm or 7.63mm Mauser automatic pistol.

All cartridge cases recovered have been brass, but steel cases may also be used.  There is a black or navy blue annulus around the Berdan-type primer.  Bullet cores are usually mild steel, and jackets are gilding-metal-clad steel.  Base markings usually give manufacturer's symbol and date of manufacture.

The Czech military designation of the round is not known, but it tentatively accepted as M48.


Characteristics
Caliber: 7.62mm (cal. 30)
Weight of cartridge: 10.64g (165 gr)
Weight of case: 4.5g (70 gr)
Weight of bullet: 5.5g (85 gr)
Weight of propellent: 0.64g (10 gr)
Length of cartridge: 34mm (1.36 in)
Length of case: 24mm (0.97 in)
Length of bullet: 14mm (0.55 in)


Packaging
 
 
Boxes have been found to contain this ammunition loaded in 8-round chargers which are used to load Czech 7.62mm submachinegun magazines.  There is no further information on this or other possible types of packaging for the cartridge.




 

 

7.62mm Blank Pistol Cartridge, Model ?
(Czechoslovakian Nomenclature Unknown)

 
This cartridge can be used for training in the Czech 7.62mm submachineguns and 7.62mm M48 automatic pistol.  It is distinguishable by the rose-petal crimp of the case.  The cartridge case is brass and has a black or navy blue primer annulus.

Base markings usually show the manufacturer's symbol or number, and the date of manufacture.  The cartridge can be used in any weapon chambered for 7.62mm Soviet Model P or German 7.63mm Mauser automatic pistol cartridges.



Characteristics
Caliber: 7.62mm (cal. 30)
Weight of cartridge: 5.3g (82 gr)
Weight of case: 4.7g (73 gr)
Weight of propellent: 0.58g (9 gr)
Length of cartridge: 24mm (0.94 in)
Length of case: 24mm (0.94 in)


Packaging


Information on packaging of this round is not available.

7.62mm Short Ball Cartridge, (Model 1952?)
(Czechoslovakian Nomenclature Unknown)

 
This cartridge has recently appeared in the hands of Czech troops.  It is reported to be used in two new Czech weapons: A semi-automatic rifle, M1952 and a light machinegun, M1952.  The cartridge represents Czech entrance into the field of short rifle cartridges.  It is not interchangeable with the new Soviet short rifle cartridge M1943.

The base marking represents the month and year of manufacture and the manufacturer's code letter.  To date, no annulus has been found on rounds of this type.  The case is brass with Berdan primer.  The bullet has a cupro-nickel jacket with mild steel core.


Characteristics
Caliber: 7.62mm (cal. 30)
Weight of cartridge: 19.06g (293.7 gr)
Weight of case: 8.7g (134.4 gr)
Weight of bullet: 8.6g (132 gr)
Weight of propellent: 1.8g (27 gr)
Length of cartridge: 59.7mm (2.35 in)
Length of case: 44.9mm (1.77 in)
Length of bullet: 28.2mm (1.11 in)


Packaging


Information on packaging of this round is not available.

7.65mm Ball Cartridge, Browning
(7.62mm Ostry Naboj Browning)

 
This cartridge is used in the M1927 and M1950 automatic pistols, and can be used in any pistol chambered for 7.65mm Browning.  The cartridge is called the .32 ACP in the United States.  Base markings usually show manufacturer's symbol and caliber. 

The round is one of the most popular of pistol cartridges, and has been manufactured all over the world.  Because it is so wildly manufactured, various bullet weights and lengths and different propellent weights may be encountered.
  
The round has a rimless brass cartridge case with a single offset flash hole, and a Berdan-type primer with a black annulus.  Powder is the flake type, and grayish-green in color.  The bullet has a lead alloy core and a cupro-nickel-plated mild steel jacket.


Characteristics
Caliber: 7.65mm (cal. 301)
Weight of cartridge: 7.5g (116 gr)
Weight of case: 2.89g (44.73 gr)
Weight of bullet: 4.49g (69.3 gr)
Weight of propellent: 0.14g (2.28 gr)
Length of cartridge: 25mm (0.97 in)
Length of case: 17mm (0.67 in)
Length of bullet: 12mm (0.48 in)


Packaging


Information on packaging of this round is not available.

7.92mm Light Pointed Ball Cartridge, Model 23
(7.92mm Ostry Naboj Vz. 23)

 
This round is designed for use against personnel.  The cartridge has been found with nickel, cupro-nickel, and gilding-metal-plated steel bullet jackets.  The bullet has a flat base with a concavity toward the center, like the Soviet 7.62mm Type L.

Large quantities of these cartridges were used by the Germans in World War II and consequently are liable to be encountered anywhere in Europe.  They can be fired in any weapon chambered for 7.92mm x 57mm cartridges.  The cartridges have a black or navy blue primer annulus.


Characteristics
Caliber: 7.92mm (cal. 311)
Weight of cartridge: 24.6g (379 gr)
Weight of case: 11.5g (177 gr)
Weight of bullet: 10g (154 gr)
Weight of propellent: 3.03g (46 gr)
Length of cartridge: 80mm (3.15 in)
Length of case: 57mm (2.24 in)
Length of bullet: 28.4mm (1.11 in)


Packaging

 


Information on packaging of this round is not available.

7.92mm Heavy Pointed Ball Cartridge, Model 34
(7.92mm Ostry Tezky Naboj Vz.34)

 
This round is designed for use against personnel.  It has a heavy spitzer-pointed and boattailed bullet consisting of a lead core and a nickel-plated mild steel jacket.  The bullet is cannelured to provide a recess into which the cartridge case is crimped.

It is identified by a green lacquered primer seal.  The case is of brass, employing a single centered flash hole (bored through the anvil) with brass Berdan-type primer cups.  Powder is the flake type and grayish-black in color.  This cartridge may be used in all weapons chambered for 7.92mm x 57mm cartridges.


Characteristics
Caliber: 7.92mm (cal. 311)
Weight of cartridge: 27.4g (420 gr)
Weight of case: 11.5g (177 gr)
Weight of bullet: 12.8g (197 gr)
Weight of propellent: 2.96g (44 gr)
Length of cartridge: 80mm (3.15 in)
Length of case: 57mm (2.24 in)
Length of bullet: 35.8mm (1.4 in)


Packaging


Information on packaging of this round is not available.

7.92mm Ball Cartridge with Mild Steel Core, Model ?
(7.92mm Ostry Naboj Vz.?)

 
This round is not mentioned in available Czech documentary sources but of late has been recovered in increasing amounts.  It is heavier than the 7.92mm Light Ball Model 23, and lighter than the 7.92mm Heavy Ball Model 34.  The weight of the bullet is the same as that of the German 7.92mm SmE (pointed ball with steel core).  The base markings indicate the manufacturer's initial or code symbol, and the date of manufacture.  The primer annulus is black or navy blue, just as is that of the 7.92mm Light Ball Model 23.

The cartridge can be used in any weapon chambered for 7.92mm x 57mm cartridges, although the label states it is for use in rifles and light machineguns.  It has a brass case with single offset or twin flash holes.  The primer is a Berdan type with flat-base brass cup.  Powder may be either flake or tubular type and is grayish-black in color.

The boattailed bullet is spitzer-pointed and has a nickel-plated mild steel jacket.  The bullet cor is of mild steel and flat nosed.  A lead filler is interposed between the bullet core and jacket.


Characteristics
Caliber: 7.92mm (cal. 311)
Weight of cartridge: 25.85g (399 gr)
Weight of case: 11.5g (177 gr)
Weight of bullet: 11.54g (178.17 gr)
Weight of propellent: 2.82g (43.62 gr)
Length of cartridge: 80mm (3.15 in)
Length of case: 57mm (2.24 in)
Length of bullet: 36mm (1.42 in)


Packaging

 

This Czech 7.92mm rifle and light machinegun ammunition is packed loosely (not in clips) in white or brown cardboard cartons.  Each carton contains 3 rows of 5 rounds each, or a total of 15 cartridges.  The tops of the cartons have white labels with Czech markings in black letters.

Eighty cartons (1,200 rounds) are packed in an unpainted wooden box having a hinged lid and rope carrying handles on either end.  There are 5 cartons in length of the box, 4 cartons in the width, and 4 in depth.  On the top and right end of the box are 2-in x 3-inch white labels with Czech markings in black letters.  A factory inspection slip is glued to the under side of the box cover.

7.92mm Armor-Piercing Cartridge, Model ?
(7.92mm Ostry Naboj Vz.?)

 
This cartridge is designed for use against personnel and lightly armored vehicles.  It is fired in both rifles and machineguns, and may be used in any weapon chambered for 7.92mm x 57mm ammunition.

The spitzer-pointed bullet has a tungsten steel core and a nickel-plated mild steel jacket, with a lead alloy filler interposed between the core and the jacket.  A cannelure on the bullet serves as the recess into which the cartridge case is crimped.  The brass cartridge case employs a single centered flash hole (bored through the anvil) with brass Berdan-type primer cups.  The propellent is a grayish-black flake type.  The round is identified by a white lacquer primer seal.


Characteristics
Caliber: 7.92mm (cal. 311)
Weight of cartridge: 24.6g (379 gr)
Weight of case: 11.5g (177 gr)
Weight of bullet: 10g (154 gr)
Weight of propellent: 3.03g (46 gr)
Length of cartridge: 80mm (3.15 in)
Length of case: 57mm (2.24 in)
Length of bullet: 33.3mm (1.31 in)


Packaging


Information on packaging of this round is not available.


 

Next Time: Czechoslovakian small arms munitions

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

Imperial Japanese Navy Explosives - Bombs (Part 5)

 
Imperial Japanese Navy Explosives



 

Type 2 No.6 Mk 21 Bomb Model 1

 

Fuzes: D-4(a)

Overall Length: 41 inches

Length of body: 38 inches (w/ nose piece)

Diameter of body: 9 and 1/2 inches

Thickness of wall: 1/16 inches

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy type suspension lug

Dimensions of tail struts: None

Material of tail: Sheet Steel
 

Type of filling: 40 1kg  high-explosive hollow-charge bombs

Weight of filling: 88 pounds

Total weight of bomb: 132 pounds

Charge/weight ratio: 66%
 

Color and markings: Gary overall.  One inch green band on nose.  Brown band just aft of green band.  Two 1/2-inch white bands on body marking the position of binding straps.
 

Description: The canister consists of a blunt-nose assembly and a light tail piece, around which are fitted three steel segments held together by two circumferential metal retaining bands.  Two steel wires, which are attached to the nose, run longitudinally along the canister and pass through the buckles of the bands locking them together.

The buckles open automatically when the wires are withdrawn.  The nose assembly is constructed of two pieces held together by four lead sealing strips.  The forward piece is hollow and has a fuze pocket.  The after piece contains a wooden disk.  Set off center in the disk is a flat, round can housing a black powder burster charge in an annular silk bag.

The eccentric position of the charge centers the ignition hole of the can directly under the fuze and places the main portion of the charge near to the point at which the two steel release wires are attached to the nosepiece.  This accounts for a more direct pull being exerted on the release wires when the burster charge detonates.

Operation: Upon release from the plane the aerial burst fuze functions.  The burster charge is fired. shearing the lead sealing strips and blowing off the forward nosepiece.  The nosepiece withdraws the release wires from the buckles of the retaining bands which frees the segments of the canister.  The 1-kilogram bombs separate and fall individually. 

1-kg Hollow Charge Bomb

 

  

Fuzes: B-5(b)

Overall Length: 17 and 1/2 inches

Length of body: 8 and 1/2 inches

Diameter of body: 1 and 3/4 inches

Thickness of wall: 1/16 inches

Material of wall: Steel

Type of suspension: Carried in clusters of 40 in a container
Suspension lug: None

Length of tail: 9 inches (w/ fuze)

Width of tail: 1 and 3/4 inches

Dimensions of tail struts:

-Length: 1 and 3/8 inches
-Diameter: 1 and 3/4 inches

-Thickness: 1/32 inch

Material of tail: Light Sheet Tin

Type of filling: Type 98 explosive and Tetryl booster
-TNT: 70%
-HND: 30%

Weight of filling: 11 ounces

Total weight of bomb: 2 pounds 3 ounces (excluding nosepiece)
Weight of tail assembly: 10 ounces

Charge/weight ratio: 31%

Color and markings: Body is a natural steel color.  The tail assembly is aluminum colored.
 

Construction of body: The body is constructed of tubular steel.  An aluminum nose cap and hollow metal cone are crimped into the nose.  The fuze and tail assembly are threaded into the base of the body.

Construction of tail: Four fins are soldered to the tail cone and braced at the after end by a circular strut.  The tail cone is secured to the fuze body by a four small screws.

The arming system consists of arming vanes at the after end of the tail connected to the inertia weight by a threaded reach rod which passes through the tail cone.  A spring-loaded safety detent which fits into the inertia weight is located on the side of the tail cone and is held in the safe position by an arming vane.

A thin metal disk attaching to the arming wire is placed on top of the arming vanes.  It prevents the vanes from rotating and acts as a drogue to withdraw the arming wire when the bomb is released.

Operation: When the bomb is released from the canister the pressure of the air on the drogue forces it from the bomb thereby withdrawing the arming wire.  The safety detent spring ejects the reach rod from the inertia weight.  The inertia weight and striker are then free to move forward on impact and hit the primer.

Type 2 No.6 Mk 21 Bomb Model 2

 
Fuzes: D-4(a)

Overall Length: 42 and 1/4 inches

Length of body: 39 inches

Diameter of body: 9 and 1/2 inches

Thickness of wall: 1/16 inches

Material of wall: Sheet Steel

Type of suspension: Horizontal
Suspension lug: Normal Navy suspension lug is held in place by a steel plate that fits over it and is riveted to the body section.

Length of tail: 3 and 1/4 inches

Width of tail: 11 inches
Width of tail fins: 2 and 1/8 inches
Length of tail fins: 8 inches

Dimensions of tail struts: None

Material of tail: 1/16-inch sheet steel

Type of filling: 36 1-kilogram high-explosive bombs

Weight of filling: 80 pounds

Total weight of bomb: 109 pounds

Charge/weight ratio: 72%

Color and markings: Gray overall with a green-tipped nose and a brown nose band.
 

Description: The hexagonally-shaped bomb container consists of a blunt-nose assembly and a light tailpiece around which are fitted three sheet steel sections held together by three metal retaining bands.  Two steel wires run longitudinally along the exterior of the container and pass through the three retaining band buckles.  One wire is attached to the nosepiece; the other is a safety wire which is removed after the container has been placed in the bomb rack.

The nose section is of two-piece construction.  The after piece is attached to the sheet steel sides by a welded stud for each section.  The forward piece is attached to the after one by three lead sealing strips.  The nosepiece, which has a fuze pocket to take the D-4(a) fuze, is filled by a wooden block.

A round metal can containing the burster charge in an annular silk bag is set off-center in the wooden block.  The initiating charge in the burster is directly beneath the fuze magazine.  The balance of the charge is off-center toward the point where the retaining band release wire is secured to the nosepiece.  The purpose of this offset is to exert a more direct pull on the release wire when the charge is detonated.

The tailpiece is held in place by a bungee cord fastened to a hook on the after end of each body section.  Two tail fins are riveted to the after portion of the sheet steel section to which the suspension lug is attached.  Two metal plates divide the container into three sections in each of which are packed 12 1-kilogram bombs.

Operation: After the bomb container is released from the plane, the aerial burst fuze functions.  The burster charge shears the lead sealing strips between the two sections of the nose, blowing the outer piece free from the container and withdrawing the release wire from the retaining band buckles.  The retaining bands open and the container sections separate allowing the 36 1-kilogram bombs to fall individually.

1-kg Antipersonnel bomb

  

Fuzes: B-5(c)

Overall Length: 11 and 3/8 inches

Length of body: 5 and 1/2 inches

Diameter of body: 2 and 3/8 inches

Thickness of wall: 1/32 inch

Material of wall: Steel
 

Type of suspension: Carried 36 in a container which is fuzed with a D-4(a) fuze

Suspension lug: None
 

Length of tail: 5 and 7/8 inches

Width of tail: 2 and 3/8 inches
Width of tail fins: approx. 1 inch at the widest point

Dimensions of tail struts:

-Diameter: 2 and 3/8 inches
-Length: 1 and 3/8 inches

Material of tail: Light tinned steel

Type of filling: Type 97 explosive
-TNT: 60%
-HND: 40%

Weight of filling: 1 pound 1 ounce

Total weight of bomb: 2 pounds 3 ounces

Charge/weight ratio: 50%
 

Color and markings: Bomb body may be a steel gray or black.  Tail assembly and fuze are aluminum colored.
 

Construction of body: The body is of one piece light steel construction.  It is cylindrical in shape, rounded at the nose and threaded in the base to receive the fuze assembly.  The inside of the body is coated with lacquer.
 

Construction of tail: The tail assembly is made of light tinned steel and is secured to the fuze body by four screws.  Four fins spaced 90 degrees apart are soldered to the tail cone and are braced by a ring strut at the after end.

An arming spindle extends from the fuze up through the tail cone, and has vanes attached at the end.  A drogue holds the vanes in a safe position.

Operation: When the bomb falls free from the container, the drogue retaining the vanes is carried away by the wind, allowing the vanes to rotate.  The motion of the vanes is transmitted through the reduction gear system to the spindle which is threaded out of the striker.  To prevent rotation of the striker, a key and keyway system is incorporated in the fuze body and striker.  As the spindle rises, it also lifts the gear frame to which is secured a pin retaining the safety detent.

The safety detent, which fits through the fuze body into the striker and holds it in position, is spring-loaded outward, and removal of the safety detent pin permits it to fly out.  With the spindle and detent removed, the heavy striker is held up only by a weak creep spring, which it overcomes on impact, initiating the gaine.

Type 3 No.6 Mk 23 Bomb Model 1

  

Fuzes: C-2(a)

Overall Length: 40 and 3/4 inches

Length of body: 21 and 3/4 inches

Diameter of body: 7 and 7/8 inches

Thickness of wall: 1/4 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy type
 

Length of tail: 18 and 1/2 inches

Width of tail: 10 and 5/8 inches (excluding tail brake)
Width of tail fins: 4 and 3/4 inches
 

Dimensions of tail struts:

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

-Thickness: 3/32 inch

Material of tail: Sheet Steel 
  

Type of filling: Picric acid of Type 98 explosive
Weight of filling: 50 pounds
Total weight of bomb: 143 pounds
Charge/weight ratio: 35%
 

Color and markings: Gray overall with a green band around the nose.  New type markings may be found.
 

Construction of body: A cast-steel nose is attached by a continuous weld and 2 rows of 10 rivets each to a tubular-steel body.  An anti-penetration ring is welded to the exterior of the nose, 4 inches forward of the rivets.  This rind is 2 and 3/4 inches long and has an outer diameter of 7 and 7/8 inches.

A tail cone is held by 1 row of 24 rivets and a continuous weld to a collar which fits into the after end of the bomb body and is held there by 2 rows of screws (14 per row).
 

Construction of tail: Four fins are spot welded to the tail cone and braced by a single set of box-type struts.  A 1/16 inch sheet steel tail brake measuring 10 inches square is welded to the after end of the tail fins.

Type 3 No.6 Mk 27 Bomb (Rocket) Model 1
Please be sure to read the last paragraph in the description

 

Overall Length: 53 inches

Diameter of body: 7.8 inches
Weight of load: 5.5 pounds
Weight of propellant: 22 pounds
Total weight: 145.2 pounds
Maximum speed: 270m/sec

Color and markings: Gray overall with green and silver nose bands and red tail struts.

General description: This rocket, along with the Type 3 No.1 Mk 28 Model 1, were the only Japanese Navy rockets which were actually under production at the end of the war.  It is an aircraft-launched rocket intended for use against formations of large enemy planes, designed to eventually take the place of the Type 99 No.3 Mk 3 for air-to-air bombing.

The bomb consists of three sections: nose, barrel, and tail.  The nose section is conical in shape, with a fuze well in the nose and contains a burster charge, and a charge of incendiary shrapnel consisting of white phosphorous filled steel pellets.  It is threaded onto the barrel, and secured in place with screws.

The barrel is cylindrical in shape, closed at the forward end, and serves as the container and burning chamber for the rocket propellant.  It is fitted with one longitudinal launching rail.

The tail section is conical in shape, and is fitted with four fins of conventional Navy type.  It is threaed onto the barrel, and secured in place with screws.  The rear end is constricted to form a venturi for the escape of the driving gases.

The propellant is in grains 350 millimeters long and 19.2 millimeters in diameter, and is of the ballistite type, packed into the barrel.  It is ignited electrically.

The fuze used in this bomb is 10-second clockwork aerial burst fuze, using the standard Navy fuze clock, housed in a special brass case with a hand operated setting ring graduated in seconds from 0 to 10.

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

Type 3 No.1 Mk 28 Bomb (Rocket) Model 1
Please be sure to read the last paragraph in the description
  

Fuze: Type 3 Mk 28

Overall Length (w/o fuze): 25 and 1/4 inches

Diameter of body: 4.69 inches
Weight of explosive: 1.32 pounds
Weight of propellant: 4.4 pounds
Total weight: 19.8 pounds

Color and markings: Gray overall with green and brown nose bands and red tail struts.

General description: In its early stages of development, this rocket was designated Mk 19.  It is constructed of a light aluminum alloy and carried a high-explosive charge.  It is intended for use against large aircraft.

 

Rocket power is supplied by 16 grains of ballistic type propellant 19.2mm x 350mm.  They are contained in the cylindrical barrel of the bomb, and are ignited electrically.

 

The nose section is ogival in shape, and carried the high-explosive charge.  A nose well is provided to take a special small impact fuze similar to the A-3(a).  The tail section is constricted to form a venturi, and is fitted with fins, riveted in place, for stabilization.  An error of 10 meters at a range of 500 meters is assumed by designers.   Two launching rails, 180 degrees opposed, are attached to the barrel of the bomb. 

 

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



 Type 4 No.25 Mk 29 Bomb
 

 

Type 4 No.25 Mk 29 was in the process of being developed at the end of the war to take the place of the No.25 Mk 3 bombs as a weapon for use against large bomber formations.  It was designed either to be dropped in the same manner as the Mk 3 bombs, or to be detonated in the plane by the pilot.  The bomb incorporates a larger explosive charge, and smaller quantity of incendiary shrapnel, than do the Mk 3 bombs of the same size.

 

The nose section of the bomb is conical in shape, and is filled with a wooden block except for a central channel filled with explosive leading into the main charge of the bomb.  An adapter is supplied at the nose to receive the Type 3 electric gaine.

 

The barrel of the bomb is cylindrical in shape, and is filled with incendiary shrapnel of the white phosphorous filled steel pipe type.  A central burster charge of high explosive is surrounded by the incendiary shrapnel.

 

The conical tail section is filled with a central burster charge surrounded by the same type of incendiary shrapnel as is found in the barrel of the bomb.  An adapter is provided at the apex of the tail cone to receive the Type 99 Mk 3 tail fuze D-2(a), without centrifugal arming.  Tail fins are standard Navy design without rotational offset, such as is found in the Mk 3 bombs.

 

The bomb is fuzed in the nose with the Type 3 electric gaine fitted with a cable which leads into a firing switch in the cockpit of the airplane.  It is to be used when the pilot desires to fire the bomb in the airplane in a suicide attack on bomber formations.

 

The tail fuze is a Type 90 Mk 3 without centrifugal arming.  It is to be used when the bomb is dropped in an air-to-air bombing attack.

 

This bomb had not gone into production at the end of the war, but was considered by the Japanese to be a practical weapon for defense against heavy bombers.

 

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

 

Next Time: Still more IJN bombs!