Imperial Japanese Navy Explosives - Bombs (Part 2)

 

 

 

 

Imperial Japanese Navy Explosives

 

 

 

 

 

No.80 Ordinary Bomb Model 1

  

 

Fuzes:
-Nose: A-1(c), A-3(d)
-Tail: B-3(b)

Overall Length: 111 and 1/2 inches

Length of body: 62 inches

Diameter of body: 17 and 1/2 inches

Thickness of wall: 3/4 inch

Material of wall: Steel

 

Type of suspension: Horizontal

Suspension lug: Two guide studs o the bomb body position a carrying band to which a suspension lug is attached.

 

Length of tail: 49 inches

Width of tail: 24 and 1/2 inches

Width of tail fins: 10 and 1/2 inches

 

Dimensions of tail struts:

-Length: 3 and 9/16 inches

-Width: 17 and 3/4 inches

-Thickness: 5/32 inch

 

Material of tail: Steel

 

Type of filling: Type 91 explosive (cone is filled)

Weight of filling: 770 pounds (approximate)

Total weight of bomb: 1,820 pounds

Charge/weight ratio: 41.7%

 

Color and markings: Gray overall.  Green nose and tail struts.  Two red lines 180 degrees removed along the longitudinal axis of the bomb.  New type markings will be found.

 

Construction of body: The bomb body is constructed of 1 piece of machined forged steel.  A fuze pocket is drilled in the nose.  A tail cone is screwed onto an adapter ring which fits into the after end of the body and is held there by 30 flat-headed screws.

 

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

 

 

 

 

  

 

 

 

No.3 Ordinary Bomb Model 2

 

Fuzes: A-1(a), A-3(a)

Overall Length: 33 inches

Length of body: 19 and 3/4 inches

Diameter of body: 7 and 1/2 inches

Thickness of wall: 1/4 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Two typical Navy suspension lugs 180 degrees removed on the circumference of the bomb body.
 

Length of tail: 13 and 1/4 inches

Width of tail: 7 and 1/2 inches

Width of tail fins: 3 and 1/4 inches
 

Dimensions of tail struts: None

Material of tail: Sheet Steel

Type of filling: Probably Picric Acid

Weight of filling: Not Available

Total weight of bomb: 70 pounds

Charge/weight ratio: Not Available
 

Color and markings: Gray overall with a green band on the nose and on the ends of the tail fins.  Two red lines diametrically opposed run the length of the bomb.  New type markings may be found.
 

Construction of body: The body is constructed of one piece of machine steel turned down to a streamlined shape.  The forward end is threaded to receive a nose fuze and the after end is threaded to receive a male base plate.  The base plate is threaded externally at both ends.  The tail cone screws onto the after end of the base plate.  There is no explosive in the tail cone.
 

Construction of tail: The tail cone consists of four sheet metal sections riveted to an internally threaded ring.  The edge of each section has a flange which turns up.  The tail fins are secured between flanges of adjoining sections by spot welds.  There are no struts to brace the fins.

 

 

 

No.6 Ordinary Bomb Model 2

 

Fuzes: A-1(a), A-3(a)

Overall Length: 42 and 1/2 inches

Length of body: 25 and 1/2 inches

Diameter of body: 9 inches

Thickness of wall: 3/8 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Two typical Navy suspension lugs 180 degrees removed on the circumference of the bomb body.
 

Length of tail: 17 inches

Width of tail: 9 and 1/2 inches

Width of tail fins: 4 and 1/36 inches
 

Dimensions of tail struts: None

Material of tail: Sheet Steel
 

Type of filling: Picric acid

Weight of filling: 65 pounds and 12 ounces

Total weight of bomb: 139 pounds

Charge/weight ratio: 47%
 

Color and markings: Gray overall with a green band on the nose and on the ends of the tail fins.  Two red lines diametrically opposed run the length of the bomb.  New type markings may be found.
 

Construction of body: The body is constructed of one piece of machine steel turned down to a streamlined shape.  The forward end is threaded to receive a nose fuze and the after end is threaded to receive a male base plate.  The base plate is threaded externally at both ends.  The tail cone screws onto the after end of the base plate.  There is no explosive in the tail cone.
 

Construction of tail: The tail cone consists of four sheet metal sections riveted to an internally threaded ring.  The edge of each section has a flange which turns up.  The tail fins are secured between flanges of adjoining sections by spot welds.  There are no struts to brace the fins.

 

  

No.25 Ordinary Bomb Model 2
  

  

Fuzes:
-Nose: A-3(a)
-Tail: B-3(a)

Overall Length: 71 and 1/2 inches

Length of body: 44 and 1/2 inches

Diameter of body: 14 inches

Thickness of wall: 5/8 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug
 

Length of tail: 27 inches

Width of tail: 14 inches

Width of tail fins: 4 and 3/32 inches
 

Dimensions of tail struts:

-Length: 10 inches

-Width: 2 and 1/8 inches

-Thickness: 1/16 inch

Material of tail: Steel
 

Type of filling: Cast Picric Acid, tail is filled

Weight of filling: 228 pounds

Total weight of bomb: 557 pounds

Charge/weight ratio: 41%
 

Color and markings: Gray overall with a green band on the nose and green tail struts.  New type color markings will be found.
 

Construction of body: The body is constructed of one piece of machined forged steel.  There is a threaded nose fuze pocket at the forward end.  The after end of the body is threaded internally to receive a tail cone.  The tail cone is explosive filled and has a fuze pocket at its apex.
 

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

No.50 Ordinary Bomb Model 2

  

     Fuzes: A-3(d), B-3(b)

Overall Length: 90 inches

Length of body: 57 inches

Diameter of body: 17 and 3/4 inches

Thickness of wall:
-Nose: 4 inches
-Base: 1/2 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: An eyebolt welded to a suspension band which fits around the bomb body.  The band is positioned by two guide studs 180 degrees apart on the bomb body.
 

Length of tail: 33 inches

Width of tail: 17 and 3/4 inches

Width of tail fins: 7 inches

 
Dimensions of tail struts:

-Length: 12 and 1/4 inches

-Width: 2 and 3/4 inches

-Thickness: 1/8 inch

Material of tail: Steel
 

Type of filling: Type 98 explosive separately cast in the body and tail.

Weight of filling: 457.5 pounds

Total weight of bomb: 1,080 pounds

Charge/weight ratio: 42%
 

Color and markings: Gray overall.  Green band around the nose and a brown band aft of it.
 

Construction of body: The body is of one piece machined steel construction.  The after end of the body is threaded internally to receive the tail assembly.  The tail cone threads into the bomb body and is secured by two grub screws.
 

Construction of tail: Four 5/32-inch steel tail fins are spot welded to the tail cone.  They are braced by a single set of box-type struts

No.6 Mk 1, Type 1 No.6 Mk 1, and Type 4 No.6 Mk 1 Bombs
Please make sure to read the "Remarks" portion for these bombs
 

    

Fuzes: Both bombs are fuzed in the nose only, with standard Navy nose fuzing, without delay.


Type 1 No.6 Mk 1 Land

Overall Length: 40 inches (without fuze)

Length of body: 21.8 inches

Diameter of body: 7.85 inches
 

No.6 Mk 1 Land

Overall Length: 42.21 inches

Length of body: 21 inches

Diameter of body: 9.45 inches

 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug 

  

Type of filling:Mustard thickened with methacrylates and poly-vinyl alcohols

Type 1 No.6 Mk 1 Land

Weight of filling: 18 kg (approximate)

Total weight of bomb: Not Available

Construction: Land Type (Type 97 No.6 Land body)


No.6 Mk 1 Land

Weight of filling: 23kg

Total weight of bomb: 69 kg

Construction: Type 99 No. 6 Mk 2 (Body without multiple struts, land type)

 

General Description: The chemical fillings for these bombs are contained in cans which fit inside the bomb casing, and are sealed in place with paraffin.  Two cans were used for each bomb; a conical can which fits into the tail cone, and a cylindrical can with a channel down its center to provide space for the central explosive burster charge.  

Besides the central burster charge, a nose charge is provided, separated from the forward end of the gas containers by a spacer disk.  The nose charge is designed the have the effect of forcing the spacer disk and chemical filling back out of the crater, and help to spread it.

Type 4 No.6 Mk 1

General Description: This bomb was designed to take the place of both of the improvised No.6 Mk 1 land, and Type 1 No. 6 Mk 1 land bombs.  It is of wooden construction throughout to save steel, and proves itself equal to the other two bombs in effectiveness in Japanese tests.  Exact dimensions are not available, but the following data is known.

The barrel, nose section, and tail fins of the bomb are constructed of light plywood, molded into the proper shape.  A steel adapter is provided in the nose to take a standard Navy instantaneous fuze and gaine.  The barrel of the bomb is cylindrical, with no cone at the tail.  It is reinforced with bands of plywood.

The tail fins are of standard shape, and are braced with steel struts.  The nose section of the bomb is a wooden block, slightly rounded, and fitted into the barrel.

The chemical filling for the bomb is contained in a cylindrical can with a central pocket at its forward end to receive the central burster charge.  A the forward end of the filling can is a spacer disk.  An explosive nose charge is provided at the extreme forward end of the bomb and extends back through the spacer disk and into the central pocket in the chemical filling can.  It is designed to prevent the chemical filling from collecting in the crater, and the spread it.

Remarks: These bombs are capable of being filled with any suitable gas, although the standard filling is mustard gas.  According to Japanese statements, attempts by Japanese chemists to produce new types of gas failed to improve on types already in common production.

The Mk 1 bombs have never been recovered outside of the Japanese homeland, indicating that there was never any immediate intention of their use, and the small number of bombs of this type found in Japan indicates that the Japanese were inadequately prepared to initiate gas warfare.  The data on these bombs is the result of incomplete investigation, and must not be considered as specific, accurate information.

 

 

 

Type 99 No. 6 Mk 2 Bomb
 

 
Fuzes: A-3(a)

Overall Length: 42 inches

Length of body: 21 inches

Diameter of body: 9 and 3/8 inches

Thickness of wall: 3/16 inch

 Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Two lug. Normal Navy type
 

Length of tail: 21 inches

Width of tail: 13 and 1/4 inches

Width of tail fins: 6 inches
 

Dimensions of tail struts:
Outer Struts

-Length: 9 and 1/2 inches

-Width: 1 and 3/4 inches

-Thickness: 1/16 inch

Material of tail: Sheet Steel

Inner Struts

-Length: 4 and 3/4 inches

-Width: 1 and 3/8 inches

-Thickness: 1/16 inch

Material of tail: Sheet Steel

 

Type of filling: Type 98 explosive

Weight of filling: 85 pounds

Total weight of bomb: 140 pounds

Charge/weight ratio: 60%
 

Color and markings: Gray overall with a green-tipped nose and a blue band aft of the green.
 

Construction of body: A cast-steel nose is attached to a tubular-steel body by a continuous circumferential weld and 2 rows of 16 plug welds.  A tail cone is attached to a collar by a continuous circumferential weld and 16 plug welds.  The collar fits into the after end of the body and is held there by 2 rows of screws (16 per row).
 

Construction of tail: Four tail fins are welded to the tail cone and are braced by four sets of box-type struts.

Remarks: This bomb may be found with only one set of struts.

 

 

 

Next Time: More ordinary and "other" bombs