Imperial Japanese Army Explosives - Bombs (Part 1)

Imperial Japanese Army Explosives

 

 

 

 

Type 92 15kg High-Explosive Bomb

    

  

Fuzes: A-2(b) or A-2(d)

Overall Length: 25 and 1/2 inches

Length of body: 14 and 1/2 inches

Diameter of body: 3 and 7/8 inches

Thickness of wall: 1/2 inch

Material of wall: Steel Rings (26)

 

Type of suspension: Vertical and Horizontal

 

Suspension lug: Normal Army suspension lug.  Rectangular hinged steel lug on a plate riveted to the body with four rivets.  A similar steel hinged lug is fastened to the end of the tail fins.

 

Color and markings: Black overall with a red band around the nose and a white band and yellow band forward of the suspension lug.  (White band may be missing)

 

Length of tail: 11 inches

Width of tail: 5 and 1/2 inches

Width of tail fins: 2 and 3/4 inches

 

Dimensions of tail struts:

-Length: 3 and 3/4 inches

-Width: 5/16 inch

-Thickness: 1/16 inch

-Material: 1/16 inch sheet steel

 

Type of filling: 3 pre-cast blocks of picric acid.  TNT is an alternative filling.

Weight of filling: 9lbs 9oz

Total weight of bomb: 33 pounds

Charge/weight ratio: 30%

 

Construction of body: A cast-steel nose is threaded onto a tubular steel body.  Twenty-six steel rings 3/8 inch wide and 3/8 inch thick are fitted around the body.  One ring to which the suspension lug is attached is 1 and 3/8 inches wide and 3/8 inch thick.  A tail cone is screwed onto the after end of the tubular body.

 

Construction of tail:  Four angular fins are welded to the tail cone and braced by a single set of box-type struts.  A suspension lug is secured to the after end of the fins.

 

 

 

Type 99 30kg High-Explosive Bomb

 

   

Fuzes: A-2(a), A-2(c); B-1(a), B-1(b); D-5(a)

Overall length: 33 and 1/4 inches

Length of body: 19 and 3/4 inches

Diameter of body: 5 and 7/8 inches

Thickness of wall: 9/32 inch

Material of wall: Tubular Steel

 

Type of suspension: Horizontal

Suspension lug: Normal army suspension lug

 

Color and marking: Black overall with a red band around the nose and a yellow band and white band around the body forward of the suspension lug.

 

Length of tail: 13 and 1/2 inches

Width of tail: 8 and 1/4 inches

Width of tail fins: 3 and 1/4 inches

 

Dimensions of tail struts:

-Length: 5 and 3/4 inches

-Width: 1 inch

-Thickness: 1/16 inch

-Material: Sheet steel

 

Type of filling: 3 pre-formed blocks

-Cyclonite: 48%

-TNT: 52%

 

Weight of filling: 25lbs 12oz

Total weight of bomb: 66 lbs

Charge/weight ratio: 39%

 

Construction of body: A cast-steel nosepiece is screwed into a tubular steel body.  A tail cone is welded to the after end of the steel body.

 

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

 

Remarks:  This bomb has been found with sheet steel plates welded to the outer edges of the fins to form a box-like reinforcement for the tail fins.  They cover the area from the after end of the fins to a point just forward of the curve in the fins.  This is an anti-shipping adaptation using the A-8(a) and B-8(a) fuzes. 

 

Documents report that an anti-penetration device is used on the tail of the Type 99 30kg bomb for minimum altitude bombing.

 

 

 

Type 94 50kg, Type 94 and Type 3 100kg High-Explosive Bombs

  

    

Fuzes: A-2(a), A-2(b), A-2(c); B-1(a), B-1(b); D-5(a)

 

50kg

Overall length: 41 inches

Length of body: 24 and 1/2 inches

Diameter of body: 7 inches

Thickness of wall: 1/4 inch

 

100kg

Overall length: 53 inches

Length of body: 31 and 1/4 inches

Diameter of body: 9 and 1/2 inches

Thickness of wall: 13/32 inch

 

Material of wall: Tubular steel

 

Type of suspension: Horizontal

Suspension lug: Normal Army suspension lug

 

Color and markings:  Black overall with a red band around the nose and a white band and yellow band around the body just forward of the suspension lug.

 

50kg

Length of tail: 16 and 5/8 inches

Width of tail: 9 and 1/2 inches

Width of tail fins: 3 and 1/2 inches

Dimensions of tail struts: 6 and 7/8 x 1 and 9/16 x 3/32 inches

Material of tail: Sheet steel

Type of filling: 3 blocks of picric acid

Weight of filling: 44 lbs

Total weigh tof bomb: 110 lbs

Charge/weight ratio: 40%

 

100kg

Length of tail: 21 and 3/4 inches

Width of tail: 13 and 1/4 inches

Width of tail fins: 5 and 7/16 inches

Dimensions of tail struts:

-Forward Struts: 9 and 7/16 x 1 and 3/16 x 3/32 inches

-After Struts: 9 and 7/16 x 1 and 9/16 x 3/32 inches

Material of tail: Sheet steel

Type of filling:

-Type 94: 4 blocks of picric acid

-Type 3: 5 blocks of picric acid

Weight of filling: 97lbs 12oz

Total weigh tof bomb: 220 lbs

Charge/weight ratio: 42.5%

 

Construction of body:

Type 94, 50kg and 100kg:  A cast-steel nose is screwed into a tubular steel body.  A tail cone is welded to the after end of the body.

 

Type 3, 100kg: A cast steel nosepiece is welded to a tubular-steel body.  A tail cone is welded to a collar which is screwed into the after end of the body.

 

Construction of tail:  Four tail fins are spot welded to the tail cone and are braced by box type struts.  The 50kg bomb has a single set of struts.  The 100kg bomb has two sets of struts.

 

Remarks:  The Type 94 100kg bomb may vary in its explosive filling:

Variations include: (1) Picric Acid - 78%; TNT - 22% in 4 pre-formed blocks. 

(2) Ammonium nitrate - 78%; RDX - 22% cast into the bomb.

 

 

 

 

Type 94 Modified and Type 1 50kg and 100kg High-Explosive Bombs

   

 

Fuzes:

-Type 94 Modified: C-3(a), B-1(a), B-1(b)

-Type 1: C-3(a), E-1(a)

 

50kg

Overall length: 40 inches

Length of body: 23 and 1/4 inches

Diameter of body: 7 and 1/8 inches

Thickness of wall: 9/32 inch

 

100kg

Overall length: 52 inches

Length of body: 30 and 1/4 inches

Diameter of body: 9 and 1/2 inches

Thickness of wall: 13/32 inch

 

Material of wall: Tubular Steel

 

Type of suspension: Horizontal

Suspension lug: Normal Army type suspension lug

 

Color and markings:  Black overall and a red band around the nose.  One yellow and one white band are forward of the suspension lug.

 

50kg

Length of tail: 16 and 5/8 inches

Width of tail: 9 and 3/4 inches

Width of tail fins: 3 and 5/16 inches

Dimensions of tail struts: 6 and 7/8 x 1 and 9/16 x 3/32 inches

Material of tail: Sheet steel

Type of filling: 3 blocks of picric acid

Weight of filling: 44 lbs

Total weight of bomb: 110 lbs

Charge/weight ratio: 40%

 

100kg

Length of tail: 21 and 3/4 inches

Width of tail: 13 and 3/8 inches

Width of tail fins: 5 and 1/8 inches

Dimensions of tail struts:

-Forward: 9 and 7/16 x 1 and 3/16 x 3/32 inches

-After: 9 and 7/16 inches x 1 and 9/16 x 3/32 inches

Material of tail: Sheet steel

Type of filling: 4 blocks of picric acid

Weight of filling: 103 lbs

Total weight of bomb: 237 lbs

Charge/weight ratio: 43.6%

 

Construction of body: A cast-steel nosepiece is screwed into a tubular-steel body.  The orifice in the nose measures 3 inches in diameter.  A tail cone is welded to the after end of the body.  A fuze adapter is welded onto the apex of the cone.

 

-Type 94 Modified: The tail fuze pocket is completely threaded

-Type 1: The tail fuze pocket has three threads and then an annular groove.

 

Construction of tail:  Four fins are welded to the tail cone and braced by box-type struts, a single set for 50kg bombs and a double set for 100kg bombs.  A tail brake is fitted to the after end of the tail of the bombs.

 

 

 

Type 1 250kg High-Explosive Bomb

  

   

Fuzes: C-3(a), E-1(a)

 

Overall length: 75 and 1/4 inches

Length of body: 45 and 1/4 inches

Diameter of body: 11 and 3/4 inches

Thickness of wall: 1/4 inch

Material of wall: Tubular steel

Type of suspension: Horizontal

Suspension lug: Normal Army type

 

Color and markings: Black overall.  One yellow and one white band (7/8 inch) forward of the suspension lug, 1 inch red band on tip of nose.

 

Length of tail: 30 inches

Width of tail: 16 and 1/2 inches

Width of tail fins: 8 and 1/4 inches

 

Dimensions of tail struts:

-Length: 11 inches

-Width: 7/8 inch

-Thickness: 1/16 inch

-Material: Steel

 

Type of filling: Preformed, paper-wrapped, paraffin sealed picric acid blocks

Weight of filling: 227 lbs

Total weight of bomb: 550 lbs

Charge/weight ratio: 43%

 

Construction of body:  A cast-steel nosepiece is screwed into a tubular-steel body.  The tail cone is welded to the after end of the body.  The nosepiece has a 3-inch orifice to accommodate the C-3(a) time fuze.

 

Construction of tail:  Four fins are welded to the tail cone and braced by two sets of box-type struts.  A fuze adapter is welded at the apex of the tail cone.  The tail fuze pocket has three threads and then an annular groove.

 

 

 

Type 92 250kg and 500kg High-Explosive Bombs

 

 
Fuzes: A-4(a), B-4(a)

 

250kg

Overall length: 76 inches

Length of body: 46 inches

Diameter of body: 11 and 3/4 inches

Thickness of wall: 1/4 inch

 

500kg

Overall length: 99 and 3/4 inches

Length of body: 57 and 1/2 inches

Diameter of body: 15 inches

Thickness of wall: 9/16 inch

 

Material of wall: Tubular Steel

 

Type of suspension: Horizontal

Suspension lug: Normal Army type suspension lug

 

Color and markings:  Black overall with a red tipped nose.  One yellow and one white band forward of the suspension lug.

 

250kg

Length of tail: 30 inches

Width of tail: 16 and 1/2 inches

Width of tail fins: 8 and 1/4 inches

Dimensions of tail struts: 11 x 7/8 x 1/16 inches

Material of tail: Steel

Type of filling: Preformed blocks of picric acid

Weight of filling: 230 lbs

Total weight of bomb: 550 lbs

Charge/weight ratio: 43%

 

500kg

Length of tail: 43 and 1/4 inches

Width of tail: 20 and 3/4 inches

Width of tail fins: 10 and 3/8 inches

Dimensions of tail struts: 11 x 7/8 x 1/16 inches

Material of tail: Steel

Type of filling: Preformed blocks of picric acid

Weight of filling: 491 lbs

Total weight of bomb: 1100 lbs

Charge/weight ratio: 46.4%

 

Construction of body: A cast-steel nosepiece is threaded into a tubular-steel body.  A tail cone is welded to the after end of the body.

 

Construction of tail:  Four fins are welded to the tail cone and braced by two sets of box-type struts.  The tail fins of the 500kg are similar to the Navy bombs in that they are angled on the outer edge, as compared to the characteristic curve on the fins of Army 30kg to 250kg high-explosive bombs.

Next Time: Skipping and thermite bombs