Imperial Japanese Navy Explosives - Bombs (Part 4)

 
 
 
Imperial Japanese Navy Explosives
 
 
 
 
 
 

Type 99 No.80 Mk 5 Bomb

  

 

Fuzes: Two B-2(b) tail fuzes

Overall Length: 95 and 1/2 inches

Length of body: 52 and 1/8 inches

Diameter of body: 16 and 1/8 inches

Thickness of wall:
-Nose: 4 inches
-Tail: 2 inches

Material of wall: Forged Steel
 

Type of suspension: Horizontal

Suspension lug: Two guide studs on the bomb bode, position a carrying band, to which a suspension lug is attached.
 

Length of tail: 43 and 3/8 inches

Width of tail: 22 and 1/8 inches

Width of tail fins: 11 and 1/16 inches
 

Dimensions of tail struts:

-Length: 15 and 1/4 inches

-Width: 2 and 3/4 inches

-Thickness: 3/16 inch

Material of tail: Sheet Steel
 

Type of filling: Type 91 explosive (trinitroanisol)

Weight of filling: 66 pounds (approximate)

Total weight of bomb: 1,641 pounds (w/o tail)

Charge/weight ratio: 4%
 

Color and markings: Gray overall.  Green band around the nose, white band aft of green band
 

Construction of body: The bomb body is constructed of one piece of forged machined steel.  There are eight recesses cut in the nose presumably to hold a windshield if the case is used as a projectile.  A male base plate which has two fuze pockets is screwed into the after end of the body.

The tail cone is formed of rolled sheet steel (3/32-inch) welded down one side.  Twelve screws fasten the unreinforced base of the cone to the base plate of the bomb which has holes drilled around the edge to receive the screws.  Three hinged doors in the cone permit access to the fuze pockets.

Two vane assembly supporting rings are located at the apex of the cone.  These rings are constructed to receive the B-2(b) vane assembly bushings which are held in place by set screws. Slots in the tail cone are located beneath the supporting rings to permit passage of the reach rods from the fuze bodies to the vane assembly.
 

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



 

Type 2 No.80 Mk 5 and No.150 Mk 5 Bombs
Please read the general description of this entry

No picture available
  
Type 2 No.80 Mk 5

Fuzes: Two B-2(b) tail fuzes
Gaines: Special Mk 5
Approximate weight of bomb: 1,760 pounds
Material of wall: Forget steel
Material of tail: Sheet Steel
Type of filling: Type 91 explosive
Approximate loading factor: 6%


No.150 Mk 5

Fuzes: Two large fuzes similar to the B-2(b) fuze
Gaines: Special Mk 5
Approximate weight of bomb: 3,300 pounds
Material of wall: Forget steel
Material of tail: Sheet Steel
Type of filling: Type 91 explosive
Approximate loading factor: 6%

 

Color and markings: Gray overall with a green and brown nose band and white tail struts
 

General Description: These two bombs were designed to fill the great need of the Japanese for armor-piercing bombs.  Prior to the design of these two, the Japanese Navy had only one true armor-piercing bomb, the Type 99 No. 80 Mk 5, an adaptation of a large caliber artillery shell produced by turning the shell down to a streamlined shape and adding a tail section and a slightly larger explosive charge.

Type 2 No.80 Mk 5 and No.150 Mk 5, although they were specifically designed as armor-piercing bombs, differ only slightly from the earlier bomb.  Type 2 No.80 Mk 5 differs from the Type 99 No.80 Mk 5 only in having a slightly larger explosive charge, and in having no recesses at the nose to hold a windshield in place.  No.150 Mk 5 is simply a larger version of the Type 2 No.80 Mk 5.

Both bombs of the No.80 size use two B-2(b) fuzes in the tail with the special Mk 5 gaine.  No.150 Mk5 has two large fuzes of similar construction to the B-2(b).  These bombs were never extensively produced and neither Type 2 No.80 Mk 5 or No.150 Mk 5 was ever found outside the Japanese homeland.

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

Note: I'm not sure what the next few paragraphs were intended for, but they are included for accuracy towards the source material.

The Mk 7 bomb was never more than an idea as far as the Japanese Navy was concerned.  It was suggested and discussed by a meeting of designers in 1935, but no experiments were carried out because the idea was considered impractical and unnecessary.  The bomb, as planned, was to consist of the 1 kilogram practice bomb, with a conical glass bottle of bacillus culture in place of the smoke mixture in the tail.

A lengthened striker was to break the bottle, and the culture was to spread by the force of impact.  A spread of 1 meter in diameter was hoped for.  No specific type of bacillus had been selected for the bomb.  Distinctive color marking for the bomb was to have been purple painted nose and tail.

Type 5 No.1 Mk 9 Model 1 and Type 3 No.6 Mk 9 Bombs

No picture available
  
Type 5 No.1 Mk 9 Model 1

Overall length: 35.4 inches

Diameter of body: 3.93 inches

Weight of explosive: 2.2 pounds

Weight of propellant: 4.4 pounds

Total weight of bomb: 33 pounds

Maximum speed: 230m/sec

  
Type 3 No.6 Mk 9
Overall length: 66.9 inches

Diameter of body: 7.87 inches

Weight of explosive: 22 pounds

Weight of propellant: 22 pounds

Total weight of bomb: 184.8 pounds

Maximum speed: 230m/sec
 

Color and markings: Gray overall. Green band on nose, with brown band just aft of green band.  Gray tail struts.
  

General description: Neither of these rockets had been put into production at the end of the war, although experiments had been finished on both of them.  Both were designed as aircraft launched weapons for use against surface targets; Type 5 No.1 Mk 9 Model 1 against surface submarines, and the Type 3 No.6 Mk 9 against landing craft and small ships.

These rockets are similar to the Mk 27 and Mk 28 rockets of comparable sizes, but both are somewhat heavier.  Both carry high-explosive loads, and the Type 5 No.1 Mk 9 Model 1 has a semi-armor piercing nose.
 
Exact fuzing is unknown, but it is known that the Type 5 No.1 Mk 9 Model 1 uses a fuze with a 0-2 second delay.  The Type 3 No.6 Mk 9 is assumed to use an instantaneous fuze.  Both of these rockets are fin stabilized, and more closely resemble American aircraft launched rockets than any of the other Japanese rockets.  However, their small propellant charges result in such low speed that their performance in no way compares with that of American rockets.

Type 98 No.7 Mk 6 Bomb Model 1
  

  

Fuzes: (w/ Magazine) A-3(a), or A-3(b)

Overall Length: 40 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 suspension lug
 

Length of tail: 18 and 3/16 inches

Width of tail: 10 and 5/8 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: Four thermite-filled electron fire pots are contained within the bomb.  The nose and tail fire pots are cylindrical, while the two in the body are semicircular.  A central channel filled with quick-match runs the length of the bomb.  A black-powder charge is located int he circular recess in the nose piece.
 

Weight of filling: 81 pounds

Total weight of bomb: 156 pounds

Charge/weight ratio: 51%

 

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

Construction of body: A cast-steel nose piece is riveted with 2 rows of 10 rivets each to a tubular steel body.  The tail cone is held by 1 row of 24 rivets to a collar which is held in the base of the bomb by 2 rows of screws (14 per row).
 

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

Operation: On impact, the magazine in the nose fuze fires the black powder and the igniting charge.  The black powder ejects the fire pots from the bomb case.  The igniting charge ignites the quick-match which initiates combustion of the thermite.

Type 98 No.7 Mk 6 Bomb Model 2

Fuzes: (w/ Magazine) A-3(a), or A-3(b)

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: Normal Navy suspension lug
 

Length of tail: 21 inches

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

 

Dimensions of tail struts:

-Length: 9 and 1/2 inches
-Width: 1 and 3/8 inches 

-Thickness: 1/16 inch

Material of tail: Sheet Steel
 

Type of filling: A central thermite core surrounded by solidified kerosene, petrol, and alcohol-soap mixture.

Weight of filling:
-20 pounds of inflammable mixture
-7.5 pounds of thermite

Total weight of bomb: 145 pounds
Charge/weight ratio: 22%

   

Color and markings: Gray overall with two longitudinal diametrically opposite thin red lines.  Red nose and red struts.  New type markings will be found.
 

Construction of body:  cast-steel nose is attached to a tubular-steel body by a continuous circumferential weld and 2 rows of 16 plug welds each.  A wood block and black powder burster charge are located in the nose.  Housed within the body is a steel cylinder which contains the incendiary filling. 
 
A central copper tube within the cylinder contains quick-match.  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 16 screws each.
 

Construction of tail: Four steel fins are welded to metal strips which are riveted (14 rivets each) to the tail cone.  The fins are braced by a single-set of box-type struts.

Operation: On impact, the magazine in the nose fuze fires the black-powder charge which shears off the tail cone and ejects the incendiary cylinder out of the bomb case.  At the same time, the quick match is ignited.  This in turn sets fire to the thermite and the inflammable mixture.

Type 1 No.7 Mk 6 Bomb Model 3 Modification 1
 

Fuzes: A-3(a)

Overall Length: 42 and 1/4 inches

Length of body: 21 inches

Diameter of body: 9 and 3/8 inches

Thickness of wall: 1/8 inch

Material of wall: Steel

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug

Length of tail: 21 inches

Width of tail: 13 and 1/4 inches

Width of tail fins: 6 inches

Dimensions of tail struts:
-Length: 9 and 1/2 inches

-Width: 1 and 3/8 inches
-Thickness: 1/16 inch

Material of tail: Sheet Steel
  

Type of filling: 182 cylindrical incendiary pellets are arranged around a central cardboard tube.  The pellets are bound together with string to form rings.  The rings surround the central tube which is filled with gray powder.  All the space in the bomb not occupied by the pellets is filled with this powder.

Weight of individual pellets: 7 ounces
Total weight of pellets: 81 pounds
Length of pellets: 2 and 1/8 inches
Diameter of pellets: 1 and 1/2 inches

Composition of pellets:
-Barium nitrate: 35%
-Ferric oxide: 28%
-Aluminum: 18%
The remainder is synthetic rubber of polysulphite type resembling "Thiokol."

Weight of igniter powder: 30 pounds

Composition of igniter powder:
-Barium nitrate: 75%
-Aluminum: 24.5%
-Oil: 0.3%
-Moisture: 0.2%

Weight of filling: 111 pounds

Total weight of bomb: 160 pounds

Charge/weight ratio: 69.4%

Color and markings: Gray overall with a 3 and 1/2-inch red band at the nose and red tail struts.  New type markings will be found.

Construction of body: A cast-steel nosepiece is attached to a longitudinally welded steel body by a continuous circumferential weld.  The nose contains a wooden block 1 and 3/4 inches thick to which a light metal gaine well is secured by three nails.

A longitudinally welded tail cone is welded to a collar which fits into the after end of the body and is held there by a single row of 16 screws.

Construction of tail: our steel fins are spot welded to the tail cone.  They are braced by a single set of box-type struts.

Remarks:
-Type 1 No.7 Mk 6 Model 3: This bomb uses the same case as that described above but differs in the filling.  It contains a high-explosive burster charge in a central tube and an explosive filling of approximately 520 wedge-shaped rubber pellets impregnated with iron and aluminum.



 

Type 3 No.25 Mk 8 Bomb Model 1
  

 

Fuzes: A-3(a)

Overall Length: 67 inches

Length of body: 39 and 5/8 inches

Diameter of body: 12 inches

Thickness of wall: 1/2 inch

Material of wall: Steel

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug

Length of tail: 27 and 3/8 inches

Width of tail: 19 and 5/8 inches

Width of tail fins: 6 and 3/8 inches

Dimensions of tail struts: None

Material of tail: Sheet Steel

  

Type of filling: Type 97 explosive

Weight of filling: 263 pounds

Total weight of bomb: 649 pounds

Charge/weight ratio: 40%

 

 Color and markings: Green band around the nose, brown band aft of green band.  Gray body and tail.

Construction of body: A cast-steel nose is attached to a tubular-steel body by a continuous circumferential weld and 12 plug welds.  A tail cone is held to a collar by 8 plug welds.  The collars fits into the after end of the body and is held there by 40 screws.

Construction of tail: The normal tail cone has been cut off 8 and 3/4 inches aft of the junction with the bomb body proper and to this has been welded a 3/16 inch steel cylinder and four 1/8 inch steel hollow tail fins.

Tail cylinder:
-Outside diameter: 5 and 5/8 inches
-Length: 18 and 5/8 inches
-Type of filling: Type 97 explosive
 
Tail fins:
-Shape of cross-section: Triangular
-Overall length: 25 and 1/2 inches
-Height: 6 and 3/8 inches
-Width at base: 2 and 1/2 inches

Reinforcement of fins:

1. A box strut made of 1/8-inch mild steel runs the length of the fin on the inside.  The box strut is 7/8-inch wide at the top and 1 and 3/4 inches high and 22 inches long.  The strut is welded along the two lower edges to the side of the fins proper and spot welded along the sides.

2. Three 1/4-inch mild steel braces, 1 and 1/2 inches wide at the top, 2 and 1/2 inches wide at the bottom and 2 inches high are welded at 5 and 1/2-inch intervals to the box strut and the sides of the fins.  The lower sides of these braces have been shaped to fit the cylinder.

3. The end of the fins is closed by a 1/8-inch steel plate welded in place.


 
 

Next Time: More IJN bombs, including cluster munitions

Soviet Satellite Country Ammunition - Czechoslovakia (Part 1)

 

Examination of Czechoslovakian Ammunition Production/Inventory

 

Czechoslovakia

At the conclusion of World War I the newly created Czechoslovak state found itself with a large munitions industry which had been built up prior to and during the war by Austria-Hungary.  As a result, Czechoslovakia became an exporter of all types of arms and ammunition.

During World War II, Czechoslovakia manufactured large amounts of ammunition for the Germans.  At the beginning of the war, eleven German division were completely equipped with Czech ordnance equipment and ammunition.  This meant even further distribution of Czech material than before.  Today, the country is still an exporter of arms and ammunition, and is the most powerful of the Satellites from the standpoint of armaments production.

Despite the ability of the country to perform original design work, it is thought that Czechoslovakia ultimately will standardize primarily on Soviet designs.  Soviet ammunition types manufactured in Czechoslovakia will probably make up a large part of future Czech ammunition stocks, and will probably also be found in many of the other Satellite countries.  In the meanwhile, existing stocks of foreign ammunition held by the Czech Army will be used for peacetime training and as an interim reserve supply.
 
The Czechs have developed two infantry anti-tank weapons since World War II.  Unfortunately, information on them and their ammunition is rather meager and contradictory.  One, the "Pancerovka," is a recoilless launcher of the "Panzerfaust" type which fires fin-stabilized HEAT projectiles.  The launcher is reported to have a caliber in the area of 45mm.  The second new weapon is called the Tarasnice.  This is a crew-served, smooth-bore recoilless weapon which utilizes a fin-stabilized HEAT round, and possibly also an HE projectile.  Its caliber is believed to be approximately 100mm.



Glossary of Czechoslovak Terms

Czech ------- Translation or equivalent 

Cervene ------- Red

Cvieny ------- Blank (literally, "training")

Dilei naplne ------- Increment Charge

Mina ------- Mortar shell

Munice ------- Ammunition

Naboj ------- Cartridge, round

Nabojnice ------- Cartridge case

OCG ------- Live shell with combination fuze (abbreviation)

OMG ------- Live shell with base detonating fuze (abbreviation)

ONG ------- Live shell with impact fuze (abbreviation)

Ostry ------- Live (round of ammunition)

Pechotni strelivo ------- Infantry small arms ammunition

Pistolovy ------- Pistol

Prachove napln ------- Propellent charge

Prubojny ------- Armor-piercing

Prubojny s tvrzenym jadrem ------- Armor-piercing with special core

Prubojny zapalny ------- Armor-piercing incendiary

Redukovany ------- Reduced (reduced charge)

Signalni naboje ------- Signal cartridge

Skolni ------- Dummy (literally, "school")

Strela ------- Bullet

Svitici ------- Tracer

Tercovy ------- Target

Tezky ------- Heavy

Trhavinu ------- Filler (for projectile)

Vyroba ------- Manufacture

Vz ------- Model (abbreviation)

Zakladni napln ------- Ignition cartridge

Zapalka ------- Primer

Zapalovac ------- Fuze

Zastrelovaci ------- Observation (incendiary ranging)

 

A. Small Arms Ammunition

 With the conclusion of World War I, the Czechs inherited a great deal of Austro-Hungarian small arms equipment, plus the facilities for its manufacture.  Within a few years after that, however, they chose the German 7.92mm as their standard rifle and machinegun cartridge, rather than the Austrian 8mm M1890 Mannlicher cartridge.  They developed a family of 7.92mm weapons which show German, French, and some U.S. influence, and exported the weapons and ammunition for them in large quantities to countries all over the world.  Therefore, Czech-made small arms ammunition is liable to be encountered in any part of the world, including the Western Hemisphere.

Czechoslovakia supplied the Germans with large amounts of materiel during World War II, and this helped to distribute Czech ammunition even more widely than before.  At the conclusion of the war, large stocks of both German and Czech-made German service ammunition were taken over by the Czech government.  This ammunition is still extensively used by the Czechs and will probably continue to be found for some time to come, as long as it is used only in normal peacetime training.  German cartridges are described in Czech ammunition handbooks, as are Soviet, as standard Czech items of issue.

The Czechs are capable of manufacturing ammunition with lacquered steel cartridge cases, and did so for the Germans.  However, so far as is known, no Czech-designed and -made cartridges in service today have steel cases.  Czech-made 12.7mm API cartridges of Soviet design have appeared with lacquered steel cases.

A 1949 commercial catalog of Zbrojovka Brno lists as available for purchase 7mm, 7.65mm, and 7.92mm rimless cartridges with a wide variety of bullets, plus the old 8mm Mannlicher (M1890) rimmed cartridge.  Twenty different types of pistol and revolver cartridges are also listed.  This nationalized firm will produce for export any caliber or type of small arms cartridge, if the order is large enough to be worthwhile.  It is known that Czechoslovakia supplied Israel and Ethiopia with small arms ammunition during the early post-World War II period i.e., 1946-1949.  In all probability Czechoslovakia has also supplied most of the Satellites and many other nations with varying amounts of small arms ammunition.  Czech commercial ammunition has long had fairly wide circulation in US trade channels.

Three significant points of interest are noted in Czech small arms ammunition design and manufacture since World War II.  The first is the recent appearance of the new 7.62mm short cartridge, which may possibly be an outgrowth of a 7.5mm short cartridge that was in development immediately after World War II.  The second point is the high muzzle velocities obtained with Czech-made 7.62mm pistol and submachinegun cartridges; up to 1,840 feet per second, when fired from the Czech 7.62mm submachinegun.  Such velocities are in the United States carbine class.  The third point of interest is the extensive use of the 7.92mm bullet with mild steel core.  This bullet seems to be modeled on the German 7.92mm SmE.  The round may be replacing both the 7.92mm light ball M23 and the 7.92mm heavy ball M34 as the standard ball cartridge for Czech 7.92mm weapons.

Current Czech manufacturers' cartridge identification markings are apparently patterned in part on the German World War II system, since 3-letter codes, like "b x n", are commonly used.

The same may be true of color markings.  Therefore, German service cartridges carried as items of issue in the Czech Army are listed below with their identifying color markings.

Caliber ------- Type designation ------- Identification Marking
 

6.35mm ------- Automatic pistol, ball ------- None

7.92mm ------- SS: heavy ball ------- Green primer annulus

7.92mm ------- SmE: ball with mild steel core ------- Blue primer annulus

7.92mm ------- SmK: armor-piercing ------- Red primer annulus

7.92mm ------- SmK. L'spr: armor-piercing tracer ------- Red primer annulus, black tip

7.92mm ------- Ls: practical ball ------- Green band across base

7.92mm ------- B: incendiary ranging (observation) ------- Black primer annulus and chrome bullet tip or black bullet with uncolored tip  

7.92mm ------- SmK(H): armor-piercing with tungsten carbide core ------- Red primer annulus, black bullet

7.92mm P.M.K.: armor-piercing incendiary ------- Black primer annulus or red band across base

7.92mm ------- Ex. Patr. S: dummy ------- Fluted cartridge case

7.92mm ------- Pl. Patr. 33: blank ------- Wooden bullet

7.92mm ------- MP43 mE: ball with mild steel core ------- Blue primer annulus

9mm ------- PP08: ball ------- None

9mm ------- PP08 mE: ball with mild steel core ------- Black bullet

9mm ------- PP08 SE: ball with sintered iron bullet ------- Black band at case mouth

9mm ------- Mauser: ball ------- None

 
 
No information is available on pre-World War II Czech small arms ammunition packaging.  The meager information on post-war packaging indicates it to be adequate, although metal liners or cans apparently are not used inside the outer wooden packing boxes, in contrast to United States and Soviet practice.
 
Cartridges are packed in cardboard cartons within the wooden box, and may be found in clips or chargers.  Boxes are apparently unpainted, except for identifying markings.  The few boxes examined to date have followed, both in construction and in markings, the pattern illustrated below.  It is possible, of course, that variations exist.

 
Czechoslovakia has shipped much ammunition overseas to foreign countries, probably often packed to the purchaser's specifications.  The Czechs are therefore probably well acquainted with all types of ammunition packaging, and they are capable of producing any type.

Next Time: Czechoslovakian small arms munitions

Imperial Japanese Navy Explosives - Bombs (Part 3)

 
 
 
Imperial Japanese Navy Explosives
 
 
 
 
 
 

Type 99 No.6 Mk 2 Bomb Modification 1

  

 

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: Normal Navy type suspension lug
 

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 3/8 inches

-Thickness: 1/16 inch

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 (approximate)

Total weight of bomb: 140 pounds

Charge/weight ratio: 60%
 

Color and markings: Gray overall with a green-tipped nose and a blue band just 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.  An anti-ricochet nose attachment consisting of a cylindrical metal ring 1/8-inch thick bent at a 90 degree angle is spot welded to the bomb at a point 1 and 1/2 inches forward of the junction of the nose and body.

The ring is 9 and 3/8 inches in diameter and 3 and 3/4 inches long.  There are two notches 7/8-inch wide and 2 and 1/4 inches deep cut into the forward edge of the ring 180 degrees apart and in line with the suspension lug.

The tail cone is attached to a collar by a continuous circumferential weld and 16 plug welds held there by 2 rows of 16 screws.
 

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



 

Type 1 No.25 Mk 2 Bomb Model 1

 

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

Overall Length: 72 inches

Length of body: 35 and 1/2 inches

Diameter of body: 13 and 3/4 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:
-First section: 21 and 1/2 inches
-Extension: 15 inches

Width of tail: 14 inches

Width of tail fins: 5 and 1/4 inches
 

Dimensions of tail struts:
Forward Struts

-Length: 5 and 1/4 inches

-Width: 2 inches

-Thickness: 1/8 inch

After Struts

-Length: 5 inches

-Width: 1 and 1/8 inches

-Thickness: 1/16 inch

Material of tail:
-First section: Sheet Steel
-Extension: Plywood

Type of filling: Type 98 explosive

Weight of filling: 317 pounds

Total weight of bomb: 572 pounds

Charge/weight ratio: 56%
 

Color and markings: Gray overall with a green band forward of a blue band on the nose.
 

Construction of body: A cast-steel nose is attached by a continuous circumferential weld and 16 plug welds to a longitudinally welded tubular steel body.  A tail cone is attached to a collar by 36 screws.  The collar is held in the base of the bomb body by a single row of 16 plug welds.
 

Construction of tail: The tail is constructed in two sections, the first section has eight 1/8-inch sheet steel fins welded to the tail cone and supported by seven steel struts.  The second section consists of eight plywood fins in steel frames supported at their inner edges by a metal cylinder 4 inches in diameter and on their outer edges by seven steel struts.  The second section is attached to the first by bolted steel plates on each of the eight fins. 

Apparently the wooden tail section is designed to come off on water impact.

 

Type 1 No.25 Mk 2 Bomb Model 1 Modification 1

 

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

Overall Length: 72 inches

Length of body: 35 and 1/2 inches

Diameter of body: 13 and 3/4 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:
-First Section: 21 and 1/2 inches
-Extension: 15 inches

Width of tail: 14 inches

Width of tail fins: 5 and 1/4 inches
 

Dimensions of tail struts:
Forward Struts

-Length: 5 and 1/4 inches

-Width: 2 inches

-Thickness: 1/8 inch

After Struts

-Length: 5 inches

-Width: 1 and 1/8 inches

-Thickness: 1/16 inch
 

Material of tail:
-First Section: Sheet Steel
-Extension: Plywood
 

Type of filling: Type 98 explosive 

Weight of filling: 317 pounds

Total weight of bomb: 585 pounds

Charge/weight ratio: 54%
 

Color and markings: Gray overall with a green band forward of a blue band on the nose.
  

Construction of body: A cast-steel nose is attached by a continuous circumferential weld and 16 plug welds to a longitudinally welded tubular steel body.

An anti-ricochet attachment consisting of a metal ring and two supporting plates is welded to the bomb at a point 1 and 3/4 inches forward of the junction of the nose and body.  The ring has a 13 and 3/4 inch diameter, is 5 inches long and 5/32-inch thick. 
 
The two semicircular supporting plates are welded to the interior of the forward end of the ring and to the nose of the bomb.  There are two notches cut into the forward edge of the ring 180 degrees apart.  One notch is in line with the suspension lug.  The supporting plates fail to meet by 7/8-inch at the two notches.

A tail cone is attached to a collar by 36 screws.  The collar is held in the base of the bomb body by a single row of 16 plug welds.
  

Construction of tail: The tail is constructed in two sections: the first section has eight 1/8-inch sheet steel fins welded to the tail cone and supported by seven steel struts.  The second section consists of eight plywood fins in steel frames supported at their inner edges by a metal cylinder 4 inches in diameter and on their outer edges by seven steel struts.  The second section is attached to the first by bolted steel plates on each of the eight fins. 

 

Apparently the wooden tail section is designed to come off on water impact.

 

Type 99 No.3 Mk 3 Bomb
  

  

Fuzes:
-Nose: A-1(b), A-3(c)
-Tail: Solid plug or D-2(a), D-2(b), or D-2(c) 

Overall Length: 24 and 1/2 inches

Length of body: 13 and 1/2 inches

Diameter of body: 5 and 3/4 inches

Thickness of wall: 3/16 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Two normal Navy suspension lugs diametrically opposed
 

Length of tail: 11 inches

Width of tail: 6 and 1/8 inches

Width of tail fins: 1 and 11/16 inches
 

Dimensions of tail struts:

-Length: 4 and 1/8 inches

-Circumference: 3/16 inch

Material of tail: Sheet Steel
 

Type of filling: Canister containing 168 phosphorus-filled steel pellets.  Picric acid in tail cone and central burster charge.
 

Weight of filling: Picric Acid - 3.5 pounds

Total weight of bomb: 70 pounds

Color and markings: Gray body and tail.  A 2-inch silver band around the nose, a 1-inch silver band on the end of the tail fins, and two red lines diametrically opposite run from nose to tail.  New markings will be found.
 

Construction of body: A cast-steel nose piece is circumferentially welded to a longitudinally welded steel body.  A canister containing the incendiary pellets is fitted inside the body.  A steel tube containing the central burster charge is screwed into the nose and extends the length of the body. 

A tail cone is circumferentially welded to a collar which threads into the after end of the body.  The tail cone is filled with picric acid.  A steel plate separates the explosive from the incendiary filler.
 

Construction of tail: Four steel fins are spot welded to the tail cone.  They are braced by a single set of 3/16-inch round struts flattened at each end and riveted to the fins.

To impart the rotary motion necessary to arm the D-2 fuzes, the ends of the tail are bent at an angle of approximately 19 degrees.

Remarks: A factory variation of the incendiary filling consists of 21 lengths of mild steel pipe, 1-inch in diameter, packed vertically in the canister.  Each length is divided into 8 equal sections by being cut completely through except for 1/4 inch of circumference left along 1 side.  The bomb contained 168 phosphorus-filled pellets.

Modification 1: A variation of this bomb listed as Modification 1 has four fins welded to the body and utilizes the new color markings.  The fins, which are 6 inches long, 1 and 1/2 inches wide, and 1/16-inch thick, are welded tot he body at 4 and 5/8 inch intervals, two between each suspension lug. 

They are offset 35 degrees from the longitudinal axis of the bomb and serve to accelerate its clockwise rotation.  The bomb is painted gray.  It has a silver nose tipped with green.  The tail struts are red.

Type 3 No.6 Mk 3 Bomb Model 1

Fuzes: D-2 series

Overall Length: 40 inches

Length of body: 23 inches

Diameter of body: 7 and 7/8 inches

Thickness of wall: 1/8 inch

Material of wall: Steel
 

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug
 

Length of tail: 17 inches

Width of tail: 7 and 7/8 inches

Width of tail fins: 2 and 1/2 inches

Dimensions of tail struts:

-Length: 5 inches

-Width: 1 and 1/2 inches

-Thickness: 1/8 inch

Material of tail: Steel
 

Type of filling: Three cylindrical steel canisters each containing 87 white phosphorus filled cylindrical steel pellets.  Each canister has a central exploder tube filled with Type 98 explosive.  A heavy wax coating covers each canister.

Dimensions of filling:
-Length of canister: 4 and 3/8 inches
-Diameter of canister: 7 and 1/4 inches
-Length of pellet: 1 and 1/4 inches
-Diameter of pellet: 1 and 1/8 inches
-Diameter of exploder tube: 1 and 7/16 inches
-Weight of individual canister: 24 pounds
  

Weight of filling: 3 canisters, 72 pounds; tail cone charge - 11.2 pounds

Total weight of bomb: 118 pounds

Charge/weight ratio: 71%
 

Color and markings: Silver nose tipped with a green band.  Body is gray overall, except for red tail struts.  Marked "Provisional designation Type 3 No.6 Mk 3 Model 1".
 

Construction of body: The bomb consists of a nosepiece, body, and tail assembly.  The conical-shaped nosepiece is welded to the body and has a steel plate welded where the fuze pocket would be.  The cavity in the nosepiece is filled with a wooden block.  The body is cylindrical in shape and is welded longitudinally. 

The tail cone is welded to a coupling ring which fits into the body and is held there by a single row of screws. A burster charge of cast Type 98 explosive is contained in the tail cone.  A perforated steel plate separates the explosive from the incendiary filling.
 

Construction of tail: The tail cone is welded longitudinally.  Four angled fins are welded to the cone and braced by a single set of box-type struts.  The angle of these fins imparts a counter-clockwise rotation in flight to the bomb, thereby arming the clockwork fuze.

Operation: Upon release from the plane the aerial burst fuze functions initiating the tail cone charge which detonates the central burster tube.  The bomb case and canisters are ruptured, scattering the incendiary pellets.  The white phosphorus is ignited when it is exposed to the air.

Type 2 No.25 Mk 3 Bomb Model 1
 

Fuzes:
-Nose: A-3(a)
-Tail: D-2(a)

Overall Length: 71 inches

Length of body: 40 inches

Diameter of body: 12 inches

Thickness of wall: 1/4 inch

Material of wall: Steel

Type of suspension: Horizontal

Suspension lug: Normal Navy suspension lug

Length of tail: 31 inches

Width of tail: 12 inches

Width of tail fins: 5 and 1/4 inches

Dimensions of tail struts:

-Width: 2 inches

Material of tail: Sheet Steel
  

Type of filling:
-Incendiary filling: 750 (approx.) steel cylinders containing an incendiary mixture
-Barium nitrate: 35.8%
-Iron oxide: 27.2%
-Aluminum powder: 13.6%
-Magnesium shavings: 10.3%
-Synthetic shavings: 13.1%

Dimensions of cylinders:
-Length: 2 and 3/4 inches
-Width: 1 and 1/16 inches
-Thickness: 1/8 inch

Packing of cylinders: The cylinders are packed in circular rows in nine perforated nitrocellulose containers.

Burster charges: Two burster charges are contained in the nose piece and in the tail cone.  The explosive is also scattered throughout the interstices of each incendiary section.

The composition of the charge is as follows:
-Barium nitrate: 75.2%
-Aluminum powder: 24.2%
-Oil: 2%

Note: Perforated steel plates in the nose and tail separate the burster charges and the incendiary filling.

Weight of filling:
-Burster charges: 73 pounds
-Incendiary filling: 300 pounds
Total weight of bomb: 550 pounds

Color and markings: Gray overall.  Silver nose tipped with green.  Red tail struts.

Construction of body: A cast-steel nose is welded to a tubular-steel body by a continuous weld and a row of 12 plug welds.  The tail cone is held by 1 row of 18 plug welds and a continuous weld to a collar which is held in the base of the bomb by 2 rows of round-headed screws, 20 in each row.

Construction of tail: Four steel fins are welded at an angle to the tail cone.  The fins are braced at the juncture with the tail cone by a steel strip welded to the underside of the bent fin and the cone.

At the after end, the fins are braced by two sets of box-type struts.  The angle of the fins imparts a counter-clockwise rotation in flight to the bomb.

Operation: The aerial burst fuze functions at a preset height.  The detonation of the burster charges ignites the inflammable trays and the incendiary cylinders and ruptures the bomb case.  The fragments are scattered over a 175 yard radius when air-burst occurs 100 feet above ground.



 

Type 3 No.25 Mk 4 Bomb Modification 1
Please make sure to read the remarks section of this entry
 

 

Overall Length: 1.9 meters

Weight of explosive: 3.5 kilograms
Diameter: 0.3 meters
Weight of propellant: 15.0 kilograms
Maximum speed: 100m/sec
Total weight: 315 kilograms

General description: Design work on this bomb was originally started in 1935, and produced the Basic 3 No.25 Mk 4 bomb, which was used for all early Japanese Navy rocket testing and research.  Production commenced on the Type 3 bomb in 1943, and a reasonable number of the bombs had been produced or were in the process of production at the end of the war.

This bomb is an example of the early ideas on the use of rocket power.  It is essentially an armor-piercing bomb, designed to utilize rocket power to increase penetration.  However, as finally produced, the bomb had a maximum velocity of only 100 meters per second, and consequently was of little value.

The bomb consists of an armor-piercing explosive nose section, a rocket motor tail section, and a cylindrical center section joining the two, and carrying the fuzes for both sections.  The armor piercing nose is of extremely heavy construction, and is fuzed in the base with a fuze incorporating a short delay.  A very small explosive charge, approximately 3.5 kilograms in weight, is used as a burster.  Type 91 explosive is used, as in all other Japanese Navy armor piercing ammunition. 

The rocket motor tail section constituted about half of the overall length of the bomb, and carried 15 kilograms of propellant of the ballistite type.  It is fuzed at its forward end for ignition of the propellant, with a fuze which operates after the bomb leaves the plane.  The tail section is equipped with standard fins for stabilization of the bomb in flight.

The cylindrical center section of the bomb has the function of joining the nose and tail sections and of carrying the fuzes for both.  Both fuzes, with arming vane extensions which project out of the side of the bomb.  Two hinged doors in the side of the bomb allow access to the fuzes.

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

Next Time: Even more Navy bombs!

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