Monday 20 June 2016

Italian Explosive Ordnance - Bombs (Part 1)








Italian Explosive Ordnance







Introduction


  
Italian bombs closely resemble Japanese bombs in that they are usually more than one-piece in construction, assembled by screws or rivets, or welded.  The Italian bomb is normally filled through the base, which is closed by a base plate attached by screws or rivets.  Normally, the tail unit fits over the base plate and is attached to the body or the base plate by screws or rivets, or, in case of the smaller bombs, by welding.  The tail units vary considerably in their design, but the tail diameter is usually the same as that of the body of the bomb to which it is attached.

Generally the bombs are of sheet steel, but some are constructed of cast aluminum alloy.  In most cases, the filling is cast TNT, but a large number have been found with an alternate filling of Amatol and TNT with aluminum powder.  A felt pad in the nose breaks the shock of impact on the explosive filler.  The bombs contain a booster, and an initiating charge in the fuze.

Normally the demolition bombs have a mild steel casing, while the armor-piercing bombs use hardened steel.  The wall thickness for the 24kg or large bombs ranges from 1/4 inch to 1/2 inch for light-cased and from 1/2 inch to 1 and 1/2 inch for heavy-cased.  This thickness varies for each bomb, increasing towards the nose.

Demolition bombs and chemical bombs, 100kg or less, usually have provision for tail fuzing only.  The tail fuzes are screwed into the base of the bomb.  These tail fuzes usually have very long arming spindles which extend the full length of the tail.  The end of the bomb tail is shaped to accommodate the arming vanes of the fuzes.  In the case of 20kg incendiary bombs, the tail unit is cut to allow the vanes to be situated half-way along the tail in order to insure limited terminal velocity for the vanes.  Nose and tail fuzing is normally used in demolition bombs of 160kg or above.

Antipersonnel bombs differ from the demolition bombs in the construction of the outer casing.  In one type, the filling is enclosed in a sheet container, on the outside of which a steel strip is wound spirally.  In another type, the filling is contained in a sheet-steel case which is enclosed by a larger container.  The space between the two containers is filled with steel fragments embedded in concrete.  These antipersonnel bombs are known as Type F and Type Mtr, respectively.

Italian bombs are either painted or galvanized as a precaution against corrosion.  The colorings are usually found on the nose and the body.  Distinguishing colors are identified as follows:


Type of Bomb ---- Body ---- Nose
Fragmentation ---- Blue ---- Red
High Explosive ---- Grey ---- Red
Antipersonnel ---- Black or Blue ---- Red
Incendiary ---- Reddish Brown ---- Red
Gas ---- Bright Yellow ---- Red
Practice ---- Grey ---- Grey
  
  



2kg Antipersonnel Bombs Types F and Mtr

 

Type F

Overall length: 6 inches
Body length: 4.5 inches
Maximum diameter: 2.75 inches
Type of filling: TNT
Weight of filling: 0.38 kilograms
Total weight: 1.72 kilograms
 
Type Mtr

Overall length: 6 inches
Body length: 4.5 inches
Maximum diameter: 2.75 inches
Type of filling: TNT
Weight of filling: 0.22 kilograms
Total weight: 1.87 kilograms

Fuzing: Tail - Type K
  
Color and markings: Overall black

Description:
-Type F: The bomb consists of a thin steel cylinder surrounded by a tightly coiled spring of rectangular cross section.  In certain assemblies of this type, the spring is enclosed by a thin case.  The object of the spring is to provide shrapnel effect.  In fragmentation, the bomb usually breaks into pieces about 1 inch by 0.2 inch by 0.18 inch.  The bomb has no tail unit.

-Type Mtr: The bomb consists of two cylinders of sheet metal.  The inner cylinder contains the explosives, and the outer cylinder is threaded at the top to take a screwed circular cover.  Between the two cylinders are small steel pellets embedded in concrete.
 
Remarks:
1. The bomb may be dropped singly or in containers.
2. These bombs are very similar to 1kg incendiary bomb and 1kg gas bomb
3. The bomb can also be used as a land mine by use of a pressure igniter.  




3kg Antipersonnel Bomb Type Mtr


Overall length: 12.1 inches
Body length: 8.2 inches
Body diameter: 2.7 inches
Tail length: 4.5 inches
Tail width: 2.7 inches

Type of filling: TNT
Weight of filling: 0.17 kilograms
Total weight: 3 kilograms

Fuzing: Nose - Type M
  
Color and markings: Overall blue or black.  Nose is painted red.
  
Description: The bomb body is thin sheet steel with a fuze adapter pressed and spot-welded into the nose.  A steel central tube, 7.1 inches long and 0.078 inches thick, contains the bursting charge of block TNT, recessed to take the base of the fuze and the detonator.  The space between the exploder container and the bomb's outside wall is filled with steel fragments embedded in concrete.  The tail is made of thin sheet metal, with four vanes strengthened by a band 0.39 inches in width.





4kg Antipersonnel Bomb Manzolini (Thermos)

  
Overall length: 12.3 inches
Body length: 7.3 inches
Body diameter: 2.75 inches
Wall thickness: 0.125 inch

Type of filling: TNT
Weight of filling: 0.67 kilograms
Total weight: 3.68 kilograms

Fuzing: Manzolini Type I and II
  
Color and markings: Overall buff or green
  
Description:  This bomb, with a steel body and aluminum top, resembles a thermos bottle.  The fuzes are very sensitive.  The fragments are lethal to 100 feet, with a maximum range of 300 yards.
Remarks:
1. Bombs fitted with self-destroying mechanism have an aluminum alloy fuze housing (visible where the fuze screws into the bomb).
2. Bomb does not explode on impact, but is designed to explode if moved, and is extremely sensitive to vibration.




12kg Antipersonnel Bombs Type F and Mtr.


Type F

Overall length: 32.4 inches
Body length: 17.3 inches
Body diameter: 3.5 inches
Wall thickness: 0.2 inch
Tail length: 14.5 inches
Tail width: 3.5 inches
Type of filling: TNT
Weight of filling: 1.93 kilograms
Total weight: 12.2 kilograms
 
Type Mtr

Overall length: 32.3 inches
Body length: 16 inches
Body diameter: 3.5 inches
Wall thickness: 0.2 inch
Tail length: 16.5 inches
Tail width: 3.5 inches
Type of filling: TNT
Weight of filling: 1.9 kilograms
Total weight: 12.88 kilograms

Fuzing:
-Type F: Nose - Type F
-Type Mtr: Nose - Type J
  
Color and markings:
-Type F: Overall sky blue; Nose: red
-Type Mtr: Overall blue or black; Nose: red

Description:
-Type F: This bomb consists of a steel container around which are wound 25 turns of square steel wire, 0.2 inches thick.  The purpose of the wire is to provide shrapnel effect in fragmentation.  The tail assembly consists of four stamped sheet-metal vanes which are spot-welded to the base of the bomb.

-Type Mtr: This bomb is very similar to the Type F in appearance, but differs in construction of the body.  The body is a double-walled steel cylinder containing steel shrapnel embedded in concrete.  In manufacturing the bomb, the concrete-shrapnel filling was poured into the base of the bomb and then the tail unit was screwed into the outer wall of the bomb.




14kg Fragmentation Bombs Types I and II


Type I

Overall length: 22.1 inches
Body length: 13.5 inches
Body diameter: 4.2 inches
Wall thickness: 0.2 inch
Tail length: 6.4 inches
Tail width: 4.2 inches
Type of filling: TNT
Weight of filling: 2 kilograms
Total weight: 14 kilograms
 
Type II

Overall length: 22.1 inches
Body length: 13.5 inches
Body diameter: 4.2 inches
Wall thickness: 0.7 inch
Tail length: 6.4 inches
Tail width: 4.2 inches
Type of filling: TNT
Weight of filling: 2 kilograms
Total weight: 14 kilograms

Fuzing: Nose - Type I
  
Color and markings:
-Type I: Overall yellow; stenciled in black P30A

IM-4-39
TNT
K


-Type II: Overall dark olive green (painted over yellow).  Red paint marks diametrically opposite on shoulders of nose and base.


Description:
-Type I: The body consists of a tubular steel cylinder on which the cast-steel nose and base sections are threaded.  A square steel wire, 3/8 inch on the side, is helically wound around the body.  The nose piece is threaded to receive the fuze.  The base has an external recess and extension rod for the tail assembly.  The tail section consists of two sheet-steel plates bent to an angle of 90 degrees and held to the extension rod.  Four pieces of wood, shaped to form a truncated cone, serve as spacers for the fins.  The assembly is held by a steel pressure cap which threads into the extension rod. 

-Type II: The body is one-piece machined steel with the nose threaded to receive the fuze, and the base recessed with an extension rod for the tail assembly.  In all other respects this type is similar to the Type I.
Remarks: Both type resemble the US 30lb Fragmentation Bomb Mk 5 in size and appearance.



24kg G.P.-H.E. Bomb
  

Overall length: 30.5 inches
Body length: 19.9 inches
Body diameter: 6.4 inches
Tail length: 14.8 inches
Tail width: 6.4 inches
Type of filling: TNT
Weight of filling: 12 kilograms
Total weight: 24 kilograms

Fuzing: Tail only - Type N-1

Color and markings: Overall grey; Nose: red

Description: The bomb is light cased, with a steel body and nose in one piece.  A sheet-metal tail including a sheet-metal strengthening band at the end, is attached to bomb by a metal band which is clamped around the body.  The suspension band is bolted around the body.

Remarks: The bomb was declared obsolete by the Italians before the end of the war.






Next Time: Italian General Purpose/High Explosive Bombs

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