British Explosive Ordnance - Introduction and Fragmentation Bombs

British Explosive Ordnance

Introduction




Note: All present-tense mentions (the British Bombs currently in service, etc) refer to the at-the-time current 1946 Technical Manual.



Designation and Classification of British Bombs

British bombs are designated by purpose, weight, and mark number.  British mark numbers, which are always written in Roman numerals, correspond roughly to the modification numbers used by the US Navy, while the British weight designation corresponds to the US Naval mark number.  Minor changes in marks of British bombs are indicated by various symbols, consisting of lower case letters, capital letters, or asterisks.


The classification according to purpose is generally indicated by the initials of the specific type.  Thus, there is a series of antisubmarine bombs designated "A.S.", a series of general purpose bombs designated "G.P.", semi armor-piercing bombs designated "S.A.P.", aircraft depth charges designated "D.C.", etc.  Occasionally, when no appropriate initials can be used, the complete name of the bomb type is employed in the designation, as "Smoke", "Practice", etc.

Therefore, in order to describe a British bomb completely, the use, weight class, and mark number must be given in that sequence; eg, GP 250lb Mk V; IB 80lb Mk IV; Smoke 500lb Mk I; SAP 500lb Mk IIC.

The following are the type classifications of British bombs and the initials used to indicate them:

Fragmentation Bombs ----- F
General Purpose Bombs ----- GP
Medium Capacity Bombs ----- MC
High Capacity Bombs ----- HC
Deep Penetration Bombs ----- DP
Semi Armor-Piercing Bombs ----- SAP
Armor-Piercing Bombs ----- AP
Antisubmarine Bombs ----- AS
Aircraft Depth Charges ----- DC
Buoyancy Bombs ----- B
Incendiary Bombs ----- IB
Smoke Bombs ----- Smoke
Chemical Bombs ----- LC
Practice Bombs ----- Practice
Infantry Training Bombs ----- IT
Target Identification Bombs ----- TI
Anti-Tank Bombs ----- AT


Construction of British Bombs

British bombs generally are highly streamlined, although the later designs, such as the MC bombs, are parallel sided, resembling the American GP bombs in external appearance.   GP and MC bombs are usually of cast, one-piece construction, although some MC bombs may be built up in welded sections of cast or forged steel.  SAP and AP bombs are always forged in one piece and heat-treated for greater strength.  The exteriors of these bombs are well machined.  HC bombs are of thin-walled, "boiler plate", construction.



Fillings of British Bombs

A great variety of main fillings are used by the British.  The most common, however, are the following: Amatol for GO, MC, and HC types; TNT for SAP; and "Shellite" for AP bombs.  RDX/TNT combinations are also commonly employed in MC and HC bombs.  Current fillings are 60/40 Amatol HC, and desensitized Pentolite or RDX/TNT for all others.


Suspension of British Bombs

British bombs are suspended by a single suspension lug attached to the bomb body by machine screws.  Later designs of British bombs, such as the MC series, are fitted with additional dual suspension lugs for carrying in American planes.  Crutches or sway bars are used with larger size bombs.


British Tail Assemblies

A unique type of tail assembly is regularly employed by the British, consisting of a sheet-steel cone with a cylindrical strut attached by means of four sheet-steel fins.  The unique feature is the fact that the arming vanes are an integral part of the tail assembly.  They are attached to the tail pistol by means of a reach rod with a fork on its lower extremity engaging a similar fork on the tail pistol.  A special short trail,. originally designed for use in American built planes, is sometimes used to permit a greater bomb load.  A third type of tail assembly, rarely used, is designed to be employed in conjunction with certain tail fuzes which have their own arming vanes.  The arming vanes on this tail assembly are omitted, and the tail cone is truncated to give clearance to the vanes on the fuze.

Tail units are attached to bombs up to 1,000 pounds by a spring clip assembly, and to bombs of 1,0000 pounds and over by means of bolts.  Since each individual bomb is provided with its own specific tail unit, the bomb designation and tail number, which are stencilled on one of the tail fins, serve as a ready means of identifying the bomb.  The word "Mark" is omitted from both the tail unit and the bomb designation.  For example, the tail unit, No. 2 Mk I, used on the GP 500lb Bomb Mk IV, should appear on the tail unit as "No. 2 . 1, GP 500lb IV".

Color Markings and Stencilling of British Bombs

The following list gives the color markings employed on loaded British bombs.


F ------  Dark green overall with red band forward of light green band on nose.


GP ------- Dark green overall with red nose band and light green body band.


MC ------ Dark green overall with red nose band and light green band on base of ogive.


HC ------ Dark green overall with red nose band and light green band on forward portion.


SAP ------ Dark green overall with a white band just forward of a red band on the nose.


AP ------ Dark green overall with nose painted light green to point of greatest diameter; white band between two red bands on nose

DP ------ Dark green overall with red band near nose


AS ------ Dark green overall with red nose band and light green band at base of ogive


DC ------ Dark green overall with red nose band and colored band indicating filling forward of the suspension lug.

B ------ Dark green overall with red nose band and green band on ogive.

IB ------ Either dull red overall or have red nose end.  Most small sizes have a bright red band between two black bands around the nose.  Large sizes have a bright red band on the body and another on the after body.

Smoke ------ Dark green overall with a red band either around the nose or the after part of the body.


LC ------ Grey overall with colored bands to indicate chemical filler
Black band - Tear Gas
Green band - Lung irritant
Yellow band - Vesicant

Practice ------ White overall with two green bands around the tail cone.
IT ------ Dark green overall with red and green bands on nose


TI -- Black overall with red band at base of ogive.  Color of band around nose plug indicates the color of the candles.  A red cross on the after part of the body indicates that explosive candles are used.

Flares and Photoflash ------ Black overall with a red band near nose.

Cluster projectiles ------ Painted an overall color according to the type of small bombs carried.


HE filled bombs were originally painted yellow by the British.  The change to dark green was made at about the same time that the United States change to olive drab.  Consequently, yellow-painted bombs may still be found.


Complete information, including weight, type, mark number, filling, date filled, filling station and lot number will be found stencilled on the outside of all British bombs.  Although the location of the various stencillings differs with different bombs, the following sketch will indicate the information to be found and its approximate location on the outside of the bomb body.






Fragmentation Bombs


Introduction

There are only two sizes of fragmentation bombs now in use by the British.  These are the 8 pound, and several different marks of 20 pound fragmentation bombs, including a modified US 20lb fragmentation bomb.

The 20lb F bomb is nose fuzed only, and is similar in construction to the 40lb GP bomb.  It may be fitted with a standard tail for purposes of stabilization, or either a standard parachute attachment, or a special small parachute for use with a 500lb Cluster Projectile No.17 Mk II may be used.  The parachute attachments are designed to reduce the bomb's terminal velocity and so insure detonation of the bomb on impact before ground penetration takes place.

Fragmentation bombs are generally painted dark green overall with a red band and a light green band around the nose end.

These fragmentation bombs are used principally against personnel.

F. 8lb Mk I (Obsolete), and Mk II (Service)

Overall length: 4.2 inches

Body length: 3.02 inches

Body diameter: 5 inches

Wall thickness: 0.125 inches

Total weight: 8 pounds (approximately)
Charge/Weight ratio: 22% (approximately)

Fuzing: Tail Fuze No. 880 or 881

Parachute No: Tray No. 12, Mk I, with parachute

Color and markings:  Dark green overall
1/4 inch red band around after part,
1/2 inch light green band around center of bomb

Body Construction: The bomb body consist of a pot-shaped, cast-steel cylinder which is open at the top,  A steel neck ring, having internal threads to receive the adapter, is welded to the open end of the body.  The parachute tray is secured to the adapter.  Extending through the adapter fuze, which is enclosed by a paper tube 2 inches in diameter, extending through the bomb body.

Parachute: The parachute is 12 inches in diameter and is encased in a cylindrical steel tray having a diameter slightly less than the maximum diameter of the bomb body.  A safety pin extends through the parachute container, and is secured by a spring clip.

Explosive Components:

Main Filling: 1 and 3/4 pounds (approx.) of TNT, or RDX/TNT 60/40;
1 and 1/2 pounds (approx.) of Amatol 50/50 or 60/40, or Pentolite/D? (When filled with explosives other than TNT, a 1/4 inch topping of TNT is added)

Remarks: The Mk I Bomb has a smaller filling hole than the Mk II.  The Mk I was never fitted or adopted for service use.

F. 20lb Stabilized Mks I and II (Obsolescent), Mk III (Service), and Mk IV (Obsolescent)

Overall length: 21.8 inches

Body length: 11.9 inches

Body diameter: 3.95 inches

Wall thickness: 0.35 inches
Tail length: 9 inches
Tail width: 3.83 inches

Total weight: 20 pounds (approximately, with pistol)
Charge/Weight ratio: 15%

Fuzing: Nose Pistol No. 29, 34, 88, or 45; Nose Fuze No. 873

Color and markings:  Dark green overall
1/2 inch red band around nose
1 inch light green band 4 inches from the nose

Body Construction: This bomb has a stream-lined, one-piece, cast-steel body, with the nose end open to take the exploder container.  The rear end is reduced to form a spigot for taking the tail assembly.  The boss on the spigot is tapped and threaded to receive the tail-securing rod.  The exploder container is cemented in position, and locked by a locking screw.

Tail Construction: A cylindrical strut is attached to the tail cone by four fines.  The tail is secured to the body by a tail rod screwed into a boss on the body spigot, and passing through a threaded adapter on the narrow end of the tail cone.  The locking nut and spring washer at both the outer and inner ends of the rod lock it in position.

Suspension:
-Mk I: Carried 12 in Small Bomb Containers, or on Light Series bomb carrier if fitted with a suspension lug.

-Mk II: Carried 12 in Small Bomb Containers, or on Light Series bomb carrier if fitted with suspension lug or band.

-Mk III: Suspension lug welded on bomb body at center of gravity for carrying on Light Series bomb carrier; can be carried 12 in Small Bomb Container.

Explosive Components:
Exploders: CE and TNT pellets. (CE only being used now)

 Main Filling: 3.3 pounds of TNT or RDX/TNT (When RDX/TNT is used, a 1/4 to 3/8 inch topping of TNT is used in the nose.

Remarks: The Small Bomb Container, 160lb, contains eight of these bombs.  The Small Bomb Container, 250lb, will hold 12 of these bombs.  These bombs are no longer being manufactured.  However, they may be encountered in the field.  They are being replaced by the 8lb fragmentation bomb.

In the Mk IV Bomb the exploder system was changed to use only CE pellets, and a special retarded tail was incorporated.

F. 20lb Parachute Mks I and II (Obsolescent), and Mk III (Service)

Same as previous entry except as follows:

Fuzing: Nose Pistol No.33

Color and markings:  Dark green overall
1/2 inch red band around body 1/2 inch from nose
1 inch light green band 4 inches from the nose

Tail Construction: The parachute tail unit consist of a tail tube with a cylindrical strut connected to its rear portion by four fins.  The parachute, which is housed in a fabric cylinder, is contained in a tail tube.  A loose-fitting metal cover in the after end of the tube is attached to the fabric cylinder.  The parachute cords are connected to a wire rope secured to an eyebolt which connects the tail adapter and the body.  The tail adapter is secured in the front end of the tail tube by four screws.  When dropped, the metal end cover in the tube is blown off by the air slip, and acts as a pilot parachute to pull the main parachute out of the tube.

 Explosive Components: Filling:
-Mk III: 3 pounds (approx.) RDX/TNT
-Mk I and II: 3.3 pounds TNT

F. 20lb For No.17 Mk II Cluster Only (Service)

Overall length: 14.5 inches

Body length: 11.9 inches

Body diameter: 3.9 inches

Wall thickness: 0.35 inches

Total weight: 20 pounds (approximately)
Charge/Weight ratio: 15%

Fuzing: Nose Fuze No. 873

Color and markings:  Dark green overall
1/2 inch red band around nose
1 inch light green band around body

Body Construction: This bomb has a stream-lined, one-piece, cast-steel body, with the nose end open to take the exploder container.  The rear end is reduced to form a spigot for taking the parachute attachment.  The exploder container is cemented and locked in position.  The No.873 Nose Fuze is locked in position by a multi-tab washer.

Tail Construction: No tail is used with this bomb, which is especially designed to be used only in the No. 17 Mk II Cluster.  It has a short parachute attachment, secured to the body spigot by a threaded stud.  The parachute tray houses an 8 inch diameter fabric parachute with six pairs of rigging lines; each pair terminating in a whipped eye.  These eyes pass through holes in the tray and are threaded onto a metal circlip(?), which is secured on the underside of the tray.  A lid over the parachute in the ? held in position by the fuze of the bomb behind it.  When the cluster opens, the air slip displaces the lid, which pulls the chute free of the tray.

Suspension: This bomb has no suspension lugs, as it is used only in the No. 17 Mk II Cluster.

Explosive Components: Two TNT, and two perforated CE pellets.

 Main Filling: 3.1 pounds (approx.) of TNT

Remarks: The bomb is issued only in clustered form, and, when clustered, the fuze has no safety pin fitted.  Hence, care should be exercised in dealing with any individual bombs which might break loose from a cluster in handling.

US 20lb Fragmentation Bomb, Modified

Overall length (fuzed): 16.2 inches

Body length: 3.64 inches

Body diameter: 11.3 inches

Wall thickness: 0.56 inches
Tail length: 4.9 inches
Tail width: 3.64 inches

Fuzing: US Nose Fuze AN-M 104, or AN-M 120

Tail No: No.14 Parachute Housing

Color and markings:  Olive drab body, yellow nose and tail

Body Construction: This bomb consists of a US 20lb Fragmentation Bomb, which has been altered by the attachment of a special British parachute housing.  The bomb consist of a cast-steel nose and tail sections threaded to a seamless steel inner tube.  Helically wrapped around this inner tube is a heavy, drawn-steel wire to provide effective fragmentation.  The nose ? sections are threaded internally; the form to receive the nose fuze, and the latter to receive the parachute housing.

Tail Construction: The British No. 14 Parachute Housing consist of a cast-aluminum tray containing a 12-inch diameter parachute.  The tray is closed by a loosely fitting metal lid to which the parachute is attached by a short loop of cord.  The shroud lines of the parachute are fitted through holes drilled around the bottom edge of the tray, and are secured by a metal ring passed through the loops of the lines.  Leading from the parachute is an arming line, spliced to the arming wire from the fuze.  Release of the parachute withdraws the arming wire from the fuze, allowing the fuze to arm after a few seconds delay.

Suspension: Although the bomb is provided with a single, U-shaped, steel eyebolt welded to the bomb body for individual suspension, these bombs will be carried by the RAF in Cluster Projectiles No. 23 Mk I and No.24 Mk I.  In these clusters the nose of one bomb bears against the parachute lid of the bone behind it, holding the lid in place until the cluster opens.  The air slip then removes the housing lid, which acts as a pilot parachute and pulls out the 12 inch diameter parachute by which the bomb is suspended.

Remarks: Because of the extreme sensitivity of the Fuze AN-M 104, an extra spring, located outside the fuze body beneath the pressure plate, is added when this fuze is employed in these bombs by the RAF.

  

Next Time:  General Purpose Bombs

French Explosive Ordnance - Mines and Traps

French Explosive Ordnance

Mines and Traps

60mm Model 1939 - Anti-Personnel Mine

Overall length: 8.25 inches
Supporting plate: 6.4 in x 4 in
Type of filling: Melinite
Weight of filling: 5 ounces
Total weight: 5.5 pounds


Description: The steel projector tube, of 60.3mm bore, is closed at its upper end by a cap with a rubber sealing washer, which is held in position by clips.  At the lower end, it is closed by a machined base plate driven into position and fixed by dowels into which a flash tube is screwed.

An igniter adapter is screwed onto the open end of the flash tube.  Located in the flash tube is a propelling charge, consisting of 0.8 grams of black powder.  Inside the projector tub, the pressed steel cap, to which is welded the fuze holder, is a push fit over the base plate.

The fuze holder is threaded externally to fit into the mortar bomb and internally to take the holder containing a detonator.  The bush containing a delay pellet is screwed into the fuze holder.  There is a small distance piece to prevent the detonator from being screwed down onto the delay pellet.  The projector tube and flash tube are fixed to a rectangular plate.  This plate is designed to fit over the hole, in which the lower part of the mine is placed, to insure that the mine remains vertical and also to prevent it from sinking if it is used with a pressure igniter.  A winged plug is provided to screw into the tail of the bomb to assist screwing it into the fuze assembly.


Operation: This mine is designed to throw a 60mm mortar bomb into the air so that it will explode at a height of between 1 foot, 7 inches, and 6 feet, 6 inches.  The flash from the cap in the igniter fires the propelling charge.  The gases produced from this charge expand into the space in the base of the projector tube and throw up the pressed-steel cap together with the mortar bomb screwed to it.  At the same time, the delay pellet is ignited and, after a delay of about 1/3 second, the detonator and the bomb are exploded.

Light Anti-Tank Mine

Overall length: 12.11 inches

Overall width: 8.11 inches

Overall height: 4.4 inches

Wall thickness: 0.5 inches

Type of filling: Picric Acid
Weight of filling: 6.09 ? (Note: No unit of measurement is given)
Total weight: 13.41 pounds
Igniter: Pressure type Models 1935 and 1936

Color and markings:
-Camouflage: Brown and Black
Markings on upper surface within fuze well: ASS, 10.39, M.F.

Description: The mine consists of a rectangular metal container loaded with picric acid.  A metal cover, which fits over the loaded container, rests on two pressure-type igniters or fuzes.  An aluminum safety ba? prevents functioning of the igniter until removed, presumable after setting the mine in the ground.

The base plate has drilling at each corner to receive the holding-down lugs.  The cover is corrugated and is strengthened internally by the two metal supports.  The mine lid is held loosely in position by the mine-cover chains which are attached at either end to the base of the mine.

Heavy Anti-Tank Mine
  

Overall length: 16.2 inches
Overall width: 9.85 inches
Overall height: 4.75 inches
Weight of filling: 3.25 pounds
Total weight: 27 pounds


Description: The mine consists of a rectangular pressed-steel base plate, to which is welded the explosive container, and a thin pressed-steel cover.  In the top of the explosive container is a single socket for the igniter, detonator, and primer.  The lid is hinged to the base plate along one side, while two wing nuts are provided on the opposite side to hold the lid shut.  The igniter is similar to that fitted in the French light A.T. mine.  Igniters of either type may therefore be fitted as follows:


Model 1935:
-Material of body and striker: Steel
Material of cap and detonator assembly: Brass
Diameter of shear pin: 0.36 inches

Model 1936:
-Material of body and striker: Aluminum
-Material of cap and detonator assembly: Aluminum
Diameter of shear pin: 0.28 inches

In arming the mine, the plug protecting the igniter socket is removed and the primer is placed in position; this latter consists of a small circular metal container with a central hole to receive the detonator.  The igniter, with detonator, is then screwed in place.


Operation: The igniter functions when a load on the mine crushes the cover and, descending onto the striker head, shears the igniter pin.  A strong steel spring then forces the striker onto the cap, thus firing the detonator, primer, and mine.  The igniter is normally supplied with a loose metal safety collar.  This collar is placed in position on the head of the igniter body during transportation to prevent any load falling on the striker head.

Next Time:  British Explosive Ordnance

French Explosive Ordnance - Bombs

French Explosive Ordnance

Bombs




Classes

French bombs may be divided into three classes.  The bombs in each class are named according to their weight, approximately in multiples of 10kg. and there follows a designation intended to differentiate several bombs of the weight.  H.E. service bombs are made of steel-hardened, forged, or drawn steel; welded sheet or cast steel.  The bomb fillings are generally as follows:

Hardened steel bombs ----- M Mn
Steel bombs ----- M Dn
Other bombs ----- D D

Fillings

The following fillings are used in French bombs:

M Mn - Trimonite (U.S.A.)
-70% melinite (picric acid)
-30% mononitionapthalene

M Dn or MFDN
-80% melinite
-20% dinitronapthalene

D D - Shellite (British)
-60% melinite
-40 dinitrophenol

Of these, "M Mn" is the most used filling for cast-steel anti-personnel bombs.  The remainder are normally filled with "M Dn", "D D" being confined to certain types which are now considered obsolete.


Flares

Flares are normally used in reconnaissance of targets or landing grounds.  They may be 10 or 30 kilograms in weight and should be used at altitudes between 1,500 and 5,000 feet.  The star burns for four or five minutes.  The smoke bomb produces, on impact, a cloud of smoke which lasts about a minute and indicates the direction of the wind.


Coloring of Bombs

1. Service Bombs
-H.E. bombs ---- Yellow
-H.E. bombs (old pattern) ---- Grey
-Flares ---- Red
-Incendiary 1kg (old pattern) ---- Blue body/Black tail
-Incendiary (new pattern) ---- Red body/Green tail
-Incendiary 10kg ---- Red body/Green tail
-Smoke ---- Black nose/Green body and tail

2. Miscellaneous Bombs
-Practice bombs ---- Yellow, blue band, or unpainted
-Instructional bombs ---- Grey or black/Blue band
-Ballast bombs ---- Grey or black/White band


Markings on French Bombs

Markings indicating manufacture are stamped on the nose of the bomb, either transversely near the nose fuze pocket or in a direction parallel to the axis of the bomb.

On mild or forged steel bombs they indicate the source of the steel, the establishments which have carried out the tempering and the manufacture, a consecutive number, the lot number, and year of manufacture.  The letter "M" shows that the bomb is of rolled steel.

On bombs of cast steel, markings indicate the foundry, the lot number, the year of manufacture, and the mark of the factory.

The nature of the explosive filling is indicated by letters 0.4 inch in height, stamped on the bomb at 0.4 inch from the nose fuze pocket.

The following markings are painted on the bombs.
In black, initials of the firm which carried out the filling, with the month and year of filling e.g. PCFD-7-22

Source and lot number of the explosive filling e.g. SF-514-20

Nature of filling
Lot number and year of filling e.g 4-22

In red, the inscription "F de Culot" on the same side as the other markings, in the case of bombs fuzed in the tail.  In addition, bombs of  100kg and over carry below all other markings a number indicating the exact weight of the bomb, to the nearest kilogram.





French Navy Bombs

Little information has been found on French Navy bombs.  Only the information in the following chart is available, except for the 125kg light case bomb, which is included in the bomb section.








10kg (P.A.) Anti-Personnel Type I and Type II

 Overall length: 21.5 inches
Body length: Unknown
Body diameter: 3.54 inches
Wall thickness: 0.5 inches
Tail length: 9.3 inches
Tail width: 5.5 inches

Type of filling:
-70% Picric Acid
-30% Mononitronapthalene

Weight of filling: 2.5 pounds
Total weight: 21 pounds

Fuzing: Nose Only
-24/31 Type H, Model 1921 R.S.A.
-24/31 Model 1925 or Model 1928

Color and markings: Overall yellow
Stamped 0.4 in. from nose fuze pocket in letters 0.4 in. in height - nature of filling.


Description: The bomb casings are single-piece steel castings, internally threaded at the nose to accommodate the tapered steel fuze adaptor.  Type II is similar to Type I, with the following exceptions: No struts are fitted to the tail unit, and strengthening is effected by pressing the lateral and longitudinal corrugations in each tail vane.  In Type I, the tail unit is formed of four similar segments riveted together, fitted over the rear of the bomb, and secured by crimping the tail cone into an annular groove out in the bomb body.

10kg (P.) Anti-Personnel Type I and Type II

 Overall length: 21.5 inches

Body length: Unknown

Body diameter: 3.5 inches

Wall thickness: 0.5 inches

Tail length: Unknown

Tail width: Unknown

Fuzing: Nose Only

-24/31 Type H, Model 1921 R.S.A.

-24/31 Model 1925 or Model 1928

Color and markings: Overall yellow

Stamped 0.4 in. from nose fuze pocket in letters 0.5 in. in height - nature of filling.

Description: 

Type I: The bomb body consists of a converted 90mm artillery shell.  A sheet-metal extension fits over the upper end of the body and is secured to it by crimping within two annular grooves machined in the body.  The tail unit is riveted to the upper half of the extension.

Type II: This bomb is similar to Type I, with the following exceptions: No conical extension is fitted, but a tail cone formed of a single-piece casting is fitted over the upper end of the bomb and is secured to it by crimping within a single annular groove.

50kg (A.) and 50kg (G.A.M.Mn.) G.P. H.E.
  

(A)
 Overall length: 39 inches
Body length: Unknown
Body diameter: 6.15 inches
Wall thickness: 0.69 inches
Tail length: 17 inches
Tail width: 7.85 inches
Type of filling: M.Dn
Weight of filling: 22 pounds
Total weight: 88 pounds

 (G.A.M.Mn)
 Overall length: 46.5 inches
Body length: Unknown
Body diameter: 7.85 inches
Wall thickness: 0.125 inches
Tail length: Unknown
Tail width: Unknown
Type of filling: M.Mn
Weight of filling: 63 pounds
Total weight: 112 pounds

Fuzing:
(A): Nose - Type H Model 1921; Tail: 3B15
(G.A.M.Mn): Tail: M. No.2

Color and markings: Overall yellow
Painted on bomb case - Type of filling and "F de Culot" if tail-fuzed only.


Description:
(A): The body of this bomb is a single-piece steel forging made from a rejected 155mm artillery shell.

(G.A.M.Mn): This bomb is made of sheet steel; it has either a longitudinal or a circumferential weld.

50kg (D.T. No.1, No.2, and No.3) G.P. H.E.

   
(No.1)
 Overall length: 46.5 inches
Body diameter: 8.25 inches
Wall thickness: 0.375 inches
Tail length: Unknown
Tail width: Unknown
Type of filling: M.Dn or D D
Weight of filling: 44 pounds
Total weight: 123 pounds

 (No.2)
Overall length: 46.5 inches
Body diameter: 7.7 inches
Wall thickness: Unknown
Tail length: 21 inches
Tail width: 10.2 inches
Type of filling: M.Dn or D D
Weight of filling: 42 pounds
Total weight: 123 pounds

 (No.3)
Overall length: 46.5 inches
Body diameter: 7.86 inches
Wall thickness: Unknown
Tail length: Unknown
Tail width: Unknown
Type of filling: M.Dn or D D
Weight of filling: 44 pounds
Total weight: 123 pounds

Fuzing:
No.1 and No.3: Tail only - 3B15

No.2: Nose - Type H Model 1921 R.S.A., Model 1925, or Model 1928.
Tail - Sch.R. Model 1938

Color and markings: Overall yellow
Painted on body - Type of filling, source, year of manufacture, etc.


Description: These bombs are single-piece forgings; No.1 made from converted 220mm artillery shells, No.3 from converted hydrogen cylinder; both made obsolete by the French.  The tail consists of four vanes fastened to teh tail cone, strengthened between the vanes by sheet metal struts.

100kg and 200kg G.P. H.E.
  

100kg
 Overall length: 56 inches
Body length: Unknown
Body diameter: 10.8 inches
Wall thickness: 0.44 inches
Tail length: 18.9 inches
Tail width: 10.2 inches
Type of filling: M.Dn or D D
Total weight: 258 pounds

 200kg
Overall length: 62 inches
Body length: Unknown
Body diameter: 14.5 inches
Wall thickness: 0.41 inches
Tail length: 27.25 inches
Tail width: 11.5 inches
Type of filling: M.Dn or D D
Total weight: 503 pounds

Fuzing:
Nose - A modified R.S.A. 30/45 Model 1930
Tail - 3B15 (100kg only) Sch. R. Model 1938

Color and markings: Overall yellow
Painted on body - Type of filling, source, etc. and "F de Culot" if tail-fuzed only.


Description: These bombs have a forged steel case.  The tail assembly consists of four vanes attached to the tail con and reinforced by struts made of strip steel.

500kg (Model 1930, No.1, and No.2) G.P. H.E.
   

Model 1930
 Overall length: 81 inches
Body length: Unknown
Body diameter: 19.3 inches
Wall thickness: 0.56 inches
Tail length: 34.2 inches
Tail width: 27.2 inches
Type of filling: M.Dn or D D
Weight of filling: 600 pounds
Total weight: 1285 pounds

 No.1
Overall length: 83 inches
Body length: Unknown
Body diameter: 21.4 inches
Wall thickness: 0.44 inches
Tail length: Unknown
Tail width: Unknown
Type of filling: M.Dn or D D
Weight of filling: 662 pounds
Total weight: 1182 pounds

No.2
Overall length: 79 inches
Body length: Unknown
Body diameter: 19.6 inches
Wall thickness: 0.625 inches
Tail length: Unknown
Tail width: Unknown
Type of filling: M.Dn or D D
Weight of filling: 595 pounds
Total weight: 1148 pounds

Fuzing:
Nose - A modified R.S.A. Mod. 1930 (except 500kg Model 1930)

Tail - 3B15 Sch. R. 1938 (500kg Model 1930 only)

Color and markings: Overall yellow
Painted on body - Type of filling, source, etc.


Description:
Model 1930: Bomb case is made of a single-piece steel forging.

No.1: This bomb is made of three sheet-steel sections welded together, presumably circumferentially.

No.2: The bomb case is made of a single-piece steel forging.

The tail assembly of these bombs consists of a tail cone with four vanes attached.

  

125kg G.P. H.E. (Naval)
  

 Overall length (w/o fuze): 61.5 inches
Body length: 36 inches
Body diameter: 12.2 inches
Wall thickness: 0.25 inches
Tail length: 26.8 inches
Tail width: 12 inches
Type of filling: TNT
Weight of filling: Unknown
Total weight: 125 kilograms (approx.)

Fuzing:
Nose: Type A
Tail: No.8

Color and markings: Unknown


Description: This bomb is light cased.  The tail assembly is secured to the bomb body by four clamping bolts which are received by four lugs on the body.  The tail unit has corrugate stiffening plates for strengthening.

40kg Fragmentation Bomb
   

 Overall length: 35.75 inches
Body length: Unknown
Body diameter: 6.25 inches
Wall thickness: Unknown
Tail length: 16.75 inches
Tail width: 7.75 inches
Type of filling: Unknown
Weight of filling: Unknown
Total weight: Unknown

Fuzing:
Nose: No.3
Tail: Unknown

Color and markings: Unknown


Description: This bomb is a converted artillery shell.  The tail unit is the cross-blade type, with the blade joined near the end of the bomb by a narrow strengthening band.

1kg Incendiaries Type A and Type B
   

 Type A
Overall length: 14.5 inches
Body length: 9 inches
Wall thickness: 0.35 inches
Tail length: 4.75 inches
Tail width: 2 inches
Type of filling: Thermite
Total weight: 1 kilogram

Type B
Overall length: 14.5 inches
Body length: Unknown
Wall thickness: 0.35 inches
Tail length: Unknown
Tail width: 2 inches
Type of filling: Thermite
Total weight: 1 kilogram

Fuzing:
Nose only - Fuzes for 1kg Incendiaries

Color and markings:
Type A: Blue body and Black tail
Type B: Red or Blue body and Green or Black tail


Description:
The bomb bodies are cylindrical castings of magnesium alloy, with the nose internally threaded to take a nose fuze.  Toward the nose, the bomb casing is perforated by two small vents, plugged with wax.  The bombs differ in tail assemblies, with Type A consisting of three sheet-metal banes supported at the ends by a circular ting and Type B consisting of a cast-alloy tail cone and eight vanes.

10kg (Model 1927) Incendiary
   

Overall length: 22.1 inches
Body length: Unknown
Body diameter: 3.54 inches
Wall thickness: Unknown
Tail length: 10.2 inches
Tail width: 5.5 inches
Type of filling: Thermite
Total weight: 1 kilogram

Fuzing:
Nose only - Fuzes for 1kg Incendiaries

Color and markings:
Type A: Blue body and Black tail
Type B: Red or Blue body and Green or Black tail


Description:

The bomb bodies are cylindrical castings of magnesium alloy, with the nose internally threaded to take a nose fuze.  Toward the nose, the bomb casing is perforated by two small vents, plugged with wax.  The bombs differ in tail assemblies, with Type A consisting of three sheet-metal banes supported at the ends by a circular ting and Type B consisting of a cast-alloy tail cone and eight vanes.

10kg Parachute Flares Old Type (A) and New Type (B)
  

  

 Type A
Overall length: Unknown (Book states Type A 10kg)
Body length: 45.3 inches
Body diameter: 4.4 inches
Wall thickness: Unknown
Tail length: Unknown
Tail width: Unknown
Type of filling: Star Composition
Weight of filling: 8 kilograms
Total weight: 13 kilograms

Fuzing:
Type A: Nose only - Time Fuze V.M.
Type B: Nose only - Time Fuze Model 1930

Color and markings:
Type A: Red overall
Type B: White overall; three grey stars painted near the head of the flare.


Description: These types of flares are very similar.  They come in weights of 10, 15, 30, and 50 kg.  The Type A is the older type and B is the newer.

Type A: The 10kg flare of this type has a body of sheet iron, tin plated.  When the fuze functions, it ignites the powder charge and this, in turn, ignites the flare composition.  At the same time the gas caused by the combustion of the powder creates sufficient pressure to eject the star and parachute through the tail of the flare, the cup of which is lightly attached to the body.

Type B: The newer type of flare is made of aluminum.  The tail cover is attached to the body by a lead strip running around the joint between the body and the tail.  The expulsion of the stars and parachute is accomplished in the same manner as in the Type A.  The head of the flare contains a ballast, as well as the powder charge which ignites and expels the contents of the flare.  The ignition of the large star is caused by the safety fuzes.  When the parachute opens, the six small stars hang around the large star.

Smoke Bomb
   

Overall length: 9.45 inches
Body length: Unknown
Body diameter: 2.75 inches
Tail length: 4.25 inches
Tail width: 3.15 inches
Type of filling: Titanium Tetrachloride
Bottle content: 100 cc

Fuzing: None

Color and markings: Green body and tail, Black nose.


Description: The casing is sheet aluminum, with the head pressed separately and soldered in several places to the body.  A glass container fits within the casing, protected from breakage by cork at the tail, felt washers along the side of the casing, and a collar supported on a helical spring at the nose.  A U-shaped safety pin holds the collar in position.  On release, the safety pin is pulled, freeing the bottle in the case.  On impact, the bottle moves forward against a spring onto four cutters in the nose of the body.

Next Time: French Mines and Traps

Italian Explosive Ordnance - Mines and Traps

Italian Explosive Ordnance

Mines and Traps

 Italian anti-personnel mines are operated by pressure or trip wires.  They were often difficult to detect, especially those operated by pressure in which only a portion of the lid or igniter may appear above the ground.  The Italians used bakelite and wood in the construction of some mines to prevent detection by magnetic instruments.

Anti-tank mines vary in appearance.  They are tubular, rectangular, or circular in shape.  Some are made of bakelite or wood to prevent detection.

Improvised mines seem to have been the Italian specialty in the field.  They used a majority of the improvised mines in Abyssinia, since the supply of standard mines was apparently limited.  Most of these mines were of wooden construction and used blocks of TNT for the explosive.  Sometimes shells were used for explosive and shrapnel for mines.

Picket Mine - Anti-Personnel Mine

Overall length (w/ picket): 17.6 inches
Overall length (w/o picket): 5.7 inches
Body diameter: 1.6 inches
Type of filling: TNT
Weight of filling: 100 grams
Total weight: 1.75 pounds

Description: The mine proper consists of a thin sheet metal cylinder around which is wound the strip metal loading.  The mine is mounted on a wooden picket and contains a 100-gram cartridge of TNT.  The mine is closed by a screw-on lid which carries the spring-loaded striker.

Riveted to the underside of the lid is the stirrup-shaped holder into the center of which is pressed the detonator-locating tube.  Passing diametrically through the lid, through slots in the side, is the aluminum cap holder, which is located in the armed and unarmed positions by the spring.  The coiled end of the spring engages in the groove in the armed position and in the groove in the unarmed position.

The loops at the ends of the cap holders enable the cap holders to be pulled into the armed position by remote control and at the same time prevent it from being pullet out completely.


Operation: To arm the mine, the striker is pulled out and a pin is inserted in the lower hold.  A trip wire is attached to the pin.  Then a detonator cap is inserted in the cap holder, and the holder pulls into the armed position.


Functioning: The trip wire is pulled, and the spring-loaded striker hits the detonator.










Mine B-4 - Anti-Personnel Mine
 

Overall length: 8 inches (approx..)
Type of filling: TNT
Weight of filling: .25 pounds
Total weight: 3 pounds

Description: The mine consists of two cylinders, one inside the other.  The space between the walls is filled with scrap metal.  The outer cylinder is flattened on one side, where there are six sharp projections for attaching the mine to a tree or post.  Two clips are provided with fireproof cord for securing the mine by special rings.

The cylinders are held together at their common base and by a cover at the top.  Into one end of the brass moulding screws a brass cap carrying the striker and the spring.  Below this, there is the percussion cap in the holder which is inserted from the side.  The lower portion of the moulding takes the detonator and the charge.  The open end of the moulding is closed by the plug.  The cavity between the brass moulding and the inner cylinder is filled with powdered TNT.  The trip release system consists of a trip-key having a ring at one end to which the cords are attached.

The key is held by the grooves in the brass cap so that it can move slightly in a direction parallel to the end of the mine.  This allows the key to fit into the groove on the striker when in the armed position.  A ring guides the cords which are wound on a bobbin, the latter being covered by a hinged flap, held closed by the pin.  The pin is used as the safety pin before setting the mine.

There is a special mechanism for detonating the mine, when a cord attached to the trip release is cut.  This mechanism is in the form of a hammer on the eye and stretching it under sufficient tension to hold the hammer at least 4 mm from the end of the trip-key.  When the cord is cut, the hammer drives the trip-key forward, releasing the striker.  This hammer is not provided on all B-4 mines.

Italian Bakelite and Wooden 1 Lb Mine - Anti-Personnel Mine

Overall length: 5.5 inches
Overall width: 2.5 inches
Overall height: 1.5 inches
Type of filling: TNT
Weight of filling (wooden): .33 pounds
Total weight (wooden): 1 pound

Description: These two mines are similar except that one case is bakelite and the other is wood.  The igniter used has a spring-loaded striker held in the cocked position by a trip-key and has a cap and detonator leading into the main charge.  The lid of the mine has, in one end, a slot which fits around the striker and rests on the trip-key.  The mine also contains metal fragmentation plates on three sides of the charge.


Operation: One to five pounds of pressure on the hinged lid presses the trip-key out of the hole in the striker.  This action releases the striker, which is driven by the striker spring into the cap, detonating the main charge.

Ratchet Mine (Railroad Mine)
 

Overall length: 9.1 inches
Overall width: 6.1 inches
Overall height: 11.8 inches
Type of filling: Unknown
Weight of filling: 5.1 pounds
Total weight: 18 pounds

Description: The mine consists of two parts: the explosive container and the housing for the ratchet mechanism.  A hinged wooden device with the leather strap is provided for carrying the mine.  The wooden base is screwed to the base of the mine, and a loop in the strap holds the ratchet winding key.

The explosive container of the mine is fitted with a short skirt which is a sliding fit over the upper portion of the housing.  The two parts are attached to each other by two bolts and held apart by two springs, which are canvas-covered to insure their free movement when buried below ground.  The bolt heads are protected by the covers.

Through the top of the housing projects a spring-loaded plunger which operates the ratchet mechanism.  The striker, which initiates the detonation of teeth on its periphery.  This latter may be set to release the striker after any desired number up to 59 depressions of the explosive container.  The setting is made by the use of a key inserted in the hole situated below the setting observation window of the side of the mine.

The mine is designed for use under railway tracks, and the ingenious use of lead shot in the hollow spring-loaded platform insures a continuous rigid underside of the railway sleeper or rail.  The lead shot is inserted before laying the mine by removal of the screw in the center of the platform.  The platform is released when the mine has been positioned by removing the retaining pin.

Repeated operations of the ratchet mechanism by successive wheels of the same train is obviated by means of a delayed return of the ratchet pawl.  Provision is made for the attachment of an additional igniter by the screw-threaded adapter in the side of the explosive container.
 

Railway Mine
 

Overall length: 12 inches
Overall height: 4 inches
Type of filling: Gelignite

Description: This mine is made of a light alloy.  The lid, which is attached to the body by four bolts, is recessed to take the four bolts with hexagonal nuts.  The lid is supported on four springs and thus holds the striker away from the detonator.

In the unarmed condition, the striker with its ring is screwed into a recess in the side of the mine.  When arming the mine, the striker is placed in position over the shoulder.


Operation: Pressure on the lid forces the springs down, and the striker pierces the detonator, setting off the main charge.

Wooden Box Mine (Anti-Tank)
 

Overall length: 9.5 inches
Overall width: 8 inches
Overall height: 3 inches
Type of filling: Gelignite
Weight of filling: 2.5 kilograms
Total weight: 3.3 kilograms

Description: The mine consists of a wooden box which houses the explosive charge, a false lid, two igniters, and a separate wooden cover.  The explosive charge smells strongly of almonds; it consist of 24 cartridges, weighing 100 grams; is 5 inches long and 1 and 1/2 inches in diameter.

In the false lid are two holes, each 1 inch in diameter to receive the igniters.  Igniters have an aluminum alloy body which tapers slightly and has a mushroom shaped head.  The head is recessed to accommodate a steel washer, through which passes the shank of the striker.  The striker spring is maintained compressed between this washer and the striker head by means of a copper shear pin.

Below the striker is the detonator and the <?> is a push-fit into the base of the igniter.  On the underside of the mine cover are two metal plates located above the igniters and intended to <?> upon the strikers.  The mine cover is held in position by two wire retaining straps, which can rotated about the pins, securing them to the mine body.  All the parts are nailed together.  The mine is creosoted inside and out.


Operation: Pressure from 185 to 380 pounds on the cover shears the copper shear pins and the springs drive the strikers onto the detonators.

Four-Igniter Mine - Anti-Tank Mine
 

Overall length: 12.25 inches
Overall width: 10 inches
Overall height: 6.25 inches
Type of filling: TNT
Weight of filling: 11 pounds

Description: Four holes in the lid of this box accommodate four igniters, and the mine is completed by the addition of a false lid which consists of a movable pressure platform attached to a wooden frame by means of canvas.

When assembled, the framework is secured to the mine body by four clips, and the pressure platform rests on top of the four igniters with the canvas fully stretched.  The whole mine is painted for camouflage.  There is a single rope carrying handle.

Two types of igniters have been used in this mine.  One consists of a bakelite cone to which a bakelite lid is cemented.  A projection below the cone fits into an ordinary detonator, and the latter is then pressed on.  Within the cone is a small paper cylinder containing small pieces of hard limestone mixed with a small quantity of a chlorate flash mixture.  Pressure on the mine lid, the bakelite cones, and friction between the hard limestone and the chlorate mixture produces a flash which ignites the detonators, initiating the mine.  The other igniter is also bakelite, but is of more robust construction.

The base of the body is screw-threaded to take the plug which retains the detonator.  The detonator contains a cap, and a thin bakelite washer is inserted above this cap to give clearance for the striker needle and to insure that the detonator is held securely by the plug.

The striker holder rests on a conical boss within the body of the igniter, and the latter is closed by a push-fit cover.  The igniter functions when pressure on the lid of the mine causes the igniter body to break down and force the needle onto the cap.  Trials have shown that the mine, when fitted with this igniter, functions under a static load of approximately 300 pounds.


Operation: Pressure on the lid causes the igniters to function, detonating the main charge.

Anti-Tank Mine B-2
 

Overall length: 3 feet 6 inches
Overall width: 5 inches
Overall height: 4.7 inches
Type of filling: TNT
Weight of filling: 7 pounds
Total weight: 33 pounds
Firing pressure (On each spring): 220 pounds

Description: This mine, the latest development of older types "S.C.G." and "hinged lid", consists of a welded sheet-metal box with a metal lid resting on two springs.  The lid has two openings covered by hinged flaps corresponding to the positions of the striker assembly and the wire-tensioning screw.

At the ends of the box are charges, each consisting of eight 200-gram slabs of TNT.  On the underside of the lid are welded two short lengths of steel tube to fit into springs; two similar lengths of tube are welded on the base of the box; all four serve to locate the springs.

The explosive compartments and the foundation of the ignition mechanism are wood.  In the center of the lid, a knife is located directly above the guides.  Through these guides passes a tension wire, fastening the striker to a brass adjustable hook.

The striker mechanism consists of a body with a slot for the percussion cap and holder, and the striker and spring.  The nut retains one end of the spring; the thread takes the nut which retains the detonator (open and toward the percussion cap);' a short length of F.T.D., and a long length of D.T.D. connecting the detonator with a second charge.

A detent with a spring provides against premature firing in the event of damage to the tension wire, and, when the lid is depressed, insures normal function by pressure on the lever, which releases the detent.  This additional safety device is not found on all types.

A safety pin placed on a hole in the body of the striker remains in position until the mine is loaded, the hinged flaps are closed, and the mine is covered with earth.  The mine functions when pressure on the lid overcomes the resistance of springs, the cutting blade descends to sever the wire holding the striker, and the lid depresses the detent lever.


Remarks:
1. Type S.C.G. differs in that the lid has only one opening and has a small charge.
 
2. Type (Hinged Lid) was the earliest type, was smaller, and was made of wood.

V-3 and V-5 - Anti-Tank Mines

Overall length: 3 feet 8.9 inches
Overall width: 2.4 inches
Overall height: 2.7 inches
Type of filling: TNT
Weight of filling: 6 pounds
Total weight: 17 pounds


Description:
V-3: The mine is made of sheet steel, its body strengthened by two partitions.  The charge extends between two firing mechanisms.  The cover is secured to the body by concave-headed nuts, engaging on actuating bolts positioned by springs resting between a nut on the underside of the cover and a plate covering the firing mechanism.

When the nuts beneath the lid are screwed down, the springs compress, increasing the pressure required to operate the mine.  Unscrewing the nuts makes the mine more sensitive to pressure, as little as 22 pound weight can be made to trip the striker.  The underside of the cover has two knives engaging in guides provided to take copper pins.  (A weight of 264 pounds is required to shear the pins.)

At each end of the body are cocking grips, pulled to cock the firing pins.  The mechanism is shown.  When the striker is held by a cotter on a U-shaped spring clip.  A percussion cap is accommodated in a holder which is inserted in a hole in the side of the mine.  The body, held there by a blade retaining spring engaging in the slot.  The actuating pin inserted through a hole in the side of the body is the connection between an actuating bolt and the U-shaped spring clip carrying the cotter.

The pressure applied to the mine cover forces down the actuating bolt against the spring which comes into contact with the actuating pin causing a U-shaped spring clip to depress against the retaining spring.  The flange thus freed allows the striker to initiate the percussion cap and fire the detonator.

V-5: Similar to V-3, except for reduction of charge to 2 pounds of cylindrical <?>hole charge, omission of shear wire, and inversion of parts so V-5 has appearance of V-3 upside down.

Pignone Type I and Type II - Bakelite Anti-Tank Mines

 
Type I
Overall diameter: 13 inches
Diameter of casing: 11.87 inches
Overall height: 5.12 inches
Type of filling: TNT
Weight of filling: 7 pounds
Activating pressure: 110 pounds

Type II
Overall diameter: 13 inches
Diameter of casing: 11.87 inches
Overall height: 5.5 inches
Type of filling: TNT
Weight of filling: 7 pounds
Activating pressure: 300 pounds

Description: The mines are constructed of moulded bakelite; both types are of waterproof design.  Metal parts in the mines when armed are:
1. The case of the detonator.
2. The brass striker pellet and its helical spring.
3. The brass bush which houses the striker pellet(?), two steel balls, and brass shear pins.
4. A perforated steel bar which slides <?> the striker from the detonator <?> the <?> position.
5. Brass tumblers in the igniter <?>
6. Nine steel helical creep springs <?> the pressure plate.
7. In Type I, the steel <?> supporting the pressure plate.

Type I:  The casing <?> is in two halves, top and bottom <?> 5/32 inch and 7/32 inch thick.  <?> a central circular chamber for the <?>.  The top is strengthened <?>.  <?> are assembled with an <?> circumferential <?> sunk joint and an inner spigoted joint.

The outer joint has rubber sealing ring and is secured by hollow plastic rivets passing through 12 pairs of lugs.  The inner joint is secured by a <?> plug threaded into the center tube formed in the top half of the casing; this joint is sealed by a rubber gasket under the flange of the plug.

The plug also gives access to the booster charge and detonator, placed in the central chamber closed at the top by the base of the igniter assembly.  A webbing carrying the handle is attached to the casing by wire loops which pass through the hollow rivets in two pairs of lugs.  There are two filler plugs threaded into 1 and 1/8 inch diameter holes in the bottom.  The holes might be adapted for anti-lifting igniters; they are, diametrically opposite, approximately 2 and 1/2 inches from the edge, but are not placed in any fixed position relative to the handle.

The igniter assembly slides in the central tube formed in the top half of the casing and is retained by a locking ring.  A rubber ring seals this joint.  The pressure plate, 5/32 inch thick, is heavily ribbed underneath and is the full diameter of the mine casing.  It rests on the top of the igniter assembly and is held in position by steel wires which are looped through four lugs, set at 90 degrees around the mine, and fastened with two plastic rivet instead of one.

The air space between the pressure plate and the top of the main casing is closed, around the circumference, by a strip of impregnated canvas fixed by two steel wires.  The igniter assembly and arming arrangement are closed by the cap screwed into the pressure plate.

Type II: The main casing is similar to that of Type I.  The pressure plate, ribbed on the underside, is only 5 and 1/2 inches in diameter; it is 3/16 inch thick.  It bears on the top of the igniter assembly, as in Type I, but on the outside circumference is held by the ring which screws into a threaded socket, formed on the top of the main casing.  The igniter assembly is sealed by two rubber rings, the latter making a joint due to the upward pressure from the helical creep springs in the igniter.

A third type of bakelite mine is stated to have been produced by Pignone.  It was similar to Type I, but smaller and having a 1 and 1/2 kilogram charge.  Because of the reduced diameter, the activating pressure was about twice the figure for Type I.  It is understood that this smaller type was not produced in any quantity.

Next Time: French Bombs