American Projectiles and Explosives - Army Practice Bombs

American Projectiles and Explosives



Practice Bombs

Army Practice Bombs

3-pound AN-Mk 5 Mod 1


See Navy Practice Bombs








20-pound M48

This is a dummy of the 20-pound Fragmentation Bomb AN-M41.  It has a two-ounce black-powder charge and uses the Fuze M110 or AN-M110A1 in the nose.  It is 21.8-inches long; weighs 19.7 pounds.  It is issued in practice bomb clusters M2 and M2A1.





23-pound M71 and M71A1


These are parachute-type practice fragmentation bombs for clustering.  They do not have a fuze or spotting charge, because of the presence of the parachute.  The parachute assembly is the M3, modified from the M4 by removal of the suspension assembly, hand assembly, and pull wire container.  M71 is 26.9 inches long; weighs 21 pounds.  M71A1 differs by the addition of the shoulder to the bomb nose.







100-pound M38A2



Overall length: 47.5 inches
Diameter: 8.13 inches
Weight (empty): 15.7 pounds
Weight (sand-loaded and spotting charge): 100 pounds


This bomb simulates a G.P. bomb of the same size.  The spotting charge is assembled in a sleeve at the base of the bomb, within the fin box.  Authorized spotting charges are M1A1, M3, and M4.






100-pound M75

Length: 47 inches
Diameter: 8 inches
Filler (hematite): 72 pounds
Total Weight: 101.3 pounds


This bomb is designed to provide a target reference for practice bombing over snow-covered ranges.  Resembling the chemical bomb of the same size, it consists of a light, sheet-metal case; a charge of red iron ore (hematite); a Burster M4; and a Fuze M108 in the nose.





100-pound M85


This model is a reinforced concrete design ordered to relieve a temporary shortage of the Practice Bomb M38A2 during the war.






Spotting Charge (Army)

M1A1

Overall length: 11.18 inches

Diameter: 3.43 inches

Weight: 4.25 pounds

Black-powder charge: 3 pounds

Bomb used in: M38A2

This type of spotting charge fits in the after end of the 100-pound Practice Bomb M38A2.  It produces a flash of flame and white smoke for observation of bombing accuracy.  When assembled in the bomb, the can of the charge protrudes two to three inches out of the bomb body.

The fuze is an integral part of the spotting charge assembly.  When the arming wire is pulled, the spring-loaded arming pin jumps out, leaving the inertia weight supported only by the combination firing pin and creep spring.  On impact, the inertia weight drives this firing pin into the shotgun-type primer, which, in turn, ignites the black powder.

M3: The Spotting charge M3 has a 2 and 1/3-pound dark smoke filling and a black-powder igniter.  It is 5/8 inches longer than the Spotting Charge M1A1, but otherwise is like it.  The M3, with its dark smoke filler, is well adapted for bombing practice over snow-covered terrain.  The black-powder igniter charge contains approximately 425 grains.  It is used in the Practice Bomb M38A2.


M5

Overall length: 7.37 inches
Diameter: 2.95 inches
Material: Glass
FS filler: 14.4 fluid ounces

The Spotting Charge M5 consists of a glass bottle filled with FS smoke mixture.  An ordinary bottle cap seals the mixture.  The bottle is held to the Practice Bomb M38A2 by a wire twisted around the neck of the bottle and attached to the tail vanes.  The charge assembly weighs 2.54 pounds.

Next Time: Guided Missiles - Introduction & Bureau of Ordnance Missiles

American Projectiles and Explosives - Explosive Bombs - "AN" Series (Part 3)

American Projectiles and Explosives



Explosive Bombs

"AN" Series

A.P. AN-Mk 33 (1,000-pound) and AN-Mk 1 (1,600-pound)

AN-Mk 33

Overall length: 73 inches
Body length: 58 inches
Body diameter: 12 inches
Tail length: 17 inches
Tail width: 16 inches

Filling: Explosive D, Cast TNT
Weight of filling: 140 pounds
Total weight: 1,025 pounds
Charge/weight ratio: 14%

AN-Mk 1

Overall length: 83.5 inches
Body length: 69.5 inches
Body diameter: 14 inches
Wall thickness: 1.3 inches
Tail length: 20.5 inches
Tail width: 20.6 inches

Filling: Explosive D, Cast TNT
Weight of filling: 215 pounds
Total weight: 1,590 pounds
Charge/weight ratio: 14%



Construction: The bodies are of single-piece, forged, machined construction, with pointed noses, parallel sides, and alight boat tailing.  The base plate is of the male type.  Suspension in the 1,600-pound A.P. Bomb Mk 1 design was by means of lugs welded to bands, the bands being positioned by grooves on the external bomb surface.  The newer designs, AN-Mk 1 and Mk 33, are suspended by fittings which screw into holes drilled into the bomb case and secured by bolts.  The normal box-type tail assembly is used on these bombs.


Filling: The main filling of these bombs is pressed Explosive "D" or cast TNT.  The tail fuze pocket requires use of the granular TNT Auxiliary Booster Mk 1.


Remarks: The later 1,600-pound A.P. Bombs Mk 1 Type were grooved to position the suspension band.  Older bombs had a stud which fitted into a hole in the bomb body.







325-, 350-pound Depth Mk 17 (TNT - Obsolete), Mk 17 Mod 1 (TNT), AN-Mk 17 Mod 2 (TNT), AN-Mk 44 (Torpex), AN-Mk 41 (TNT), and AN-Mk 47 (Torpex)

AN-Mk 17 Mod 2; AN-Mk 44

Overall length: 52.5 inches
Body length: 31.1 inches
Body diameter: 15 inches
Wall thickness: 0.06 inches
Tail length: 20.2 inches
Tail width: 20.6 inches

AN-Mk 41; AN-Mk 47

Overall length: 49.9 inches
Body length: 27.8 inches
Body diameter: 15 inches
Wall thickness: 0.06 inches
Tail length: 24.6 inches
Tail width: 15.4 inches


AN-Mk 17 Mod 2
Filling: TNT
Weight of filling: 224 pounds
Total weight: 325 pounds
Charge/weight ratio: 68.9%


AN-Mk 44
Filling: Torpex
Weight of filling: 249 pounds
Total weight: 350 pounds
Charge/weight ratio: 71.1%


AN-Mk 41
Filling: TNT
Weight of filling: 227 pounds
Total weight: 347 pounds
Charge/weight ratio: 65.4%


AN-Mk 47
Filling: Torpex
Weight of filling: 252 pounds
Total weight: 355 pounds
Charge/weight ratio: 70.9%

Nose construction: Depth Bombs AN-Mk 17 Mod 2 and AN-Mk 44 have round noses, and can use the flat-nose attachment; AN-Mk 41 and AN-Mk 47 are flat-nosed.


Body construction:
-AN-Mk 17 Mod 2 and AN-Mk 44: These depth bombs are made with round noses welded to a cylindrical steel tube.  There is a strengthening disc around the nose and a steel strip along the suspension lugs to reinforce the body.  The transverse fuze pocket is 11.9 inches abaft the nose.  To prevent ricochet and improve underwater trajectory, a flat-nose attachment is made for these bombs, the attachment being in the shape of a bucket which fits down over the nose and is filled with plaster of paris, increasing the weight of the bomb by 44 pounds.  The bomb case is extremely thin.

-AN-Mk 41 and AN-Mk 47: These bombs are constructed with a flat nose, there being a slight taper from the walls to the nose.  The body is in three pieces.  The sides are tubular with a transverse fuze pocket tube welded in place 15 inches abaft the nose.


Suspension: Suspension of these bombs is by the usual dual or single lugs, the lugs being welded to the bomb.  The single lug is actually somewhat different than is usually found, being in the form of a bracket rather than a lug.  Trunnions on a band are for displacement gear in dive bombing.


Tail construction: Instead of employing the box-type tail, these bombs use a drum tail.  As seen from the after end, it is circular and has four fins extending at right angles to each other.  The fins are spot-welded to a cone which fits over the after end of the bomb.  The fins are also spot-welded to the drum shroud.  The tail is bolted onto the base of the bomb.


Markings: TNT-loaded bombs have weight and Mark number stencilled in yellow; Torpex-loaded bombs have these items stencilled in blue.


Remarks: The 325-pound Depth Bomb Mk 17 is TNT-loaded but has a light tail assembly; the Mk 17 Mod 1 is the same, except that a sturdier tail assembly is used.  The AN-Mk 17 Mod 2 is similar to the Mod 1, but has a larger filling hole.

The Mk 17 is obsolete; the Mk 17 Mod 1, AN-Mk 17 Mod 2, AN-Mk 44, AN-Mk 47, and AN-Mk 41 are obsolescent.








325-, 350-pound Depth AN-Mk 53 Mod 1 (TNT),  AN-Mk 54 Mod 1 (HBX), Mk 53 (TNT), and Mk 54 (Torpex)

Overall length: 52.5 inches
Body length: 33.25 inches
Body diameter: 13.8 inches
Wall thickness: 0.06 inches
Tail length: 24.5 inches
Tail width: 13.9 inches


AN-Mk 53 Mod 1; Mk 53
Filling: TNT
Weight of filling: 225 pounds
Total weight: 330 pounds
Charge/weight ratio: 68%


Mk 54
Filling: Torpex
Weight of filling: 250 pounds
Total weight: 354 pounds
Charge/weight ratio: 70.6%


AN-Mk 54 Mod 1
Filling: HBX
Weight of filling: 250 pounds
Total weight: 354 pounds
Charge/weight ratio: 70%



Body construction: The cylindrical welded sheet-steel body has a flat nose.  A base closing plate is secured to the rear of the bomb by four bolts.  A base closing plate is secured to the rear of the bomb by four bolts.


Suspension: These bombs are suspended horizontally by two lugs seven inches on each side of the center of gravity, or by a single lug at the center of gravity and 180 degrees removed from the other lugs.  There is no external band, the bombs being strengthened internally by a band which is fitted into the bomb at the center of gravity.  Trunnions for dive bombing may be threaded to the case and internal strengthening band.


Tail construction: Welded to the tail cone are four vanes which are strengthened by interior box-type struts, and an exterior wide ring strut.  The tail cone is secured to the base closing plate by four bolts.


Markings: Olive drab overall.  "Mk 53 - 325 lb. Depth Bomb", "Mk 54 - 350 lb Depth Bomb" stencilled on the respective bomb bodies in yellow if the filling is TNT, or in blue if the filling is Torpex.


Remarks: These two bombs (identical except for filling) have been designed to replace depth bombs using athwartship fuzes, since difficulties have been encountered at times in the past with the Athwartship Fuzes AN-Mk 224 and AN-Mk 234.  The Depth Bombs Mk 53 and Mk 54 will use the Tail Hydrostatic Fuze AN-Mk 230 and a nose fuze, having no athwartship pocket.

The Depth Bombs AN-Mk 53 Mod 1 and AN-Mk 54 Mod 1 differ from the Depth Bombs Mk 53 and Mk 54 respectively in that the suspension lugs are welded on, instead of being of the screw type.  In addition, the walls of the explosive cavity of the two bombs are coated with an asphaltic composition known as Hot Melt.  The AN-Mk 54 Mod 1 is loaded with HBX rather than Torpex.

Only the modifications of the Depth Bombs Mk 53 and Mk 54 have been standardized as AN bombs.











1,000-pound Aircraft Mine AN-Mk 26 Mod 1 (Ground, Influence-Fired)

Overall length (w/ parachute pack): 68.5 inches
Overall length (w/o parachute pack): 64.5 inches

Diameter:
-Case: 18.625 inches
-Tail section: 15.75 inches
-Parachute pack: 18.5 inches

Filling: TNT
Weight of filling: 465 pounds
Total weight: 1,000 pounds
Charge/weight ratio: 46.5%
Negative buoyancy: 400 pounds

or

Filling: Torpex
 Weight of filling: 525 pounds
Total weight: 1,060 pounds
Charge/weight ratio: 49.5%
Negative buoyancy: 460 pounds


Construction: The 1,000-pound Aircraft Mine AN-Mk 26 Mod 1 consists of a cylindrical steel case welded with hemispherical nose and tapered tail section.  The tail is closed by a concave cover secured with cap screws.  A ring for mounting the parachute assembly is welded around the after end of the case.  The Tail Parachute Pack Mk 1, containing Parachute Mk 2, is fitted to the tail when the mine is installed in plane.  This parachute slows the fall of the mine through the air to lessen the shock of water impact, and is released from the case on striking water by an impact release mechanism.  Suspension is horizontal, two standard lugs being welded onto the body 14 inches apart and placed 90 degrees from the side pockets.

There is a removable British single-suspension lug 180 degrees removed.


Markings: Black overall


Remarks:
-Normal Use: As ground, magnetic induction mine.  Aircraft-laid, with parachute (release altitude - 200 feet or higher).  Laid offensively in depths of water from 16 feet to 120 feet against surface craft, and up to 500 feet against submarines.  Extender and clock starter are caused to function by hydrostatic pressure at depths of 16 feet or greater.  Clock delay runs off in 170 minutes to arm the mine.

-Use as bomb: This mine is poorly suited for use as a bomb, since accurate dropping by parachute is difficult; and if parachute is not used, the case tumbles.  Fuzes require longer air travel to arm than usual, because of the shape of the mine and the manner of fall through the air.






20-pound Frag. AN-M41, and AN-M41A1

Overall length: 19.5 inches
Body length: 11.3 inches
Body diameter: 3.6 inches
Wall thickness: 0.56 inches
Tail length: 9.26 inches
Tail width: 5.1 inches
Tail weight: 1.6 pounds

Filling: TNT
Weight of filling: 2.7 pounds
Total weight: 20.3 pounds
Charge/weight ratio: 13%



Body construction: This bomb is constructed of cast-steel nose and tail pieces, a seamless steel inner tube, and a helically-wrapped drawn steel wire wrapping around the inner tube.  The tube is threaded to hold the nose and tail sections.


Suspension: For individual suspension of this bomb, a U-shaped eyebolt of steel is welded to the body at the center of gravity for horizontal suspension, and an eyebolt is welded to the tail for vertical suspension.

The bomb may be dropped in a cluster of six bombs in the Cluster Adapter AN-M1A2 or M1, forming the Cluster AN-M1A1 or M1.  The cluster adapter is made of sheet steel, and does not use eyebolts of bombs for suspension.


Tail construction: Four rectangular sheet-steel vanes are welded to a length of one-inch cast-iron pipe which screws into the base filling plug.


Remarks: This bomb is a high-level fragmentation bomb and should be dropped from a minimum altitude of 400 feet.

The A1 modification of this bomb consists of adding a 1 and 1/2-inch shoulder around the nose to facilitate clustering with unfuzed bombs.  Heretofore, the spacers of the cluster adapter have fitted against the fuze, thereby making it requisite that the bombs be clustered and shipped with fuzes inserted.








23-pound Para-Frag. AN-M40, AN-M40A1, M72, and M72A1

Overall length: 26.7 inches
Body length: 11.3 inches
Body diameter: 3.6 inches
Wall thickness: 0.56 inches
Tail length: 13.9 inches
Tail width: 4.35 inches
Tail weight: 5.3 pounds

Filling: TNT
Weight of filling: 2.7 pounds
Total weight: 24.5 pounds
Charge/weight ratio: 11%



Body construction: These bombs are constructed of cast-steel nose and tail pieces, a seamless steel inner tube, and a helically-wrapped drawn steel wire wrapping around the inner tube.  The tube is threaded to hold the nose and tail sections.


Suspension: For individual suspension of these bombs, a U-shaped eyebolt of steel is welded to bomb at the center of gravity.

The 23-pound Para.-Frag. Bombs AN-M40 are always clustered, three of the bombs with the Cluster Adapter AN-M3 forming the Cluster AN-M4.

The 23-pound Para.-Frag. Bomb M72 is a slightly modified version of the AN-M40.  It is adapter for individual suspension and can be carried in vertical cellular racks by several types of Army planes.


Tail construction: The 23-pound Para.-Frag. Bombs AN-M40 and M72 are fitted with cylindrical sheet-steel parachute housings which have end caps at the rear end and contain a white silk parachute.  The Parachute Unit M3 is used in the Para.-Frag. Bombs AN-M40 and AN-M40A1; the Parachute Unit M4 in the Para.-Frag. Bombs M72 and M72A1.


Remarks:  The AN-M40 and M72 are low-level fragmentation bombs and should be dropped from a maximum altitude of 400 feet.


The A1 modification of these bombs consists of adding 1 and 1/2-inch shoulder around the nose of the bomb to facilitate clustering with unfuzed bombs.  Heretofore, the spacers of the cluster adapters have fitted against the fuze, thereby making it requisite that the bombs be clustered and shipped with the fuzes inserted.  Bombs with this modification are designated the 23-pound Para.-Frag. Bombs AN-M40A1 and M72A1.






Fragmentation clusters and cluster adapters



Cluster AN-M1A1, Cluster Adapter AN-M1A2: This cluster, consisting of the Cluster Adapter AN-M1A2 or M1 and six Fragmentation Bombs AN-M41, is made of sheet metal and does not use eyebolts for suspension.


Cluster AN-M1A2, Cluster Adapter AN-M1A3: With the modification of Fragmentation Bombs AN-M41 to permit fuzing in the field, the following changes are made in the Cluster Adapter AN-M1A2: (1) flat springs are substituted for the fuze lock plates; and (2) the suspension lugs are changed from a strip type to a type similar to those on G.P. bombs.  The new lugs were designed to permit suspension of the clusters in all existing types of bomb racks.  The modified cluster adapter becomes the AN-M1A3, forming, with six Fragmentation Bombs AN-M41A1, the Cluster AN-M1A2.

If the modified Cluster Adapter AN-M1A3 is used with unmodified Fragmentation Bombs is used with modified Fragmentation Bombs AN-M41; or the unmodified Cluster AN-M1A1 is used with modified Fragmentation Bombs AN-M41A1; or the unmodified Cluster Adapter AN-M1A1 is used with unmodified Fragmentation Bombs AN-M41, no change will be made in the designation of the Cluster AN-M1A1.  The bombs, in these latter cases, will be fuzed when the bombs are clustered at the loading plant.

The unmodified Fragmentation Bomb AN-M41 with Cluster Adapter AN-M1A1 is not suitable for Navy use.  The modified Adapter AN-M1A2 can be used, and the cluster is designated S1ZVL.


Cluster AN-M4, Cluster Adapter AN-M3: The cluster Adapter AN-M3 and three Fragmentation Bombs AN-M40 form the Clsuter AN-M4.


Cluster AN-M4A1, Cluster Adapter AN-M3: When Para.-Frag. Bombs AN-M40A1 are clustered, the Cluster Adapter AN-M3 is still used without any alteration in design, but the designation of the cluster is AN-M4A1.


Cluster M26, Cluster Adapter M13: The Fragmentation Bomb Cluster M26 consists of a Cluster Adapter M13 to which are secured twenty 20-pound Fragmentation Bombs AN-M41A1, in two groups of ten.  The cluster is 53 and 1/2-inches long, 14 and 11/16-inches wide, and 13 and 3/4-inches high.  The cluster adapter is a steel framework consisting of a tubular suspension bar to which the suspension lugs are fitted, steel separator plates, and two metal straps secured by release buckles.  The separator plates located before each group of the bombs are built with arming vane stops for the Nose Fuzes M110A1 used in the individual bombs.  The cluster can be adapter for either quick or delayed opening.

Quick opening is accomplished by the arming wires, which are fed through the release buckles and are withdrawn on the release of the cluster from the plane.   In delayed opening, a Mechanism Time Nose Fuze M155 (T71) or M1111A2 is screwed to the fuze adapter in the forward end of the tubular suspension bar.  When the fuze detonates at the preset delay, the explosion drives a steel slug rearward to cut the shear wires in both the forward and the after release buckles, thereby permitting the cluster to open.

Tumbling of the Cluster M26 prevents the Nose Fuze M111A2 from arming correctly, and therefore the fuze has been modified by the substitution of an anemometer-type arming vane for the standard vane.  So modified, the fuze is known as the T77.  Modification can be accomplished in the field by kits now being issued.








220-, 260-pound Frag. AN-M88 (220-lb) and AN-M81 (260-lb)

AN-M81
Overall length: 43.7 inches
Body length: 32.8 inches
Body diameter: 8 inches
Wall thickness: 1 inch
Tail length: 11 inches
Tail width: 11.5 inches
Tail weight: 4.1 pounds

Filling: Composition B
Weight of filling: 34.1 pounds
Total weight: 260 pounds
Charge/Weight ratio: 14%



AN-M88
Overall length: 43.7 inches
Body length: 32.8 inches
Body diameter: 8 inches
Wall thickness: 1.25 inches
Tail length: 11 inches
Tail width: 11.5 inches
Tail weight: 4.1 pounds

Filling: Composition B
Weight of filling: 46.9 pounds
Total weight: 216.17 pounds
Charge/Weight ratio: 21.6%


Construction: The Fragmentation Bomb AN-M88 differs from the M81 only in that it has a 0.75-inch steel coil steel coil around the body instead of the one-inch coil.  Both bombs are constructed in these two ways.  In initial production, nose and tail pieces are of cast-steel construction and screw onto a central section of seamless steel tubing.  A square helical steel spring is wound around the steel tubing.  The nose and tail pieces are partially cut through to afford greater fragmentation (this is similar to the M82, except for the provision for tail fuzes and the Auxiliary Booster M104 in the larger bombs).  The majorite of AN-M88's and M81's however, have a one-piece steel tubing, and the helical steel spring is wound around the steel tubing, for the entire length of the body.

Suspension is horizontal; two eyebolts are welded to body along the longitudinal axis of the bomb, 14 inches apart.  A third eyebolt is welded to the body at the center of gravity 180 degrees removed from the other eyebolts.  The tail is the normal box type, secured to the bomb by a locking ring.


Remarks: The initial bombs were filled with TNT; later productions are filled with Composition B with TNT surrounds.

Present production of these bombs does not include Auxiliary Booster M104, as this was found unnecessary.

Next Time: Army Experimental Types, and Introduction for Chemical, Incendiary, and Smoke Bombs

British Explosive Ordnance - Obsolete Bombs

British Explosive Ordnance

Obsolete Bombs Introduction


The various bombs of different types included in this section have all been declared obsolete, but because of the possibility that they still may be encountered, it is deemed desirable to give complete information regarding them.

Older obsolete bombs, included only as a matter of interest, are listed in chart form at the end of the chapter.









AT 9lb, Mk I  (Obsolete)

Overall length: 14 inches
Maximum body diameter: 4 and 1/2 inches squared

Total weight: 8.5 pounds
Charge/weight ratio: 80%

Fuzing: Tail Fuze No.847
  

Color and markings:  Dark green overall,
1/2-inch red band around nose.

  

Body Construction: The body is made of thin metal, approximately rectangular in shape, having a square cross section with rounded corners.  It tapers slightly from the rear toward the nose.  The body is closed at the nose end by a front cover housing a nose cup, which is taped and cemented in place.  The nose cup of the rear bomb forms a safety device for the fuze in the front bomb of a pair, as bombs are dropped in pairs.  The rear cover is located approximately in the middle of the bomb.  The bomb incorporates a steel, cone-shaped charge.


Tail Construction: The tail is integral with the body, being only a continuation of the thin metal case.  The rear bomb of a pair has a retarder plate to pull the rear bomb free of the front one when dropped from the container.  The tail also has a safety tube of light-gauge metal with a  cardboard inner sleeve, forming a safety device for the fuze of the rear bomb of a pair.  A locating plate near the rear of the safety tube locates the tube in the tail of the bomb.

 
Suspension: These bombs are carried in the 250lb Small Bomb Container, which holds 24 bombs.  They are loaded in pairs, with the nose of the rear bomb houses in the tail of the front bomb.


Filling:
-Exploder: CE pellet housed in the bottom of the exploder container
-Filling: Nobel's explosive No.808, with shaped charge effect.


Remarks: The bomb is designed for use against tanks and armored vehicles.  It will blow a hole approximately nine inches in diameter in armor plating 2 inches thick, and is effecting at striking angles up to 45 degrees.

The 9lb AT Practice Bomb Mk I is approximately the same shape, size, and filled weight, and has the same approximate ballistic characteristics.  However, it has neither exploder nor detonator.  Its body breaks up on impact with the target to release a white filling, clearly visible from the air.

HE 20lb Mk I (Obsolete)

   

Overall length: 25 inches
Body length (w/o tail adapter): 11 inches (approx.)
Body diameter: 5.175 inches
Tail length (w/ tail adapter): 12 inches (approx.)
Tail width: 6 inches (approx.)

Total weight: 27 pounds (approx.)
Charge/weight ratio: 20% (approx.)

Fuzing: Nose Pistol No.16
  

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

  

Body Construction: The bomb has a steel, semi-steel or malleable-iron body, hollow and open at both ends, with the forward end threaded internally to receive the nose adapter, and the after end internally threaded to take the tail adapter.  The nose adapter has three different-sized threads, to take the detonator-holder and the exploder container from the rear,a nd the pistol from the front.  The flange of the nose adapter is externally threaded to receive a screw-on pistol cover.  The tail adapter is tapered to conform to the rearward streamlining of the body, with a central bore threaded to receive the tail rod.


Tail Construction: The bomb has a wooden tail cone, conforming to the streamlined shape of the body.  Two diametrical saw-cuts at right angles extend from the after end, over a slightly greater length than that of the tail vanes, to accommodate the four sheet-metal tail vanes, which are made in integral pairs.  The tail cone is bored axially to take the tail rod, and fits into the cavity in the tail adapter.


Suspension: A wrought-iron or mild steel suspension lug is riveted to the bomb body.


Filling:
-Exploder: 3 sold and 1 perforate CE pellets.
-Filling: 5 pounds (approx.) TNT


Remarks: This bomb was intended for attacking personnel, air strips, and road transports.

RL 112lb Mks V, VI, and VIII (Obsolete)
   

   

Overall length: 18 inches
Body diameter: 8 inches
Wall thickness: Solid body

Total weight: 10 pounds

Fuzing: Nose Pistol No. 8 Mk I, or Nose Pistol No.19 Mks I and II; Tail Pistol No.5B Mks I and II
  

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

  

Body Construction: The body of these bombs is a single streamlined casting, steel for Mks V and VII and iron for Mk VI, threaded at the nose and tail to take adapters for the central exploder tube.


Tail Construction:
Mk V: The tail of the Bomb Mk V consists of four tail fins, which fit over the body and are fastened in place with screws.  Two sets of box-type struts reinforce the tail fins.


Mks VI and VII: The tail assembly of the Bombs Mk VI and Mk VII consists of a tail cone, which slides over the after end of the bomb body and sis secured by a locknut on the exploder tube.  Four tail fins are riveted on the cone and are held in place by two sets of box-type struts.


Suspension: The Bomb Mk V has a U-shaped eye-bolt secured to the body with screws at the center of gravity.

The Bombs Mk VI and Mk VII have a U-shaped eye-bolt fastened to a suspension band around the center of gravity.


Filling:
-Exploder: TNT and CE pellets
-Filling: Amatol 80/20, or TNT
  

GP 120lb Mks I and II (Obsolete)
     

Overall length: 42.4 inches
Body length: 21.5 inches
Body diameter: 8.1 inches
Wall thickness: 0.5 inches
Tail length: 15.7 inches
Tail width: 8 inches

Total weight: 120 pounds (Amatol 80/20)
Charge/weight ratio: 25%

Fuzing: Nose Pistol No.19; Tail Pistol No.21
  

Color and markings:  Yellow overall,
1/2-inch red band around nose and 1 inch light green band around body,
longitudinal green bar on body and tail indicates explodering scheme..

  

Body Construction: The body is a streamlined steel casting or forging, threaded at the nose to take the nose adapter, which holds the central exploder tube.  At the other end of the casting is a threaded base plug through which the exploder tube passes.  Welded to the end of the casting is a streamlined section of thin metal, containing no explosive, which is tapered to take the tail ring.  The exploder passes through this section also.


Tail Construction: A truncated cone fits over the rear section of body and is held to it by a locknut over the exploder tube.  Three mild-steel fins are fastened to the cone, and are reinforced by a cylindrical strut.


Suspension: The bomb uses a single suspension lug secured to the body by four screws.


Filling:
-Exploder: TNT and CE pellets
-Filling: 36.5 pounds TNT, or 30 pounds Amatol 80/20

 

GP 500lb Mks I, II and III (Obsolete)
     

Overall length: 68.7 inches
Body length: 35.7 inches
Body diameter: 13 inches
Wall thickness: 7/8 inches
Tail width: 13 inches

Total weight: 509 pounds (TNT)
Charge/weight ratio: 28%

Fuzing: Nose Pistol No.19; Tail Pistol No.17 or 22
Tail No.: No.1 Mk I (Mk III bomb only)
  

Color and markings:  Yellow overall,
1/2-inch red band around nose and 1 inch light green band around body,
light green bar on body and tail indicates explodering scheme..

  

Body Construction: The body is a streamlined steel casting or forging threaded at the nose to take the nose adapter, which holds the central exploder tube.  At the opposite end is a threaded base plug through which the exploder tube passes.  Welded to the after end of the body is a streamlined cone of thin metal, containing no explosive, which is tapered to take the tail ring.  The exploder also passes through this section.


Tail Construction: The tail has a truncated cone, which fits over the rear section of the body and is held to it by a locknut over the exploder tube.  Four mild-steel fins are fastened to the cone, and are reinforced by a cylindrical strut.


Suspension: The bomb is suspended by a single suspension lug secured to the body by four screws.


Filling:
-Exploder: TNT and CE pellets
-Filling: 143 pounds TNT, or 134 pounds Amatol 80/20

Remarks: The tail fins are usually painted red when time pistols are used.

HC 2000lb Mk I (Obsolete)

   
Overall length: 162 inches

Body length: 99.5 inches

Body diameter: 18.5 inches
Wall thickness: 0.19 inches
Tail length: 60 inches
Tail width: 18.6 inches

Total weight: 1842 pounds
Charge/Weight ratio: 73%

Fuzing: Nose Pistol No.27, 42, or 44
Tail No.: No.32 Mk I, or No.10 Mk I or II, or Parachute Attachment
  

Color and markings: Dark green overall,
1/2-inch red band 3 and 1/2 inches from front edge of cylindrical shell,
2-inch light green band 16 inches from edge.

Body Construction: The body consists of a cylindrical steel shell with a hollow, conical nose piece welded to one end, parallel sides, and a closing plate bolted to an angle ring which is welded in position a short distance within the other end.  A radial strengthening band is welded internally at the center of gravity, and its ends are welded to a steel block.  Holes tapped through the shell and steel block receive the suspension lug screws.  Side pockets for supplementary fuzing are present near the base end, but are not used.  The shell is strengthened longitudinally by two channel beams welded to each end of a central steel block and to the shell interior.


Tail Construction: The Tail No.32 Mk I assembly consists of a cylinder of light-gauge metal with a metal tray secured in its forward end and a strengthening ring in its open rear end.  The tray has a series of equispaced bayonet dogs for attaching to the body bayonet joints welded to it.  The cylinder has a number of openings to give it stability.

The parachute attachment has a parachute 5 feet, 6 inches in diameter, attached to a metal tray having bayonet dogs for attaching it to the body.  The parachute is retained by waterproofed fabric and a retaining pin.  The retaining pin is attached to a static cord stitched on the outside of the last protective panel, and connected to the bomb carrier or aircraft.  On release the cord pulls the retaining pin and chute free, and breaks off from the plane when the chute is extended.
 

Suspension: The bomb is suspended by a single suspension lug bolted to the body and an internal steel block at the center of gravity.  The screw holes are closed by transit screws until the bomb is to be used, at which time the lug is attached.
  

Explosive Components:
Exploders: A central exploder tube extends from the nose exploder container.  The tube contains eight 33 and 1/4 ounce TNT exploders.  The exploder container contains a 9 ounce TNT exploder.

Filling: 1340lb Amatol 60/40 sealed at each end with an approved composition


Remarks: This bomb may be fitted with a nose attachment of light-gauge metal to retard the bomb in flight.  It consists of a cylinder fitting over the forward end of the body shell and projecting forward beyond it around the conical nose piece.  Two side fuzing pockets are usually not used, but might contain the Time Pistol No.47.

 

AS 35lb Mks I and II (Obsolete)

Overall length: 29.2 inches

Body length: 17.2 inches

Body diameter: 7 inches
Wall thickness: 0.064 inches
Tail length: 17 inches (approx.)
Tail width: 7 inches

Total weight: 35 pounds
Charge/Weight ratio: 46%

Fuzing: Nose Fuze No.866
  

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

Body Construction: The bomb has parallel sides, with a nose adapter and a tapered rear section.  A tail adapter secures the tail to the body.  The explosive charge is cone shaped, employing the principle of Munroe shaped charge.  A cylindrical nose attachment is welded onto the nose adapter by four tack welds.  The exploder is in the rear of the body, and is initiated by a flash from the nose fuze, communicated through the supporting tube extending from the nose cavity to the exploder.


Tail Construction: The tail consists of a long hollow tube with a cylindrical strut attached to it by six fins.  The tail threads into the tail adapter, and is secured by a locking screw.  The six fins are formed by three sets of W-shaped supports welded to the tail tube.
 
Suspension: The Bomb Mk I has a single lug for suspension in aircraft.  The Mk II has no lug, as it is intended to be fired from shipboard.
  

Explosive Components:
Exploder: CE pellets
Filling: 16lb RDX/TNT 60/40.  The after end is sealed by a 1/4-inch topping of TNT.

Remarks: The Bomb Mk I was designed for use by Coastal Command and was intended to be dropped from aircraft.  The Bomb Mk II has no suspension lug, and is intended for spigot projection from ships.



 






DC 450lb Mk VII (Obsolete)

Overall length: 67.25 inches
Body length: 27.75 inches

Body diameter: 17.5 inches
Tail length: 32 inches (approx.)
Tail width: 17.5 inches

Total weight: 450 pounds
Charge/weight ratio: 64%

Fuzing: Mk X** pistol and depth adjuster
  

Color and markings: Dark green overall with circumferential red and green bands

Body Construction: The body consists of a welded cylindrical case, closed by two covers connected by a central tube called the primer tube.  This tube, housing the primer, pistol, and depth adjuster, has an internal diameter of 3.5 inches.  Three lifting eyes with rings are provided, one on the cover at the primer end, and two on the cover at the opposite end.  The cover at the primer end has two filling holes which are closed by bungs.  It may or may not have a nose attachment and tail.  The bomb is carried on aircraft with the primer end forward, except when fitted with the parachute attachment, in which case the pistol and depth adjuster are forward.


Nose Attachment: The bomb may use a hemispherical hollow nose held on by the side straps, which also secure the tail assembly.


Tail Construction: The tail, when fitted, consists of a cylindrical strut attached to a hollow tail cone by four fins.  Three brackets, equispaced around the cone, are fitted to take the ends of the straps which secure the nose and tail attachments, both of which break off on impact with water.  The bomb may have a parachute attachment on the primer end if dropped from high-speed aircraft.

 
Suspension: The bomb is suspended by a single lug on a suspension band around the center of gravity.


Explosive Components:
Filling: 290lb Amatol

IB 25lb Mks I and II (Obsolete)

Overall length: 32.6 inches
Body diameter: 5.03 inches

Tail length: 13.55 inches

Total weight: 25 pounds

Fuzing: Simple impact striker
  

Color and markings: Dull red overall,
two 1/2-inch black bands separated by 1/2-inch red band painted around the nose.

Description: The Bomb Mk I consists of a cylindrical steel tube secured to a hollow, sharp-pointed nose by a nose adapter (built up externally to streamlined form by a cardboard fairing), a column of seven closed containers, termed fire-pots, accommodated in the body tube, a flanged base adapter which affords a mounting for a cap holder, a tail cone with a cylindrical tail vane secured to it by four vane supports, and a tail tube which accommodates a striker pellet, with a shear wire and creep spring, and a safety rod.

Each of the seven fire-pots consists of a cylindrical container made of magnesium alloy and formed with a central tube, which communicates, through a fire hole, with a recess in a central boss on the base of the container.  The container is closed by a magnesium alloy lid, which has a shallow central recess in its outer side.  Holes through he lid place this recess in communication with the interior of the container.  The ignition cap contains a layer of gunpowder and a layer of detonating composition.

The central tube of each of the fire-pots houses a delay charge and is surrounded by a delay charge and a priming charge for the thermite and magnesium filling, which occupies the remainder of the annular chamber in the fire-pot.  A loop of quickmatch extends into the bore of the central tube and has its two ends carried out through the slots in the tube and through two of the holes in the lid.  An ejection charge of gunpowder is retained in the recess in a central boss of each fire-pot by a paper disc, which is secured in position by shellac.

The tail cone fits over the flange of the base adapter and is held assembled to the bomb body by a tail nut, which screws onto the rear end of the tail tube against a tail adapter.  The tail adapter fits into the rear end of the tail cone.

The striker pellet has a sharp point at the forward end and is held in the safe position by a shear wire passed through holes in the striker pellet and tail tube.  The ends of the shear wire are soldered to prevent removal.  The rear end of the striker pellet receives the forward threaded end of the safety rod.  The creep spring is house in the forward end of the tail tube and bears against the cap holder and the striker pellet.  The safety rod passes through the tail tube and is screwed into the threaded bore of the striker pellet.

The Bomb Mk II has only a slight difference in the tail plate.


Parachute Attachment: Either a Parachute Attachment No.1 Mk I or a No.1 Mk II may be used with this bomb.  The Attachment No.1 Mk I consists of a small parachute housed in a container of sheet metal, consisting of a cylindrical housing plate and a cover.  It fits loosely in the cylindrical strut of the bomb tail.  The chute is 15 inches in diameter and vented at the peak.  The Attachment No.1 Mk II is similar, except that it is housed in a collapsible cardboard container between cardboard packing discs.


Striker Attachment: There are two striker attachments, the No.1 Mk I, and the No.1 Mk II.  No.1 Mk I consists of a coupling fork, snatch rod, striker rod, coupling socket, and a retaining sleeve, which houses a spring.  The No.1 Mk II is similar, except that the coupling fork is fitted with a quick-release pin.


Functioning: Whent he bomb using the Parachute and Striker Attachments No.1 Mk I is released, the cover pulls the chute out.  The chute opens and pulls the snatch rod against the action of the spring until the striker rod retaining balls escape into the annular recess in the retaining sleeve.  The striker rod then moves down against the striker pellet.  On impact, the inertia of the rod and pellet combine to shear the shear wire, overcome the creep spring, and pierce the ignition cap, igniting the blowing charge and blowing the base adapter and complete tail and parachute assembly from the body tube.  The quickmatch, which passes through the lid and into the central tube of the rearmost magnesium alloy fire-pot, is also ignited, and, in turn, the quickmatch ignites the delay charges in and around the central tube of the fire-pot.

While the central tube delay charge is burning through, the outer delay charge initiates the surrounding priming charge, which, in turn, ignites the incendiary composition around it.  Meanwhile, the central delay charge burns through and fires the ejection charge in the base of the fire-pot.  This has the effect of ejecting the activated fire-pot from the bomb and also igniting the quickmatch of the second fire-pot, etc.  Each ejected fire-pot will continue to burn for approximately 10 minutes; the magnesium alloy container and lid being consumed.

Finally, the quickmatch in the lod closing the nose of the bomb is ignited by the last ejection charge and initiates the priming charge, which, in turn, ignites the incendiary composition of the nose, and provides an additional fire source.

When used with the Parachute and Striker Attachment No.1 Mk II, the parachute is blown out of the cylindrical shroud on the tail and the chute opens, freeing the striker mechanism.  Functioning after this is the same as that with Attachments No.1 Mk I.

Suspension: The bombs may be carried in a Small Bomb Container, or from a bomb carrier by a lug on a suspension band.


Explosive Components:
Filling: 1lb Thermite, and 5lb, 4oz Magnesium

IB 250lb Mks I and II (Obsolete)



Overall length (w/o fuze): 61 inches (approx.)
Body length: 34.1 inches

Body diameter: 12 inches
Tail length: 27.2 inches
Tail width: 11.7 inches
Fuel weight: 68 pounds

Total weight: 193 pounds

Fuzing: Nose Fuze No.36 Mk II with Ejector Charge No.2 Mk I
Tail No.: No.1 Mk I
  

Color and markings: Red overall,
two 2-inch black bands separated by a 2-inch bright red band near nose.

Description: The bomb has a cylindrical body with a hemispherical nose and parallel sides.  An ejector-charge container is screwed and cemented into the nose and takes the nose fuze.  The tail consists of a tail cone and a cylindrical strut attached to the cone by four fins.  The after end of the body is closed by a tail plate, which is lightly secured to the body.


Functioning: On impact, the fuze functions and ignites the gunpowder ejection charge, which in turn ignites the incendiary filling and ejects it with the tail and tail plate.


Suspension: The bomb is suspended by a single suspension lug.


Filling: The Bomb Mk I is filled with a phosphorus-rubber-benzene mixture.  The Bomb Mk II is filled with a "sticky flammable liquid."  The ejector charge consists of black powder.

Remarks: This bomb was intended primarily for attacking forested areas, and can be dropped from heights up to 8,000 feet.

Next Time: Target Identification Bombs