German Explosive Ordnance - PD and Miscellaneous Small Bombs (Part 1)

German Explosives

PD 500kg

Overall length: 6 feet 11 inches
Body Length: 4 feet 6 and 1/2 inches
Body Diameter: 11 inches
Tail Length: 2 feet 6 and 1/2 inches
Tail Width: 1 foot 11 inches

Filling: (109) RDX/Wax/A1.  The filling, designation 109, has previously been found in PC 1800 RS, associated with a nose filling block of nitroguanidine.

Weight of filling: 32 kilograms
Total Weight: 500 kilograms (approx.)
Charge/Weight Ratio: 6.4%


Color: Sky blue overall with a red stripe on tail cone.


Construction: The body of the PD 500 is constructed of drawn steel.  Compared to the weight of the bomb, it has a very small explosive cavity.  In place of the normal transverse fuze pocket, there is a charging head.  Electrical leads pass from the charging head tot he fuze which is found in the base plate.

The magnesium alloy tail unit is screwed to the base of the bomb with 24 screws.


Suspension: Horizontal by means of an H-type lug.


Remarks: The bomb is stated to be intended for attacking armored targets, especially warships.  It is dropped in horizontal flight from a height of at least 11,500 feet.

The penetration of armor is stated to be 5 and 1/2 inches, increased in later models to 6 and 1/4 inches.  It is of two-piece construction.  The leads from the charging head traverse through a machined hole in the drawn steel bomb body.  This bomb employs an H-type carrying lug.

1/2kg Anti-Personnel Parachute Bomb

Overall length: 4 and 1/4 inches
Body Length: 2 and 1/4 inches
Body Diameter: 1 and 7/16 inches
Wall Thickness: 3/16 inches

Weight of filling: 1 ounce
Total Weight: 16 ounces
Charge/Weight Ratio: 6.6%

Color: Canister unpainted aluminum.  One red bar on closing plate indicates 2-second delay.  Two red bars on closing plate indicates 4 seconds delay for the pull percussion igniter.


Construction: The assembly is composed of two parts: the bomb and the canister.  The body is cylindrical and made of cast steel.  The base and head are internally threaded, the base to accept a suspension hook and the nose for a steel closing plug.  Attached to the suspension hook is a cord which is also tied to a split ring.  The parachute is attached to the split ring by eight cords.  The split ring is also attached to the pull friction igniter which is threaded into the steel closing plug.

The bomb assembly is housed in a barrel-shaped aluminum canister, the body of which is formed in two separate sections and closed at the ends by twin closing plates.


Operation: On release of bomb, the canister comes apart and bomb falls clear.  When the parachute opens, the shroud pulls the striker release plate out.  The striker is then forced into the percussion cap.  This action explodes the bomb.


Suspension: Thought to be carried in large containers.







1kg SD Mortar Bomb, SD 1, SD 1 FRZ

SD 1

Overall length: 6.7 inches
Body Length: 4.25 inches
Body Diameter: 2 inches
Wall Thickness: 0.4 in nose; 0.2 inches tail
Tail Length: 1.25 inches
Tail Width: 2 inches

Filling: Cast TNT
Total Weight: 2 pounds


FRZ
Overall length: 6.06 inches
Body Length: 3.75 inches
Body Diameter: 2 inches
Wall Thickness: 0.12 inches
Tail Length: 1.22 inches
Tail Width: 2 inches

Filling: Amatol 30/70; Granular TNT
Total Weight: 1.1 pounds



Color: SD1 yellow, FRZ is mustard color.  Tail (sheet steel) black, (cast aluminum) natural color.  Ogive is painted red on Amatol-filled bombs.

Markings on FRZ:

Construction: Both bombs have a steel body.  The SD 1 tail assembly is of light metal fins and a drum.  Tail assembly screws into the bomb.

The FRZ tail assembly also screws into the base of the bomb.  It is in the form of a cup with three sheet metal pieces spot welded on to it to form six fins.  Both sheet steel and aluminum tails were used.


Suspension:
-SD 392 bombs in AB 500-1 container; 224 bombs in AB 250-2 container; 50 bombs in AB 70-D1 container.

Packing is nose to tail with tail cup of each forming a safety device for fuze behind it.

FRZ bombs are carried in AB 70-D1 container and packed in the same manner as the SD1 bombs.


Remarks: The FRZ is a French bomb used by the Germans.






2kg "Butterfly" SD 2A and SD 2B

Overall length: 3.5 inches
Body Length: 3.1 inches
Body Diameter: 3 inches
Wall thickness: 3/8 inches

Filling: Cast TNT surrounded by a layer of bitumen composition.

Weight of filling: 7.5 ounces
Total Weight: 4,4 pounds
Charge/Weight Ratio: 11.4%

Color: Body of bomb may be painted either black, lead-grey, red, yellow, or field gray.  If the bomb is painted field gray it may have a 3/4-inch yellow band on the body, the wing assembly will be painted field grey with a yellow stripe on the inside and outside of the wings and may have a 3/4-inch red stripe at right angles to the yellow stripe on the wings.  If the bomb body is painted yellow, the wings will be painted yellow with a 3/4-inch strip of red on the wings.  In addition to the specific color combination given, the wings may be field grey or unpainted.

Construction: The body of the bomb is a cylindrical cast iron casing.  A fuze pocket is situated transversely in the side of the body.  The SD 2A and SD 2B differ only in the method in which the fuze is secured in the bomb.  The fuze is threaded into the SD 2A while it is secured in the SD 2B by a bayonet joint and two U-shaped safety clips.

The bomb body is encased in a thin sheet steel container made in four pieces - two end flaps and two pieces covering the sides of the bomb.  These parts are hinged together, the hinges being mounted with torsion springs tending to force the parts of the wings away from the body, but are prevented from opening until a safety pin is pulled when container opens.

After release, the wings, because of their air drag, rise to the upper end of the 6-inch wire cable connected to the fuze.  The rotation of the wings relative to the bomb body arms the fuze.  When fuze (41) A is employed in the bomb, the wings consist of two triangular shaped flaps.

Suspension: 23 bombs in the AB 23 SD 2 container; 108 bombs in the AB 250-3 container; 6 bombs in the Mark 500 Roden container; 24 bombs in the AB 24t container.

SB 3kg

Overall length: 13 and 5/8 inches

Body Length: 13 and 5/8 inches
Body Diameter: 3 and 3/16 inches
Wall thickness: 1/16 inches
Tail Length:  [Left blank in manual]
Tail Width: [Left blank in manual]
Filling: [Left blank in manual]

Weight of Filling: 4 pounds
Total Weight: 6.5 pounds
Charge/Weight Ratio: 61.5%


Color and Markings: Two yellow stripes, diametrically opposite, run length of case.

Stenciling in black on case:
SB 3
114
Wurfur AB 36
10 bb 242


Construction: The case consists of a welded steel tube 1/16 inch thick, which has a pressed steel filler cap threaded on to the nose.  Two cardboard discs cover the filling under the nose cap.

A steel fuze adapter, of spot welded construction, is crimped on to the base of the bomb.  No fuzes were found in the specimen recovered, but enemy documents indicate that these bombs are fitted with the mechanical impact all-ways acting (23) A fuze.  Design of adapter in base confirms documentary evidence.

There is no form of tail or stabilizing ring.


Suspension: Thought to be carried in containers.


Remarks: Captured documents have pointed to the existence of the 3-kg SB 3 but only one specimen has been found.

Next Time: Miscellaneous Small Bombs (Part 2)

Source: German Explosive Ordnance Vol. 1: Bombs, Rockets, Grenades, Mines, Fuzes & Igniters

American Projectiles and Explosives - Explosive Bombs - "M" Series (Part 2)

American Projectiles and Explosives



Explosive Bombs

30-pound Frag. M5 (Obsolete)

No picture available

Overall length: 25.5 inches
Body length: 13.05 inches
Body diameter: 4.2 inches
Wall thickness: 0.6 inches
Tail width: 6.5 inches

Type of filling: TNT
Weight of filling: 4.66 pounds
Total weight: 29.8 pounds
Charge/weight ratio: 16.3%
Fuzing: Mk XIV

Body Construction: The body consists of a seamless steeel tube over which are fitted rings cut from cast-steel pipe.  Cast-steel nose and base pieces thread onto this center tube.


Suspension: The bombs may be suspended horizontally, vertically, or in a cluster.  U-shaped eyebolts are welded to the bomb at the center of gravity and to the rear of the tail.  Later issues of bombs were in the Cluster M3, which contained six 30-pound Frag. Bombs, M5.


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

2,000-pound S.A.P. M103

Overall length: 89.29 inches
Body length: 68.5 inches
Body diameter: 18.63 inches
Wall thickness: 1.3 inches
Tail length: 25.6 inches
Tail width: 25.8 inches
Tail weight: 52.7 pounds

Type of filling: Picratol
Weight of filling: 556 pounds
Total weight: 2039 pounds
Charge/weight ratio: 27%

Fuzing: Unlike smaller S.A.P. bombs, the M103 has a solid nose, permitting tail fuzing only.


Construction: The body of the M103 is fabricated from seamless steel tubing, somewhat streamlined in shape and with a semi-pointed nose.  No provision is made for nose fuzing in this bomb.  Suspension lugs are welded tot he case in a manner similar to the G.P. bombs.  Trunnions on a band may be fitted for dive-bombing.  A box-type tail is employed as on the G.P. bombs.


Filling: Picratol, a mixture of 52% Explosive "D" and 48% TNT, is poured as the main charge, with a wax pad in the nose to cushion the explosive against premature detonation on impact with a hard target.


Remarks: The suspension lugs are 30 inches apart.  Suspension bands are under development and will be issued, when available, for installations requiring 14-inch suspension.

4-pound Frag. "Butterfly" M83

Overall length: 3 inches
Body length: 3 inches
Body diameter: 3.1 inches
Wall thickness: 0.25 inches

Type of filling: TNT
Weight of filling: 0.47 pounds
Total weight: 3.2 pounds
Charge/weight ratio: 15%

Fuzing: M129 Air or Ground burst, M130 Time, maximum 30 minutes, or M131 Anti-Disturbance.

Body Construction: The bomb body is cylindrical in shape, cast in two halves and welded together.  The fuze cavity is situated athwart-ships in the body, is 1 and 3/4 inches in diameter, and is threaded with a left-hand thread.  The left-hand thread is to prevent unscrewing of the fuze while the bomb is in flight.


Arming vane assembly: The vane assembly consists of four pieces hinged together - two semi-cylindrical surfaces (wings) and two discs (propeller blades) inclined at a slight angle.  While the bomb is still in the cluster, the vane assembly is folded around the bomb to form a cylindrical casing which can be closed against the pressure of the vane coil springs by means of a safety clip.  The arming spindle projects through the bomb casing.

When the bombs are packed in the cluster adapter, the safety clips are removed by the bombs remain in their closed status because of their proximity to each other.  When the cluster adapter bursts open, the bombs scatter and the vane assembly on each bomb is spread open by the force of its coil springs.  The vane assembly is forced by air resistance to the top of the arming spindle, where the square head on the spindle engages the square hole in the assembly.  The two wings reduce the velocity of descent of the bomb.  The two propellers, being set at angles to each other, case the vane assembly to turn in a counterclockwise direction, thereby screwing the arming spindle out of the fuze body and permitting the fuze to arm.  The arming spindle is not completely withdrawn from the fuze, being retained in the fuze by a collar on the spindle.


Markings: The bombs are painted olive drab, with a half-inch yellow band running horizontally around the folded wings.

90-pound Frag. M82

Overall length: 28 inches
Body length: 19.8 inches
Body diameter: 6 inches
Wall thickness: 0.94 inches
Tail length: 9.3 inches
Tail width: 8.1 inches
Tail weight: 2.8 inches

Type of filling: Composition B
Weight of filling: 12 pounds
Total weight: 91.6 pounds
Charge/weight ratio: 13.1%

Construction: Nose and tail pieces of cast steel 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.  The bomb is suspended by single lug or in a cluster (M27) of six bombs.  The tail is of normal U.S. box construction and is secured to the bomb by a locking ring.

120-pound Para-Frag. M86

Parachute container length: 35.5 inches
Diameter: 6.5 inches


Description: The M86 consists of the 90-pound Fragmentation Bomb M82, and a Parachute Unit M5 which is screwed to the base of the bomb body in place of the normal tail fin assembly.  Both units are issued separately and must be assembled prior to use.

The Parachute Unit M5 consists of a cylindrical container housing the parachute.  The lid of the container is fastened by a latch, which is secured by the arming wire.

The bomb is fuzed with the Fuze AN-M120 or AN-M120A1 by using the Adapter Booster M117.

Suspension: The bomb can be used ina  bomb station having the clearance of a 500-pound bomb, and may be suspended singly or as a two-bomb cluster with the Cluster Adapter M12.  One suspension lug is welded to the bomb at the center of gravity, and two suspension bands are issued with the parachute unit.  The larger-diameter band is secured on the parachute unit to be used in conjunction with the suspension lug or the smaller-diameter band secured on the bomb body.


Operation: Thea arming wire, which is fastened to the bomb shackle, passes through the lug of the rear suspension band and the latch on the parachute container, but not through the fuze.  This secures the latch and prevents the parachute from opening until immediately after release of the bomb.  The arming wire which passes through the fuze is fastened to the parachute by the arming cord.

On release, the arming wire is withdrawn from the latch on the container.  As the bomb falls, the air stream removes the lid from the container and allows the parachute to open.  The arming cord is attached ot the shroud line and is pulled as the parachute opens, thereby permitting the fuze to arm.

Fragmentation Bomb Clusters

M1 - Adapter M1

100-pound size for six 20-pound Frag. Bombs AN-M41.  It is 46.75 inches long and weighs 125 pounds.  It has lugs for double-hook suspension only.  The release mechanism operates by means of a cartridge and firing mechanism.



M27 - Adapter M14

500-pound size cluster for six 90-pound Frag. Bombs M82.  The adapter consists of two longitudinal steel tubes, 56 inches long, to which are welded four steel plates forming the support for the six bombs.  The lower tube serves as the backbone of the cluster; and the upper tube carries the suspension lugs, the buckles for the releasing straps, and the adapters for the nose and tail fuzes.  The Nose Fuze M111A2 or M155 is used; however, there is no mechanical time fuze in the tail.

The cluster may be adjusted to release the bombs immediately or, through the use of mechanical time fuzes, to discharge the bombs 5 to 92 seconds after the release of the cluster from the plane.  If it is intended that the cluster is to open immediately, the shear wire is cut after the arming wire is installed, and no fuze is used.  The immediate opening of the cluster produces the most favorable impact pattern.  The cluster must open at a minimum altitude of 1,000 feet in order that the bomb fuze may arm.

M28 - Adapter M15A1

100-pound size for twenty-four 4-pound Frag. Bombs M83.  It is a cylindrical sheet-metal case, which opens longitudinally, being hinged at the rear and closed by a nose cup.  It is 47.35 inches long and 8 inches in diameter, and weighs 155 pounds loaded.  It uses Fuze M155 or AN-M146.

These clusters are released from altitudes of not less than 3,000 feet and not more than 5,000 feet.  Fuze settings for function after release are varied from five seconds at minimum release altitude to eight seconds at maximum release altitude.  When the fuze fires, it releases the nose closing cup, allowing the adapter to open and release the bombs.  The bombs scatter to form a pattern over an area of approximately 300 by 200 feet.

M28A1 - Adapter M15A1

The Cluster M28A1 is the same as the M28, except that it incorporates a spoiler ring around the nose and a drag plate secured ot the tail by four screws.  These two devices were added because the dropping altitude for the M28 was limited by the high velocity attained by the clusters at high altitudes, resulting in damage to the butterfly when the cluster opened.  When drag plates and spoiler rings are used, the recommended release altitude is 1,500 feet with a six-second fuze setting, or any high altitude which will open the cluster at a height between 1,000 to 2,5000 feet.

M28A2 - Adapter M15A2

This A2 modification has a new locking cup, which is secured to the adapter by two slotted screws.  Otherwise, it is the same.

M29 - Adapter M16A1

500-pound size for 90 4-pound Frag. Bombs M83.  The container is like the M15, except for size.  In the Adapter M16, the bombs are loaded in "wafer" assemblies.  This cluster has a third single lug for British suspension.

M29A1 - Adapter M16A2

This A1 modification has the new locking cap, secured to the adapter by two slotted screws.  Otherwise, it is the same.

Remarks

For Navy usage, the Bureau of Ordnance recommends that the case-locking bushing it has developed be used with all "Butterfly" fragmentation clusters, including the M28, M28A1, M28A2, M29, and M29A1.  One end of the bushing screws into the fuze adapter, and the other end is threaded internally to receive the fuze.  The locking cup is retained positively by a safety wire which passes through a hole in the locking-cup tab and around a cotter pin placed int he bushing.  When the fuze fires, the locking cup is blown into the cluster, shearing the loops of safety wire and allowing the adapter to open.

Next Time: Navy "MK" Series (Part 1)