American Guided Missiles - Bureau of Aeronautics Missiles

American Projectiles and Explosives



Missiles

Bureau of Aeronautics Missiles

"Little Joe" 650-pound Surface-to-Air Missile

Overall length: 8 feet 6 inches
Span: 4 feet 9 inches

Total weight (4 rockets): 591 pounds
Total weight (6 rockets): 651 pounds

Warhead: 100-pound G.P. Bomb AN-M30


General: "Little Joe" is a short-range (10,000 foot) radio-controlled, flare-sighted anti-aircraft missile with a 100-pound G.P. warhead, launched from a shipboard catapult with the aid of standard rockets.  A Canard-type airframe with cruciform wing and bow plane, it was designed to intercept Baka-type bombs and suicide planes.  The missile is powered by a JATO unit.

The missile would be launched from a catapult 20 feet long mounted in a 40mm gun position.  It would attain a velocity of 300 to 400 mph after two seconds.


Control: By observing the flare track, the launcher guides the missile to its target with radio signals sent to the receiver in "Little Joe".  The AN/ARW-17 receiver actuates signals which, in turn, operate the servo mechanisms to position the control surfaces.  A gyro system provides the stability.


Propulsion: An 8AS1000 E JATO unit serves as the main propulsive motor.  This unit weighs 139 pounds and contains about 75 pounds of Galcit propellant.  It delivers 1,000 pounds of thrust for eight seconds.


Four or six 3.25-inch Aircraft Rocket Motors Mk 7 are used to assist in launching.


Warhead: The 100-pound bomb has only the V.T. fuze.







1,400-pound "Lark" Ship-to-Air Missile

Overall length: 12 feet 6 inches
Wing span: 6 feet 2 inches
Tail span: 4 feet
Total weight: 1,361 pounds

Warhead: Undetermined; probably a specially designed fragmentation head.


General: The "Lark" is launched from a shipboard catapult for attacking high-altitude bombers.  It has cruciform wings and tail surfaces, the tail surfaces being offset 45 degrees from the wings, and is powered by two liquid-fuel rocket motors, one continuous and one intermittent.  It is radio-controlled in the first part of its flight, its position determined by the launching ship's radar.  When it comes within radar homing range of the target, the homing mechanism takes control.

It is launched at 150mph from a multiple-charge shipboard catapult by means of two 12AS1000 F JATO units which are jettisoned after exhaustion.  With a range of 80,000 yards, an optimum ceiling of 30,000 feet, and a rate of climb of 8,200 feet per minute, it may develop a maximum speed of 650 mph.  Designed strength permits a maximum lateral acceleration of 4g.  Slant range is estimated to be 45 miles, with time of flight of about five minutes.


Control: By use of the ship radar intelligence, radio control will maintain the missile in the center of the tracking radar beam during the initial phase of flight.  When the range of the automatic homing radar is reached, it will take over and navigate a collision course with the target.  Both remote radio control and radar homing devices are connected to control surfaces by servo mechanisms.  It is gyro-stabilized for roll, with a yaw angle-of-attack indicator.


Propulsion: Two acid-aniline liquid rocket motors furnish the propulsion.  One 200-pound thrust continuous rocket is augmented by a 400-pound thrust intermittent motor.  The latter is governed by a Mach Number meter so that a more or less constant speed is maintained.  Both rockets total about 75 pounds in weight and have a supply of 490 pounds of fuel.  The two 12AS1000 F JATO units are used to assist launching and are jettisoned after exhaustion.


Warhead: The proposed warhead is a fragmentation type of explosive activated by a fuse to be fired electrically or on impact.










1,700-pound "Gorgon IIC" Ship-to-Surface Missile

Overall length: 18 feet
Wing span: 11 feet
Total weight: 1,688 pounds

Warhead:
-1,000-lb G.P. Bomb AN-M65
-500-lb G.P. Bomb AN-M64


General: The "Gorgon IIC" is a radar-radio controlled, resojet-powered, Canard-type airframe carrying a 500- or 1,000-pound G.P. bomb.  Launched from a catapult, it has a range of 90 miles and a ceiling of 8,000 to 10,000 feet.  It is designed mainly for ship-to-shore round-the-clock area bombardment with an expected dispersion of one mile at maximum range.  It is radio-controlled and radar-tracked.  Launched from a 150-foot, multiple-charge type, level catapult, giving the missile an initial velocity of 240 mph, the "Gorgon IIC" has a rate of climb of 600 feet per minute, and reaches an impact speed of 450 mph.  Its radius of turn is 10,000 feet.


Control: Intelligence on the target area is provided by AN/APN-33 A1 radar, range 70 miles.  Radio control of the missile is accomplished by the receiver AN/ARW-17 (for combat the AN/ARW-37 is proposed) which has a range of 70 to 100 miles.  Radio signals from this receiver actuate servo controls which maneuver the missile.  A gyro system applies stability.


Propulsion: A resojet, of 14-inch by 10-inch diameter and 9 feet long, provides 200 pounds of thrust for 10 to 20 minutes on 174 pounds of gasoline.  Specific impulse is 1,030 pound-seconds per pound.


Warhead: The bomb is held in its cradle by two bands.  Installation of the Fuzes Mk 235 and Mk 236 is standard.










1,600-pound  LBD-1 "Gargoyle" Air-to-Surface Missile

Overall length: 10 feet
Wing span: 8 and 1/2 feet
Total weight: 1,646 pounds

Warhead:
-1,000-lb S.A.P. Bomb AN-M59 or
-1,000-lb G.P. Bomb AN-M65


General: The "Gargoyle" is a JATO-powered glide bomb with radio control and flare observation.  It is designed for launching from carrier aircraft against maneuvering targets on the surface, visibility permitting.  Launching should be at a speed of 200 mph to avoid stalling the missile.  It has a range of 26,000 feet in a 30 degree dive if launched from the optimum altitude of 15,000 feet.  Speed of the parent aircraft is reduced 10 mph and the take-off distance is increased 15 to 80 feet, but maneuverability is not greatly affected.  The missile has a turning radius of 2,550 feet, and is designed for a lateral acceleration of 4g's.  Top speed: 600 mph.


Control: On the V-tail, control is pitch is accomplished by "rudavators" working together; control to left and right is accomplished by the rudavators working individually.  These control surfaces are positioned by servo motors which take their signal from the radio receiver.  The receiver, AN/ARW-17 (the AN/ARW-37 is proposed for combat) weighs 20 pounds and has an estimated range of about 28 miles, depending on the antenna employed.  Weight of servo system: 125.6 pounds.


Power: A standard 8AS1000 JATO unit, weighing 150 pounds, provides a propulsive thrust of 1,000 pounds for eight seconds.  The fuel is 80 pounds of solid Galcit 63C propellant contained in a 9 and 1/2 by 28 and 7/8 inch casing.

Suspension: Exact specifications are not now available; but in test drops D-6 shackle and sway braces were employed.  When the G.P. bomb is used, two steel straps 1/16 inch by 1/2 inch through the suspension lugs on the bomb hold it to the cradle.  If the S.A.P. bomb is loaded, a strap through the single British suspension lug is used; also, an adapter block is placed in the cradle to provide a snug fit for the smaller diameter of the S.A.P. bomb.


Warhead: The proposed warhead is a fragmentation type of explosive activated by a fuse to be fired electrically or on impact.

Next Time: A.A.F Missiles

American Guided Missiles - Introduction & Bureau of Ordnance Missiles

American Projectiles and Explosives



Missiles

Introduction

General

One of the newest trends [c.1947] in American ordnance development, guided missiles became service items in the last months of World War II.  Guidance was applied to modified bombs, winged glide bombs, and standard aircraft, and in jet- and rocket-propelled airframes.

Guided missiles have great range, high payload capacity, and extreme accuracy; and their progress in designed has proceeded so rapidly that on only a few items has the design become standardized or "frozen".  All the missiles included here were at least in the testing stage and were being pursued as active projects at the time of writing.  Furthermore, only those missiles designed for combat or military purposes - none of the basic research items - are included; and, of these, only their ordnance components can be described in detail.


Guidance

American missiles are usually guided by remote radio control, the receiver in the missile acting through servo units to position the air foils.



Intelligence

The person controlling the flight of the missile will guide its path on the basis of information obtained visually, through a television receiver, or by ordinary radar tracking.  Some missiles have automatic guidance features, of such a nature that, once the target has been "shown" to the missile's intelligence unit, it will automatically "home on" to its destination unassisted.



Propulsion

Depending on the particular item, a missile may be powered by gravity, aircraft, engines, JATO units, rocket motors, or jet motors.



Warheads

Thus far, guided missiles have adapted standard bombs as their explosive payloads.  Fuzing of these bombs differs from the standard fuzes in that the fuzes must be made in an elbow shape, in order to fit in the fuze pockets and, at the same time, permit vane arming.



Cognizance

For the Navy, the Bureau of Ordnance and the Bureau of Aeronautics are developing guided missiles; for the Army, the Air Forces are in charge of the program.






Bureau of Ordnance Missiles

1,200-pound "Dove" Bomb Mk 64 (Air-to-Surface Missile)

Overall length: 84.5 inches
Overall diameter: 18.75 inches

Weight of intelligence units and special tail: 183 pounds
Warhead (1,000-pound G.P. Bomb AN-M65): 975 pounds

Total weight: 1,160 pounds



General: The Bomb Mk 64 is an experimental heat-homing bomb, consisting of a detecting, computing, and guiding mechanism housed in a nose attachment fitted on the 1,000-pound G.P. Bomb AN-M65.  It is designed for attack on maneuvering targets and is effectively employed in both high-angle and dive-bombing runs against objects which have sufficient thermal contrast to their background.

"Dove" is designed to fit the normal plane stowage, but carrying capacity is sometimes reduced because of the missile's increased length.  The special Bomb Fin Mk 1 is a box-kite shape and eight inches longer than the standard tail for this bomb.


Control: Aerodynamic control is effected in range and azimuth by means of four movable nose deflectors independently controlled, which thus form quadrants of a cylindrical surface whose axis is parallel to that of the bomb.  The deflectors may be extended a maximum distance of 4 and 1/2 inches.  The movement of the deflectors is determined by the intelligence unit, which consists of the heat-detecting eye, gyro system, auxiliary electronic relays, servo motors, and battery.







1,600-pound "Bat" S.W.O.D. Mk 9 (Air-to-Surface Missile)

Overall length: 11.9 inches
Wing span: 10 feet
Total weight: 1,600 pounds
Warhead: 1,000-pound G.P. Bomb AN-M65


General: S.W.O.D. (Special Weapons Ordnance Device) Mk 9, or "Bat", is a glide bomb equipped with a radar homing set mounted in the nose.  It is designed primarily for attacking marine targets, and is effective for night or day attacks upon shipping in any weather in which the parent plane can fly.  The launching planes need not stay in the vicinity of the target, and may release as many as four of these missiles in salvo.

The airframe consists of plywood sections which are fitted around the Bomb AN-M65.  Control surfaces consists of an elevon on each wing which can be moved to control pitch or bank.  There are no control surfaces on the tail.

To ensure destruction of the intelligence system, the Demolition System Mk 122 is used.

Installation of the Fuzes Mk 235 and Mk 236, with their outside windmills and flexible arming stems, is standard.


Control: This missile has its own radar transmitter and receiver.  When the target is located on the scope of the monitor unit in the plane, it is put into the range step of the missile's scope and is automatically kept there.  At the correct instant, determined by a glide ratio scale, the missile is released and is guided to its target by the radar signal in its own scope.  The guiding radar supplies corrections to the servo system, which is also controlled by a gyro pilot, the device which maintains flight attitude.


Suspension: Standard bomb lugs are employed on the airframe.  Also, there is the multi-conductor cable connecting the missile's radar with the monitor set in the plane, known as the umbilical cord.


Demolition System: This destructor assembly consists of the S-122-11G switch, Junction Box Mk 1 Mod 0, primacord connectors, and ten Demolition Charges Mk 4.  The S-122-11G switch incorporates an inertia weight, held by a spring tension of 11G, which will topple if that force is exceeded in an impact.  When this inertia weight topples (it is mounted on a universal pivot) the contact bar, which has been transmitting the spring tension to the inertia weight, rotates because of the spring load and completes the electrical circuit across the contacts.  This switch has an arming stem, connected to windmill vanes mounted on the outside of the missile fuselage, which unscrews to arm the switch.  These vanes have an arming wire to prevent rotation before release from the parent aircraft.  On one side of the switch is a clear plastic inspection port.  Tension on the spring is pre-set at 11g when the switch is assembled at the factory.

When the switch completes the circuit, current from the battery sets off the electric blasting cap in the junction box, which fires the primacord connectors and then the TNT blocks, placed around the intelligence unit.


Remarks: The S.W.O.D. Mk 9 is commonly known as "the 1,000-pound Bat".  The S.W.O.D. Mk 10, built around a 2,000-pound bomb is not being actively developed, because it is felt that the 1,000-pound size is large enough for currently projected use.

Next Time: Bureau of Aeronautics 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