German Explosive Ordnance - German Mines and Grenades (Part 4)

    

German Explosives

T. Mi. 29 (T-5) (A/T)

Diameter/Width: 10 inches

Depth: 2.75 inches

Total Weight: 13.25 pounds

Explosive: Cast TNT

Explosive Weight: 10 pounds

Material: Zinc

Pull or Pressure required: 100 to 275 pounds

Color: Olive Green

Description: This is a light anti-tank mine.  The zinc casing is in two parts: the top, and the base.  The top slides into the base and is secured by eight tabs which pass through slots in the base, and are bent over and soft soldered.  The internal surfaces are painted with shellac.  The base is dished for strengthening with six rectangular troughs.  The top is slightly domed and has three adapters sweated into shallow recesses.  The adapters have sockets to take Z.D.Z. 29 igniters.

There are three additional sockets provided fitting anti-lifting igniters.  Two of these are in the side of the casing, diametrically opposite to one another and 4 inches to the right of center of each handle; the other is in the center of the base.  All of these igniter sockets are sweated into the casing, and in addition, have a locating device in the form of two brass pins, which fit into slots on either side of the hole in the mine casing.  Two steel carrying handles are held within loops of brass strip sweated to the casing.  The handles are shaped to fit close to the casing when folded.

Operation: Sufficient pressure on one or all of the igniters, fires the igniter, booster, and main charge.

Topf Mine A (A/T)

Diameter/Width: 12.5 inches

Depth: 5.5 inches

Total Weight: 20 pounds

Explosive Weight: 12.5 pounds

Material: Plastic

Pull or Pressure required: 330 pounds

Color: Black

Description: The main parts of the Topf are the mine body, the primer plug assembly and the igniter.

Mine Body: The mine body is a hollow cylindrical disk of plastic material filled with H.E.  Its top face is formed as a circular pressure plate surrounded by a shear groove.  The cylindrical recess in the center of the mine body accommodates the primer plug.  The carrying handle is fixed to the mine bottom by two glass screws.  Another glass screw in the mine bottom acts as a filler plug.

Primer Plug Assembly: The primer plug assembly consists of a glass screw cap and the cylindrical igniter seating, made of compressed bituminous cardboard material.  The top face of the igniter seating bears a deep pocket with an inside screw thread to accommodate the Topf mine igniter.  The remaining space between the glass screw cap and the igniter seating is filled with the primer charge.  In addition to the pocket for the Topf mine igniter, there is a subsidiary igniter socket leading into the primer charge from the bottom through a hole in the glass screw cap.  This subsidiary igniter socket has a standard igniter screw thread, and a thin bakelite detonator pocket to protect it against moisture.  A circular ridge, moulded on the side of the glass screw cap nearest to the mine body presses against a rubber washer when the primer plug assembly is fitted into the mine.

Igniter: The igniter is an entirely non-metallic pressure igniter without a safety device, and functions on chemical-mechanical action.  It is used, together with a non-metallic detonator, as the main igniter for the Topf mine.  The main parts of the igniter are a hollow cylindrical glass igniter body, and a hemispherical pressure head fitting into the igniter body.

Inside the igniter body there is a circular celluloid disk with two small spherical glass capsules, containing liquid chemicals, fixed on to it by means of an adhesive.  The lower part of the igniter body has two male screw threads, the larger one fitting into the igniter seating, while a protective detonator pocket of plastic material is held by the smaller screw thread.  A circular shear ridge halfway up on the pressure head rests on the top rim of the igniter body and so holds the head in position with its flat portion slightly projecting into the igniter body, just above the two glass capsules.

Operation: Under a load of at least 150 kg (330 pounds) the pressure plate of the Topf mine shears along its shear groove and thus comes to rest on the pressure head of the igniter.  This in turn gives way by the severing of its shear ridge and thus smashes the two small chemical glass capsules inside the igniter body.  The chemicals therein make contact with each other causing a flash which sets off the detonator, and so the mine.

R Mine 43 (A/T)

Length: 31.5 inches

Diameter/Width: 3.75 inches

Depth: 3.5 inches

Total Weight: 20.5 pounds

Explosive: TNT

Explosive Weight: 8.8 pounds

Material: Sheet Steel

Pull or Pressure required: 880 pounds at center; 440 pounds at ends.

Color: Light Khaki.  "R. Mi. 43" stenciled on lid.

Description: The mine consists of three main parts: a sheet steel tray, an encased charge of TNT contained in the tray, and a lid which fits over the tray and acts as a pressure plate.

Tray: The tray is of spot-welded sheet steel construction.  Shear wires are threaded through the tray 7/8-inch from the bottom, to support the charge.  Reinforcing strips are welded inside the  tray at the shear points.  Each end of the tray is folded over on top to form slotted pressure plates to actuate Z.Z. 42 igniters fitted to each end of the charge.  Reinforcing plates, welded to the sides of the tray in the corners, are bent over as supports to these pressure plates.  Swivel clips are provided to protest the igniters.  1 and 1/2 inches from each end are holes through which safety bars are threaded to keep the charge clear of the shear wires in the unarmed condition.  These bars are secured by safety pins attached by cord which may be wound around the mine.  Spring-loaded shutters are provided to block the holes on withdrawal of safety bars.  The shutters are in the form of a spring-loaded angle strip which swings on pivot pins.  These shutters can be manipulated from the bottom of the tray through holes 3/8-inch from the end by means of a bar or large nail.  One side of the tray is slotted in two places accommodate anti-lifting igniters which may be fitted to sockets provided in the one side of the charge.  There is a thin red band painted along the sides of the tray 1/2-inch from the bottom to indicate the correct position of the lid when the mine is armed.

Charge: The charge which has a metallic casing is provided with five igniter sockets.  Two are for the main igniters, type Z.Z. 42, one at each end; these are not visible from the outside when the mine is laid.  The other three are for anti-lifting igniters; one is in the center of the top of the charge; and the other two in one side 5 inches from the ends.  Two shear battens fixed to the bottom of the charge insure double shear action.  Two channels are also fixed to the bottom of the charge; these fit over the safety bars.

Lid: The lid is of spot-welded sheet steel construction.  It is fitted with a handle at one end.  Holes are positioned ot correspond with the sockets provided for anti-lifting igniters in the charge.  Two slots are provided for the shear wires; these may be bent over after the lid is fitted.  There are also two slots into which the safety bars slide, and with paint marks are found above these slots to correspond with similar marks on the tray.  Mines are transported singly in a wooden packing case with main igniters and safety bars in position.  Protecting paper strips cover the igniter holes in the lid.  The cords attached to the safety bars are wound round the mine.

Operation: After the mine is laid and the anti-lifting or trip wire igniters are fitted, the two safety bars are withdrawn.

The mine is fired by one of four ways:

1. Pressure on the lid sufficient to show one or both of the shear wires.

2. Functioning of the anti-lifting or trip wire igniters fitted into the sockets provided.

3. Electrically by remote control

4. Reverse of one main igniter, type Z.Z. 42, with its wings below the end pressure plate so that it will function if an attempt is made to lift the charge from the tray.  Only one igniter can be reversed to operate in this manner.

The mine also lends itself to the usual booby trap devices such as a trip wire attached to the handle of the lid.

Next Time: German Mines and Grenades (Part 5)

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

German Explosive Ordnance - German Mines and Grenades (Part 3)

   

German Explosives

Tellermine 35 (A/T)

Diameter/Width: 12 and 1/2 inches

Depth: 3 inches

Total Weight: 20 pounds

Explosive: TNT

Explosive Weight: 12 pounds

Material: Steel

Pull or Pressure required: 200 to 400 pounds

Color: Gray or Dark Green (European pattern); Tan (Desert pattern)

Description: The body of the mine is a circular metal box with a dome-shaped top surface containing 11 pounds of high grade pressed TNT.  A "floating" cover is held down by a heavy metal ring attached to the body and is supported in the center by a heavy spring.  A compressible rubber ring serves as a cushioned seat for the bottom of the igniter.  A threaded washer locks in the detonator and an adjusting collar serves to position the igniter.  The igniter is screwed into the mine cover until it bears firmly on the rubber washer.

There are two receptacles in the mine body, one in the side and one in the bottom, threaded to receive secondary firing devices.  Either pull friction igniter Z.Z. 35 or ZDSCHN. ANZ. 29 with a detonator is used for the secondary firing.

A rubber strip seals the junction between the cover and the body of the mine against the entry of water and dirt.

Operation: Pressure of 200 to 400 pounds on the cover depresses the cover and the igniter housing.  The igniter housing presses on top of the striker, shearing shear pin which holds the striker in the cocked position.  Driven by the striker spring, the striker spring sets off the percussion cap, detonator, booster, and main charge.

Remarks: The operation of the mine is affected by the position of the adjusting collar in the body.  If the collar is screwed beyond its correct position, a greater pressure on the mine cover is required to compress the spring sufficiently to cause the igniter to fire.  Conversely, if the collar is screwed in short of its correct position, less pressure is required on the mine cover and the mine is relatively more sensitive.

Tellermine 35 (Steel) (A/T)

Diameter/Width: 12 and 1/2 inches

Depth: 3 and 1/2 inches

Total Weight: 21 pounds

Explosive: TNT

Explosive Weight: 12 pounds

Material: Steel

Pull or Pressure required: 250 to 400 pounds

Color: Gray

Description: The Tellermine 35 (Steel) is a modification of the Tellermine 35.  The pressure plate is corrugated for extra strength and a booster charge has been added under the detonator and around the secondary igniter wells.

When either the T. Mi. Z. 42 or T. Mi. Z. 43 igniters is employed a screw plug in the top of the mine covers the igniter.

Operation: Operation of the mine, when fuzed with the T. Mi. Z. 35, is the same as that described for the Tellermine 35.

When either the T. Mi. Z. 42 or T. Mi. Z. 43 is used, sufficient pressure on the pressure plate causes the screw plug to bear on the top of the igniter, breaking the shear wire and causing it to fire.

Tellermine 42 (A/T)

Diameter/Width: 12 and 3/4 inches

Depth: 4 inches

Total Weight: 20 pounds

Explosive: TNT

Explosive Weight: 12 pounds

Material: Steel

Pull or Pressure required: 250 to 400 pounds

Color: Gray

Description: The Tellermine 42 is similar to the Tellermine 35 except that the pressure plate is much smaller and does not include the entire top surface.  The main igniter, the T. Mi. Z. 42, is placed in the receptacle in the center of the mine.  Then the pressure cap is screwed onto the pressure plate and comes to rest on the head of the striker.

Operation: Pressure of 250 to 400 pounds on the pressure plate forces the pressure cap down, since it is fuzed to the pressure plate, and compresses the heavy spring and detonates the mine.

Tellermine 43 (Pilz or Mushroom) (A/T)

Diameter/Width: 12.5 inches

Depth: 4 inches

Total Weight: 18 pounds

Explosive: TNT

Explosive Weight: 12 pounds

Material: Steel

Pull or Pressure required: 250 to 400 pounds

Color: Gray

Description: This mine is similar to the T. Mi. 42 except that the pressure plate is solid; i.e., there is no threaded hole for the insertion of the igniter and no screw cap.  The entire pressure plate will unscrew from the mine and reveal the T. Mi. Z. 42 or T. Mi. Z. 43 igniter.  The walls of the mushroom-shaped pressure plate are thin and there is no heavy spring under the pressure plate.

Operation: Downward pressure on the mushroom will crush the walls and force the head of the striker down, igniting the mine.

Next Time: German Mines and Grenades (Part 4)

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

German Explosive Ordnance - German Mines and Grenades (Part 2)

  

German Explosives

Wooden Box Mine 42 (Holzmine) (A/T)

Length: 13 inches

Diameter/Width: 12 inches

Depth: 4 and 1/2 inches

Total Weight: 18 pounds

Explosive: Amatol 50/50

Explosive Weight: 11 and 1/2 pounds

Material: Wood

Pull or Pressure required: 200 to 400 pounds

Color: Gray with red band on one end.

Description: The mine consists of a compartmented wooden box which contains the explosive charge.  As shown in the cutaway drawing, a Z.Z. 42 igniter, which rests on a supporting block, projects into the explosive charge.  A pressure block, immediately above the igniter, is supported by a shear flange which is secured to the outer wall of the box by wooden dowel pins.

Operation: A pressure of 200 pounds of more on the pressure block shears the dowels.  Shear flange, forced down, pushes out the pin in the Z.Z. 42.  The freed striker, driven by spring, sets off a percussion cap-detonator-booster-main charge.

Markings:

German

V.B.Mi.1

bestehend sus: 26 Sprengkorpern ohne Bohrung

1 Sprengkorper mit Bohrung

Verpackt, H. Ma. Bg 28643 E1942'3

Zugehorige Zundungen in besonderem Packgefass

Translated

V.B.Mi.1

consisting of: 26 1928 pattern 200gm charges without igniter sockets

1 1928 200gm charge with igniter socket

Packed H. Ma. Bg 28643 E1942'3

Igniter assembly packed separately.

Spreng Riegel, 8-kg (A/T)

Length: 33 inches

Depth: 3.25 inches

Explosive Weight: 17.6 pounds

Color: Dull Black

Material: Steel

Pull or Pressure required: 880 pounds center; 440 pounds end.

Description: The mine consists of two main components, the tray, and the charge.

Tray: This is of sheet metal and carries a horizontal rib slightly above the shear wire holes.  On its underside is the word UNTEN (bottom).  Two shear wires pass through the holes in the sides of the sheet 4 inches from each end.  Holes 3/16 inch in diameter are located approximately 1 and 1 and 2/5 inches from each end and can be closed by small shutters on the outside of the tray.  At the ends of the tray are flanges, of which one is solid while the other carries a central slot to permit insertion of the stirrup of the Z.Z. 42 actuating pin.  On the outside of the tray at each end is a rotatable arrow which can be sent to SICHER (safe) or SCHARF in a counterclockwise direction (viewed from the outside)  Rotation of the arrow will rotate the disc in a clockwise direction (viewed form the inside) and lift the arm into a horizontal position, where it is locked by the spring-loaded catch.  In this position the Z.Z. 42 igniters bear against the flange of the arm and will function if the charge is depressed.  The only method by which the catch can be withdrawn, allowing the arm to be lowered and disarming the mine, is by inserting a pin upwards through a small hole, 1.8 inches in diameter, in the base of the tray about 3/16 inch from its end.  This forces upwards the arm of an angle-shaped piece; the other arm of this piece engages in the end of the catch and withdraws it.

Charge: This is encased in a metal container which is provided with four igniter sockets - two end sockets for the main Z.Z. 42 igniters, as in the standard R-Mine 43, and two subsidiary sockets, also in the ends of the charge near the top left-hand corner when the charge is viewed end-on.  These last two sockets are normally kept closed by screw plugs.

Operation: The mine will fire under a pressure of 440 pounds at the ends or a pressure of 880 pounds in the center.  When these pressures are applied, one of both shear wires are sheared and the charge falls into the tray.  As the charge falls, the detent pin is pushed out of one of both of the igniters by the shoulders of the actuating plate thus firing the mine.

Remarks: Principal differences between the Riegel Mine 8 kg and the Riegel Mine 43 are listed below:

1. There is no lid, the mine consisting of charge and tray only.

2. There is no spring-loaded shutter arrangement.

3.The arming device permits the mine to be transported in an unarmed state.

4. There are auxiliary igniter sockets at the ends of the charge, but none in the top or sides.

5. The shutters for closing the safety bar holes are on the outside of the tray and are not spring-loaded.

6. There is no reinforcing bar on the charge where it rests on the shear wire, nor is the tray lines inside to insure a neat shearing.  Thus, in the specimen found, the shear wires had suffered noticeable sagging without being sheared.

Heavy Anti-Tank

Length: 17 inches

Diameter/Width: 15 and ¾ inches

Depth: 10 and 1/2 inches

Total Weight: 300 pounds

Explosive: TNT

Explosive Weight: 37 pounds

Material: Cast Iron

Pull or Pressure required: Varied

Description: This mine is rectangular in shape, and its case and many of its component parts are made of cast iron.  It consists of a box, a cover plate, a removable plug, and one or more firing mechanisms.

1. Box: The box is made of cast iron and its dimensions are the same as those given in the description of the mine.  Within the box is placed the main charge consisting of 84 blocks of TNT.  The charge weighs 37 pounds and is contained in a zinc or galvanized iron box, the lid of which is held in place by either a wire or a webbed strap.  Three posts, which are drilled and tapped at the top, project vertically from the floor of the box and support a base plate which in turn supports the main firing mechanism.  The base plate is screwed to the supports by studs.  Holes are provided in the floor of the box for anchoring it in place by either bolts or stirrups.  A centrally located hole is also provided, to take the standard pull igniter Z.Z. 35 for the purpose of connecting an additional explosive charge in the form of a booby trap.  Adjacent to the top corners of the box and away from the firing mechanism end, journals are provided in which trunnions formed in the cover plate have bearing.  The journals and the trunnions form hinges for the cover plate.  The supporting plate is fastened by studs to the posts.  A stud is screwed into the plate and supports a helical spring in a vertical position.  The spring is formed from square section spring steel approximately 1/8 inch square.

2. Cover Plate: The cover plate fits into and covers the top of the box.  When the cover plate is in position, the trunnions are fitted into the journals and a lug formed under the free (swinging) end of the cover plate rests on the helical spring which holds the cover plate level with the top edges of the box.  One corner of the cover plate has a rectangular recess into which is fitted the removable plug.  The cover plate is provided with top recesses into which road material may be inserted to match the surrounding road surface.  The undersurface of the cover plate is deeply grooved or scored to form a grid so that the cover will form shrapnel when the mine explodes.  The cover plate is also provided with a pedal housing into which a pedal is inserted.  The pedal is found with several short strings or wires attached to its end.  The exact purpose of the pedal is not clear, but it is assumed that it is used to extract the safety pins of the firing mechanism by means of the strings or wires.  It is stated in the latest information available that a pressure of 100 pounds on the pedal may fire the mine.  However, the exact construction is not clear.  The pedal may also be fastened to a booby trap, and therefore great care must be taken in removing it from the cover plate.  A U-bolt is provided on the top surface of the cover plate for lifting the plate.

3. Removable Plug: The removable plug is rectangular in shape and fits into the corner recess of the cover.  To its underside is attached an eyed rod which projects through the hole of the cover plate when the plug is in place.  On the top side of the plug is attached a U-bolt which is used to lift the plug.  The plug provides access to a locking pin.

4. Firing Mechanism: The firing mechanism consists of the following:

A: Main Push Igniter - Standard push igniter, type Z.Z. 35 is mounted on the base plate by being screwed into the hole provided for it in this plate.  A detonator and booster charge is mounted beneath the plate.  The booster charge is 4 inches long and 1 and 3/4 inches in diameter.  When pressure is applied to the cover plate, the head of the igniter is depressed downward, and the igniter fires the detonator and booster charge and the main charge.

B: Pull Igniter - Standard pull igniter, type Z.Z. 35 is used as a booby trap device for the mine.  The igniter is mounted on the base plate and is provided with a second detonator and booster charge mounted below the supporting plate.  The projecting head of the pull pin is connected by a cord or wire to an auxiliary firing assembly.  A dowel pin is mounted on the base plate.  A small helical spring rests on the head of the dowel pin and is held in place by a sleeve which rides over the dowel pin.  The closed head of the sleeve is provided with a loop to which the wire is fastened.  When the cover plate  is in place, the lug presses on the eye loop, thus compressing the spring.  To keep the sleeve from rotating, it is provided with a lug which rides in a groove formed in the dowel pin.  The locking pin passes through the loop and is locked to the cover plate by a bracket.  If the cover plate is lifted, the sleeve is pulled upward, and at the same time the wire pulls and fires the igniter.  The igniter fires the detonator and booster, which in turn explodes the main charge.  Even if the locking pin is removed, care must be exercised not to lift the cover quickly, as the spring, which is in compression, will force the sleeve upward with sufficient strength to fire the igniter.  This firing mechanism constitutes a booby trap.

C: Additional Booby Trap Devices - Pull igniters may be installed to provide booby traps while the mine is disarmed.  A wire may be attached to the eye of the rod and to a pull igniter below the cover plate, which will be fired if the removable plug is extracted.  It is also stated that pull igniters may also be inserted within the blocks of the charge.  It is the practice of the Germans to insert, in each standard block of explosive, a threaded metal sleeve to accommodate a standard pull igniter.  Thus any two blocks may be interconnected by an igniter which will fire upon being separated.  This also is of the nature of a booby trap.  An additional firing device and charge may be connected to the hole in the base of the box, which will fire if the box is lifted.  This also is considered a booby trap.

Operation: The mine is fired by a downward pressure exerted on the cover plate, which pivots on the trunnions.  This pressure compresses the main pressure igniter, which fires the charge.  The height of the pressure igniter head may be adjusted so that varying degrees of compression of the helical spring, holding up the cover plate, will fire the mine.  Thus, the mine may be set to fire under the weight of a man or reconnaissance vehicles, or it may be set so that it will explode only under heavy tanks.  Also, when the mine is provided with booby traps it may be actuated in a number of different ways.  The main booby trap is the pull igniter.  The mine may also be fired by lifting the removable plug when dismantling the charge, when removing the pedal, or when removing the box from its hole in the road.

Employment: This mine is used for road blocks where action has been static for a period of time.  The length of time required to lay the mines prevents their effective use in fast moving warfare.

Next Time: German Mines and Grenades (Part 3)

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

German Explosive Ordnance - German Mines and Grenades (Part 1)

 

German Explosives

Pappmine (A/T)

Diameter/Width: 12 inches

Depth: 5 inches

Explosive: Pressed TNT

Explosive Weight: 11 pounds

Color: Black

Material: Cardboard

Pull or Pressure required: 750-790 pounds

Description: The Pappmine is an antitank mine made entirely of nonmetallic materials to prevent detection by electric mine detectors.  It derives its name from the material of the mine body, "pappe", or paper cardboard.  The mine, which is black in color, consists of a container and lid, the lid covering the full depth of the container.  The top and bottom edges are rounded and lid and container are held together by a band of cardboard.

In the center of the lid is a 2 and 3/4 inch pressure plate of thick green glass which resembles a threaded and knurled glass stopper.  Inside the mine is a glass igniter set into about 11 pounds of pressed TNT.

Igniter Assembly: In the center of the top of the charge is a hole, approximately 1 inch across and 2 inches deep, which houses the igniter assembly.  The igniter, which is entirely of glass, resembles the R. Mi. Z. 42 in shape, including the pin through the striker.

The body of the igniter is stated to taper toward the bottom and contains a central tube containing an ignition mixture of unknown reddish composition.  The bottom of this tube is connected to a short chamber containing what appears to be a priming charge.

Operation: Pressure on the pressure plate forces its undersurface down on the head of the igniter.   This crushes the internal glass tube, and the initiating flash passes to the priming charge at the base of the tube, thus exploding the main charge.  A 3-second delay may be incorporated in the igniter.  Pressure on the cardboard side of the mine will not set it off.

Remarks: This information is taken from a captured German document.

Panzerschnell Mine (A/T)

Length: 10 and ¾ inches

Depth: 4 inches

Explosive: Picric Acid

Explosive Weight: 13.2 pounds

Color: Buff and Green

Material: Wood

Pull or Pressure required: 6-11 pounds

Description: These two wooden box mines are similar to the Schumine although somewhat larger.  Both A and  B types are very similar, consisting of a wooden box containing 6 kg of picric acid in damp proof paper.  The initiating charge in each case is a standard 200-gm charge built up on wooden blocks to enable the igniter to fit into it.  On the inside cover of the box is painted the letter A or B showing the type of mine, and a label, giving instructions for installation.

Operation: Type A is actuated by pressure on the box lid, causing the shearing of two 1/2-inch wooden dowels and pressing out the link pin of the ZZ 42 igniter.

Type B is actuated by pressure on the box lid shearing 3/4-inch wooden dowels and exerting pressure on the head of the two Buck chemical igniters.

Magnetic Antitank Charge (Panzerhandmine 3)

Length: 5 and ½ inches

Depth: 10 and ¾ inches

Total Weight: 8 pounds

Explosive: TNT or RDX/TNT

Explosive Weight: 2 and ⅓ pounds

Material: Paper Board

Description: This charge is an assault weapon designed to be placed on enemy tanks or similar targets, to which it adheres by means of magnets.

The body is of ppaer board and encases the charge and the magnets.  A web-carrying handle is attached to a metal neck band.  The hemispherical cavity of the hollow charge is closed with a sheet metal liner.

Three pairs of magnets are mounted on the inside of the paper board skirt.   They are protected in transit by an iron keeper ring which has a web handle fastened to it to facilitate withdrawal.  On one side of the keeper are three equidistant spikes so that the charge can be attached to a wooden surface.  In transit the keeper is reversed and the spikes are positioned between the magnets.  

The charge is fired with a 7 and ½ second friction igniter.

Operation: Information is lacking as to how the charge is placed and fired.  It is apparently designed to be placed by hand on the tank and the igniter pulled after it has been positioned.  German documents make no mention of the charge being thrown.

Next Time: German Mines and Grenades (Part 2)

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

German Explosive Ordnance - Rockets (Part 20)

German Explosives

8.6-cm R. Sprg L/5.5 Rocket

Motor

Propellant: Diglycol

Nozzles: 10

Throat Diameter: 5.25

Cant Angle: 17 degrees

Nozzle K: 495

Performance

Thrust: 57 degrees

Burning Time: 0.52

Impulse: 185

Velocity (max): 300 m/sec

Range: 4,500 meters

Description: The 8.6-cm R. Spgr L/5.5 rocket has a longer motor and a smaller payload than the Spgr L/4.5.  The details of construction of the motor are similar to the Spgr L/4.5 in that the motor closure is not fixed permanently to the motor tube.  A KLAZ 40 impact-firing nose fuze is employed.

The propellant grain consists of two concentric cylinders of a diglycol propellant, extended to different diameters than for the other grains.  The length is 220 mm and the diameters are 66/41 and 32/71, with a total weight of 1,000 grams.  The forward igniter is a 40 mm disk of incendiary material.

Remarks: This rocket has the same design factors as shown for the 8.6 cm RLg 1000 rocket except for the throat diameter and uses the same type launcher.

8.6-cm R. Sprg L/4.5 Rocket

Motor

Propellant: Diglycol

Nozzles: 4.6

Throat Diameter: 6.9, 5.25

Cant Angle: 12 degrees

Nozzle K: 460, 525

Performance

Thrust: 243

Burning Time: 1.22 minutes

Impulse: 116

Velocity (max): 250 m/sec

Range: 3,500 meters

General: In July 1944, a new series of 8.6-cm R. Spgr's was designed; the L/4.5 being the smallest rocket of the new series.  The nozzle plate is threaded on to the motor tube and the loose motor closure design is employed.  The body of the projectile has been lightened and the base fuze cavity eliminated.  A KLAZ 40 impact-firing nose fuze is used in place of a self-destructive pyrotechnic time fuze that is used with the Spgr L/4.8.

Description: The ignition train for the motor consists of a percussion cap, rear igniter of granular black powder and a flash tube running up the central hole of the inner propellant grain to the forward igniter.  The forward igniter consists of a 30-mm diameter disk of incendiary material, which is not black powder.

The propellant grains are two concentric cylinders, 130 mm in length, having diameters of 70/40 and 35/7 mm and weighing 680 grams.  The grains and igniters are held in place by a light three-armed grid of plastic.

Remarks: This rocket has the same design factors as shown for the 8.6-cm RLg 1000 rocket except for the throat diameter and uses the same type launcher.

21-cm R-Lg. Rocket

Ballistics

Caliber: 21 cm

Bourrelet Diameter: 21.4 cm

Total Weight: 60 kg

Length: 5.1 cal.

Length (fuzed): 109 cm

Maximum Velocity: 560 m/sec

Maximum Ordivate: 5,400 meters

Spin Velocity: 11,900 rev/sec

Moment of Inertia:

Longitudinal: 0.0334 mkg/sec²

Transverse: 0.363 mkg/sec²

Stability Factor: 1.5

Launching Velocity: 19.1 m/sec

Launching Time: 0.118 seconds

Motor Performance

Nozzle K: 500 cm²/cm²

Burning Time: 3.3 seconds

Impulse: 3,040 kg sec.

Velocity 560 m/sec

Motor Volume: 12,600 cm³

Number of Nozzles: 6

Throat Diameter: 1.48 cm

Nozzle Area: 10.3 cm²

Nozzle Length: 7.5 cm

Cant Angle: 9 degrees

Expansion cone angle: 12 degrees

Description: The rocket projectile is a high-altitude, rearward-ejecting parachute-suspended flare.  The rocket consists of two concentric cylinders, the inner tube containing the flare and the outer containing the rocket propellant.  Six nozzles, arranged symmetrically around the base of the motor, are canted to provide the spin necessary to stabilize the projectile.  The launcher used for the tests at Unterluss was a single-barreled launched designated "21-cm R Ag M 42", which had a barrel 1.12 meters in length.

Rocket Motor: The 21-cm R Lg rocket motor has a unique design, considering the usual German construction.  The motor tube has a groove cut into the inner wall, one near each end of the tube.  The purpose of the two grooves is to provide a seat for a ring-type retainer to secure the closure plates.  The closure plates have thin obturator disks to prevent the escape of the hot propellant gases around the closures.  The upper closure uses one obturator disk and the lower closure two.  The second obturator disk is unnecessary at the top of the motor because of the threaded fit of the central tube containing the flare unit and the upper closure.

The assembly procedure is rather complicated due to the closure plate system.  First, the nozzle plate is assembled with the grid and obturators.  The assembled nozzle plate is fitted into the tube and the locking ring retainer seated in the retainer groove.  An annular locking plate, which has the skirt crimped onto it, is bolted to the nozzle plate.  The locking plate seats on the base of the motor tube and stresses the nozzle plate against the ring retainer.  Three bolt positions, 180 degrees apart, are used to attach the nozzle plate and the locking plate.

The propellant grain consists of a single tube of R 6 m diglycol propellant 19.2 by 10.8 cm in diameter and 51 cm in length, weighing 15.2 kg.  This grain is placed upon the grid in the motor tube.  An igniter of 70 grams of black powder, contained in a ring-shaped plastic case; is placed ont he top of the propellant grain.  The front motor closure is then secured to the motor by means of a retainer ring and locking plate.  

A chamber for the electric igniter is permanently attached to the top closure and provided with a screw-on cap to enable insertion of the igniter after the motor has been loaded.  After insertion of the electric igniter, the flare unit, with the wind-shield attached, is fitted into the motor and threaded into the upper motor closure.  The manner in which the electric igniter makes an external contact cannot be determined from the information available.

Two construction designs are given for the nozzle assembly.  Both types have insert nozzles, ie, the nozzles are individually assembled to the nozzle plate.  In both cases, the nozzle plate is drilled and reamed 6 places, 60 degrees apart, at the desired cant angle of 9 degrees.  The hole is then drilled out to a larger diameter for a short distance on the exit side of the plate forming a seat for the flange on the nozzle.  The inside of the nozzle plate hole is made slightly conical in the first design.  After the nozzle has been inserted, the entrance cone of the nozzle is swaged outward into this cone, thus securing the nozzle to the nozzle plate.  The newer design shows the nozzle pressed into a cylindrical hole in the nozzle plate omitting the swaging operation.  This is sufficient, since the effect of the high-pressure gases flowing out of the nozzle is to have a net forward thrust on the nozzle, thus forcing it more firmly against the shoulder of the nozzle plate.

Flare Unit: The flare unit is contained in a cylinder which is equal to the full length of the rocket.  The front of the cylinder forms the nose of the rocket and carries the time-fuze and the ejecting charge.  The ejecting charge consists of 35 grams of black powder.  A thin conical windshield streamlines the forward end of the flare chamber into the body of the motor.  The flare unit contains 7.5 kilograms of illuminant and has a burning time of 120 seconds.  The flare unit fits in the forward part of the tube and the parachute in the rearward part of the tube.  The parachute is contained in a split metal container which transmits the thrust of the ejecting charge to the base closure plug.  The base closure plug is attached to the central cylinder by 3-mm diameter wires which are sheared by the thrust from the ejecting charge.  The entire flare unit fits into the rocket and threads onto the forward closure.  The rearward end of the flare unit projects through the nozzle plate and is obturated by a thin collar.

Remarks: This rocket has the same design factors as shown for the 8.6 cm RLg 1000 rocket except for the throat diameter and uses the same type launcher.

Next Time: German Mines and Grenades (Part 1)

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