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

German Explosive Ordnance - PC Bombs

German Explosives

PC 500kg, D500 E, and D500 L

D500 E
Overall length: 68.2 inches
Body Length: 42.3 inches
Body Diameter: 15.6 inches
Wall Thickness: 1.4 wall to 9 inches at point
Tail Length: 27.5 inches
Tail Width: 15.5 inches
Filling: Cast TNT: 60/40 Amatol; TNT and Wax.
Weight of filling: 75 kilograms
Total Weight: 539 kilograms
Charge/Weight Ratio: 14%


D500 L
Overall length: 78.8 inches
Body Length: 53.8 inches
Body Diameter: 15 inches
Wall Thickness: 0.9 wall to 9.3 inches at point
Tail Length: 30.5 inches
Tail Width: 16 inches
Filling: Cast TNT; TNT and Wax.
Weight of filling: 78 kilograms
Total Weight: 416 kilograms
Charge/Weight Ratio: 19%


Color: Field gray or aluminum overall.  Dark blue stripe on tail cone.


Construction: There are two types of the PC 500: Type E and Type L.  Both types have a one-piece forged steel body and one transverse fuze pocket.  The fuze pocket is located aft the horizontal suspension lug.  The bomb is machined to accommodate a male type tail closing plug.  The tail assembly can be either of sheet steel or magnesium alloy.  The tail unit in either case is of the cylinder type.  Both types have the sheet metal ring which is used for bracing the fins.  The tail unit is secured to the bomb body by means of 12 screws.


Suspension: Horizontal by means of an eyebolt or T-type lug.

PC 1000-kg ESAU

Overall length: 85.5 inches
Body Length: 58.5 inches
Body Diameter: 19.8 inches
Wall Thickness: 1.5 inches at wall to 13.4 inches at point
Tail Length: 32 inches
Tail Width: 19.8 inches

Filling: TNT and Wax
Weight of filling: 160 kilograms
Total Weight: 1,000 kilograms
Charge/Weight Ratio: 16%

Color: Sky blue with aluminum tail.  Blue stripe on tail cone.


Construction: The body of the PC 1,000-kg armor-piercing bomb is of one-piece forged steel.  The nose is very heavy and this construction decreases the size of the explosive cavity.  There is one fuze pocket located aft the suspension lug.  Through the center of the explosive cavity is an additional exploder tube.

The tail unit is constructed of magnesium alloy and is attached in the same manner as used with the SC 1,000 series.


Suspension: Horizontal.  This bomb uses a suspension band with the H-type lug secured to it.  At 90 degrees from the suspension lug in both directions are two trunnion bolts for dive-bombing.





PC 1,400-kg FRITZ

Overall length: 110.8 inches
Body Length: 75.7 inches
Body Diameter: 22 inches
Wall Thickness: 1.25 in wall to 12.5 inches at point
Tail Length: 43.3 inches
Tail Width: 22 inches

Filling: TNT and Wax; Trialen
Weight of filling: 300 kilograms
Total Weight: 1,400 kilograms
Charge/Weight Ratio: 21.4%

Color: Sky blue overall or sky blue with aluminum tail.  Red or blue stripes on tail.


Construction: The bomb body is of one-piece forged steel construction.  There is one transverse fuze pocket located aft of the carrying lug.  Two exploder tubes containing tetryl run lengthwise through the explosive cavity just left of the fuze pocket.  The base of the bomb body is closed with a male base plate.

The bomb tail is of the cylinder type, the cylinder being 6 inches deep.  It is constructed of either cast aluminum or magnesium.


Suspension: Suspension of the bomb in the racks is horizontal by means of an H-type lug or by two trunnions on the carrying band.






PC 1,600-kg

Overall length: 110.8 inches
Body Length: 65.7 inches
Body Diameter: 21 inches

Filling: RDX, aluminum and wax
Weight of filling: 230 kilograms
Total Weight: 1,600 kilograms
Charge/Weight Ratio: 14.4%

Color: Blue stripes on tail.

Construction: The body is of two-piece construction with a cylinder type tail.  It is designed to penetrate 180mm of panzer steel or 2.5 meters of reinforced concrete at a striking angle of 60 degrees.

Suspension: Horizontal.

Remarks: Usually dropped at an altitude of 4,000 to 6,000 meters.

The production of this bomb was stopped in October 1942.  Bombs then on hand were used and not replaced.

PC-RS Bomb Series

Description: This series of rocket assisted armour piercing bombs consists of the following missiles; PC 500 Rs, PC 1000 Rs, and the PC 1800 Rs.  In general, the three types are of similar three piece construction; the warhead, the distance piece, and the tail section.  The tail section contains the rocket motor.

Each series is fitted for horizontal suspension by means of a single "eye" or H-type suspension lug.  In addition to the suspension lug, there is a set of trunnions fitted to the bomb.  They are located 90 degrees around from the lug and approximately 2 inches further aft.  The trunnions are used for suspension only under dive-bombing conditions.

Warhead: The warhead is identical to the normal armour-piercing (PC) bombs of respective size except for the fuze pocket arrangement.  In the PC-Rs series the transverse fuze pocket has been omitted.  The impact fuze is part of the 49 series and is found screwed into the base of the warhead.  The warhead is filled through the base and the explosive cavity is then closed by means of a male type base plate.

Distance Piece: The distance piece is a steel cylinder internally threaded at both ends.  Its main purpose is to connect the warhead to the tail section.  The charging head for the fuzing system is threaded into the after end of the distance piece just forward of the tail piece junction.  The electrical leads from the charging head pass through this cylinder; one to the impact fuze and the other to the pyrotechnic rocket igniter.

Tail Section: The tail section is another steel cylinder with twelve stabilizing fins at the after end.  This total of 12 fins is made up of 4 large fins and 8 smaller fins.  The end of the tail unit is closed by means of a fixing plate.  The fixing plate has six circular openings positioned so as to take the end of the venturi tubes from the rocket motor.  The large opening in the center of the fixing plate will allow any gas emitted from the pressure release valve in the rocket motor to escape.

Rocket Motor: The rocket motor is housed within the tail section.  It consists of the following parts: main pressure chamber, six propulsion venturi, six metal spacers at each end of the pressure chamber to hold and properly space the propellant sticks, an igniter pad of black powder, and a spring loaded pressure release valve used as a safety measure.

There are 19 sticks of rocket powder in each motor, dimensions of which can be found in the accompanying chart.  The latest type of rocket powder used in these missiles was dinitrodiglycol.

Operation: When the missile is released from the mother aircraft, an electrical charge is imparted to the charging head.  This charge is passed on to both the pyrotechnic fuze and the electrical impact fuze.  The pyrotechnic delay is ignited immediately.  After 3 or 4 seconds it burns through to the black powder igniter.  The black powder then ignites and starts the propellant powder in motor burning.

The electrical charge which is passed on to the impact fuze loads and the condensers and arms the fuze.  On impact one or all of the trembler switches close.  This action completes the firing circuit and sets off the electrical detonator which in turn sets off the gaine and finally the main charge.

PC 500 RS

Overall length: 81 and 3/4 inches

Body Length: 33 inches
Body Diameter: 11 and 1/4 inches

Filling: Very pure cast TNT in an aluminum container in the nose.
Rest of filling is alternate layers of good and poor quality TNT.

Weight of Filling: 14 kilograms
Total Weight: 490 kilograms
Charge/Weight Ratio: 3%


Color and Markings: NL 6 40
PC 500 RS is stenciled in black on the side of the bomb.


Construction: The rocket container is attached to the base of the bomb by a cylindrical steel distance piece which is threaded internally on both ends - one end threading over the bomb base and the rocket container threading into the other end.

In the side of the distance piece is filled an electric fuze head marked (49) B1 with charging plungers connecting to (49) B11 and (49) B111 fuzes.  Fuze (49) B11, a pyrotechnic fuze with a delay of 3 seconds is used for igniting the rockets.  Fuze (49) B111 is an electrical impact fuze fitted into the base plate of the bomb, giving a fractional delay action to the bomb after striking the target.

Nineteen rockets are placed in the rocket container.  Twelve are 25 and 5/8 inches long by 2 and 1/16 inches in diameter, and seven are 27 and 5/8 inches long by 2 and 1/16 inches in diameter.  Weight of rocket section is 146 kilograms.

The tail is 2 feet 4 inches (large diameter): 1 foot 10 inches (small diameter)


Suspension: Horizontal.

PC 1000 RS

Overall length: 86 and 3/4 inches

Body Length: 45 inches
Body Diameter: 14 and 1/2 inches

Filling: Very pure cast TNT in an aluminum container in the nose.
Rest of filling is alternate layers of good and poor quality TNT.

Weight of Filling: 54 kilograms
Total Weight: 987 kilograms
Charge/Weight Ratio: 5.5%


Color and Markings: Sky blue.  Blue stripes between tail fins.

Stenciled:
Achtung vor Beladun
ZSK Ausschalten
Abwerf Z.S.K.O.V. Schalten
unt 28, 5, 41
PC 1000 RS

Construction: The rocket container is attached to the base of the bomb by a cylindrical steel distance piece which is threaded internally on both ends - one end threading over the bomb base and the rocket container threading into the other end.

The rockets consist of candles contained in a separate compartment at the base of the bomb and are held in position by spacers.  This compartment forms a pressure chamber from which the gases generated by the candles escape through six propulsion venturi tubes.  The tubes are sealed with pitch until combustion is effected.  The pressure chamber is provided with a spring-loaded pressure release valve at the base.

It is stated that the rockets burn for approximately 3 seconds after ignition and leave a trail of flame 150 feet long behind the bomb.

The bomb is usually of A.P. design, but instead of the exploder pocket lying transversly with the fuze head at one side, it is fuzed through the base plate which lies ahead of the rocket compartment.

The pyrotechnic fuze ignites the rocket about 2.5 seconds after the bomb is released.  Actually, bomb can be dropped without the rocket being ignited.


Suspension: Horizontal.

PC 1800 RS

Overall length: 107 inches

Body Length: 66 and 1/2 inches
Body Diameter: 21 inches

Filling: Very pure cast TNT in an aluminum container in the nose.  Two pre-cast Trialen charges in thick cardboard cylindrical cartons which are waxed into the bomb casing, completes the filling.  One specimen had 3 blocks of nitroguanidine in the nose and 10 blocks of RDX/Wax/A1 in two cardboard cylinders in the body.

Weight of Filling: 360 kilograms
Total Weight: 2,057 kilograms
Charge/Weight Ratio: 17.5%


Color and Markings: Bomb body and tail are sky blue in color.  Rocket unit and distance piece are olive drab.

Stenciled:
Konus vor Velastungen
Schutzen
unt 13, 10, 42
Achtgun vor beladung
Zsk Aussenalten
PC 1800 RS

Construction: Typical rocket bomb construction with single fuze pocket in distance piece.

Nineteen rockets are used: ten 22 and 1/2 inches long, eight 20 and 7/8 inches long and one 11 and 1/4 inches long.

All have a diameter of 2 and 15/16 inches.  Rocket unit weighs 422 kilograms.


Suspension: Horizontal.

Next Time: PD and Miscellaneous Small Bombs


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

German Explosive Ordnance - SD Bombs

German Explosives

SD 50 (D50; D50D; D50L)

Overall length: 43 inches
Body Length: 23.5 inches
Body Diameter: 8 inches
Wall Thickness: 0.4 wall to 1.8 inches in nose
Tail Length: 23.5 inches
Tail Width:
-Type I: 11 inches
-Type II: 10.5 inches

Filling: TNT
Weight of filling: 16.4 kilograms
Total Weight: 55 kilograms (approx.)
Charge/Weight Ratio: 30%

Color: Bomb is dark green overall and tailcone is striped with red.


Construction: The body of the SD 50 is a one-piece steel casting.  When machined down it has provisions for one transverse fuze pocket just forward of the horizontal carrying lug.  It is threaded at the base to accept a male type filling lug.

Either the Type 1 or Type 2 tail assemblies can be used.  Type 1 has a cast alloy adapter with sheet steel vanes.  The four vanes are not supported by struts.  Type 2 is a one-piece construction assembly of cast magnesium alloy with no strut supports for the tail fins.

In addition to the horizontal carrying lug, there are threads machined in the nose to take an "eye" type lug for vertical suspension.


Suspension: Horizontal or vertical.


Remarks: A small angle iron kopfring is normally fitted to the bomb.  In addition to the kopfring a 24-inch dinort rod may be added to obtain penetration detonation of the bomb.  An extension rod used with the (55) A can be used for the same purpose.

When the bomb is used against water targets, the tail fins are removed.  It is claimed that the ballistics are not changed by removing the tail fins providing the dropping range is less than 200 meters.  The E1AZ (38) fuze with a maximum delay of 5 seconds allows for water travel of 12 to 18 meters.

SD 70-kg

Overall length: 43.2 inches
Body Length: 28 inches
Body Diameter: 8 inches
Wall Thickness: 0.4 inches
Tail Length: 16 inches
Tail Width: 11 inches

Filling: TNT
Weight of filling: 21 kilograms
Total Weight: 66 kilograms
Charge/Weight Ratio: 39%

Color: Bomb is field gray overall.  Red stripes on tail fin.


Construction: The SD 70 body is of one-piece forged steel and is normally fitted with a kopfring.  The tail is of sheet steel construction and the fins are ribbed to supplant the diagonal fin braces.

This bomb, on occasion, is fitted with a parachute.  The tail unit is removed and a sheet metal cylinder 18 inches long and 7 and 3/4 inches in diameter is attached to the base of the bomb.  Contained in the cylinder is a red lattice type parachute 5 feet square with four double shroud lines.  The shroud lines are secured by means of four U-shaped brackets to a collar over which the base plate screws.  The overall length of the cylinder and bomb is approximately 45 inches.


Suspension: Horizontal or vertical suspension is used.


Remarks: Parachute bomb apparently designed to give air burst.





SD 250 kg D250, D250 JB, D250 L, D250 DL

Overall length: 64.5 inches
Body Length: 34.4 inches
Body Diameter: 14.5 inches
Wall Thickness: 0.6 wallpoint 3.5 inches
Tail Length: 38.2 inches
Tail Width: 20 inches

Filling: TNT
Weight of filling: 79 kilograms
Total Weight: 250 kilograms
Charge/Weight Ratio: 32%

Color: Bomb body and tail are painted dark green, sky blue, or aluminum.
Tail cone is striped with red or blue.


Construction: Bomb is of three-piece construction.  Nose and tail pieces are welded to main part of body.  One fuze pocket.  A female base plate is used.

The tail is of sheet steel construction.  Four vanes are welded to a cone.  There are also box-type struts of bar steel.  Extension cylinder has a dummy fuze head.


Suspension: Horizontal or vertical.






Nose Spikes for SC 50 Stabo, SD 70 Stabo, SC 250 Stabo, and SC 500 Stabo

SC 50 Stabo

Total weight: 62 kilograms
Length of spike: 47 centimeters
Diameter: 4.5 centimeters

SD 70 Stabo

Total weight: 77 kilograms
Length of spike: 47 centimeters
Diameter: 4.5 centimeters

SC 250 Stabo

Total weight: 282 kilograms
Length of spike: 57 centimeters
Diameter: 7.5 centimeters

SC 500 Stabo

Total weight: 305 kilograms
Length of spike: 60 centimeters
Diameter: 7.5 centimeters

Construction: Stabo bombs have a threaded lug forged to the nose of the case.  Stabo spikes screw on to this threaded lug.  The same spike fits both SC 50 and SD 70 and is of one-piece construction.  The SC 250 and SC 500 Stabo spikes have an additional piece, a pressure plate, which fits between the bomb case and spike to increase the rigidity.  The spikes are used in low altitude attacks to prevent ricochet.  A 1-cm hole through the spike allows use of a bar to screw spike securely to bomb.

Remarks: Stachebomben, or "Stabo" for short, are used in low altitude attacks to ensure the bomb does not ricochet.  The SC 250 and SC 500 are both two fuze pocket bombs and fuzing is usually a time fuze 17 or 57 and an antidisturbance fuze (50).  The SC 50 Stabo and SD Stabo are normally fuzed with a (55).

Discs fitting on the end of these spikes have been found.  It is thought nose switches have been used to give instantaneous action.

SD 500, SD 500A and SD 500E

Overall length: 82 inches

Body Length: 54 inches
Body Diameter: 17.5 inches
Wall Thickness: 1 inch wall; point 5 inches
Tail Width: 18 inches
Tail Length: 35.5 inches

Filling: Amatol 60/40; TNT and wax
Weight of Filling: 200 kilograms (approx.)
Total Weight: 535 kilograms
Charge/Weight Ratio: 37%


Color: Field grey overall with red stripes on cone.  "D500 stg" stenciled on body in black.


Construction: All bombs in the SD 500 series are of one-piece drawn steel construction.  The main difference between the three modifications is the variation in wall thickness.

One transverse fuze pocket is located aft the suspension band.  To insure high order detonation, a central exploder tube has been inserted longitudinally through the explosive cavity.

The tail unit is constructed of sheet steel and has a ring type strut.  The unit is secured to the bomb in the same manner as the tail on the SC 1000 bomb.

A parachute type tail unit for this bomb has been found.  This unit is composed of a detachable sheet metal parachute container, open lattice type parachute, and a standard base plate with an additional web and ring of cast steel spot welded together to form an anchorage for the parachute shackles.  (Only one such unit has been found.)


Suspension: Horizontal, by means of an H-type lug secured to a suspension band.

SD 1700

Overall length: 129.6 inches

Body Length: 92 inches
Body Diameter: 26 inches
Wall Thickness: 0.9 inches wall to nose 3.5 inches
Tail Width: 24 inches
Tail Length: 46.5 inches

Filling: TNT; Amatol 60/40
Weight of Filling: 730 kilograms
Total Weight: 1,703 kilograms
Charge/Weight Ratio: 43%


Color: Black or sky blue overall.  Red stripes on tail.
"D1700" stenciled on opposite sides of body in letters 40mm high.


Construction: Body is of one-piece, forged steel construction.  A single fuze pocket is used with an extension cap fuze in the nose.  The base of the bomb is threaded to take a normal female type base plate.  A cast steel kopfring is welded to the nose as a preventative against excessive penetration.

The tail is made of light alloy and is of the cylinder type.  The 8-inch wide band is attached to the fins by rivets.  This band is known as a ring-type strut.


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

Next Time: PC Bombs


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

German Explosive Ordnance - SB Bombs

German Explosives

SB 400 Kugel K - "Kurt" Apparatus

Description: The German "KURT" apparatus is a spherical, hydrostatically operated, aircraft-laid, skip bomb; a copy of a similar device used by the British.  It was designed to operate like a skipping stone over a smooth water surface for use against ship targets, power plants, lock gates, tidal installations and similar harbor facilities.

The information contained in this report was obtained through the interrogation of German scientists and prisoners of war.  Complete specimens of this device have been shipped to the United States Nay Ordnance Investigation Laboratory.

Development of the "KURT" apparatus was commenced in the late 1943 at the German airforce experimental center (E-Stelle), Travenmunde, Germany.  The original model was a sphere approximately 30 inches in diameter and weighing 400-450kg.  It contained two fuzes; one, a type 59 fuze with a 23-second powder delay train, and the other, a hydrostatic, type 44 fuze.  The effective range of this spherical missile was calculated at 400 meters.  To increase the range to 4,000 meters a rocket propulsion unit was fitted to the sphere.  Some experiments were carried out with the propulsion unit but no actual tests were made.  Work was stopped on this device in August 1944 when efforts were directed to more advanced projects.  Because of the scarcity of documents and test datum it is impossible to substantiate adequately the information obtained through interrogation.

The first experiments were carried out with a model having the same weight and dimensions as the final "KURT" warhead.  The ideal altitude for the attacking plane was calculated at 20 meters and at a speed of 700km/h.  It was found that under ideal conditions, the missile had an effective range of 400 meters.  To increase the range and to offer more protection for the attacking aircraft, a rocket propulsion unit was added.  The modified "KURT" with rocket assistance included an air tail with its elevators preset to an angle of 10 degrees to prevent sharp trajectory as in the case of the sphere without rocket assistance.  (Because of the essentially shorter running distance of the sphere without rocket assistance, sharp trajectories and slight deviations from the target course were disregarded.)  This modification proved unstable in flight because the assembly tended to rotate about its longitudinal axis, deviating from the target course to such an extent that the target would be missed completely.  To obviate this large deviation and to give the missile directional stability, a gyroscope was installed.  However, no further tests were made.


Details:

A. Warhead

-Diameter: 750mm
-Thickness of case: 10-12mm (Steel)
-Weight of charge: 300kg
-Total weight of sphere: 400-450kg

The warhead, a spherical shell, is filled with cast hexanite and contains two fuze pockets.  A transverse pocket, housing two KRUPP hydrostatic fuzes which replaced the type 59 fuze, runs through the sphere and is open at both ends.  The other pocket is set at an angle of 45 degrees to the transverse pocket and contains a type 44 hydrostatic fuze.


B. Mid-Section

The cylindrical mid-section houses a gyro unit which is operated by a gas evolved from a burning element.  It also houses the lifting lug and the explosive coupling which severs the warhead from the propulsion unit.


C. Rocket Section

The rocket section is a steel cylinder 18 inches in diameter and 36 inches long.  It houses the rocket propellant and 18 venturis.  The weight of the propellant is approximately 90 kg.


D. Air Tail

The air tail is the same as used with the bomb-torpedo.  It is made of plywood and its elevators are controlled by the gyro.  Dimensions of the air tail: 18 by 36 by 50 inches.  Total length of the KURT apparatus is 80 inches.



Operation:

A. Without Rocket Propulsion

-Plane speed: 700km/h
-Plane altitude: 20m minimum - 50m maximum
-Speed of Kugel on impact: 180 meters/second
-Effective distance: 400 meters


B. With Rocket Propulsion

-Plane speed: 700km/h
-Plane altitude: 20m minimum - 50m maximum
-Speed of Kugel with rocket assistance: 330 meters/second
-Speed of Kugel on impact: 180 meters/second
-Distance through air before impact: 1,000 - 1,500 meters
-Effective distance: 2,500 - 4,000 meters


C. The range depends on:

1. Height of plane
2. Speed of plane
3. Surface of water


Under ideal conditions the Germans considered the Kugel without propulsion 100 percent accurate at a range of 400 meters when dropped from an altitude of 20 meters at 700km/h.  If the missile was dropped from heights greater than 50 meters or at speeds less than 700km/h the effective range was decreased due to deviations from the target course.  Rough waters also caused serious deflections which could not be controlled.


D. Fuzes

In the original Kugel without propulsion, two hydrostatic fuzes were used; a type 59 fuze that was designed to operate after a delay of 23 seconds, and a type 44 fuze designed to operate at a depth of 8 meters.  The sphere was later modified to accommodate two Krupp fuzes for normal hydrostatic operation at 8 meters, and an electrical time delay fuze in case the missile penetrate the ship's hull.


E. Condenser Fuze

A condenser fuze, E1AZ 49, functions in the following manner:

1. Ignites an explosive element which starts the gyro immediately upon release of the missile from the plane.

2. Ignites the rocket propellant by exploding a 1-kg black powder charge after a delay of 0.5 seconds.

3. Allows either one of two possible types of electric fuzes used, to be armed.

4. Fires the explosive coupling after a delay of 4.5 seconds.


When the rocket propellant is ignited it burns from 3 to 4 seconds.  One-half second after the rocket impulse ceases, the explosive coupling fires, severing the sphere from the after body.  The rocket section drops off and the sphere continues toward the target.  The missile then hits the target and sinks.  When at a depth of 8 meters, one of the hydrostatic fuzes is actuated to fire the main charge.

SB 1000

Overall length: 104 inches
Body Diameter: 26 inches
Tail Width: 26 inches
Tail Length: 26 inches

Filling: RDX/A1/Wax biscuits in Trialen 106 matrix

Weight of filling: 735 kilograms
Total weight: 1,000 kilograms (approx.)
Charge/Weight ratio: 0.74% (approx.)



Construction: The bomb has a welded sheet metal body.  A drawn steel threaded nose piece is of streamlined construction to reduce air resistance while the bomb is attached to the plane.  (Earlier models had a welded nose piece.)  There is no base plate.  The bomb is filled through the nose and an exploder tube runs along the central axis from the fuze pocket to the nose.  It is filled with TNT pellets.

Electric leads run through the center of the bomb connecting fuze and nose switch.

Bomb has a drawn steel cone-type tail.


Suspension: Horizontal by H-type lugs or trunnions for use if carried by dive bombers.


Remarks: Due to its thin case and brisant explosive, this bomb is sensitive to small arms fire.





SB 1000 Parachute Bomb

Overall length: 72 inches
Body Length: 65 and 1/2 inches
Elliptical Body: 31 by 16 and 1/2 inches
Wall Thickness: 0.06 to 0.125 inches

Filling:
Main charge: Dinitro benzine (48%); RDX (15%); ammonium nitrate (37%)
Biscuit filling: ammonium nitrate (51%); calcium nitrate (31%); RDX (16%)

Charge/Weight ratio: 80%

Color: The bomb casing is painted field gray with the following markings stenciled in black along the body.


Construction: The parallel sided body of the SB 1000 is made of steel plate and is roughly elliptical in end section.  It is formed by two halves which are welded together externally.  The bomb body is strengthened by a longtudinal bulkhead and two perforated diaphragms all welded into position.  The base plate is welded into the body 2 and 1/2 inches from the end.  The recess so formed is used to house the parachute container.

The fuze pocket is welded into a slot in the longitudinal bulkhead.  Nose plate is welded into position and has in it filling holes.  There is a nose extension in the center of the nose plate which houses the impact switch 55 A/M fuze.  The fuze pocket is connected to the impact switch by two wires which are house in a metal tube.  The parachute container, a thin metal box, is positioned between two ribs riveted to the base plate.  It is secured to the base of the bomb by bolts.  Inside the outer box an inner container is welded to the base of the outer box.  Four extension springs are secured to the base of the inner container and are also attached to a plywood platform which is the base for the parachute.  The parachute is folded on the plywood, the platform depressed, compressing the spring then held in place by canvas flaps secured over the top.  The under flap carries a loop of cord which is threaded through eyelets of the other three flaps, a quick release pin is passed through the loop, thus retaining assembly against action of the spring.


Operation: On release from the aircraft the quick release pin is withdrawn from the loop by a time parachute release which can be set for delays of 2, 3, 4, 5, or 6 seconds.  This device obtains its delay by means of a spring and cog wheel.

The parachute is of coarse weave vegetable matter.  Red, green, and blue parachutes have been found.  There are 16 double parachute shroud lines.


Suspension: Horizontal.






SB 1000/410 - 52A+, 52A

No picture available

It has been assumed that the figure "410" refers to the type of aircraft by which the bomb is carred. ME 410.

SB 2500-kg

Overall length: 145 inches
Body Length: 87 and 3/4 inches
Body Diameter: 31 inches
Wall Thickness: 17/32 inches
Tail Width: 33 inches
Tail Length: 66 and 1/2 inches

Filling: 40/60 Amatol or Trialen 105

Total Weight: 2400 kilograms


Color: Sky blue overall.  Two yellow stripes are painted on the body between the tail fins.  SB 2500 is stenciled on the body.


Construction: The main difference between this and the SC 2,500-kg type Max are: the construction is of steel instead of aluminum alloy and the filling extends into the tail cone with the object of keeping the charge/weight ratio as high as possible.  The case is constructed in three parts, a cast steel nose, with a cast steel base welded to the cylindrical body.  The nose of the bomb is fitted with a filling plug to which is fitted a tube extending to the forward fuze pocket, the tube houses a rod which on impact crushes the impact fuze and activates the bombs.  There are two transverse fuze pockets; the forward pocket houses the anti-break-up fuze and the after pocket is for the normal impact type fuze.

The tail unit is a four fin drum type.  The cone portion is sheet steel and the fins and tail drum are constructed of alloy.


Suspension: Horizontal by an H-type lug.  The suspension lug is keyed to a securing plate locked by bolts.

Next Time: SD Bombs


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