German Explosive Ordnance - Rockets (Part 15)

German Explosives

8-cm R Lg 1000 Rocket

Description: The 8.6 cm R lg 1000 (flare) and the 8.6 cm R Dg 1000 (wire) differ only in the contents of the body.  The flare rocket contains a parachute-suspended flare having a burning time of 30 to 35 seconds.  The wire rocket contains, in place of the flare element, a spool of wire which is suspended by the parachute.  No explosive is attached to either the parachute or the wire.  

The flare element is contained in a light metal can which is directly above the base delay pyrotechnic fuze.  The parachute fits above the wooden plug midway up the tube.  The forward end of the body is closed with a light ballistic cap which is pushed out by the ejecting parachute-flare unit.  The base of the body is closed with a wooden block which rests on the lip of the adapter.  The adapter is welded to the body and serves as a bourrelet as well as the attachment between the motor and the body.  The pyrotechnic time base fuze of 8.5 seconds burning time is ignited by the burning of the propellant in the rocket motor.

The motor is similar to that of the 8.6 cm R Sgr L/4.8 except that the nozzles are changed to accommodate the reduced propelling charge.

The black powder propellant grains 100 mm long and 70 mm in diameter, weighing 750 grams, is mounted in a manner similar to the Spgr L/4,8.  The diglycol propellant consists of two concentric cylinders 80 mm in length and having diameters of 70/40 and 35/5 mm, weighing 420 grams.  A flash tube runs through the central 5-mm diameter hole of the inner grain from the rear igniter up to the forward igniter.  The igniters and grains are held in position by a three-armed grid at each end of the grain.  It is indicated that the grid is of plastic material instead of the usual metal construction

Motor:

Propellant: Black powder, Diglycol

Nozzles: 8, 4

Throat Diameter: 4,5, 5.45

Cant angle: 9 degrees

Nozzle K: 234, 480

Performance:

Thrust: 150

Burning Time: 1.2

Impulse: 80

Range: 1,000 meters

Nozzle:

Diameter of Jet ring: 69±0.1 mm

Entrance cone angle (first): 60 degrees

Entrance cone angle (second): 15 degrees ±15 min

Length of cone (first): 1.5 mm

Length of cone (second): 5.5 mm

Throat Length: 3.0±0.5 mm

Expansion cone angle: 1 degree ±10 min

Launching: The launcher used in the various tests consists of a single barrel weighing 40 kg.  It is denoted as the 8.6 cm R Ag M 42.

8.6-cm Anti-Aircraft Rocket (Spin Stabilized)

Overall Length: 16.5 inches

Diameter: 3.39 inches

Total Weight: 11 pounds

Description: This rocket is constructed of steel in four sections; Projectile body, parachute container, cable container, and rocket motor.

Projectile Body: The projectile body consists of a cylindrical container, internally threaded aft to receive the rocket motor and open at the forward end to receive the parachute container.  The body of the projectile has a raised pressing near the center of its length to provide a forward bearing surface while in the projector.

Parachute Container: The parachute container is divided longitudinally into two halves held together by adhesive tape and is a sliding fit in the forward end of the body.  The parachute measures 20 inches deep by 36 inches in diameter when open, and is made of yellow silk with a red stripe running down the center of each gore.

Cable Container: The cable container is located in the body just aft of the parachute container.  The cable container is nothing more than a steel cylinder filled with 310 feet of steel wire.  The forward end of the wire is attached to the parachute shrouds.  Separating the cable container from the head of the motor is a perforated wooden distance piece, which is recessed to form a seating for an ejection charge and centrally bored to house a delay tube containing black powder.

Rocket Motor: The motor consists of a steel tube 1/8-inch thick, closed at its forward end, which is drilled centrally and threaded to receive the delay tube.  The propellant grain is a single solid cylinder, and is primed at the base end with gunpowder.  The motor is closed at the after end by a threaded venturi assembly drilled around the outer periphery to form 8 jets.  A percussion cap is fitted in a central hole in the base of the venturi assembly.

Operation: Near the end of the burning period of the rocket motor, the delay tube is initiated by the heat of the burning propellant and eventually ignites the ejection charge at the base of the cable container.  The explosion of this charge ejects the cable and parachute containers from the forward end of the body and splits open the parachute container.  The parachute opens and withdraws the coiled cable from its falling container.

Remarks: This round was originally designed to protect small naval vessels and merchant shipping from low-level attack, but it may have played a ground role as well.  The ceiling of the rocket is estimated at about 8,000 feet.

Next Time: Rockets (Part 16)

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

German Explosive Ordnance - Rockets (Part 14)

German Explosives

8-cm Raketen Sprenggranate (H.E. Aircraft Rocket)

Caliber: 78 millimeters

Overall Length: 28.5 inches

Weight (complete round): 15 pounds 3 ounces

Filling: Flaked TNT

Warhead Material: Steel

Rocket Motor Material: Steel

Warhead Length: 8 inches

Warhead Diameter: 3 inches

Rocket Motor Length: 12.8 inches

Rocket Motor (outside): 3.07 inches

Rocket Motor Diameter (inside): 2.75 inches

Rocket Motor Weight: 4 pounds 5.25 ounces

Venturi Material: Steel

Venturi Length: 7.48 inches

Outside length of fins: 5.31 inches

Rear diameter across fins: 

-External: 7.87 inches

-Internal: 3.34

Venturi Weight: 2 pounds 0.25 ounces

Inlet Maximum Diameter: 2.48 inches

Inlet Minimum Diameter: 0.782 inches

Inlet Length: 0.92 inches

Throat Diameter: 0.782 inches

Outlet Maximum Diameter: 1.653 inches

Outlet Minimum Diameter: 0.782 inches

Grid Diameter: 2.72 inches

Grid Thickness: 0.51 inches

Grid Weight: 3 ounces

Propellant: Double base powder in mono perforated stick form.

Description: This is a fin-stabilized projectile with an appearance typical of small caliber aircraft rockets.  The internal arrangement of the projectile suggests that it was possible copied or adapted from a standard Russian aircraft rocket.  Although this rocket almost certainly was designed primarily as an aircraft weapon, it was also fired from a multiple-frame ground launcher known as the 8-cm Raketen Vieflachwerfer.  The projectile consists basically of an H.E. warhead, a rocket motor, and a tail unit incorporating a single venturi and stabilizing fins.

Warhead: The warhead of the projectile is a steel cylinder with an ogival nose into which is built a fuze system.  The rear of the head is closed by an adapter plug which also forms the junction with the rocket motor.

The main H.E. filling consists of a pressed flake TNT and is built up from three perforated pellets which fit around the exploder tube incorporated in the fuzing system.  At the nose end is a small cardboard washer; at the base are two waxed-paper washers; and around the exploder magazine is a waxed-cardboard tube.  Between the shell wall and the explosive is a thin layer of bituminous material.  The outer surfaces of the pellets are waxed.

Rocket Motor: The body of the motor is formed by a cylinder which is machined down slightly between the ends.  The forward end of the cylinder is threaded internally to screw over the adapter plug which forms the junction with the warhead.  Four studs in the body, two at each end, guide the projectile in the launcher.  The base of the motor body is closed by the motor closing plate, which is in the form of a single venturi to which four stabilizing fins are spot welded.

The propellant consists of six sticks, of which two are slightly shorter than the other four.  The four longer sticks are located by a supporting grid which is a push fit in the venturi assembly.  The other two sticks are supported on the two primary igniters attached internally to the walls of the rocket motor.

The ignition system consists of two ignition charges, one at each end of the propellant, and a primary igniter.  The primary igniter is in the form of two copper tubes, each screwed internally over the end of the steel guiding studs which pass through the motor body at the rear end.  A brass rod, insulated by a rubber sleeve, passes through the guiding stud and bears against a brass contact inside the copper tube.  This contact passes through the tube into a small cardboard container holding a loose composition charge of gunpowder.  Wires from the contact to the walls of the copper tube serve to ignite the charge.  The circuit is presumably formed by two leads, one to the brass rod in each guiding stud, and is grounded to the rocket body.

Fuzing System: This rocket has a fuze which has been designed specifically for it.  The fuze consists of a steel nose piece which contains a light alloy striker supported by a light creep spring.  Below the nose piece is a steel magazine tube, into the forward end of which is screwed the detonator housing.  Directly below the magazine tube is the arming mechanism which consists of a metal sleeve, containing a spring loaded screw and the plunger.  Holding the spring loaded screw and the plunger in position is a fusible metal ring.  When assembled, the plunger fits into the lower end of the magazine and the booster pellets rest on it.

When the rocket is fired, the heat of the burning propellant is conducted through the wall of the spigot and melts the fusible metal ring.  The plunger, magazine, and detonator are then free to move forward under the action of the spring.  The extent of this forward movement depends upon the acceleration of the rocket.  Approximate measurements indicate that if this is less than 40-50 grams the detonator is sufficiently forward to be fired by the striker.

8.6-cm H.E. Rocket (Spin Stabilized)

Nature of Projectile: Multiple base-venting, spin-stabilized pusher rocket.

Caliber: 8.6 centimeters

Overall Length: 16.25 inches

Overall weight: 17 pounds 15 ounces pounds

Nature of filling: H.E.

Nature of the fuze: Base

Warhead Length: 9.55 inches

Warhead Diameter: 3.35 inches

Type of Filling: Cast TNT

Rocket Motor Length: 6.7 inches

Length of Propellant Chamber: 6.08 inches

External Diameter: 3.18 inches

Internal Diameter: 2.94 inches

Weight of Filled Motor: 6 pounds 12.25 ounces

Propellant Length: 5.9 inches

Diameter of Propellant: 2.78 inches

Weight of Propellant: 2 pounds 7.75 ounces

Analysis:

-Potassium Nitrate: 75.5 percent

-Carbon: 15.35 percent

-Sulphur: 9.15 percent

-Volatile Material: 0.86 percent

Description: This rocket consists of a H.E. head, a motor, and a venturi assembly.  An integral base fuze, centrifugally armed and pressure fired, is located int he base of the H.E. head.

The H.E. head threads over the rocket motor housing, which contains a single, multi-perforated, propellant grain.  A venturi assembly, with eight jets drilled in it, is threaded to the base of the motor.  A single threaded hole in the center of the venturi assembly contains a percussion primer.  On the forward end of the motor housing is a fitting which receives one of three interchangeable delay trains.  The rockets bear markings to indicate which of the delay trains have been assembled.  Those marked "/400/" and "/800/" contain, in addition to the delay train, a fuze with a striker retained by four arming balls and a spring collar.  A light anti-creep spring is placed between striker and the detonator.

Centrifugal force causes the balls to move outward against the collar and arm the fuze.  The delay train is initiated by the propellant grain, and when the delay expires, the pressure developed forces the striker against its spring and into the detonator.  Impact with some resistant object before the expiration of the delay will force the striker into the cap.  In the case of the round marked "/600/" no striker mechanism is included, and the delay initiates the detonator and booster directly, giving only self-destroying action.

Remarks: This is a naval round, designated "8.6 cm R. Spr. 400 Wsm. (600 Wsm, 800 Wsm)."

The H.E. head is painted canary yellow overall; the motor body, dark green.

It is estimated that this projectile would reach a maximum height of 8,000 feet, if fired at a quadrant elevation of 90 degrees.

Next Time: Rockets (Part 15)

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

German Explosive Ordnance - Rockets (Part 13)

German Explosives

7.3-cm Propagandagranate 41

Weight (w/o Leaflets): 7 pounds 3 ounces

Length Overall: 16.1 inches

Weight of the Propellant: 1 pound 1 ounce

Weight of Propellant Unit: 3 pounds

Maximum Diameter: 2.85 inches

Description: The projectile consists of two steel tubes, screwed into a central joint.  The lower tube contains the rocket motor and the upper tube serves as a container for the leaflets.  The projectile is spin stabilized and is fired from the Propagandawerfer, which is a single launching tube.

The rocket motor is formed by the lower tube and a screwed-on base plug.  The base plug has 12 venturi set in 2 rings; those in the inner ring are straight and those in the outer ring are offset.  A copper percussion cap is located centrally in the base of the plug.

The propellant consists of a cylindrical stick with nine longitudinal drillings.  One of these is central, and the other eight are in a ring around the central drilling.  An ignition charge is located in a holder at the forward end of the propellant.  This is fired by the flash from the percussion cap passing up the central hole of the propellant.

The upper tube is the leaflet container and it is closed by a bakelite cap.  The leaflets are contained within a cylinder split longitudinally and are wrapped around a steel spring which is kept under compression.  Below the leaflets, one bakelite washer and two cardboard washers, is the bursting charge, incorporating a delay train which is fired by the heat from the ignition charge for the propellant.

Operation: The operation of this projectile is very simple.  When the heat from the ignition charge ignites the bursting charge, the contents of the upper tube are ejected; as the split cylinder emerges, it falls apart and allows the compressed spring to scatter the leaflets packed around it.

7.3-cm Raketen Sprenggranate

Caliber: 7.29 centimeters

Overall Length: 11.09 inches

Overall weight: 6 pounds

Nature of the fuze: Nose percussion

Warhead Material: Steel

Overall Length: 4.22 inches

Maximum Diameter: 2.85 inches

Diameter at Nose: 0.81 inches

Wall Thickness: Varies from 0.23 inch aft to 0.12 inch forward

Weight of Filling: 0.62 pounds

Overall Length (Body Tube): 6.34 inches

Overall Diameter (Body Tube): 2.6 inches

Wall Thickness (Body Tube): 0.1 inches

Overall Diameter (Base): 2.86 inches

Overall Height (Base): 1.29 inches

Number of Venturi: 14

-7 offset (outer circle)

-7 straight (inner circle)

Description: This is a spin-stabilized projectile of conventional design, consisting of a warhead and a rocket motor.  The projectile is essentially the same as the 7.3cm propagandagranate 41, except that a warhead provided with a percussion fuze and self-destroying delays has replaced the leaflet container.

The projectile is fired from the Fohn Gerat, a 35-frame launcher with fast elevating and transverse gears.  The launcher is capable of firing 35 rockets simultaneously.

The self-destroying feature of the rocket plus the characteristics of the launcher suggest that the projectile is intended for use against low flying aircraft in the form of barrage fire.

Warhead: The warhead is ogival in shape and open at the rear where it is threaded internally to receive the rocket motor.  The explosive filling is a preformed charge of 280 grams of RDX/TNT/wax pressed in a block and wrapped in wax paper.

The warhead is double fuzed, being fitted with a nose percussion fuze and a self-destroying base fuze.  The RAZ 51 is screwed directly into the nose of the warhead.  In the base of the charge is a cavity which accommodates the self-destroying delay, located in a tube screwed into a metal plug int he forward end of the motor.  The delay consists of a quick-fire igniter, initiated by the motor ignition charge, and what appears to be a tracer composition.  When the tracer composition burns out, it flashed through an orifice into a primer-detonator which detonates the main charge.

Rocket Motor: The rocket motor consists of a plane cylindrical body and a cup=shaped base plate.  The body is screwed into the warhead at the forward end and into the flange of the base plate at the rear.  The forward end of the rocket motor has a flange below which is located a metal closing plate which separates the warhead from the propellant compartment and also holds the rear end of the self-destroying assembly for the explosive charge.  Below this plate is a stamped metal supporting ring containing the ignition charge for the propellant.

The base plate, which screws on the rear end of the body, has seven outer offset venturi, seven straight venturi, and a central drilling for a percussion primer. 

The propellant charge consists of a single cylindrical stick with a central perforation and eight outer perforations.  Raised ribs around the circumference of the propellant serve to keep it clear of the motor body and permit external burning.  Two 1/8-inch blocks of powder, cemented tot he base of the charge, act as spacers and keep the venturi free from obstruction.

The charge is ignited by the flash from the percussion primer.  The flash is transmitted along a celluloid tube in the central drilling to the ignition charge at the froward end of the propellant.  The celluloid tube is of conventional design.  It contains a quickmatch train and is closed at each end by a cylindrical block of gunpowder.

Next Time: Rockets (Part 14)

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

German Explosive Ordnance - Rockets (Part 12)

German Explosives

A-9 / A-10 Long Range Missile

Description

The A-9 is similar in appearance and results to the A-4b but is of different internal construction.  It was proposed to develop and manufacture the A-9 in place of the A-4; however, this would require much reconversion and the A-4b, which could be put into operation much quicker, was being pushed as a stop-gap.  It was to have a Salbei-Visol rocket motor very similar to the missile Wasserfall.  It is shot into the air like a V-2 and vent toward the target, but rather than falling, it glides over the target where it goes into a vertical dive.  It would travel about 600 km in 17 seconds.

A proposal was made to launch it from a catapult at supersonic speed to increase the range.  It was also proposed to install a pressurized cabin and use a human pilot.  The pilot would drop the warhead on the target and then return to his base.  A retractable landing gear would be used in the landing which, it was felt, could be carried out at a speed as low as 160 km/h. 

Although the A-10 was never built, the calculations were completed for this unit which was to be used as an assist take-off motor for the A-9.  It supplies a thrust of 200 tons and would be jettisoned after it had served its purpose.  When the A-10 is jettisoned, the A-9 would have a velocity of 1,200 meters per second and the A-9 motor would begin to function.  The ultimate velocity was expected to be 2,800 meters per second.  The A-9/A-10 combination was expected to have a range of 5,000 km. 

It was also proposed to use a human pilot in this combination.

Next Time: Rockets (Part 13)

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

German Explosive Ordnance - Rockets (Part 11)

German Explosives

Great Enzian

Description

The Enzian was conceived as a ground to air flak weapon.  Its secondary purpose was that of an air-to-air weapon.  Models E-1, E-2, and E-3 were the test and experimental articles.  All flight tests were carried out with the E-1.  The E-4 was the production design using an improved rocket motor, designed by Dr. Conrad instead of the Walter biliquid used int he earlier designs.  As the foregoing is the only major difference in the four models, they will be discussed as one: however, there exists another type, E-5, which being a basically different type will be covered in a separate report to avoid confusion.

The E-4 is a flying wing design of striking similarity to the Me-163.  Its total weight is 1,800 kg which includes the weight, 320 kg of the four assisted take-off units.  The warhead's weight is 500 kg.  The airplane is constructed of wood, having an overall length and span of four meters.  It attained its velocity of 300 m/sec with a main thrust unit delivering 2,000 kilograms initially decreasing to 1,000 kilograms during the flight.  Duration of power was 72 seconds, resulting in a vertical range of 16,000 meters and a horizontal range of 25,000 meters.

The four assisted take-off units deliver a combined thrust of 6,000 kilograms for 4 seconds, giving the missile which attains an end speed of 24 m/sec and an acceleration of 3.6 g from a launching ramp 6.8 meters in length.  The assisted take-off units are jettisoned after 5 seconds.

Although it was anticipated that E-4 would be used as an air-to-air weapon with slight modification, principally reduced fuel load, all experimental flight testing had been done from ground to air.  A standard 88 mm gun carriage was adapted for use as a launching platform by the simple addition of two iron rails 6.8 meters long.  A traverse of 360 degrees and a vertical firing arc from 0 to 85 degrees were obtained.  Air launching of the device was routine; i.e., dropping free from underneath the parent aircraft flying in the direction of the target.

The speed on leaving the launching rails is 24 m/sec; to avoid the possibility of stall no control is applied until the flying speed has reached approximately 55 m/sec.  For practical purposes an elapsed time of 5 seconds is allowed between the triggering of the launching mechanism and the first control signal.  The Enzian, as were practically all German guided missiles, was directed to the target vicinity by radio control.  When the target approach was within the range of the homing device, the latter took charge of the missile's final run in.  Coincidence or line of sight navigation was used under favorable conditions; however, several methods were accepted for night or reduced visibility use.



Airframe


The Enzian E-4 airfram was a flying wing type having no horizontal stabilizer and a fixed vertical fin.  Control was effected through trailing edge flaps which act together as elevators and differentially as ailerons.  The basic dimensions are as follows:


Length: 4 meters
Span: 4 meters
Maximum Diameter (Fuselage): 0.88 meters (Circular cross section)

Root Thickness: 20% root chord
Tip Thickness: 10% root chord
Wing Area: 5 square meters
Airfoil: NACA symmetrical; no twist.
Dihedral: Zero
Chord Root: 1.25 meters
Chord Tip: 0.98 meters
Sweepback: 30 degrees

Weight (E-4 Complete): 1,800 kilograms
Empty (including Warhead): 833 kilograms
Warhead: 500 kilograms
Motor: 97 kilograms
Fuel: 550 kilograms
Assisted Take-off Units: 320 kilograms
Airframe (including Control Gear): 333 kilograms


For the purposes of an air-to-air missile, the fuel weight was reduced to 150 kilograms and the assisted take-off units discarded.

The airframe was designed to be built of wood because of current metal shortage, but provisions were made for conversion to metal stampings.  The production process was to use hot plate gluing methods for fabricating a pressed or plywood material.



Aerodynamic Peculiarities and Characteristics


Aerodynamically, the E-4 appears normal.  Its stability in flight tests was accepted as good.  The E-4's design performance follows:

Maximum Velocity (Design): 300 m/sec
(Measured Walther Motor): 240 m/sec

End Speed Launching: 24 m/sec
Minimum Speed for Safe control: 55 m/sec

Vertical Range: 16,000 meters
(Measured Walther Motor): 7,000 meters

Horizontal Range: 25,000 meters
Turning Radius: 500 meters



Propulsion Unit


Although the Walther power plant was originally intended fo rthe Enzian and was used in the test flights, it was entirely unsatisfactory and replaced by the Conrad motor.

The bifuel liquid rocket motor uses Salbei (92% HNO3 + 8% H2SO4) and Visol, the ratio of weights being 1.4 to 1.  The total quantity of fuel, 550 kg, is exhausted in 72 seconds during which time the thrust is reduced from its initial 2,000 to 1,000 kg at the end of burning.  As pressure reduction between the air bottle and liquid tanks is through a simple orifice plate, the progressive reduction in the combustion chamber operating pressure is the direct result of the air bottle's gradual exhaustion.  Equal pressure is applied to both liquids and metering is effected by the resistance of the connecting pipes and not that of the nozzles.  The total impulse (108,000 - 110,000 kg sec) corresponds to a mean S.I. of 199; however, Wurster states that the mean propellant consumption 5.5 gm/kg sec rises to 5.6 at start and end of burning operation and that the S.I. is of consequence approximately 182.

Although the mixture, Salbei and Visol, is spontaneously inflammable, the Enzian motor used an electrically ignited powder starter in the combustion chamber to effect ignition.  This system had the advantages of smoother ignition and less risk of explosion than spontaneous combustion.  A further precaution against explosion was taken by starting the Salbei feed first by shortening its supply pipes and setting its bursting disks at slightly lower pressure than those of the Visol system.

The propulsion unit's arrangement, dictated by C.G. considerations, as follows: (1) Air bottle; (2) Visol tank; (3) Salbei tank; (4) Combustion chamber.  The air flask was originally inflated to a pressure of 200 atmos.

The liquids are retained in their tanks by means of bursting disks selected to rupture at 15 atmospheres at entry and 36 atmospheres at exit.  All tanks are made of mil steel 2 mm thick and no corrosion treatment, enamel, or protective coating was employed as the only General Staff requirements was that the containers should withstand 6 months storage after being filled with Salbei and fuel.

The weights of component parts of the motor are as follows:


Combustion Chamber: 24 kilograms
Air Bottle: 19 kilograms
Spherical Tank: 30 kilograms
Spherical Tank: 24 kilograms; 97 kilograms
Fuel Weight: 550 kilograms

Effective S.I. Fuel and Motor = 199 x (550/647) = 170

Relative to use of an air pressure fuel feed system versus a turbine-pump system, Wurster states that according to German figures, the former is lighter up to impulses of 200,000 kg/secs and has the additional important advantage of requiring no time for running up to speed.  He cited the Me-163 which requires 4-5 seconds to run the turbine up to its operational speed of 30,000 pointing out that such delay is prohibitive for a flak rocket.


Intelligence and Control Systems


Operationally it was expected to use the Enzian in the following manner:  Launch it toward and direct it to the target vicinity under radio control using the new German equipment Kogge and either line of sight or radar navigation.  When the missile's approach to the target came within the operating range of the particular self-seeking head employed, the latter would assume control and direct the Enzian to the target's proximity on a modified homing course.  The proximity fuze at pre-determined distance activates the warhead which was designed to ensure maximum coverage and effective damage of the target from 45 meters.

It is considered pertinent to note here that the Germans were doing extensive research work on the theory of homing courses.  Their principal investigations appeared to be based on compromises lying between a pure chaser or homing course and a straight interception route procured by interjecting self-navigation into the intelligence system

Initial planning provided for the Enzian's use of one of several typo homing devices and proximity fuzes currently being developed or combinations of the above.  Tests had not progressed beyond operation with the standard German radio control, the 6-meter "Strassburg-Kehl", developed by Telefunken and Strassfurt Rundfunk.  The "Kogge" designed by Telefunken to operate on a 24-cm wave length was destined for use in the production Enzians.

The I.R. device, "Madrid", developed by Kepka of Vienna, an acoustic device developed by Telefunken and Messerschmitt, or an electronic device were projected for use as homing heads.  These articles had been laboratory tested by their manufacturers only as separate entities.

Metamorphosis of the internal control system from two axis stabilization involving the use of four gyros to acceptance of one axis stabilization using a Horn gyro having two gymbal rings is outlined above under experimental testing.  Standard Siemens electric servos are used to actuate the control surfaces.



Warhead and Fuzing


Three types of wrhead of equal weight, 500 kilograms, were projected for the E-4.  The type which seemed to have accrued the most favor among the Messerschmitt engineers and the local flak officers was built up of a metal shell or container 1.5 mm thick.  The shell was lined with cylindrical pellets cast of mild steel 20 by 30 mm containing an incendiary core!  The explosive cast into the resulting cavity contained a booster charge and fuze in its forward end on the longitudinal axis.

Tests of the above type warhead showed that it could be expected to put 1.5 pellets in an area of 1 square meter at a range of 65 meters.

The second type of warhead incorporated 550 small rockets driven by gunpowder which had been developed by one of the SS laboratories and were to be used as part of the armament of the Me-262.  The rockets were mounted in the warhead to fire forward in a 30 degree cone from a maximum range of 300 meters; their effective range, however, was 550 meters and at that range each rocket was considered capable of destroying a bomber.

The third type warhead was straight explosive dependent only on concussion to destroy the target.

Both proximity and self-destruction fuzes were provided.  The proximity fuzes were projected on the I.R., Electronic, and Acoustic principles; however, the latter had essentially been dropped by the designers as the maximum range at which the actuating impulse was of sufficient magnitude was too small to derive most effective results from the warhead.



Auxiliary Equipment


Four powder jets assisted take-off units delivering a total of 6,000 kilograms thrust for 4 seconds are used to launch the Enzian.  The JATO's produced by Rheinmetall-Borsig weigh 80 pounds each.  They are attached by explosive bolts which release the cases by firing at the end of burning.  Small wings fitted to the JATO's assist in the jettisoning.

Next Time: Rockets (Part 12)

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

German Explosive Ordnance - Rockets (Part 10)

German Explosives

Feuerlilie Model F-55

Description

The F-55 is another of the Feuerlilie series of rocket-propelled guided missiles which the LFA (Luftahrtforschungsanstalt Hermann Goering E.V.) located at Volkenrode/Braunschweig, Germany was developing in order to obtain aerodynamic data in the transonic region.  Although the primary purpose of the Feuerlilie series development work was to obtain aerodynamic test data, there is evidence that a certain amount of thought was being given to the possibility of using the F-55 as a weapon.

The Feuerlilie F-55 has a fuselage 4.8 meters in length and a diameter of 55 cm.  The wing span of the two main fins which are attached to the afterbody of the fuselage is 2.6 meters.  The first F-55 had a solid propellant rocket drive, but later models used a liquid rocket motor with a dry powder assisted take-off unit.

The F-55 was to be ground launched and it was expected to reach an altitude of 4,800 meters with a maximum horizontal range of 7,500 meters.  Elaborate plans were also being made to install telemetering and to follow the flight path of the missile by cine-theodolites.

History of Development

Development work on the F-55 was started about May 1944 by Dr. Gerhard Braun of LFA.  The body for the F-55 was built by Ardelt Werke, Eberswalde, Breslau.

The production scheduled for experimental models of F-55 for the year 1945 called for a total of 35 with deliveries of at least 3 per month for the first 10 months of the year.  These were to be tested with various stabilizing systems and the later models were also to be equipped with telemetering and remote control equipment.

The first model of F-55 with solid propulsion was tested at Leba, Pomerania in May 1944, with satisfactory results, a Mach number of 1.25 being attained.  The second model with a liquid fuel system and take-off unit was tested at Poenemunde on 11 December 1944; this model went into a spin about its pitch axis shortly after leaving the launching track.  The third model had been sent out to Poenemunde for testing, but had not yet been tested.


Conclusions

Since the Feuerlilie F-55 was primarily a research project, it is of interest largely from the standpoint of the methods tried and the techniques of flight observations used.

As the F-55 like the F-25 was a manifestation of the Velkenrode research groups' ideas, it undoubtedly represents a high order of an aerodynamic development and requires treatment as such.  The Braunschweig documents, duplicated by the United States Army Air Forces and evacuated to Wright Field, Dayton, Ohio, include comprehensive reports on the Feuerlilie series.


Details

Airframe

The airframe of the Feuerlilie F-55 consists of a fuselage 4.8 meters long, and having a maximum diameter of 55 cm.  There are two sharply swept back wings having a span of 2.6 meters.  Two vertical fins are mounted at the extremities of the wings, this position being chosen to keep them out of the wake of the body.

The outer halves of the training edges of the wings are movable so as to give aileron control.  No rudder is provided, yaw control being obtained from aileron action.


Power Plant

The power plant used for the first model of F-55 was the RI 503 solid propellant type built by Rheinmetall-Borsig.  For the second and third propulsion unit designed by Dr. Contrad of DVX (Deutsche Versuchsanstalt fur Kraftfahrzeug und Fahrtzeugmotoren) located in Berlin.  In addition, an assisted take-off unit.  "Pirat," a solid propellant rocket was used.




Design Data

SG 20
Thrust: 6,400 kilograms
Time of burning: 7 seconds
Weight of fuel: 210 kilograms
Impulse: 45,000 kg/sec


Pirat ATO
Thrust: 10,000 kilograms
Time of burning: 2.7 seconds
Weight of fuel: 150 kilograms

Impulse: 27,000 kg/sec



Control System

On the first model of F-55, no roll stabilization was used.  On the second and third models, gyro equipment developed by Fischl of DFS (Deutsche Forschungsanstalt fur Segelflug) was tried.  This system used a single gyro with Askania pneumatic rubber servos.

It was expected that the rubber would provide the necessary mechanical damping, but due to the fact that the only test flight on which this system was used failed, it was impossible to determine whether or not this was the case.  On subsequent models, it was proposed to use a Horn gyro system consisting of two gyros, one of which was used for damping only.  This system was also to be used with the Askania pneumatic servo systems of remote control.

In connection with the Feuerlilie program, a new telemetering system "Stuttgart" had been developed which had 12 channels and gave 20 values per second with an accuracy of plus/minus 5 percent.  This system was designed by the Forschungsanstalt Graf Zeppelin, located at Stuttgart/Ruit.


Warhead and Fuzing

Since the F-55 was primarily a research missile in the early stages of its development, there was no provision made for a warhead.  Like the F-25, a Rheinmetall-Borsig time fuze was used to ignite the flares mounted on the wing tips to insure satisfactory tracking of the missile in flight by means of cine-theodolites.


Launching

The F-55 was launched from an inclined ramp built by Ardelt Werke, Breslay.  The launching angle was 20 degrees to the vertical.

Rheintochter

General Description

The Rheintochter is a radio-controlled anti-aircraft rocket designed for ground launching against bomber formations.  The first model Rheintochter 1, is a two-stage rocket having a total launching weight of 1,750 kg.  The starting rocket has a burning time of only 0.6 seconds, after which it drops off, the main stage then being automatically ignited.  Stabilization was achieved by six fins attached to the rear of the main body of the rocket and four fins attached to the starting unit.  The rocket was to be remote radio controlled with the possibility of using an infra-red homing device together with a proximity fuze to detonate the missile in the midst of the bomber formation.  The control surfaces were located at the nose of the missile.  It attained a final velocity of 360 meters per second, and could reach a height of 6 kilometers with a maximum horizontal range of 12 kilometers.

The Rheintochter 1 was replaced by the development of the Rheintochter 3.  The remainder of this discussion will be on the second model and will go into considerable detail.

In the Rheintochter 3, the rear take-off unit was dispensed with and replaced by two auxiliary take-off units mounted on the sides of the body of the rocket.  The main rocket stage could be either a liquid or a solid propulsion unit, depending on the availability of fuels.  The Rheintochter 3 is designated as R-3f when a liquid propulsion unit is used and R-3p when a solid propellant is employed in the main rocket stage.  The control and steering mechanism are identical in both Rheintochter 1 and Rheintochter 3.  The Rheintochter 3, however, is allowed to rotate about its axis in flight and instead of six stabilizing fins, it is provided with only four.

Details

Airframe

The Rheintochter 3 consists of a main fuselage 500 cm long and 54 cm in diameter, having four large swept-back main fins and two auxiliary take-off units mounted on the sides of the body between the two pairs of fins.  As in the Rheintochter 1, the control surfaces are mounted in the nose section but are of a somewhat different aerodynamic design. 

The main fin span is 220 cm, the four fins being attached to the body so that the angle between successive fins is 90 degrees.

As in Rheintochter 1, the main fuselage is constructed partly of aluminum plate, partly of steel alloy plate and partly of a material called ELEKTRON.  The fins were to be constructed of LIGNOFOL, a highly compressed laminated wood, but for mass production purposes, plywood could have been used.



Design Data


Length: 500 centimeters
Span: 220 centimeters
Diameter: 54 centimeters

Weight (Empty): 525 kilograms
Take-off Units: 440 kilograms
Main Stage Fuel: 88 kilograms
Main Stage Oxydizer: 336 kilograms
Main Stage Compressed Air: 18 kilograms

Explosive (Weight): 160 kilograms
Launching Weight: 1,570 kilograms
Weight at Target: 685 kilograms



Power Plant

A. R-3f Liquid Propulsion Unit: The R-3f liquid propulsion unit requires fuel tanks carrying 336 kg of Salbei, 88 kg of Visol and 18 kg of compressed air at a pressure of 250 atmos to provide pressure feed to the combustion chamber.


B. R-3p Solid Propellant Unit: The R-3p solid propellant unit utilizes 5 rods of diglucol dinitrate weighing 90 kg each, making a total weight of 450 kg.



Design Data (R-3f)

Launching Altitude: Angle
Total launching impulse: 105,000 kg/sec
Velocity at end of combustion: 410 m/sec
Velocity at target: 400-200 m/sec

Take-off units: 2 dry powder rockets
Take-off unit impulse: 25,000 kg/sec
Take-off unit thrust: 28,000 kg/sec

Main stage rocket impulse: 80,000 kg/sec
Main stage burning time: 45 sec
Main stage thrust: 1,700 to 2,300 kg



Control System

Since remote control radio roll stabilization was found to be unsatisfactory, it was decided that Rheintochter 3 would be allowed to rotate at the rate of one revolution per second about its longitudinal axis, just as X-4 rotates.  Since the X-4 gyrocommutator system for converting control impulses to the proper control surfaces in turn was available, it was thought that this system could also be used for Rheintochter 3.

The combination radar tracking and remote control system "Elsass" or possibly "Brabant", the decimeter version, was to be used for guiding the flight of the Rheintochter 3, just as proposed for Rheintochter 1.  However, the "Elsass" development was not far enough along to permit field tests to determine whether it was satisfactory.



Warhead and Fuzing

In the liquid propulsion version R-3f, the warhead is carried between the Salbei and Visol fuel tanks in that section of the main fuselage to which the main fins are attached.

In the solid propellant version R-3p, the warhead is located farther forward between the control compartment and the propelling charge.  The warhead consists of 150 kg of high explosive.

The fuzing system for Rheintochter 3 had not been finally decided upon.  Several plans were under consideration, all of which contemplated the use of a complicated fuzing system, which would not only serve to detonate the missile, but also take care of detaching the ATO units after one second and igniting the main jet.  In addition, of course, a time feature would be embodied to detonated the missile after 50 seconds in the air so that it would not fall and explode on friendly territory.  The Rheintochter 3 was also to be fitted with an impact fuze and a proximity fuze of some sort, either acoustic, infra-red, or radio.  Among the proximity fuzes considered were "Kranich", "Kakadu", "Marabu", "Fox", and several others.

As pointed out, plans were also under way to utilize some sort of homing device in Rheintochter, but these plans were still in a very nebulous state.


Auxiliary Equipment


Like Rheintochter 1, Wasserfall, and the other guided AA rockets, Rheintochter 3 requires a great deal of auxiliary ground equipment, such as computers, optical gear, range finders, etc, for remote control purposes.



Launching Equipment

The launching equipment for the Rheintochter 3 is identical to that used by the Rheintochter 1.

Next Time: Rockets (Part 11)

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