By mid-1942 the shortage of tungsten needed for production of anti-tank artillery shells was so critical that the Heereswaffenamt issued a specification calling for a Panzerabwehrrakete (anti-tank missile) fitted with hollow charge warhead.
Early in 1943, Dr. Otto Kramer began the development of a wire-guided missile at the DVL Research Institute.
In January 1944 the Oberkommando der Heeres (OKH) placed a development contract for the Kramer missile to Ruhrstahl Presswerke AG, under the “X7 Rotkäppchen” codename.
Kramer decided to use the wire-control system Detmold FuG 238/Düsseldorf FuG 510
to steer the missile by means of a single gyro-stabilized spoiler.
During the flight the X7 rotated around its axis twice per second with the spoiler acting as a ruder or elevator depending on the rotation sequence.
It was launched from a WASAG 88-mm R-Werfer 43 Pupchen platform using a 300V battery for rocket engine ignition.
The WASAG 109-506 had a first stage for take-off with 68 kg peak thrust and 2.5 seconds life and a second stage for sustained flight with 5.5 kg thrust and 8 seconds life.
The solid propellant consisted in two concentric blocks of Diglykol separated by an anti-thermic layer of Polygan (mixture of asbestos, graphite and calcium silicate).
The rocket used two angled venturi nozzles to generate rotational motion.
Launch tests were performed on September 21, 1944.
Ru 8-347 Rotkäppchen technical data
Wingspan: 630 mm, length: 796 mm, height: 330 mm, diameter: 150 mm, weight: 9 kg, warhead: one 88-mm R.Pz.BGr 4992 hollow charge with impact fuse, max speed: 360 km/h, range: 1,200 m (limited by the length of guidance wires), power plant: one solid-propellant rocket motor WASAG 109-506 rated at 73,5 kg peak thrust, guidance system: FuG 238/FuG 510.
The aircraft-launched variant was developed in 1944.
The low speed of the rocket (lower than that of the launcher aircraft) did not allow the use of the wire-guidance system and the experience gained during the tests of the X4 missile demonstrated the difficulty of using the joystick in a single-seat aircraft. It was necessary to develop an automatic infra-red target acquisition device named Zielsuchgerät Steinbock.
On February 1, 1945, the new air-to-ground variant was flight tested at Karlshagen using one Focke-Wulf Fw 190 F-8 fitted with two ETC 70 underwing racks.
Ru 8-347 Steinbock (January 16, 1945) technical data
Wingspan: 600 mm, length: 1,000 mm, height: 258 mm, diameter: 150 mm, weight: 9 kg, warhead: one 88-mm R.Pz.BGr 4992 hollow charge with impact fuse, max speed (with Fw 190): 650/700 km/h, range (with Fw 190): 2,500-3,000 m, power plant: one solid-propellant rocket motor WASAG 109-506 rated at 73,5 kg peak thrust, guidance system: IR seeker.
It was proposed one ground-to-air variant against low-flying aircraft fitted with a brand-splitter warhead with time fuse and an electrooptic tracking device named Pfeifen (a simple form of TV camera). This Ikonoskop was designed to produce contrast between the target and the background.
Over 300 units were produced between late 1944 and February 1945.
Mass production was intended at Ruhrstahl AG-Brackwede (Rotkäppchen) and
Elektromechanische Werke-Neubrandenburg (Steinbock) but the Project 347 was cancelled on March 20, 1945 and the type never saw operational service.
Early in 1943, Dr. Otto Kramer began the development of a wire-guided missile at the DVL Research Institute.
In January 1944 the Oberkommando der Heeres (OKH) placed a development contract for the Kramer missile to Ruhrstahl Presswerke AG, under the “X7 Rotkäppchen” codename.
Kramer decided to use the wire-control system Detmold FuG 238/Düsseldorf FuG 510
to steer the missile by means of a single gyro-stabilized spoiler.
During the flight the X7 rotated around its axis twice per second with the spoiler acting as a ruder or elevator depending on the rotation sequence.
It was launched from a WASAG 88-mm R-Werfer 43 Pupchen platform using a 300V battery for rocket engine ignition.
The WASAG 109-506 had a first stage for take-off with 68 kg peak thrust and 2.5 seconds life and a second stage for sustained flight with 5.5 kg thrust and 8 seconds life.
The solid propellant consisted in two concentric blocks of Diglykol separated by an anti-thermic layer of Polygan (mixture of asbestos, graphite and calcium silicate).
The rocket used two angled venturi nozzles to generate rotational motion.
Launch tests were performed on September 21, 1944.
Ru 8-347 Rotkäppchen technical data
Wingspan: 630 mm, length: 796 mm, height: 330 mm, diameter: 150 mm, weight: 9 kg, warhead: one 88-mm R.Pz.BGr 4992 hollow charge with impact fuse, max speed: 360 km/h, range: 1,200 m (limited by the length of guidance wires), power plant: one solid-propellant rocket motor WASAG 109-506 rated at 73,5 kg peak thrust, guidance system: FuG 238/FuG 510.
The aircraft-launched variant was developed in 1944.
The low speed of the rocket (lower than that of the launcher aircraft) did not allow the use of the wire-guidance system and the experience gained during the tests of the X4 missile demonstrated the difficulty of using the joystick in a single-seat aircraft. It was necessary to develop an automatic infra-red target acquisition device named Zielsuchgerät Steinbock.
On February 1, 1945, the new air-to-ground variant was flight tested at Karlshagen using one Focke-Wulf Fw 190 F-8 fitted with two ETC 70 underwing racks.
Ru 8-347 Steinbock (January 16, 1945) technical data
Wingspan: 600 mm, length: 1,000 mm, height: 258 mm, diameter: 150 mm, weight: 9 kg, warhead: one 88-mm R.Pz.BGr 4992 hollow charge with impact fuse, max speed (with Fw 190): 650/700 km/h, range (with Fw 190): 2,500-3,000 m, power plant: one solid-propellant rocket motor WASAG 109-506 rated at 73,5 kg peak thrust, guidance system: IR seeker.
It was proposed one ground-to-air variant against low-flying aircraft fitted with a brand-splitter warhead with time fuse and an electrooptic tracking device named Pfeifen (a simple form of TV camera). This Ikonoskop was designed to produce contrast between the target and the background.
Over 300 units were produced between late 1944 and February 1945.
Mass production was intended at Ruhrstahl AG-Brackwede (Rotkäppchen) and
Elektromechanische Werke-Neubrandenburg (Steinbock) but the Project 347 was cancelled on March 20, 1945 and the type never saw operational service.
