Nazi Germany (1944)

Type: Ground anti-aircraft rocket – 83 Launchers Built

By late 1944, the Germans were losing on all fronts and the Allies were steadily advancing into Germany itself. To make matters worse, the extensive losses in manpower and equipment had become irrecoverable. As a result, various makeshift, improvised, and even obsolete weapons were brought to the front lines in a desperate attempt to halt the Allied advance. One such last-ditch effort was the creation of a 73 mm rocket launcher, intended as a close range anti-aircraft weapon by firing a volley of small rockets. While the official project name has been lost to history, it is often referred to as the 73 mm Föhn-Gerät.

German Early Rocket Development

Throughout history, rockets in combat were typically a cheap complement to artillery. While early rocket designs lacked the destructive power of conventional artillery, their primary role was to disrupt enemy lines and instill chaos, acting more as psychological weapons than as tools of mass destruction. By the onset of the Second World War, however, rocket technology had advanced significantly, rockets could now fire over greater ranges and deliver larger payloads, making them far more effective in both tactical and strategic contexts.

In Germany, early rocket development was largely driven by civilian efforts to explore new technologies and their potential applications. Much of this work focused on using rockets to power aircraft, exemplified by Fritz von Opel’s experimental work in the 1920s. Von Opel was assisted by another prominent aircraft designer Alexander Martin Lippisch. While technically speaking these were not real rocket-powered flights, given that these gliders did not take to the sky using purely the rocket engine but were towed to altitude. Nevertheless, these flights showed that considerable investment was going into rocketry, with the desire for it to break into new roles.

Over the following years, Lippisch became quite interested in rocket technology and joined the Deutsche Forschungsinstitut DFS, where he worked as an engineer. There, he developed a series of new glider designs, like the DFS 40, to test rocket propulsion. This work would eventually lead to the creation of the Me 163 rocket-powered aircraft. Another major stepping stone in rocketry was the work of Wernher von Braun. In 1932 and 1934, von Braun managed to successfully launch two rockets using liquid-fuel rocket engines. In 1935 he managed to come into contact with Dr. Ernst Heinkel 1935. With financial and infrastructure support, von Braun would participate in the creation of the first operational rocket-powered aircraft, the He 176.

In the early 1930s, the German military began to take an interest in using rockets to produce new artillery systems. The Germans had a unique motivation to develop rocket technology, as it was not prohibited by the terms of the Treaty of Versailles. The pioneering work of engineers like Hauptmann Dr. Ing. Walter Dornberger and von Braun played a significant role in advancing German rocket programs. Their work made it possible to create rockets that rotated around their longitudinal axis, effectively stabilizing them during flight. This innovation reduced the need for specialized wings and fins that would otherwise be required to maintain stability. As a result, a simpler, smooth-barreled launcher could be used, significantly lowering production costs while also creating lightweight launchers.

Due to its unique characteristics and capabilities, the artillery rocket held great potential as a formidable weapon. With the ability to fire over long ranges, multiple rockets could be launched rapidly from a single launcher, allowing it to carry outa rapid salvo compared to contemporary artillery pieces. Additionally, rockets could carry a larger payload than artillery shells of the same caliber, increasing their impact. However, they lacked precision and were less effective against fortified targets.

The German army formed its specialized Nebeltruppe (Eng. Smoke Troops) in 1929. These were initially equipped with large caliber mortars. As rocket launchers became available, these were then integrated in Nebeltruppen. Initially, rockets were used primarily to obscure enemy positions with smoke-generating rounds, rather than for direct attacks. Although chemical rounds were also developed, these were not employed in combat. Interestingly, they also employed rocket launchers to deliver propaganda leaflets, although they were rarely employed.

The first mass-produced rocket launcher was the 15 cm Nebelwerfer (Eng. Smoke Thrower) 41. Development of this weapon began in 1934, and it officially entered service in 1940. Designed to be simple and cost-effective, the Nebelwerfer utilized existing components to streamline development. The base of the launcher was adapted from the 3.7 cm PaK anti-tank gun carriage, and with the gun and shield removed, it was fitted instead with a six-tube launcher, each tube 15 cm in diameter. A folding pad was added to the front of the carriage for stabilization during firing.

A Literal  Propaganda Weapon

Besides using rockets to deliver deadly payloads or smoke, the Germans also employed them in a rather unconventional manner: distributing propaganda leaflets over enemy lines. In 1941, they introduced the Propagandagranate 41 (Eng. propaganda grenade), a specialized 7.3 cm rocket designed for this purpose.

The Propagandagranate 41 was slightly over 3 kg in weight and about 40 cm long. It was launched from a metal frame stabilized by three fixed spades. After setting the correct firing angle, the rocket was placed into the mount and at a distance from the base of the tube. This arrangement was necessary because the rocket was ignited using a percussion-firing system, essentially functioning like a mortar.

To fire the rocket, the operator would retreat to a safe distance and pull a string to release the captive rockets. This action allowed the rocket to slide down into the base, striking a firing pin that ignited the percussion primer located at the rear.

These rockets were assigned to specialized propaganda units known as Propagandatruppen. While it is difficult to assess the exact effectiveness of this method, it was undoubtedly a unique way to distribute propaganda leaflets during the war.

A New Life For The Failed Propaganda Weapon

While rockets developed during the war were primarily forms of artillery, they were not limited to this role. The flexibility of unguided rockets allowed them to be adapted for use against aerial targets and even ships. Once again, the Germans tested various such weapons when their fortunes declined, including ground-to-air missiles, intended to counter the escalating Allied bombing raids. These projects mixed results and failed to achieve the level of success their designers had hoped for. Notably, attempts to build various surface-to-air missiles were met with only limited success. As resources became scarce and the war more desperate, the Germans sought simpler, cheaper, weapon systems designed to saturate the sky with numerous rockets in the hope of bringing down enemy aircraft. One such project appears to have been initiated in 1942.

Starting such a project from scratch was not considered an option at this stage of the war. Instead, the Germans attempted to repurpose what they already had. This is where the 73 mm propaganda rocket came into play. Since the tooling for its production still existed, it was feasible to use it for creating new anti-aircraft rocket launchers. The overall design was quite simple, consisting of a box launcher, rail cages, and a control cabin, and was set on a fixed or mobile carriage.. By 1944, work on this project ran at a slow pace and not many such launchers were built.

As this was a late-war project produced under desperate conditions, not much is known about who precisely initiated it. It is known that they were developed by the Waffenprüfstelle der Luftwaffe Tarnewitz (Weapons Testing Center of the Air Force Tarnewitz). Based on several sources, it appears that the launchers were constructed by Rheinmetall. Other sources claim that Henschel built and developed it. What is certain, however, is that these weapons entered production and service in late 1944.

Production

The production of the launchers progressed at a slow pace. By 1944, only 50 units had been completed. By February 1945, this number had increased by 83, or increased to 83, though sources are somewhat unclear on the exact figure.

Designation

No official designation for this system is known to have survived. In available sources, it is often mentioned that the Germans simply referred to it as the 73 mm Föhn-Gerät. The word Föhn refers to a certain type of wind, while Gerät translates to Device.

Some internet sources also designate it as the Henschel Hs 297. Interestingly, captured systems examined by the Western Allies were designated as the 7.5 cm Multiple Fortress Rocket Launcher. This designation is incorrect in both caliber and intended purpose. For the sake of simplicity, throughout this article, we will refer to the system as the 73 mm Föhn rockets.

In Combat

A small number of these launchers were built and deployed for frontline use near the end of the war. They were primarily used to protect bridges over the German rivers on the Western Front. In particular, a few were defending the area around the Remagen bridge in 1945.

Design

Cradle and Carriage

The 73 mm Föhn cradle features a simple conical base, above which is a saddle with two trunnions that securely hold the rocket rail box in place. The entire system could either be bolted to a concrete base, or mounted on an older 3.7 cm Flak 18, two-wheel carriage for mobility. The stationary configuration was chosen for defending critical ground targets where mobility was unnecessary. In contrast, the mobile version was likely intended for use by ground forces as a standard anti-aircraft weapon. When deployed in the field, the rocket system would be lowered to the ground, and the crew would unfold two sheet metal plates designed to provide them with a standing platform.

Controls

The controls for the 73 mm Föhn system were located on the left side of the assembly and housed within a partially enclosed cabin. The front and the right side, which faced the rocket launcher, were shielded by thin sheet metal plating. This housing was not designed to protect against enemy aircraft fire but rather to guard against the exhaust generated when firing the rockets.

At the upper front of the cabin, there was a large, curved glazed window, providing the operator with a mostly field of view. The controls themselves were straightforward; elevation was adjusted using a handwheel, while traversal was managed with a simple flat metal bar, likely welded to the right-side armor of the cabin. To traverse the system, the operator would push the bar forward or backward with their left hand, pivoting the box launcher on its mount.

Armament

The project was based on the 73 mm propaganda rocket but required several modifications. The rocket’s steel body was shortened to 28.2 cm, and weighed 2.74 kg, including 0.48 kg of propellant, and a 0.28 kg explosive charge. Propulsion was achieved through seven small venturi nozzles, which provided rotational stability during flight. This rotation ensured the rocket’s stability without the need for fins.

Two types of explosive charges were available. The first consisted of a mixture of 60% cyclonite (RDX) and 40% TNT, while the second comprised 55% cyclonite, 40% TNT, and 5% wax. The rocket’s 73 mm nose warhead was equipped with a percussion fuze, meaning it had to strike the target to detonate in mid-air. Although not intended, they could be used against ground targets in case of an emergency.

To prevent unexploded ordnance from littering the battlefield, the Germans incorporated a self-ignition detonator. This safety feature ensured that unused rockets would not remain a hazard after missing the intended target. The rocket had a velocity of 380 m/s, and could reach a maximum height of 1.2 km.

The rockets were launched from box-shaped launchers, each equipped with 35 guide rail tubes arranged in a grid of five rows horizontally and seven columns vertically. The dimensions of the launcher were 58.4 cm in width, and 81.3 cm in height, with each guide rail tube measuring 78.7 cm in length. The launchers had an elevation range of -12° to +90° and a full 360° traverse capability.

The loading process for the 35 rocket remains somewhat unclear. However, the launcher tubes were constructed in two distinct parts. The front section serves as a guide for the rocket, while the rear section is loaded separately, already containing the rocket inside.

Once the system was prepared and a target identified, the operator aimed at the approaching enemy aircraft. Upon sighting the target and ensuring it was within range, the operator activated the rockets. All 35 rockets were fired in a single salvo. The idea behind this approach was to saturate the area around the target, increasing the chances that some rockets would hit.

However, this method had significant drawbacks. The rockets were low-velocity and imprecise, making them an unreliable means of bringing down aircraft beyond extremely close range. Additionally, the smoke generated during firing revealed the launch position. While mobile launchers could relocate after firing to avoid detection, stationary ones were left exposed and vulnerable to Allied aircraft.

Reloading the launcher was likely a tedious process, requiring considerable time to prepare all 35 rockets for another volley, or reload from additional racks. Once the rockets were expended, the ground crew could do little but wait for the enemy aircraft to move on. Theoretically, operators could control the number of rockets fired by removing or securing the rockets’ safety pins. How practical this would be is another question.

Crew

The exact number of crew members required to operate this launcher is not specified in the limited available sources. However, at least one operator would have been necessary to operate the launcher. Additional crew members were likely stationed nearby to assist with loading the rocket launcher or preparing it for transport, and it is reasonable to assume that a commander was also part of the team.

Ground Attack Variant

During their advance toward Germany in 1945, the Allies managed to capture a vast collection of abandoned vehicles and weapons. Many of these were outdated and obsolete, brought into action out of desperation. Among the captured equipment were several improvised weapons, including a 73 mm rocket launcher that appeared to be designed to provide fire support against ground targets. However, little is known about this particular weapon, as it seems to have been a hastily constructed, improvised device created as a last-ditch effort.

Surviving Systems 

Despite its rarity and late introduction during the war, a few of these launchers have survived to the present day. One example is preserved at the Russian Military Historical Museum of Artillery in St. Petersburg, while another is housed at the Swedish Army Museum in Stockholm.

Conclusion

The effectiveness of these weapons in combat remains uncertain, but they likely performed poorly. The rockets had a short range and produced excessive exhaust fumes which marked the position of the weapon. They could only be fired in single salvos, meaning that if they missed their target, enemy aircraft could return and engage them without fear of retaliation. Additionally, the rockets were notoriously imprecise, making the chances of hitting an enemy aircraft quite low despite the large salvo the weapon could deliver.

73 mm Föhn-Gerät Specifications
Caliber	73 mm
Crew	One (likely more but it is unspecified in the soruces)
Length	28.2 cm
Wight	2.74 kg
Wight of explosive charge	0.28 kg
Velocity	380 m/s
Range	1.2 km
Elevation	-12° to +90°
Traverse	360°

Illustration

 

Credits

• Article written by Marko P.
• Edited by  Henry H.
• Illustration by Oussama Mohamed “Godzilla”

Sources: 

• T. J. Gander (1972) Field Rocket Equipment OF The German Army 1939-1945, Almark Publication
• S. J. Zaloga (2006) Remagen 1945, Osprey Publishing
• P. Chamberlain and T. Gander (1975) Mortars and Rocket, Arco publishing
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• T. J. Gander (1972) Field Rocket Equipment OF The German Army 1939-1945, Almark Publication
• S. J. Zaloga (2006) Remagen 1945, Osprey Publishing
• P. Chamberlain and T. Gander (1975) Mortars and Rocket, Arco publishing
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• https://www.lonesentry.com/ordnance/tag/rocket-launcher/