The following information is taken from a field Intelligence Bulletin dated November, 1943.
The Nebelwerfer was referred to a "Screaming Mimi's" by the Allies because of the ear shattering, high pitched sound they created.



"Six-Barrel Rocket Weapon (The Nebelwerfer 41)" from Intelligence Bulletin

SIX-BARREL ROCKET WEAPON
(THE "NEBELWERFER 41")

I. INTRODUCTION

Whenever the fortunes of the German Army take a new turn for the worse, Nazi propagandists attempt to encourage the people of the Reich—and influence public opinion in neutral countries—by spreading rumors of new and formidable developments in German ordnance. Recently the Nazis have been releasing propaganda declaring that spectacular results are being achieved with the German six-barrel rocket projector known as the Nebelwerfer (smoke mortar) 41. Actually, this is not a particularly new weapon. Its name, moreover, is extremely misleading. In the first place, the Nebelwerfer 41 is not a mortar at all, and, in the second place, it can accommodate both gas-charged and high-explosive projectiles, as well as smoke projectiles.

It would be just as foolish to discount the German claims 100 percent as it would be to accept them unreservedly. Although fire from the Nebelwerfer 41 is relatively inaccurate, one of the weapon's chief assets appears to be the concussion effect of its high-explosive projectiles, which is considerable when the weapon's six barrels are fired successively, 1 second apart. The high-explosive round contains 5 pounds of explosive; this is comparable—in weight, at least—to the high-explosive round used in the U. S. 105-mm howitzer.

In view of the mass of misleading information which has been circulated regarding the Nebelwerfer 41—or, as the Germans sometimes call it, the Do-Gerät [1]—it is hoped that junior officers and enlisted men will find the following discussion both timely and profitable.

2. DESCRIPTION

The Nebelwerfer 41 (see figs. 1 and 2) is a six-barreled (nonrotating) tubular projector, with barrels 3 to 3 1/2 feet long and 160 mm in diameter. The projector is mounted on a rubber-tired artillery chassis with a split trail.

[Figure 1. German Nebelwerfer Six-barrel Rocket Projector (side view).]
Figure 1.—German Six-barrel Rocket Projector (side view).

There is no rifling; the projectiles are guided by three rails, each about 1/3-inch high, which run down the inside of the barrels. This reduces the caliber to approximately 150 mm.

The barrels are open-breeched, and the propellant is slow-burning black powder (14 pounds set behind the nose cap). This propellant generates gas through 26 jets set at an angle. As a result, the projectiles rotate and travel at an ever-increasing speed, starting with the rocket blast. The burster, which is in the rear two-sevenths of the projectile, has its own time fuze. The range is said to be about 7,760 yards.

The barrels are fired electrically, from a distance. They are never fired simultaneously, since the blast from six rockets at once undoubtedly would capsize the weapon. The order of fire is fixed at 1–4–6–2–3–5.

The sighting and elevating mechanisms are located on the left-hand side of the barrels, immediately over the wheel, and are protected by a light-metal hinged box cover, which is raised when the weapon is to be used.

Each barrel has a metal hook at the breech to hold the projectile in place, and a sparking device to ignite the rocket charge. This sparker can be turned to one side to permit loading and then turned back so that the "spark jump" is directed to an electrical igniter placed in one of 24 rocket blast openings located on the projectile, about one-third of the way up from the base. About one-third of the length of the projectile extends below the breech of the weapon.

[Figure 2. German Six-barrel Rocket Projector (front view).]
Figure 2.—German Six-barrel Rocket Projector (front view).

The projectile itself resembles a small torpedo—without propeller or tail fins. The base is flat, with slightly rounded edges. The rocket jets are located about one-third of the way up the projectile from the base, and encircle the casing. The jets are at an angle with the axis of the projectile so as to impart rotation in flight, in "turbine" fashion.

The propelling cl1arge is housed in the forward part of the rocket. A detonating fuze is located in the base of the projectile to detonate the high-explosive or smoke charge. In this way, on impact, the smoke or high explosive is set off above ground when the nose of the projectile penetrates the soil.

3. NOTE ON OPERATION

The following note on the operation of the Nebelwerfer 41 is reproduced from the German Army periodical Die Wehrmacht. It is believed to be substantially correct.

The Nebelwerfer 41, or Do-Gerät, is unlimbered and placed in position by its crew of four men. As soon as the protective coverings have been removed, the projector is ready to be aimed and loaded. The ammunition is attached to the right and to the left of the projector, within easy reach, and the shells are introduced two at a time, beginning with the lower barrels and continuing upward. Meanwhile, foxholes deep enough to conceal a man in standing position have been dug about 10 to 15 yards to the side and rear of the projector. The gunners remain in these foxholes while the weapon is being fired by electrical ignition. Within 10 seconds a battery can fire 36 projectiles. These make a droning pipe-organ sound as they leave the barrels, and, while in flight, leave a trail of smoke (see cover illustration). After a salvo has been fired, the crew quickly returns to its projectors and reloads them.

4. HOW THE GERMAN ARMY USES IT

The following statements have been made by a high-ranking German Army officer, and may be accepted as an authoritative expression of German ideas concerning the employment of this weapon.

Units of Nebeltruppen (smoke-laying troops) are organized as rocket-projector regiments (Werferregimenter), which are fully motorized and therefore extremely mobile. A rocket-projector regiment is divided into battalions and batteries, like those of the artillery. Since rocket-projector regiments are capable of playing a decisive part in battle, they may be concentrated at strategically important points along a front. ... The organization of a rocket-projector regiment is much like that of a motorized artillery regiment; organizationally, the motor vehicles and signal equipment of both are also much the same. Since the projector units usually are kept close behind the forward infantry line, their batteries may also be equipped with antitank guns. Because of the light construction of the projectors, a 3-ton prime mover is sufficient for traction purposes, and can also carry the gun crew and some of the ammunition. ...

The Nebelwerfer 41 can fire three different types of projectiles: high-explosive shells, incendiary projectiles, and smoke projectiles.

The high-explosive shells include those with supersensitive fuzes and those with delayed-action fuzes. The latter can penetrate reinforced cover. Because of their fragmentation and concussion effect, high-explosive shells are used primarily against personnel. It has been found that the concussion has not only been great enough to kill personnel, but occasionally has caused field fortifications and bunkers to collapse.

The incendiary projectiles are psychologically effective, and under favorable conditions can start field and forest fires.

The smoke projectiles are used to form smoke screens or smoke zones.

Rocket-projector troops are employed as battalion and regimental units, in keeping with their task of destroying hostile forces by concentrated fire. One of the advantages of the Nebelwerfer 41 is that it can mass its projectiles on a very small target area. By means of a shrewd disposition of the batteries, a carefully planned communication system, and a large number of observation posts with advanced observers, the infantry can assure for itself maneuverability and a concentration of its fire power upon the most important points. Projectors are placed well toward the front—almost without exception, at points forward of the artillery—so that they will be able to eliminate hostile command posts, destroy hostile positions, and even repulse sudden attacks effectively. The firing positions of the projectors are always carefully built up so that the weapons can give strong support to the infantry.

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