German Use of Smoke, WWII Tactical and Technical Trends, No. 6, August 27, 1942 (Lone Sentry)

Research on German use of smoke as a weapon has produced considerable information on the organization of German smoke units and the large-scale use of smoke in tactical roles.

The idea that climatic conditions in the Middle East made the use of smoke impracticable has been proved by experience to be incorrect. Conditions will vary, but it will frequently be possible to use smoke effectively.

German Smoke-Producing Units (Nebelwerferabteilungen)

Six of these units have thus far been identified in the German Army. It is possible that eventually each Corps will include a smoke-producing unit. These have been identified in regimental chemical headquarters but only as administrative, non-operational headquarters.

Engineer Units. These are believed to be equipped with smoke projectors manned by sections of two to three men. The scale of equipment is not known.

Employment of Smoke in the Field. Captured documents point out the danger of interfering with neighboring troops and supporting weapons. There is also difficulty of observation. Because of these elements, unless a smoke screen can be guaranteed to affect a particular sector only, its use must be directed by a superior commander.

Army and corps commanders allot smoke troops, equipment, and ammunition to subordinate formations for large-scale screening operations. The divisional commander usually decides on the use of smoke, and its exploitation by artillery fire and troop movements. In employing smoke heavy concentrations are usually sought. The following uses are quoted:

(a) Attack

(1) Concealment of forward movements, and initiation of surprise attacks.

(2) Reduction of casualties.

(3) Assistance in taking open ground

(4) Covering river crossings.

(5) Blinding enemy positions and observation posts.

(6) Economy of ammunition, and reducing artillery's task.

(7) To some extent replacement of covering fire.

(8) Assistance to the main effort of the attack.

(9) Concealment of weakness in the secondary attack or of gaps in the attacking forces.

(10) Protection of flanks.

(b) Defense

(1) Blinding enemy observation posts.

(2) Concealing activities in the main line of resistance.

(3) Concealing troop movements to prevent observation from ground and air.

Throughout German teaching it is emphasized that smoke must always be laid on the enemy and not on friendly troops. The normal use of smoke to assist daylight withdrawal and to blind the enemy is also mentioned.

An interesting use of smoke is found in the suggestion that screens might be put down purely as a deceptive measure to mislead the enemy as to intentions.

The following principles are laid down for German troops when fighting in smoke:

(1) Smoke impedes defense rather than attack.

(2) Route-finding by compass is essential.

(3) Units should be guided through pre-assigned sectors.

(4) Close combat is decisive.

(5) Careful preparation of fire plans is essential in defense.

(6) Particular points of danger should be protected by units armed with bayonet.

(7) Counterattack should take place, as a rule, after the dissipation of a smoke screen.

(8) Gas masks should be worn until it is definitely known that no chemical warfare gas is mixed with the smoke.

It should be noted that no distinction is made between smoke laid down by enemy or friendly troops.

Instructions have been given for the handling of "smoke acid", which has been described as a mixture of chlorosulphonic acid and sulphur trioxide.

It is said that smoke acid is extremely corrosive and must not be used on exercises involving other than chemical warfare troops. It burns through uniforms, eats into the skin, and burns all crops. It must not be used in areas occupied by friendly troops or areas which they intend to enter during the smoke laying. Anticorrosive suits, and either anticorrosive masks or gas masks without filter, must be worn when handling smoke acid.

Equipment

(a) Smoke Candle Nb K 39. This is used to lay small local screens of short duration. It consists of an air-tight, water-tight container filled with a smoke-producing agent ignited by means of a fuse. The candle weighs 1.8 kgs. (about 4 pounds) and is fitted with a carrying handle. It is intended to be placed on the ground and ignited, or thrown by hand or by means of a sling passed through the carrying handle. For ease of throwing, a 30-cm. (11 3/4 in.) stick, to which the handle is attached, may be fitted. The safety pin must be withdrawn before the apparatus can be ignited.

The candle burns for 4 to 7 minutes; the density of the screen is increased if two are placed together, although more than two must never be used together since the heat generated raises the screen. The best effect can be obtained if these candles are used in quantities.

(b) Smoke Hand Grenade Nb Hgr. 39. This weapon approximates in appearance the normal stick grenade, but is filled with the same type of smoke-producing agent as the smoke candle Nb K 39. Its weight is 0.850 kgs. (1 3/4 pounds). The smoke is produced approximately 7 seconds after the pin has been pulled out, and lasts for 1 to 2 minutes.

(c) The Improvised Smoke Projector. This weapon can project the Smoke Candle 34, up to a range of 500 meters (550 yards). It consists of a steel barrel, 94 mm. (3.7 in.) in diameter, 4 mm. (.157 in.) thick, and 600 mm. (23.62 in.) long. The base plate, 200 mm. (7.87 in.) square and 10 mm. (.39 in.) thick, is welded on. A bipod is attached to the barrel by a ring just behind the muzzle. The best results are produced when using an elevation of about 45 degrees, which gives the maximum range for any of the three charges which may be used. These charges are made up of 25 (.54 pound), 50 (1.08 pounds), and 100 (2.16 pounds) grams, respectively, of propellant explosive in small packets of gauze or cellophane. The method of operation is to insert the charge into the barrel and drop in the smoke candle with the safety pin already withdrawn; this ignites the charge and the candle is projected to a distance depending on the charge, the angle of projection, and the wind. The rate of fire is 3 r.p.m. The average ranges attainable are:

With 25 grams propellant      100 meters (110 yards)
With 50 grams propellant      200 meters (220 yards)
With 100 grams propellant     500 meters (550 yards)

The most effective use of this projector is said to be the engagement of entrenchments and dugouts, and as a covering for river crossings. It can be mounted in the assault boat issued to engineer units.

(d) Tank-Mounted Smoke Candle Rack. All German tanks carry, projecting from their rear, a rack on which 5 smoke candles are held. These candles cannot be projected but are dropped from inside the fighting compartment. No definite evidence on their effect has yet been received.

A captured German General Order dated April 1942, mentions the fact that the smoke-candle discharger apparatus fitted to tanks has not proved successful and that a new type is being designed.

(e) Smoke-Producing Agents. For smoke candles and grenades a solid substance composed of zinc powder and hexachlorethane is used. This is quite normal. The shell is said to contain sulphur trioxide, but a 75-mm. shell which has actually been examined was found to contain oleum. Certain types of smoke generators sometimes use chlorosulphonic acid in conjunction with oleum or sulphur trioxide. In this connection, there have been two recent reports from the Western Desert of a thick cloud over 100 yards deep having the appearance of chlorine, but not in fact composed of this gas. The cloud was said to be used tactically on both occasions, and to be heavier and more intense than clouds normally caused by smoke-producing apparatus. In appearance, however, clouds produced by chlorosulphonic acid could be mistaken for chlorine.

The average height of a normal smoke screen is said to be 10 to 15 meters (32 to 49 feet), and the width 25 to 30 meters (82 to 98 feet). The length is:

Smoke Candles and Sprays     200 - 300 meters (220 - 330 yards)
Smoke Shell                  100 meters (110 yards)
Smoke Hand Grenades          30 - 50 meters (33 - 55 yards)

German teaching is that the most effective height from which aircraft can release smoke is 120 to 150 feet or less. Morning and evening (particularly twilight) are recommended as the most suitable times, and little or no wind is considered an advantage. The most favorable conditions for laying aerial smoke screens are the highest possible air humidity, cloudy weather, a temperature not lower than 5° C. (41° F.) and a wind speed for smoke producers of 6 to 21 ft. per second, and for smoke bombs from 9 to 18 ft. per second.

German manuals warn their troops that a smoke screen laid by enemy aircraft must immediately be countered by a reconnaissance, as it may mean a gas attack. It is very probable that the Germans themselves might utilize this form of deception in chemical warfare.

Smoke screens by aircraft are recommended as a means of obstructing enemy antiaircraft defenses as well as of concealing targets from opposing reconnaissance aircraft. Provided that rapid and reliable advance information of the movements of enemy bombers is available, the employment of such smoke screens against actual air attack is also taken into account.

Blinding observation posts and machine-gun posts, obstructing cooperation between the enemy's artillery and infantry, covering withdrawals, and cooperating with naval units in screening ship movements and guarding damaged ships are some of the other functions prescribed by the Germans for their smoke-laying aircraft. It is believed that such aircraft, flying below troop-carrying planes, sometimes emit a smoke cloud through which parachutists descend. Parachutists in Holland are reported to have carried smoke generators.

Large-Scale Use of Smoke

In screening targets covering a considerable area, smoke has been used to a large extent by the Germans for over a year. As early as March 1941, reports were being received of large-scale smoke generators, and it was known then that E-boats were equipped with a smoke apparatus having a gross volume of 20 gallons. In the report of actual use of this apparatus, particular, reference was made to the remarkable rapidity with which the smoke was generated, and to its persistence. The smoke was believed to be produced by chlorosulphonic acid. At about the same time two reports were received from R.A.F. pilots of smoke screens which they had observed over Berlin. Smoke started from a series of straight lines E.S.E. of the city. It produced an effective screen estimated at two miles wide, stretching across the city N.N.W. beyond the Tegeler Lake 15 miles distant from the source, the effective length being estimated in one report as 20 to 30 miles. Another report said that the screen was very dense, effectively covering the town, and that the smoke appeared to come from containers roughly 20 yards apart, quickly merging into one continuous smoke screen. The cloud was dark gray in color.

In January 1942, a captured document disclosed the existence of an apparatus described as the Smoke Generator 41. This was to be used, according to the document, for screening large areas, or for screening for prolonged periods (up to two hours) single buildings, bridges, battery positions, etc. The generator was strong and simple and contained 20 gallons of smoke acid.

The most exact knowledge of German large-scale use of smoke comes from the Brest area where detailed information has been received from reliable sources. Apparently the screen here is put up immediately on the sounding of an air raid warning, and within 20 minutes the docks and town are completely enveloped in smoke. It is reported that the screen is so dense that visibility on the ground is only a few yards. The generators appear to be fairly simple, and alongside each generator there is a 40- to 50-gallon drum for recharging. By this means it is considered that the smoke screen can be maintained at full strength for some hours, and on one occasion the screen was in fact maintained throughout a raid which lasted 4 hours. The apparatus is served by army personnel, three to each generator. The generators and recharging drums are brought up in trucks and placed in position at dusk in the streets around the town and docks, on the breakwaters, and as far as the suburbs of St. Anne (Portzec). In addition about 20 small motor fishing craft, (10 to 12 tons) each equipped with one of these generators, put out at dusk into the middle of the Rade de Brest to screen the wharves. The generators on land are collected by trucks every morning. The smoke itself is described as issuing from the generator in the form of a liquid which immediately vaporizes. It is the color of tobacco smoke, and is odorless and harmless although a little irritating to the throat. If any of the liquid is spilled on the ground everything with which it comes into contact is burned, and grass and green leaves are turned yellow. From the description given there can be little doubt that the charge is either oleum or chlorosulphonic acid, or a mixture of the two. The dimensions quoted for the generator indicate a capacity of 40 to 55 gallons; allowance for air space reduces the actual quantity of liquid.

It is known that the German firm of Stolzenburg and the Czech firm of Chema have produced generators of the type used at Brest, ranging in capacity from 22 to 55 gallons.

Smoke has not been used so far on an extensive scale by any of the other members of the Axis.