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S-mine 35
An American paratrooper demonstrates the process of removing a live S-mine. On the left is a Mark I trench knife.
Typebouncing anti-personnel mine
Place of originGermany
Service history
In service1935–1945
Used byGermany, Axis Powers, Finland, Viet Cong
Wars World War II, Winter War, Continuation War, Vietnam War
Production history
No. built1,930,000+
VariantsSMi-35, SMi-44
Mass4.1 kg (9 lb 1 oz)
Height127 mm (5 in)
Diameter102 mm (4 in)

Filling TNT
Filling weight182 g (6.4 oz)
Various, including:
S.Mi.Z 35 (pressure),
Z.Z.35 (pull),
Z.U.Z.Z. (tension release),
E.S.Mi.Z (pressure and electric)

The German S-mine (Schrapnellmine, Springmine or Splittermine in German), also known as the "Bouncing Betty" on the Western Front and "frog-mine" on the Eastern Front, is the best-known version of a class of mines known as bounding mines. When triggered, these mines are launched into the air and then detonated at about 1 meter (3 ft) from the ground. The explosion projects a lethal spray of shrapnel in all directions. The S-mine was an anti-personnel mine developed by Germany in the 1930s and used extensively by German forces during World War II. It was designed to be used in open areas against unshielded infantry. Two versions were produced, designated by the year of their first production: the SMi-35 and SMi-44. There are only minor differences between the two models. [1]


The S-mine entered production in 1935 and served as a key part of the defensive strategy of the Third Reich. Until production ceased in 1945, Germany produced over 1.93 million S-mines. [2] These mines inflicted heavy casualties and slowed, or even repelled, drives into German-held territory throughout the war. The design was lethal, successful and much imitated.[ citation needed ]


French soldiers encountered the S-mine during minor probes into the coal-rich German Saar region on September 7–11, 1939, during the Saar Offensive. The S-mine contributed to the withdrawal of these French incursions. [3] The mine's performance in the Saar region affirmed its effectiveness in the eyes of the German leadership and prompted the United States and other countries to copy its design. [4] After their experience, the French nicknamed the mine "the silent soldier".

The Third Reich used the S-mine heavily during the defense of its occupied territories and the German homeland during the Allied invasions of Europe and North Africa. The mines were produced in large numbers and planted liberally by defending German units. For example, the German Tenth Army deployed over 23,000 of them as part of their defense preparation during the Allied invasion of Italy. [5]

S-mines were deployed on the beaches of Normandy in preparation for the anticipated invasion as part of a general program of heavy mining and fortification. On the Îles-St.-Marcouf, just off Utah Beach, where the Allied planners feared the Germans had established heavy gun batteries, Rommel had ordered S-mines to be "sown like grass seed." [6] To build the Atlantic Wall, Germans deployed millions of mines of various types, anti-personnel mines (such as the S-mine), dug hundreds of kilometers of trenches, laid barbed wire, and constructed thousands of beach obstacles. [7] The mines were subsequently used to defend German positions during the Battle of Normandy and in the defense of Northern France and the German border. S-mines were typically used in combination with anti-tank mines to resist the advances of both armor and infantry. [3] The Allies removed an estimated 15,000 unexploded mines from dunes by Pouppeville after the initial invasion. [8]

The S-mine acquired its odd nickname "Bouncing Betty" from American infantrymen. [9] The S-mine had a great psychological effect on Allied forces because of its tendency to maim, rather than kill, the infantryman. The German habit of laying the mines around anti-tank and anti-vehicle mines contributed to the reputation. If a vehicle was disabled by a mine, the soldiers would be trapped in it until someone came to rescue them. [10] In particular, limbs and genitalia were the most vulnerable. In his book Mine Warfare on Land, Lt. Col. Sloan described the S-mine as "probably the most feared device encountered by Allied troops in the war." [3] Exact death tolls inflicted by the S-mine are not known. The Allies did not record whether a death was caused by a particular type of weapon, only whether or not the death occurred in the course of battle. Regardless, some unofficial assessments credit the S-mine with having caused significant casualties. The 12th Infantry Regiment at Utah Beach suffered what it termed as "light" casualties in the landing, most of which were caused by S-mines. [11]

S-mine production ceased after the end of World War II. No information has been discovered as to the exact fate of the remaining stockpiles of the S-mine, but it can be assumed a majority were destroyed as part of the disarmament of Germany after its surrender, although possibly some were preserved for study and reverse engineering by the Allies. Many direct imitations of the S-mine appeared in the years following World War II.

During the military occupation of Germany and the postwar rebuilding of Europe, the American Army Corps of Engineers, the newly established French government, and the British Ministry of Defence engaged in one of the most prolonged and successful mine-clearing operations throughout Western Europe. France deployed a variety of personnel to undertake this task, including 49,000 German prisoners of war. This joint operation eliminated a majority of the remaining fields of mines on the war-torn western half of the continent and was greatly assisted by the German policy of clearly marking and accurately recording the locations of minefields. [3]

However, incidents involving accidental explosions of mines in North Africa, the former Warsaw Pact countries, France, and Germany still occur sporadically. North Africa and Eastern Europe have a particularly large amount of uncleared World War II-era minefields, lost in the desert sands or forgotten by authorities. In Libya, for example, the Red Cross estimates that over 27% of farmland is unusable due to World War II minefields.[ citation needed ] While German documentation says the S-mine had an effective lifespan of two to seven years once planted, the explosive charge could still operate in mines to this day.


S-mine in a museum Schrapnel allemand.JPG
S-mine in a museum

The German S-mine was a steel cylinder approximately 15 centimetres (5.9 in) tall without its sensor and around 10 centimetres (4 in) in diameter. A steel rod protruding from the mine's top held the main fuse, where its trigger or sensor was attached. The SMi-35 had a central fuse, while the SMi-44 had an offset fuse. It weighed approximately 4 kilograms (8.8 lb), with the weight depending on whether it was loaded with the lighter powdered or the heavier poured TNT. [1]

The main charge of the mine used TNT as its explosive; the propelling charge was black powder. The standard pressure sensor used a percussion cap to ignite it. [12]

The main fuse was designed to delay the firing of the propelling charge for approximately four seconds after the mine was triggered. The explosion of the propelling charge sent the mine upwards into the air and activated three short-delay pellets between the propellant charge and the three detonators. These short-delay pellets delayed the mine's detonation long enough for it to reach an appropriate height before exploding.

The standard pressure sensor was designed to activate if depressed by a weight of roughly 7 kilograms (15 lb) or greater. This ensured the mine was not detonated by wildlife or natural impact of blowing leaves, branches, or other normally occurring phenomena. [1]


Diagram of S-mine detonation Bouncing-mine.svg
Diagram of S-mine detonation

The S-mine was normally triggered by a three-pronged pressure fuse. It could also be modified to be triggered by a tripwire. A special tripwire adapter was provided by the German army. The steel tube that held the fuse was threaded to accept any standard German ignition or trigger, allowing the sensor to be removed and the mine to be deliberately triggered by a human operator. [1] When triggered, the mine functioned in three stages (see diagram).

  1. First, the mine was fired 0.9 to 1.5 meters (3 to 5 ft) upwards by a small propellant charge.
  2. Approximately a half-second later, the main charge detonated at the optimum height to kill or severely injure anyone in the immediate area.
  3. The main charge of the mine was surrounded by roughly 360 steel balls, short steel rods, or scrap metal pieces. These became metal shrapnel that sprayed horizontally from the mine at high velocity.

The time between triggering and ignition of the propelling charge varied between 3.9 and 4.5 seconds, depending on the age and condition of the mine. According to German documentation, the S-mine was lethal within 20 meters (66 ft) and could inflict casualties within 100 meters (330 ft). [1] American training manuals warned of casualties at up to 140 meters (460 ft). [12]

A common misconception prevailed that the S-mine would not detonate until its victim stepped off the trigger. This fallacy was propagated by incorrect United States propaganda during World War II. The mine would detonate whether the trigger was released or not. Standing still or attempting to run from the S-mine would be equally dangerous. The most effective way to survive the mine's detonation would not be to flee but to fall to the ground lying face down as quickly as possible.

Armored vehicle discharger system

A S-mine mine launcher ("Minenabwurfvorrichtung" in German) in the form of angled tubes attached via brackets to the hull, were also used for anti-infantry defense by Wehrmacht armored vehicles. Early versions of the Tiger I were equipped with five such devices with command variants being equipped with four. Beginning in January 1943 all new Tiger Is were equipped with this system. These were removed in October 1943 and replaced in March 1944 by the Nahverteidigungswaffe or "close defense weapon" (full deployment was delayed due to production delays) which could launch anti-personnel grenades as well as smoke grenades or signal flares in all directions. [13]

Detection and disarming

An American infantryman probes for mines using a knife. Mine-detecting.jpg
An American infantryman probes for mines using a knife.

The S-mine was constructed mostly of metal, so it could be easily detected by metal detectors. However, such expensive and bulky equipment was rarely available to infantry units and was prone to malfunction. The mine could also be detected through careful manual probing, a time-consuming process. Using a knife or a bayonet, an infantryman would probe at a low angle through the soil. It was important to probe at an angle that would not accidentally depress the pressure sensor. [12]

Once an S-mine was discovered, disarming it was fairly simple. To prevent triggering while the mine was being planted, the German pressure sensor featured a hole where a safety pin kept the sensor from being depressed. This pin was removed once the mine was planted. If the discovered mine was fitted with the pressure sensor, the disarming personnel would slip a pin (such as a sewing needle or pin) into this hole. If the device was armed with a tripwire or electrical trigger, this could simply be cut. Germans were known to use booby traps to discourage this, so caution was suggested. The mine could then be removed carefully from the ground and the sensor easily unscrewed. If it was deemed necessary to render the mine completely inert, three plugs on the top granted access to the three detonators inside the mine. These could be unscrewed and the detonators removed. [12]

Internal components

The following diagrams show the SMi-35 mine's internal mechanism, together with the three-pronged pressure fuse. The safety pin for the fuse and the three removable plugs for the detonators are clearly visible. These diagrams were issued as part of a US Army field manual on mines in 1943.

Smine-diagram.jpg Smine-sensor.jpg


Cutaway American M16A2 Bounding Mine, developed from the S-mine M16a2mine.png
Cutaway American M16A2 Bounding Mine, developed from the S-mine

The S-mine was an extremely successful design. Bounding mines based on its design were introduced by other countries.

The Finnish army began purchasing the SMi-35 model S-mine from Germany following the Winter War. This was part of a larger military assistance agreement between the two nations. Finnish forces experienced great success with the S-mine, but its monetary cost was considerable. During the Continuation War, the Finns unsuccessfully attempted to produce their own version of the mine. [2] The Finnish nickname for the mine was Hyppy-Heikki ("Hopping Henry").

The French Mle 1939 mine was inspired by the success of the S-mine. In 1940, Major Paul Delalande of the French Corps of Engineers managed to escape the German conquest of his country and reached the United States with the Mle-1939 plans. These plans led to the development of the American M2 mine, which was fielded in 1942 but proved deficient in combat. [4] The American army was impressed by the S-mine's role in thwarting the French offensive in the German Saar region at the beginning of World War II and continued further work on bounding mines. After the war, the American army developed their M16 mine directly from captured S-mine designs. [4]

The Soviet Union also based the design of its OZM series of mines on the German S-mine. Soviet mines tended to be far simpler internally; instead of being filled with steel balls or scrap metal, the OZM-4 mine was given a solid cast-iron body that would fragment on its own. Later, the OZM-72 bounding mine was filled with steel rods, returning to the original concept of the S-mine. Both of these mines are still being produced by Russia.

Yugoslavia also built a PROM-1 bounding type of anti-personnel mine loosely based on the S-mine. The mine was widely used during the Croatian War of Independence by both sides. The mine was also found in Bosnia, Chile, Eritrea, Iraq, Kosovo, Mozambique and Namibia.

Other nations that have produced S-mine-inspired designs include the People's Republic of China, Sweden (called Truppmina 11), and Italy. The use of mines remains a controversial issue to this day. Antipersonnel mines like the S-mine have been the subject of repeated treaties and human-rights objections. Their use is the subject of extensive international debate.

Related Research Articles

Land mine Explosive weapon, concealed under or on the ground

A land mine is an explosive device concealed under or on the ground and designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it. Such a device is typically detonated automatically by way of pressure when a target steps on it or drives over it, although other detonation mechanisms are also sometimes used. A land mine may cause damage by direct blast effect, by fragments that are thrown by the blast, or by both.

A booby trap is a device or setup that is intended to kill, harm, or surprise a human being or an animal. It is triggered by the presence or actions of the victim and sometimes has some form of bait designed to lure the victim towards it. The trap may be set to act upon trespassers that enter restricted areas, and it can be triggered when the victim performs an action. It can also be triggered by vehicles driving along a road, as in the case of improvised explosive devices (IEDs).

Firing pin Part of the firing mechanism in a firearm

A firing pin or striker is part of the firing mechanism used in a firearm or explosive device, designed to ignite combustions/detonations by delivering an impact force to shock-sensitive compounds known as primers. Firing pins may take many forms, though the types used in fuzes for single-use devices generally have a sharpened point. In contrast, firing pins used in firearms usually have a small, rounded portion designed to strike the primer of a cartridge, detonating the priming compound, which then ignites the propellant (inside) or fires the detonator and booster.

Anti-tank mine

An anti-tank mine is a type of land mine designed to damage or destroy vehicles including tanks and armored fighting vehicles.

Bounding mine Explosive antipersonnel device designed to inflict casualties in a large area

A bouncing mine is an anti-personnel mine designed to be used in open areas. When it is tripped, a small propelling charge launches the body of the mine 3 to 4 feet into the air, where the main charge detonates and sprays fragmentation at roughly waist height.


The MRUD is a plastic bodied, convex rectangular directional type anti-personnel mine designed to wound or kill by fragmentation. It is broadly similar to the M18A1 Claymore mine.

M16 mine Bounding anti-personnel mine

The M16 mine is a United States-made bounding anti-personnel mine. It was based on captured plans of the World War II era German S-mine and has similar performance. The mine consists of a cast iron body in a thin steel sleeve. A central fuze well on the top of the mine is normally fitted with a pronged M605 pressure/tension (tripwire) fuze. Sufficient pressure on the prongs or tension on an attached tripwire causes the release of a striker. The freed striker is forced into a percussion cap which ignites a short pyrotechnic delay. The purpose of this delay is to allow the victim to move off the top of the mine, to prevent its upward movement from being blocked. Once the delay has burned through, a 4.5-gram black powder charge is ignited, which launches the inner iron body of the mine up into the air. The charge also ignites a second pair of pyrotechnic delays.

Anti-personnel mine Form of land mine designed for use against humans

Anti-personnel mines are a form of mine designed for use against humans, as opposed to anti-tank mines, which are designed for use against vehicles. Anti-personnel mines may be classified into blast mines or fragmentation mines, the latter may or may not be a bounding mine.


The PROM-1 is a Yugoslavian manufactured bounding anti-personnel mine. It consists of a cylindrical body with a pronged fuze inserted into the top of the mine. It is broadly similar in operation to the German S-mine.


The OZM-3, OZM-4 and OZM-72 are Soviet manufactured bounding type anti-personnel mines. (fragmentation-barrier mine, in the Russian and other post-Soviet armies as informally called "frog mine" or "witch" )

The PMN series of blast anti-personnel mines were designed and manufactured in the Soviet Union. They are one of the most widely used and commonly found devices during demining operations. They are sometimes nicknamed "black widow" because of their dark casings.

Valmara 59

The Valmara 59 is a large cylindrical Italian bounding anti-personnel mine. It is the first in the "Valmara" family of mines produced by Valsella Meccanotecnica, and was followed by the Valmara 69 and VS-JAP. The mine's body is metal with a distinctive five-pronged head. The central prong has a hole, to allow the threading a trip wire. The inner body of the mine has a main charge surrounded with approximately 1,000 steel cubes, below which is a steel wire connecting it to the base of the mine. When the mine is triggered a small charge launches the mine into the air approximately 45 cm before the steel wire is pulled taut, the jolt of which pulls a striker into the detonator. A secondary time fuse triggers the mine after three seconds if it has not detonated after being triggered.

The NR-413 is a Belgian trip wire activated anti-personnel stake mine. The main body of the mine is wine bottle shaped, with an NR 410 tripwire fuse screwed into a fuse well on the top of the mine. Under the fuse well is a detonator and a row of booster pellets. Wrapped around the detonator and booster pellets is the main charge. An internally square cross-sectioned steel wire is coiled around the outside of the mine, which give a fragmentation effect. The mine produces 600 fragments with a velocity of approximately 1,660 metres per second. It has an effective range of around 15 metres. A variant is produced with a cast steel fragmentation jacket.

The MBV-78-A2 is a small cylindrical Vietnamese anti-personnel fragmentation stake mine. It is unrelated to the MBV-78-A1. The mine has a large plastic head which contains the main charge wrapped around the detonator. A fragmentation layer of steel pieces set into wax surrounds the main charge. The plastic head has two mounting lugs for stake mounting the mine. A Vietnamese copy of the Russian MUV fuze is typically used with the mine, although other fuzes could be used.

Anti-handling device Component of a munition

An anti-handling device is an attachment to or an integral part of a landmine or other munition such as some fuze types found in general-purpose air-dropped bombs, cluster bombs and sea mines. It is designed to prevent tampering or disabling, or to target bomb disposal personnel. When the protected device is disturbed, it detonates, killing or injuring anyone within the blast area. There is a strong functional overlap of booby traps and anti-handling devices.

M2 mine Antipersonnel mine

The M2 is a United States bounding anti-personnel mine used during World War II. A number of variants of the mine were produced and although the mine is no longer in US service, it can be found in Cyprus, Iran, Iraq, Korea, Laos, Oman, Rwanda, Tunisia and the Western Sahara. Copies of the mine were produced by Belgium, Pakistan (P7), Portugal (M/966) and Taiwan.

Modèle 1939 (mine)

The Mle 1939 was a French bouncing anti-personnel mine used at the start of the Second World War, it was developed largely in response to the German S-mine bounding mine. It saw very little service before the fall of France. The plans escaped to the US via Major Pierre Delalande, a member of the French Corps of Engineers, and were used as the basis for the American M2 bounding mine which saw wider service during the war but was considered largely ineffective. The M2 mine was replaced almost immediately afterwards with the M16 bounding mine, an almost exact copy of the German S-mine. The French also later produced a copy of the S-mine, the Mle 1951 mine.

In military munitions, a fuze is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze designs can be seen in cutaway diagrams.

A.P. Shrapnel Mine Bounding mine

The A.P. (anti-personnel) Shrapnel Mine is a British bounding mine of World War II.

The A.P. Mine No. 5 was a British Anti-Personnel mine of World War II.


  1. 1 2 3 4 5 US War Department Technical Manual TM-E 30-451: Handbook on German Military Forces, 1945 (Ch. VIII, Sec. V.5.a-b). (available online)
  2. 1 2 JTV. Finnish Army 1918–1945, last updated 12 March 2005.
  3. 1 2 3 4 Lieutenant-Colonel C.E.E. Sloan, Mine Warfare on Land, Brassey’s, London, 1986.
  4. 1 2 3 Lieutenant-Colonel John Ingraham & Col. Dalton Jones. Technical Intelligence Bulletins 8(5), 2003. (available online)
    • Klaus H. Huebner, Long Walk Through War: A Combat Doctor's Diary, Texas A&M University, College Station, 1987.
  5. Cornelius Ryan. The Longest Day. New York: Simon and Schuster, 1994, ISBN   0-671-89091-3, p. 162163.
  6. Stephen E. Ambrose. D-Day, June 6, 1944: the climactic battle of World War II. New York: Simon & Schuster, 1994, ISBN   0-671-67334-3, p. 577.
  7. p. 283.
  8. Ambrose, p. 281.
  9. Alex Kershaw. The longest winter: the Battle of the Bulge and the epic story of WWII's Most Decorated Platoon. Cambridge, Ma. Da Capo Press 2004, ISBN   0-306-81304-1, pp. 21, 47.
  10. Ambrose, p. 292.
  11. 1 2 3 4 US Army Field Manual FM 5-31, 1943.
  12. Green, Michael; Brown, James D. (15 February 2008). Tiger Tanks at War. Voyageur Press. p. 88. ISBN   9780760331125.

Further reading