S-mine

S-Mine 35
An American paratrooper demonstrates the process of removing a live S-mine. On the left is a Mark I knife
Type	Bounding anti-personnel mine
Place of origin	Germany
Service history
In service	1935–1945
Used by	Germany, Axis Powers, Finland
Wars	World War II, Winter War, Continuation War
Production history
Produced	1935–1945
No. built	1,930,000+
Variants	SMi-35, SMi-44
Specifications
Weight	4.1 kilograms (9.0 lb)
Height	127 millimetres (5.0 in)
Diameter	102 mm
Filling	TNT
Filling weight	182 grams (6.4 oz)
Detonation mechanism	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", is the best-known version of a class of mines known as bounding mines. When triggered, these mines launch into the air and then detonate at about 0.9 meters (3 ft). 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.

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. 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. The S-mine remains one of the definitive weapons of World War II.

French soldiers encountered the S-mine during minor probes into the coal-rich German Saar region in September 7–11, 1939, during the Saar Offensive. The S-mine contributed to the withdrawal of these French incursions. 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. 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.