An incident weapon is typically an anti-vehicle device intended to inflict disabling damage or prevent escape without killing the vehicle operators. Incident weapons were used by military personnel during the

Cold War The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 unt ...

to discourage clandestine use of

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

s within territorial waters without causing casualties which might escalate into warfare.

Historical use

The

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

was a vital access route for

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

shipping to reach the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

. Both

Warsaw Pact The Warsaw Pact (WP), formally the Treaty of Friendship, Co-operation and Mutual Assistance (TFCMA), was a Collective security#Collective defense, collective defense treaty signed in Warsaw, Polish People's Republic, Poland, between the Sovi ...

and

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

had a strategic interest in possible blockades of that access. The western shore of the Baltic was controlled by then neutral

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. Swedish submarine incidents occurred as foreign submarines explored Swedish territorial waters to assess the feasibility of evading future blockading warships and

naval mine A naval mine is a self-contained explosive weapon placed in water to damage or destroy surface ships or submarines. Similar to anti-personnel mine, anti-personnel and other land mines, and unlike purpose launched naval depth charges, they are ...

fields.

Examples

The United States developed a modified Hedgehog projectile substituting a magnet and clapper for the explosive charge. If the magnet stuck to the submarine hull, flow along the hull as the submarine moved through the water caused the clapper to oscillate, hammering against the hull. Sweden deployed several incident weapons in 1983 to discourage such exploration after ran aground while exploring Swedish waters in 1981.

''Elma''

''Elma'' was a small bomb intended to be dropped by aircraft or ships in patterns similar to Hedgehog. If one of these bombs landed on the submerged submarine, a magnet would position it on the hull to focus a shaped charge capable of making a small hole in the pressure hull. The amount of water entering the submarine in shallow coastal waters was intended to encourage the submarine to surface.

''Malin''

''Malin'' was similar to ''Elma'', but substituted an acoustic transmitter for the shaped charge to simplify tracking under difficult sonar conditions in coastal waters.

Torpedo

The standard Swedish Torped 42 anti-submarine torpedo warhead was replaced by a smaller explosive charge intended to merely damage submarine

propeller A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working flu ...

s or

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...

s after acoustic homing.

Sources

{{reflist Non-lethal weapons Weapons of Sweden