#14 Underwater Explosives: Torpedoes and Mines

What are the primary physical characteristics of underwater shock waves compared to air?

They have higher velocity, shorter duration, and greater peak overpressure.

How does distance affect the intensity of an underwater shock wave?

It undergoes exponential attenuation with distance.

What is the primary mechanism by which underwater warheads damage a ship's hull?

The interaction between the steam void created by the explosion and the hull of the ship.

Underwater warheads

Uses interaction between steam void created by explosion and hull of ship. Two distinct cases: surface target, submerged target.

What percentage of energy is typically dissipated after the first expansion and contraction of an underwater explosion against a ship?

90%.

What are the four main components of a torpedo?

Guidance and control, warhead, fuel, and tail/afterbody.

Control + Guidance component

Brains of the torpedo + passive and active sonar capable

Warhead component

High explosives

Fuel component

Otto fuel - not requiring external oxygen

Trail and Afterbody Component

Propeller, Torpedo Mounted Device (TMD) - allows torpedo's wire to be connected to fire control systems

What is the function of a Torpedo Mounted Device (TMD)?

It allows the torpedo's wire to be connected to the fire control system.

What type of fuel is commonly used in torpedoes and why is it advantageous?

Otto fuel; it does not require external oxygen.

What are the four main classifications of naval mines?

Moored mines, propelled/upward rising mines, oscillating (drifting) mines, and bottom mines.

Propelled/Upward Rising classifications

Waits for target, then releases torpedo or floating mine

Current US Torpedos

MK-44, MK-46, MK-50 + MK-54, MK-48

Mine delivery methods

Air-delivered mines, surface-delivered mines, submarine-delivered mines, asymmetric (civilian)

Mine detonation

Contact mines, command detonation, influence mines

What is the primary characteristic of an oscillating mine?

It is untethered and free-floating (not currently used by the U.S.).

What are the five primary strategies/tactics used in mine warfare?

Asset protection, interdiction, attrition, terrorism, and force multiplication.

Define 'Force Multiplication' in the context of mine warfare.

Influencing the movement of enemy units to specific locations to engage them with other weapons like shore-launched missiles or air attacks.

Asset Protection

Impeding/defeating enemy attack (confederacy in Civil War)

Interdiction

Obstructing shipping lanes, critical areas, perhaps far from friendly forces

Attrition

Attempting to trap enemy High Value Units (HVUs) into a selected area

Terrorism

Disruption of commerce, political motives

What are the three main influence methods for mine detonation?

Magnetic, acoustic, and pressure + combination.

How is a 'Command' detonated mine triggered?

Detonation is triggered by a shore-based observer. Limited to near-shore applications

How is a 'Contact' mine triggered?

By crushing one of the 'horns' located around the top of the mine.

What are the three self-protection measures against influence mines?

Silencing (acoustic), degaussing (magnetic), and steaming slowly (pressure).

What is the difference between mine sweeping and mine hunting?

Mine sweeping involves clearing areas using towed sleds or noise makers, while mine hunting involves using sonar to search for and neutralize individual mines.

What is the purpose of cable cutting in mine countermeasures?

It is used to clear moored mines by cutting the mine case free from its anchors so it can be collected and destroyed.

Which aircraft are capable of dropping the Mk-54 torpedo?

The P-8 Poseidon.

What is the primary goal of the 'Attrition' strategy in mine warfare?

Attempting to trap enemy High Value Units (HVUs) into a selected area.

What is the primary goal of the 'Interdiction' strategy in mine warfare?

Obstructing shipping lanes and critical areas, often far from friendly forces.

What are the three methods used for clearing or removing mines?

Cable cutting, detonation by towed sled, and the use of remotely-operated robotic vehicles.