Ask any ship captain what he fears the most in combat, and the answer will probably be submarines. Ever since subs became operationally viable, they have proved to be a menace for surface combatants and commercial shipping. 

During World War One and World War Two, for example, the German Navy almost starved the United Kingdom out of the fight with submarine “wolfpacks” that roamed the Atlantic Ocean in search of vulnerable convoys. 

The tactic remains highly relevant.

The Mark 48 Heavy Torpedo 

The Mk 48 is a heavyweight acoustic-homing torpedo designed to take out enemy shipping. The munition is equipped with a sophisticated sonar, an all-digital guidance and control system, a digital fusing system, and a robust propulsion system. 

Designed and built by Lockheed Martin, the Mk 48 has a modular design that allows updates to its digital guidance system software. This is an essential feature, as it allows weapons systems to remain in mission-capable service for longer periods of time. 

The latest version of the Mk 48 heavy torpedo is the MOD 7. The product of a joint development program with the Royal Australian Navy, the Mk 48 MOD 7 is designed both for deep-water and littoral missions. It contains advanced countermeasures to avoid detection and diversion. This latest version of the Mk 48 has improved software and destructive capabilities. 

The Mk 48 heavy torpedo is not cheap. Each munition comes with a price tag in the range of $5 million. In comparison, many U.S. Navy submarines can also fire Tomahawk land attack cruise missiles, and these cost about $2 million each. 

A Mk 48 heavy torpedo weighs around 3,700 lbs, is nineteen feet long, and has a twenty-one-inch diameter. It carries a 650-lb high-explosive warhead and has an operational range of up to thirty-one miles at lower speeds. If it is up against a fast-moving target, the Mk 48 can reach speeds close to sixty-five miles per hour.   

If you want to see the destructive ability of the Mk 48 heavy torpedo in action, watch this video released by the Navy in 2021. It is a sinking exercise, or SINKEX, in which Naval vessels and aircraft test their munitions against a decommissioned ship. The Mk 48 torpedo is the last munition to strike the warship. As you will see, it literally cuts the target in half. 

All U.S. submarines, regardless of their role, pack the Mk 48 for anti-submarine warfare (taking out other submarines) and anti-surface warfare (taking out surface combatants, support ships, and commercial shipping). 

The Royal Australian Navy, Royal Canadian Navy, Royal Netherlands Navy, and Brazilian Navy also operate the Mk 48 heavy torpedo. Taiwan has purchased a small number of these torpedoes for its small fleet of attack submarines.

About the Author: 

Stavros Atlamazoglou is a seasoned defense journalist specializing in special operations and a Hellenic Army veteran (national service with the 575th Marine Battalion and Army HQ). He holds a BA from Johns Hopkins University and an MA from the Johns Hopkins School of Advanced International Studies (SAIS). His work has been featured in Business Insider, Sandboxx, and SOFREP.