How this 'dog' blasted Axis subs to smithereens

Just before America’s official involvement in World War II, Fido was born. It took a while for Fido to be ready to serve, though. Only 4,000 were fielded – down from a planned 10,000 — largely because Fido was so effective.

For Fido, though, the mission was a one-way trip.

Now, you dog lovers out there, don’t go flying off the handle. Fido wasn’t some poor canine conscripted for use in war to be blown to bits while killing the enemy. No, this “Fido” — as the sailors who used it against enemy subs took to calling it — was purely machine. A torpedo, to be exact.

Okay, technically Fido’s designation was as the Mk 24 Mine, but this torpedo was unique in that it could sniff out enemy submarines.

Diagram of the Mk 24. (US Navy graphic)

According to UBoat.net, Fido’s “nose” consisted of four hydrophones placed at equidistant points around the body of the Mk 13 aerial torpedo. These gave the torpedo steering directions as they detected the skulking submarine and guided the torpedo to a direct impact on the hull. That’s when a 100-pound high-explosive warhead would do its job. The result should be a sunken enemy submarine.

Fido could go at a speed of 12 knots and its batteries would last for 15 minutes. It could be dropped from up to 300 feet high by planes going as fast as 120 knots. Submarines could increase their speed to try to outrun it, but their batteries would run out very quickly, forcing them to the surface, where they’d be sitting ducks to American guns. If they didn’t go fast, the torpedo would catch them.

Fido was used on anything from a TBF Avenger to the PBY Catalina. It took a little less than a year and a half for Fido to make it from the drawing board to its first enemy kill. Fido claimed 33 Axis submarines in the Atlantic (32 German, one Japanese), and four more in the Pacific (all Japanese).

USS Roosevelt (DG 80) launches a Mk 54 MAKO torpedo, the evolutionary descendant of the Mk 24 Fido. (US Navy photo)

Fido was, in one sense, the progenitor of today’s advanced air-dropped anti-submarine torpedoes, the Mk 46, the Mk 50 Barracuda, and the Mk 54 MAKO. Such is the legacy of a torpedo that sniffed out Axis subs.

TOP ARTICLES
This is how missing or captured troops get promoted

According to the Department of Defense, prisoners of war and those under missing status continue to be considered for promotion along with their contemporaries.

6 reasons Charleston might be America's most gung-ho military city

From Charles Towne Landing to the Medal of Honor Museum, go grab a pint where George Washington drank and read about the military legacy of South Carolina's Atlantic jewel.

This is how long South Korea thinks it will take to conquer the North

South Korea says they are developing new plans to defend against advancing North Korean threats after a data breach left their outdated plans vulnerable.

This stunning video shows how well 100-year-old ammo works today

While original 1911 pistols surely still function today, turns out so does the ammo from that era.

This could be the Army's next rifle — and it's totally awesome

Textron debuted its newest rifle, the Intermediate Case-Telescoped Carbine, at AUSA. It's lighter and more deadly than the current M4.

16 jokes Germans could die for telling under the Nazi regime

The Nazi Party was well short of a majority when it came to power. So it's easy to believe that not everyone was a big fan of Hitler or his ideas.

These really smart people say bigger is better when it comes to building aircraft carriers

In an effort to reduce its fiscal footprint, the Navy is looking at making smaller ships. But these defense researchers say it's a terrible idea.

Now that ISIS is on the ropes, these guys have turned the guns on each other

Two US allies, which were armed and trained by US forces, have turned their weapons on each other, and there isn't much the US can do about it.

This is the definitive history of the world's most advanced fighter jet

The new F-22A Raptor fighter jet is the most advance fighter jet in the world, and it dominates on every level imaginable.

This is how the $102 million B-1A almost replaced the B-52

The plan was to buy 240 B-1As to replace the B-52 as the Air Force's primary strategic bomber, but eventually, they each found their place in the force.