Shape, mission and power plant drives the creation of modern submarines

James Harrison, director of Naval Sea Systems Command (NAVSEA) Combatant Ships Division, speaks to employees at Naval Surface Warfare Center, Carderock Division, in West Bethesda, Md., on April 15, 2019, about submarine origins in his presentation “Sink or Swim: The Decade that Forged the Modern U.S. Submarine.” (U.S. Navy photo by Kelley Stirling)
April 22, 2019

The U.S. Navy submarine force is probably the most sophisticated technology of war in the world. How did it get there? In another historical presentation on April 15, his 12th at Naval Surface Warfare Center, Carderock Division, in West Bethesda, Maryland, James Harrison delved into what he thinks is the era that molded the current submarine force.

In “Sink or Swim: The Decade that Forged the Modern U.S. Submarine,” Harrison explained how in the 1950s, the U.S. Navy made changes to the hull form, power plant and mission of the submarine.

“Coming out of World War II, the submarine force had a pretty good war, as all things went,” said Harrison, director of Naval Sea Systems Command (NAVSEA) Combatant Ships Division. “The U.S. Navy built about 238 fleet boats during the war, and they were extremely successful against Japan, sinking nearly half of the ships sunk by the U.S. Navy.”

Harrison said the primary mission of the submarines during the war was commerce interdiction and attrition. And since Japan is an island nation, he said it helped the war effort tremendously to wipe out the Japanese merchant marine fleet. Search and rescue was another mission, something Harrison said the Japanese didn’t care as much about.

In terms of hull form, Harrison talked about three types that distinguished this time period of submarine development: the fleet boat, the Type XXI and the teardrop.

“The fleet boat was basically a surface ship that could submerge when it was convenient to do so, but really would prefer to operate more on the surface of the ocean,” Harrison said.

Harrison said that by the end of the war, the Germans turned up with the Type XXI submarine, having the topside much more streamlined than the fleet boats. In comparison to the fleet boats, which were almost twice as fast surfaced as they were submerged, the speed of the Type XXI hull form was roughly the same surfaced as submerged.

The United States got ahold of a few Type XXI submarines and started remaking the War World II fleet boats in what was called the Greater Underwater Propulsion Power Program, or GUPPY.

Not long after the war, the Navy was struggling to prove its worth, and with six submarines under construction at that time, the Navy was trying to figure out what mission the submarines would have.

“Now we are in the era of nuclear warfare,” Harrison said. “And the thinking of the time was if you’re not involved in nuclear warfare, you’re kind of not involved.”

And Japan was no longer the adversary, and sinking Soviet merchant marine ships did not strike quite the blow to the U.S.S.R., who was also building its own fleet of Type XXI submarines.

With the advent of the Tang class, the U.S. Navy moved into the role of attack submarine. It was a Type XXI hull with a diesel engine, and torpedo tubes fore and aft.

“Probably one of the most famous submarines we built was the Nautilus,” Harrison said. “As long as you’re burning diesel or some kind of fossil fuel, in order to run your submarine, you have to be near the air so you can suck in enough air, or you have to get into technology that didn’t become available until the 80s and 90s with the air-independent propulsion. With nuclear reactor, nuclear power, now you have all the power you need without having to exchange anything with the air. And that, of course, is what Nautilus is.”

The speed of Nautilus was about the same both submerged and surfaced, and a bit faster than earlier submarines. As a Type XXI hull form, she carried torpedo tubes fore and aft. The ship was delivered in 1954 and on Jan. 17, 1955, Nautilus became the first ship anywhere in the world to get underway on nuclear power. She also became the first ship to pass under the ice at the North Pole.

Moving on from Nautilus, the Skate class became the first line production of nuclear submarines built in the U.S., with four delivered between 1957 and 1959. Still a Type XXI hull form, the Skate class was essentially a nuclear Tang class, again with torpedo tubes fore and aft.

While these Type XXI hull-form submarines were being built, the Navy was looking at the fundamental shape of the submarine, and in 1953, the Navy developed the Albacore class, the first teardrop hull form. Vice Adm. Charles Momsen wanted to build a submarine with this shape, and in order to speed the acquisition process, the Navy designed it as a “target” submarine with no weapons.

“To build this submarine, with a whole new hull form, it required a totally different test program,” Harrison said, adding that although the design and testing work was done at Carderock, hull form resistance testing was also done in a wind tunnel at Langley Air Force Base in Virginia.

With the teardrop hull form, the submarines were built with one shaft, therefore the armed submarines with this hull form had the torpedo tubes only forward. And, the speed submerged became much faster than the surfaced speed. The Navy ultimately came to the end of the 1950s with the submarine of choice having a teardrop hull and nuclear power.

The Skipjack class became the first teardrop hull form, nuclear powered submarines, with the first commissioning in 1959. Typical of submarines with this hull form, they have only one screw and travel about twice as fast underwater as on the surface.

Again copying the Germans, the U.S. Navy developed the Regulus cruise missile, fitting both the Grayback and Halibut classes to carry the missile. As missile technology advanced, the guided-missile submarines became obsolete within four years of the first cruise missiles entering service.

“Now we have a new shape, new power and new missions, and now we are going to bring them altogether,” Harrison said.

The George Washington class, which was the installment modification of the attack submarine Skipjack class, was the first set of ships built as nuclear-powered ballistic-missile submarines, carrying the Polaris ballistic missile, leading into the next decades of the modern and most sophisticated submarines in the world.