By Samantha L. Quigley

Nearly three months after the March 1, 1939, commissioning of USS Squalus, a diesel-electric submarine, Navy Lieutenant W.T. Doyle made three successful test dives aboard the vessel during sea trials.

The following day would play out to a far different conclusion. Doyle found himself in the middle of an underwater crisis near New Hampshire’s Isle of Shoals when the Squalus suffered a catastrophic valve failure. The submarine began taking on water, and the partially flooded vessel sank to the bottom, coming to rest on its keel in 243 feet of water.

That was May 23. On May 24, Doyle officially became a survivor of the Squalus incident when the USS Falcon lowered a McCann rescue chamber—a revised version of a diving bell—to the wreck, saving 33 crew members in 13 hours.

The Squalus was raised in September 1939 and formally decommissioned that November. It was reborn the USS Sailfish in February and recommissioned May 15, 1940. It remained in service through October 27, 1945.

It would be 24 years before another U.S. Navy submarine would suffer the same fate—this time taking the entire crew of 129 sailors and shipyard personnel with her.

The nuclear powered Thresher, commissioned August 3, 1961, was the most advanced attack submarine of its time—faster, quieter and able to dive deeper than any submarine built at that point.

Like the Squalus, she was built at Portsmouth Naval Shipyard. After lengthy trials and exercises—and a collision with a tug boat while moored off the coast of Port Canaveral, Florida—Thresher headed home, and in July 1962 began a “post-shakedown availability” to make repairs and corrections resulting from the trials. The six-month project extended to nine months, but the sub was recertified April 8, 1963.

While technology has made Undersea Rescue Command’s job easier, it’s still a mechanical process. From lowering a rescue unit into the water to manually operating the 1,500 pound Atmospheric Diving Suit, the machines make the job possible, but ultimately, it’s the sailors who knock on the hatch to let the crew know help has arrived. | Photo credit Navy photo

The following day, post-overhaul trials began and Thresher completed a dive to half-test depth. It remained submerged overnight, reestablishing communications with the submarine rescue ship USS Skylark the next morning as it prepared to begin deep-dive trials. Thresher began circling slowly down, pausing every 100 feet to check the integrity of its systems being stressed by the increasing pressure.

As she neared test depth, Skylark received scrambled messages from Thresher reporting minor difficulties. It was Thresher’s last communication. Six major sections of the submarine were later found resting in 8,400 feet of water. An investigation indicated a failed saltwater piping system had likely set off the catastrophic failure that led to the destruction of Thresher between 1,300 and 2,000 feet below the surface.

“When the USS Thresher went down in 1963, we recognized that our old idea of having submarine rescue ships with submarine rescue chambers didn’t work out very well for a modern navy,” said Commander Andy Kimsey, commander of Undersea Rescue Command (URC). “The submarine rescue chambers were designed and built in the 1930s by (Vice Admiral Charles) Swede Momsen and divers at Navy Experimental Dive Unit … but they didn’t work very well for where the Thresher was when she went down.”

The loss of Thresher prompted the creation of URC’s predecessor, Submarine Rescue Unit.

It also made the Navy realize the need for two things.

“They said, ‘Hey, we need a deep-rescue capability,’” Kimsey said. “That started the whole Deep Submergence Rescue Vehicle (DSRV) design and procurement. The second thing was we need to provide a rescue capability during sea trials, [so] if a submarine on sea trials again goes down, we can go get her, go get the sailors on board.”

The Navy also started limiting the depth of water in which a submarine could conduct sea trials, he said. Currently, submarine sea trials take place in water that’s deep enough to get to test depth, but shallow enough that if they should sink, the hull shouldn’t crush. The depth of the water is also well within the range of URC’s rescue capabilities.

Today, having also been known as Deep Submergence Unit between 1989 and 2012, URC carries on with its predecessors’ original mission.

“We have two missions. Our first and primary mission is we support every submarine that has a hull cut,” Kimsey said. “So, a new construction, overhauls that have a hull cut, refueling overhauls, we support all those sea trials. We’ll go to a higher state of readiness to support those.

“Outside of that time, we have a worldwide response capability, where we kind of become the fire department for submarine rescue,” he said. “You know, a submarine goes down across the world somewhere—we’re primarily set up to support U.S., but we do support our national partners as well—they call 911 and we’re the ones who get the call to go out and rescue.”

While requests for help are infrequent, Kimsey said there are several close calls each year.

“Unfortunately, the submarine force has had a, I won’t say higher than average, but has had a steady occurrence of collisions at sea,” he said. “Each time a submarine collides with a surface ship, there is a potential for it to sink and go to the bottom.”

He noted the USS San Francisco’s collision with an undersea mountain. The damage to San Francisco was so severe that she almost sank in what Kimsey said would have been 650 feet of water—a retrievable depth.

It also seems the Strait of Hormuz, located between the Arabian Sea and the Persian Gulf, is not a friendly place for submarines, as USS Newport News and USS Hartford can attest. Newport News suffered a gash in a ballast tank just three inches from the inner pressure hull. That inner hull normalizes atmospheric pressure inside the vessel.

Hartford nearly lost her sail—the tower-like structure on the top of a submarine—when she hit the USS New Orleans, an amphibious transport dock, in the busy strait.

“The bellweather, the one that really kind of woke us up to the current state of affairs was the Kursk in 2000,” Kimsey said. “We mobilized for it. We had the DSRVs sitting on the C-5 (transport plane), right outside our fenceway here, ready to fly to Russia.

“Russia didn’t ask for it, though. And with a foreign country … they have to ask for it before we can fly away to get there.”

The commander said a Navy rescue crew could have reached the site and gotten one of the DSRVs to the Kursk to see if anyone was alive far sooner than the Russians made it to the vessel. “By the time they actually got down there, it was several weeks later. It was a (recovery) operation, really.”

Photo credit Navy photo by Chief Mass Communication Specialist Daniel Ball

An Indian sailor looks up through a hatch during INDIAEX 2012, a bilateral exercise designed to demonstrate interoperability between the U.S. submarine rescue system and Indian submarines.

While the command doesn’t get lots of 911-type calls, they do receive many requests for demonstrations of their expertise, Kimsey said. In October 2012, it was India on the other end of the line.

“We flew over to India and operated for about five days with different Indian submarines,” he said. “It was kind of a sales pitch. India was looking at a submarine rescue capability—what they wanted to do, what they wanted to get—and then, if they wanted to buy our system or not.

“The second thing was a kind of a partnering with India, just showing them, ‘Yes, we could support you if you call,’ type of thing.”

Because everything they do is unclassified, Kimsey said URC is a very powerful tool that allows the U.S. military to engage with other nations.

Since calls for help are few and far between, it would seem the URC team has lots of free time. Not quite. This is a dangerous job that requires precision and expert knowledge of the equipment. So, as with many military occupations, the more than 130 active-duty and reserve sailors and contractors train for every scenario they think they might encounter.

“There’s a lot of training that goes into this,” he said. “You can’t just send these guys out with a joystick and tell them to go.”

In the past, URC has taken one of their two rescue systems to sea on alternating calendar quarters. The new movement is toward taking each system to sea each quarter, Kimsey said.

“We’re looking to spend about 30 percent of our time at sea. And understand, this is a shore command so that’s a significant unforeseen expectation on the sailor’s part, but we have to go to sea to train,” he said. “We can do some training in port. For example, we’re setting up to dive our intervention system in the pool out here. We can dive next to the pier with the submarine rescue chambers, but you just don’t get the same level of effort. You don’t get the same focus. You don’t get the same value as you do when you go to sea.”

And when these sailors and contractors do go to sea for the real deal, their training is critical, but their equipment is just as important—and impressive.

The Atmospheric Diving Suit (ADS), used to examine downed submarines and clear their escape hatches before the rescue effort begins, looks like something out of an old science fiction movie. With its bubble facemask, the 1,500-pound metal suit can protect divers in waters up to 2,000 feet deep, and sustain them for up to 24 hours, if necessary, with its self-contained oxygen source and CO2 scrubbers.

“About five hours is the longest we ever had a diver in a suit,” said Navy Lieutenant Commander Andrew Platten, the URC’s executive officer.

Though tethered to the cage that lowers it into the water, and monitored by personnel on a support ship, the suit is actually a diver-operated vehicle once it’s released from the Lift and Recovery System. Despite its robot-like appearance, the suit is mechanical. There are no motors to help move the nearly one-ton suit forward, or bend the heavy metal arms. Even the forward propulsion, referred to as “flying,” is provided by the diver.

“We actually call it flying because the pilot (diver) is sitting in the suit on a bicycle seat,” Platten said. “His feet are actually on pedals and he’s using the pedals to control the thrusters. “They get exhausted from doing that.”

To intensify the situation, the suit does not regulate its internal temperature.

“If we’re diving off Catalina and the water is 50 degrees, the suit becomes 50 degrees,” Platten said. “That’s relatively easy to fix. You just put the pilot in fleece.

“But if you’re in India and the water is 90 degrees and the temperature of the suit is 100 degrees because it’s been sitting in the sun before you launch it, it’s going to stay 90 degrees and it’s going to be very hot.”

Once the diver in the ADS has completed his mission, it’s time for one of the other two pieces of rescue equipment at URC’s disposal—the Pressurized Rescue Module (PRM).

Though manned by two personnel, the PRM is actually controlled remotely. When the module reaches the downed submarine, the attendants in the module are responsible for draining the water from the space between the submarine hatch and the PRM.

“If you remember from the movie Hunt for Red October, where they bang on the hatch, that’s what we still do,” Platten said. “So they bang on the hatch to tell them to open the hatch, help the people up into the PRM, get them all settled … and control the atmosphere as they come to the surface.”

It can accommodate up to 16 people in addition to its two attendants. That makes for a long rescue if the downed submarine is an Ohio class, which can hold around 160 sailors.

“We’re getting a system next year called Transfer Under Pressure, which the PRM will tie to. The system we’re getting will hold 64 people,” Platten said.

The third system URC can call on is called a Submarine Rescue Chamber (SRC). They were built in the 1940s and are still in use today. Though they’re only viable to depths of 850 feet, they’re far quicker to deploy, Platten said. “We can put the SRC in a vessel in about 12 hours. So it’s a lot quicker to get on the scene.”

While the maximum depths of the three rescue systems may seem insufficient when considering the waters submarines operate in, they’re actually quite adequate.

“Most submarines operate in pretty shallow water,” Platten said, acknowledging that the majority of the ocean is far deeper than 2,000 feet. “Submarines are going to be near the surface when they’re transitioning in and out of a port, or when they’re near a country doing something. Otherwise, we stay deep.

“So it’s places like the Strait of Hormuz, the Persian Gulf, large parts of the (Mediterranean), the North Seas, the coastal shelves around the United States are where we spend most of our time at the surface or near the surface, and that’s where you’re most likely to have an accident.”

And if that should occur, or if it’s just a close call, the sailors and civilian contractors of URC stand ready to respond.

–Samantha L. Quigley is the editor in chief of On Patrol.