USS Nautilus: A record-breaking sub
It's 60 years since the world's first nuclear-powered submarine was launched. The USS Nautilus was the first "true" submarine as it did not need to be refuelled and could remain submerged for months. So what was it like living on it?
"I was teased that if I was going to this nuclear power programme, I might become irradiated and sterile and not have any children."
Jerry Armstrong was a 23-year-old sonar operator when he volunteered to work on a new top-secret submarine. His wife was four months pregnant at the time and they knew they wanted another child.
"I was concerned, I discussed it with my wife but we knew that other naval and civilian personnel were already working on a prototype so we decided it would be safe."
Armstrong hadn't told anyone about his decision so his family and his in-laws were surprised when they got a visit from the FBI, asking what kind of student he had been and other questions about his lifestyle. His wife's family background was checked closely. Some of the others who'd volunteered for the programme were rejected.
"They were just picked up from the classroom and we never saw them again. The only thing we heard was that their family history didn't satisfy the investigation."
Armstrong was then sent to work on the prototype nuclear reactor in the desert in Idaho, where he and the others spent nine months learning about nuclear fission. Before then, his knowledge of nuclear power was limited to the atomic bombs dropped on Japan.
They were constantly monitored as they worked, he says. "The crew wore two testing devices. One was a film badge… literally made of photographic film which was worn on our belts. The other was a dosimeter which was like a ballpoint pen which we wore in our shirt pockets and would record any radiation."
Finally the Nautilus was ready and on 21 January 1954 it was launched into the Thames River in Connecticut. Twenty thousand people flocked to see it. The wife of President Eisenhower, Mamie, "christened" the submarine by breaking a champagne bottle on it as it slid into the water.
From the outside the Nautilus didn't look all that different to a World War Two submarine but inside there was much more space because the old diesel-powered subs had to have fuel tanks to carry 90,000 gallons of diesel fuel.
"Previously submarines stayed under for up to 48 hours and then they had to surface to refuel, recharge batteries or take on air but the nuclear-powered submarine could stay submerged for years if need be," says naval historian and author Don Keith, so it could go anywhere in the world without detection.
"That is the ultimate in stealthiness and what gives it the amazing military advantage. They made their own oxygen, their own water and the reactor core could survive for years without having to be serviced."
Armstrong remembers that the recycled air had a strange effect on him.
"I hated cottage cheese, but one time we stayed submerged for a long time and when the ship surfaced I began to crave cottage cheese. I think breathing the recycled air changed my metabolism."
When they surfaced and began to pump fresh air back into the Nautilus "it was so clean and so sweet it made you light-headed".
The Nautilus began going to sea in 1955. During these sea trials it was soon breaking all sorts of records - going deeper, further and faster than any previous submarine. It was able to dive to 700ft.
"For every 100ft in depth, there's 44lb of pressure per square inch of the vessel. So when we went deep in the ocean, the hull would compress and the locker doors would pop open."
Keith says submariners have to be competent in every area - so the cook has to be able to drive the submarine too. "I don't think I've ever seen anything as close as the brotherhood of submariners," he says.
But because the vessel would be remaining submerged for much longer than ever before, there were concerns this brotherhood might now be tested.
"The US Navy sent psychologists on board the Nautilus because they were concerned about the effects on the personalities and mental health of the men who would be confined in such a small amount of space for long periods."
They found no impact, he says, but some submariners would talk gibberish and pretend to be crazy.
In 1958 the Nautilus conducted its most daring experiment - becoming the first submarine to travel under the North Pole.
This sent an important signal to the Soviet Union that the US could operate in its backyard without detection. That same year the Soviets commissioned their first nuclear submarine.
Jerry Armstrong and his wife did go on to have another child, and he says he could not have played his part in the story of the Nautilus without his wife's generosity and understanding.
"When we launched in January 1954, the families went to watch us. One elderly man there said 'that thing is going to go to sea and blow up like an A-bomb'. You can only imagine the effect on the families. It takes a special breed of woman to be a military wife."
The Armstrongs have been married for 60 years.