Silent Hunter: The Untold Story of the NR-1, America’s Smallest Nuclear Submarine
In the early 1960s, the world was witnessing a significant leap in submarine technology that opened an entirely new front in the global nuclear standoff situation. This front was darker and deeper than any previous threat. The Americans had always strived to identify where the Soviet siloes and launch sites were located to intercept any attempt if the worst came to pass. Similarly, supersonic interceptor fighters were on standby to stop enemy strategic bombers from reaching the population centers in the west.
However, nuclear-armed fission-reactor-powered submarines were a whole new story. They could wander the depths of the oceans for months in almost complete silence. Moreover, they could already be operating off American coasts, preparing to unleash their nuclear hail storms at any moment. An enemy warhead would take only mere minutes to reach its target at that distance, making an interception almost impossible. A whole new approach was needed, and thus the NR-1 was born.
The NR-1, the American submarine, would be the smallest nuclear-powered submersible in the world, a tiny silent hunter that would scour the seas in search of the much larger Soviet nuclear vessels. With few options left, the US backed the project as the only way to successfully track the Soviet underwater menace and its possible cataclysmic implications.
To contend with the growing threat that Soviet nuclear submarines posed to the United States in the 1960s and to simultaneously attempt to steal vital information from the Soviet underwater communications networks, the US Navy became interested in building a one-of-a-kind nuclear submarine specialized in reconnaissance and research. The project was assigned to the Electric Boat Company, which was seen as the only organization with sufficient experience and talent to reconceptualize the entire idea of a nuclear-powered submarine.
As the designer and manufacturer of the first American nuclear-powered submarine, the Nautilus, and dozens of other submarine designs, the Electric Boat Company had the skill set and infrastructure necessary to take on the unprecedented challenge. Even so, the project’s scope was transcendental, as it was a paramount solution to one of the most significant threats to America. Thus, Admiral Hyman Rickover, the father of the nuclear Navy, led the project and aided in the vessel’s design. The NR-1 was Rickover’s baby, and he would invest dearly in the unprecedented venture.
With nuclear-submarine technology already widely used around the globe, it could be hard to understand why the endeavor was so technically challenging, but everything came down to scale. Nuclear submarines were built around detailed specifications that stemmed from the unmovable requirements of having a functioning nuclear reactor chamber onboard a vessel operating several hundred meters underwater. Vessels such as the Nautilus had to be equipped with a massive nuclear reactor capable of powering all of its systems; at the same time, the reactor had to be properly isolated, and the rest of the submarine shielded from the radiation created by the fission process.
Such requirements called for considerable space, an imperative that dictated the size of a nuclear submarine, making them extremely heavy and oversized. That philosophy had to be turned on its head now, as the US required a small, light, and considerably maneuverable nuclear submarine that could stealthily hunt down Soviet objectives. The NR-1 submarine needed to be at least half the size of a conventional nuclear submarine, or only about 130 feet long. It was also meant to be much lighter than other submarines, with her final structure displacing only 400 tons in contrast to the average 5,000 tons displaced by a nuclear-powered submarine.
To achieve the project’s ambitious goals, the engineers started with a completely specialized reactor design explicitly concocted for the NR-1 project. While conventional nuclear-powered submarine reactor cores are massive structures that usually occupy huge compartments with dimensions comparable to a three-story building, the new reactor core designed for the NR-1 had the approximate size of a household refrigerator.
Moreover, the reactor core is not the only element that makes a nuclear submarine so massive, as the compartment is shielded by several layers of radiation protection to keep the crew safe at all times. When the reactor is running, the radiation levels inside the compartment are hazardous, and the door is locked at all times. The crew must be able to transit through additionally shielded passageways to access the rest of the submarine’s systems, making the vessel require large amounts of space to work correctly. Only the Engineering Duty Officer is responsible for opening and closing the door during shifts and has access to the keys and the core compartment.
Attempting to design a tiny nuclear submarine with the equivalent amount of shielding as the full-sized vessel would have been impossible. As such, the shielding configuration was wholly redesigned, scraping most of the all-around protection in exchange for a single wall of led shielding that divided the crew compartments from the reactor compartment. The compromise meant the crew did not have the same level of radiation protection as the one operating in larger submarines, but that was the price Rickover was willing to pay for the smallest nuclear submarine in the world. Consequently, the rest of the vessel’s components also had to be designed and manufactured from the ground up to accommodate the smaller scale.
Admiral Rickover was famously exacting when it came to guaranteeing the best performance possible from the components and the outer hull, and he insisted on having the most perfectly round pressure hold possible. As such, the 12.5-foot-diameter hull was only allowed to be out of round by 1/16th of an inch, giving the NR-1 the most perfect pressure hull of any submarine in the world at the time she was built.
The NR-1’s small reactor had the ability to operate silently underwater for months without having to surface. But the shrinking of the nuclear reactor technology came at a cost, and the propulsion system only produced 130 horsepower, which translated to a top speed of only five knots. After years of delays and budget outstrips, the NR-1 was finally launched on January 25, 1969, several years after she was initially planned to debut. However, Admiral Rickover’s demanding demeanor seemed to pay off as the vessel quickly passed all of its seafaring trails to be commissioned as part of the Naval Submarine Base New London, Connecticut, in the same year.
Even so, the submarine’s lack of speed was a concern, especially if the vessel encountered faster enemy ships that she could not outrun. Nevertheless, the NR-1 made up for its lack of speed with unparalleled maneuverability, which was achieved thanks to her several thrusters pointing in almost every direction possible. Because of the thrusters, the vessel could be easily steered while submerged and could perform sharp turns and sudden changes in direction that were just impossible to do in larger ships. Astonishingly, the tiny nuclear submarine could accomplish a 180-degree turn within her own length.
To make her reconnaissance work at seabed levels more manageable, the submarine was equipped with retractable wheels at the bottom of her hull, similar to the landing gears of modern aircraft. The wheels allowed the submarine to drive on the bottom of the sea while using her thrusters to move with unmatched agility and freedom. Mounted on the hull, a pair of hydraulic manipulator arms gave the NR-1 the ability to grab and recover objects on the seabed or even tamper with deep sea communication lines. And to make the most out of the manipulator arms and the embedded thrusters, the submarine had several portholes around the hull that gave the crew significant environmental awareness.
Despite the ambitious goals, operating the NR-1 would prove much more challenging
and impractical than previously calculated. The vessel was driven by a 10-man crew, but she was ill-equipped to sustain the team for prolonged periods as she lacked shower facilities or a working kitchen. Additionally, the necessary submarine oxygen recycling system and compressed air tanks could only function autonomously for a short time. Thus, the NR-1 ended up being deployed to and from a specialized mothership tasked with replenishing her systems.
Soon, the most miniature nuclear submarine in the world was denied one of her most promising features, her independence and long-range capabilities. This development and the sociopolitical situation at the start of the 1970s made the NR-1 mostly unsuitable for her original task of tracking down Soviet Nuclear vessels. Despite her limitations, the NR-1 was heavily used for the following decades in highly classified missions whose specific nature has never been revealed. Officially, the submarine has been used for various research and science-related tasks.
Even so, unofficial reports claim the vessel has been part of several espionage operations, including tapping into deep sea cables, recovering enemy assets from the bottom of the sea, and installing a secret underwater communication network near the Azores. While most of her operation is veiled behind top secret labels, some of her missions have been well publicized, like when she helped recover a highly valuable Phoenix missile mounted on an F-14 Tomcat that had been swept from her carrier and plummeted into the bottom of the sea.
The NR-1 was finally retired in 2009 after 39 years of continuous service, making her the longest-serving submarine in US history. Not bad for a “merely research vessel” that supposedly never conducted warfare operations.
