45 years under the sea
Boeing holds role as leading supplier of sub navigators
BY DIANE STRATMAN
March 2004 (pretty old article)
In the late 1950s, a Boeing product helped the U.S. Navy submarine Nautilus do what Jules Verne could only fantasize about in his classic novel 20,000 Leagues Under the Sea: The submarine crossed under the North Pole's ice cap, an impregnable barrier to seafarers of past centuries.
Beneath the Arctic ice, the 116-man Nautilus crew traveled 1,830 miles in 96 hours and on Aug. 3, 1958, crossed from west to east under the ice cap to open the fabled Northwest Passage. Eight days later, a second submarine, the USS Skate, repeated the "impossible" feat and crossed the pole from east to west.
These long voyages under the polar ice cap demonstrated the potential of the U.S. Navy's first nuclear-powered submarines. They also put Boeing on the map as a pioneer in the development and production of military inertial navigation equipment-a role that continues today.
Conventional navigation techniques did not function properly in polar regions, but the N6A-1 inertial navigator (built by what was then North American Aviation's Autonetics Division) enabled both voyages.
Light does not penetrate far into the ocean, so submarines navigate virtually blind. Underwater, a sub's inertial navigation system keeps track of position, velocities and attitude using gyroscopes and accelerometers to sense the ship's movements.
The N6A-1 system led to Boeing's development of the Ships Inertial Navigation System in the early 1960s. SINS provided submarines with enhanced stealth through increased navigational accuracy, and precise navigational data without the need for continuous external position references or reliance on the standard dead-reckoning techniques of plotting a ship's position. That capability gave SINS a key role in the development of U.S. fleet ballistic missile submarines from the early Polaris to the current Tridents. Today, Boeing inertial navigation systems are aboard all fleet ballistic missile submarines.
SINS proved its value in 1960 when the U.S. Navy launched its first 60-day operational patrol by an American fleet ballistic missile submarine. SINS enabled the USS George Washington to take advantage of nuclear propulsion and remain submerged for extended periods of time. This minimized the probability of detection and enabled the George Washington to remain ready to fire its Polaris missiles.
In 1976, Boeing augmented the SINS capability with Electrostatically Supported Gyroscope technology. The ESG extended the time interval between position resets, which reduced the need for a submarine to resurface and become vulnerable.
ESG monitoring equipment is installed on all Trident I submarines, which are also equipped with two SINS. The monitor provides correction data and reset information to the SINS, which enable the ships to navigate more accurately for longer periods of time without an external reference reset. ESG Navigators are installed in Trident II submarines. In addition, they provide position, attitude and velocity data to align the missile guidance system before launch. The ESG Navigator is the most advanced inertial navigation system in the U.S. Navy and is also installed on all United Kingdom Trident II submarines.
Today, Boeing Integrated Defense Systems continues to work aggressively at its Anaheim, Calif., site to maintain its role as the leading supplier of navigators for the U.S. Navy's ballistic missile submarine fleet as well as British Royal Navy Trident submarines. Last year, the U.S. Navy awarded Boeing IDS (in a joint effort with Honeywell) a contract to design and develop the Interferometric Fiber Optic Gyro-which will replace the electrostatically supported gyroscope as the inertial reference in navigation systems on Trident submarines. The IFOG will let the navigation systems provide performance accuracy equal to the current ESG navigators, as well as significantly reduce life cycle costs compared to ESG.
Under a contract with the U.S. Navy, the Boeing IDS Naval Electronics & Navigation team at Anaheim is developing a Fiber Optic Gyro Navigator. The FOGN will utilize the IFOG currently in development as well as other innovations required for the system to operate. Current plans call for deployment of this system to the fleet around 2011.
"Producing the world's most accurate submarine navigators for 45 years is something the Naval Electronics & Navigation team at Anaheim takes great pride in," said Dick Yuhnke, director of the team. "And it's a legacy we intend to maintain."
