Harold E. 'Bud' Froehlich, 84; Designed Alvin Deep-Sea Vessel
Wednesday, May 23, 2007; 8:12 AM
Harold E. "Bud" Froehlich, 84, the designer and chief engineer of the Alvin deep-sea research vessel, which has located sunken bombs, underwater life forms and the Titanic, died May 19 at St. John's Hospital in Maplewood, Minn. He had multiple myeloma.
Mr. Froehlich was an aerospace and mechanical engineer at General Mills when he was named project manager of the Alvin in the early 1960s.
Better known as a food company, Minnesota-based General Mills also made precision military equipment and high-altitude balloons. The second was Mr. Froehlich's specialty, and his knowledge of creating small spheres able to endure hostile environments was crucial to his work on Alvin. He told a reporter that "the same basic engineering principle is used to control both -- ballast."
Although submersibles existed before Alvin, they were limited because of their mechanics. One designed by Jacques Cousteau was viable only in shallow waters, and deep-diving bathyscaphs had restricted maneuverability because they weighed so much.
While at General Mills, Mr. Froehlich helped build a mechanical arm for the U.S. Navy-owned bathyscaph Trieste in 1960 that descended more than 35,000 feet underwater with explorer Jacques Piccard at the helm.
Alvin took advantage of a new buoyant material called syntactic foam to attain broader movement underwater and reach reasonable depths. Mr. Froehlich and his collaborators combined syntactic foam with large, hollow aluminum spheres to build the vessel.
The result was a smaller vehicle better suited to the needs of the Navy's Office of Naval Research and its scientific collaborators at Woods Hole Oceanographic Institution, a nonprofit research organization in Massachusetts that had an oversight role on Alvin.
Mr. Froehlich participated in one the first test dives made in 1964 near Woods Hole, Mass. -- "to the great depth of 27 feet," he later said.
Refinements to Alvin followed, and by the next year, the vessel was able to take two passengers 6,000 feet underwater. In later years, with a stronger titanium shell replacing the original stainless steel, Alvin could reach depths of more than 14,000 feet.
Now operated by Woods Hole, Alvin has made more than 4,000 dives. The vessel is scheduled to be replaced about 2010 with a vehicle that can reach more than 21,000 feet and cover 99 percent of the ocean floor, said Alvin project manager Bob Brown.
Harold Edward Froehlich, whose father was a cabinetmaker, was born in Minneapolis on July 13, 1922.
After service in the Navy as a signalman during World War II, he graduated from the University of Washington with bachelor's degrees in aeronautical and mechanical engineering. He received a master's degree in aeronautical engineering from the University of Illinois at Urbana-Champaign.
After early work in aeronautical engineering for Boeing and other companies, Mr. Froehlich began working on high-altitude balloons for the General Mills aeronautical research labs in the early 1950s.
One balloon meant to help the CIA peer into Soviet-controlled Eastern Europe was downed by heavy winds and landed in New Jersey. On Navy contracts, he designing breathing systems and helium gas valves for balloons.
General Mills made a successful bid in 1962 for the Navy contract to build the self-propelled Alvin. Mr. Froehlich led the team that created a workable prototype with several large portholes that could withstand great pressure and featured clawlike hydraulic arms.
His earlier design for a self-propelled, two-man deep-sea vessel called the Seapup was instrumental to General Mills beating out such competitors as Lockheed and North American Aviation.
Mr. Froehlich told Minnesota Public Radio years later that winning the bid was an astonishing feat, because the Navy initially "was skeptical about a Wheaties company designing a submarine."
The Alvin overseen by Mr. Froehlich could hold three people, including a driver. It measured 22 feet and was eight feet at its widest. According to "Water Baby," an Alvin history, he chose the width "because it was the legal width limit of any object that could be transported on a highway without special permits or an escort."
Mr. Froehlich moved on to other work in 1964, soon after the Alvin was completed, but his basic design survived the decades as the vessel undertook a series of important missions. In 1966, Alvin was used to find a hydrogen bomb that had dropped after a U.S. military plane crashed off the Spanish coast.
In later decades, scientist Robert D. Ballard found giant tube worms and other previously undiscovered aquatic life near intensely hot sea vents 7,000 feet down off the Galapagos Islands. Ballard also guided a trek to the North Atlantic in 1986 to find the Titanic, which rested more than 12,000 feet underwater.
Despite Mr. Froehlich's role, Alvin was named for Allyn Vine, a Woods Hole scientist who had been an early vocal proponent of federal funding of manned undersea missions.
With Vine and Navy official Charles B. Momsen Jr., Mr. Froehlich received the 1989 Elmer A. Sperry Award for "the invention, development and deployment of the deep diving submarine, Alvin." The award is sponsored by prominent engineering societies.
Also in 1989, Mr. Froehlich retired from Minnesota-based 3M, where he designed surgical equipment, including skin staplers. He lived in St. Anthony, Minn., a Minneapolis suburb.
Survivors include his wife of 61 years, Avanelle Olson Froehlich of St. Anthony; two children, Steve Froehlich of Grasston, Minn., and Jane Hansen of Deerwood, Minn.; a sister; and eight grandchildren.