Herman Barkmann, an engineer who helped design the hydrogen bomb and then pioneered energy technology and was active in many community organizations, died Saturday at his home in Nambé. He was 92.

Barkmann was born May 5, 1918, and raised in Leavenworth, Kan. His father, Ernst Henry Barkmann, was a structural engineer who designed railroad bridges and military-landing craft. At the University of Kansas, Barkmann was a track star, graduating in 1941 with a degree in mechanical engineering. A leg injury he suffered in college prevented him from serving in World War II. His dream had been to become a pilot and fly "the hump" over the Himalaya.

Barkmann came to Los Alamos in 1948, when it was still a closed city. He worked with a firm of consulting engineers developing facilities at the lab, including "S" site, where the high-explosive parts of atomic bombs were developed.

He met lab employee Frances Sharp at Sawyer's ski hill, the predecessor of today's Pajarito Mountain Ski Area. The couple was married at the Church of the Holy Faith in 1949 and bought a small farm in Nambé. Fran said that at first, their colleagues thought they "were nuts," but eventually living in the valley became more fashionable.

After joining the Los Alamos Scientific Laboratory staff in 1951, Barkmann began working on the initial design for the trigger of the hydrogen bomb, along with Hans Bethe and Stan Ulam.

For the first test, his team was allowed five weeks to prepare the bomb at Eniwetok Atoll in the South Pacific. In a speech he gave to the Chile Club in 1976, he said that since the men had done all their work so well in New Mexico, they spent many days shell hunting, swimming, snorkeling, eating steak, and drinking martinis and beer. Barkmann was on the team that took the bomb ashore and armed it.

Other tests were performed atop high towers at the Nevada Test Site, onto which he helped raise the bombs. Back in the South Pacific again, his team tested a dry-hydrogen-fueled weapon (previous bombs had used liquid hydrogen). After the successful test, Harold Agnew (later director of LASL) sent a cable to lab director Norris Bradbury: "Why get a cow when powdered milk is so cheap?"

The work was all top secret, but Barkmann's son Peter remembers how tense his mother was when his father went away on business trips.

Beginning in 1956, he worked on the Lab's breeder reactor program, also a top-secret project. He left Los Alamos in 1963.

Six years later he and a partner founded Q-dot Corporation, which developed an innovative heat exchanger. After selling the company in 1973, he worked as a consulting engineer, designing and constructing active and passive solar energy systems.

Barkmann was always active in the community. He helped start the Río Grande chapter of the Sierra Club. When the Denver and Río Grande Railroad from Chama to Antonito was in danger of being abandoned, he worked to save it. Today it is the Cumbres and Toltec Scenic Railroad.

He was a founder of the Santa Fe Preparatory School and an early board member of the Chamber Music Festival. He served as senior warden at the Holy Faith Episcopal Church, and for 35 years was treasurer of Nambé's Acequia de la Comunidad commission. He ran, unsuccessfully, as a Republican for the Santa Fe County Commission.

He and his wife were members of the first volunteer ski patrols at the Los Alamos and Santa Fe ski areas. They were present on the first day Ski Santa Fe opened at its current location.

He was an elegant fly fisherman, having learned when he was young on family excursions to the Frying Pan River in Colorado.

Barkmann is survived by his wife Fran; daughter Gretchen Barkmann of Wenatchee, Wash.; son Peter Barkmann of Conifer, Colo., and his wife Gay, daughters Elyn and Nina; daughter Lee Stevenson of Silesia, Mont., and her husband Jim, children Luke and Rita.

Services will be 10 a.m., Saturday at the Church of the Holy Faith. In lieu of flowers, the family requests donations to the Lobato Trestle Restoration Fund, Friends of the C&TS Railroad, 6005 Osuna Road NE, Albuquerque 87109, or to the donor's favorite charity.