Harrison Randolph Griswold of Simsbury, CT passed away unexpectedly on April 26, 2025, at age 89. He was taken to John Dempsey Hospital by ambulance where he had family by his side in his last hours, still able to smile. He had been slowly declining from Alzheimer’s for several years, at home with his wife Dagny. He had just spent Easter weekend in Massachusetts with his daughters, sons-in-law and four young grandchildren. He leaves behind his wife of 44 years, Dagny Hultgreen Griswold, two daughters and their husbands Heidi & Brian Kelly (of Colchester, VT) and Becky & Aaron Mariano (of Scituate, MA), three sons by a prior marriage and their wives: Eric & Mara Peters (Darien, CT), Scott & Astrid Peters (Darien, CT), Craig Peters & Kathy Vanderlaag (Belmont, CA), and 13 grandchildren ranging in age from 2 to 23, one great grandson, and “Aunt” Barb Perry of Canton. He was predeceased by his sister Mary Ellen McDermott of South Windsor.

Harry is a descendant of the Griswold’s who founded Windsor, CT in 1633. He was born in New London, CT on February 6, 1936, to Frederick William Griswold and Helen Barnard Griswold. Harry spent most of his life in Connecticut, graduating from Manchester High School in 1954, where he played football and baseball. He went into the Air Force, spending time in Korea, where he was rescued by a Japanese fishing fleet when his plane went into the Pacific Ocean. He went to UConn on the GI bill, graduating with honors in 1961 as an electrical engineer, then went on to get a master’s degree in aerospace engineering and another master’s in computer science, then a PhD in mathematics from Rensselaer Polytechnic Institute (RPI). In his spare time he was a pool shark, ski instructor (skied the bowl at Tuckerman’s Ravine at Mount Washington), was a camp counselor handling horses at a dude ranch in Colorado, went sky diving, rock climbing, taught math at the University of Hartford, and later scuba-dived with astronauts in water tanks to simulate weightlessness while teaching them to use tools tethered in space. He went on to work at Pratt and Whitney and was an engineering manager at Hamilton Standard where he traveled to Tokyo, Rome and Stockholm to give presentations at Aerospace conferences. He worked on life support systems for astronauts and submarines and got a ride on the Coast Guard Eagle from New London to the Panama Canal while helping to scatter the ashes of a navy admiral. He flew in the SR71 Blackhawk to the edge of space and went deep into the ocean in submarines and enjoyed sailing with friends. After a career with UTC, he started some small businesses with other engineers. His last position, before retiring at age 81, was as Vice President of Rotating Composite Technologies (RCT) in Kensington, CT which designed and made prototype composite propellers for small planes and helicopters. They were part of a team that developed the X2 technology for a Sikorsky demonstrator helicopter (precursor to the X-97 Raider) that won the national aviation award, the Collier Trophy, in 2010. The prototype is in the Smithsonian in Washington, D.C.

Besides his intellect and accomplishments, Harry had a fun and outgoing personality, was handy and liked to fix and build things, including a wonderful playhouse in the yard enjoyed by his daughters and grandkids. He and a friend who worked on building sets for the Theatre Guild of Simsbury, cut a hole in our roof to put in a skylight, that did not leak. Harry was a good father and grandfather who would make up fun stories for bedtime. He enjoyed gardening with Dagny and would hide “pirate treasure” and “dinosaur eggs” in the vegetable gardens for kids to find. He also enjoyed going to antique shows and coming home with unusual items to decorate the house, such as a deep-sea diving helmet, ox yoke, sleigh bells and stained-glass windows. The biggest antiques were: 1) a pool table for the basement and 2) a player-piano with rolls of show tunes used for parties after Dagny sang and danced in Theatre Guild shows. Harry and Dagny were also involved with the Simsbury Historical Society and the construction of a new blacksmith shop on the campus.

He loved his family and will be sorely missed. Although Alzheimer’s took its toll on his memory and cognitive functions, he maintained a pleasant personality to the end.

A celebration of life will be held for family and friends in Simsbury, CT on July 7, 2025. In lieu of flowers, donations can be made to the Alzheimer’s Association or Simsbury Historical Society (www.simsburyhistory.org ) in his honor. Please visit Harry’s Book of Memories at www.vincentfuneralhome.com for online tributes.