William R. Thomas, an electrical engineer by training who maintained a relentless pace in retirement as a volunteer refurbishing bicycles for needy children, helping hospital patients and feeding the homeless, died Thursday.

Mr. Thomas, who lived in a one-bedroom Castle Shannon apartment crowded with the bicycles he was repairing, was 83.

Spry and energetic, Mr. Thomas was able to live on his own terms almost until the end. Although he battled lung congestion last month and was not feeling 100 percent, he was still able to haul bicycles onto the rack of his car and drive to Kraynick's Bike Shop in Garfield for parts, said his friend, Jerry L. Kraynick.

But on June 5 Mr. Thomas felt ill enough to call an ambulance to his apartment and entered St. Clair Hospital in Mt. Lebanon.

Suddenly the man who had spent more than a decade at St. Clair as a volunteer delivering mail and pushing other people in their wheelchairs found himself in the same facility as a patient.

What began as pneumonia cascaded into more serious health problems until Mr. Thomas' family followed his wishes Thursday and took him off life support.

Mr. Thomas had logged nearly 7,000 hours over 12 years at St. Clair -- and he repaired nearly 900 bicycles since 2004, according to Georgianne Williams, St. Clair's director of volunteers.

Using a black pen to write numbers in a small, black day planner he got from his longtime employer, Westinghouse Corp., Mr. Thomas kept an annual tally of the bicycles he fixed.

His neat penmanship tells the tale: In 2004, he spruced up 63 bikes for poor kids who otherwise might never be able to afford their own ride; he did 247 last year. There is no final entry for 2009.

"He liked to do it. It kept him busy. He could use his tools. He loved to tinker. It was his way of being able to help kids who didn't have bicycles," said Maria Shields, 44, of Peters, the oldest of his four children.

At St. Clair, he was known as "the Bike Man" and had an ad on the hospital's bulletin board asking anyone with bicycles to donate to call him.

"I asked him once why he did all these bikes. He would come in to volunteer in the hospital, his hands would be bruised, his nails broken and sometimes they would be bleeding because of all the work he put into these bikes," recalled Mrs. Williams.

"He felt it was so important that poor kids had an opportunity to ride a bicycle, get outdoors and have something they could call their own."

Mr. Thomas would pay for parts out of his own pocket, pick up bicycles on the cheap and steadfastly use his own basic tools instead of the specialty ones at Mr. Kraynick's shop.

Over the past few years, Mr. Thomas was one of the mechanics who helped Mr. Kraynick with The Bike Before Christmas program, which he coordinated with Pittsburgh police to distribute rehabilitated bicycles to underprivileged children. In 2007, Mayor Luke Ravenstahl awarded Mr. Thomas a proclamation for his efforts.

"He just had a very big heart. He just loved doing this for the kids. It was amazing. About every week it seemed like I got a phone call from him saying he had some more bikes ready," Officer Melissa Gutch said.

Mr. Thomas was born in the Sharpsburg area, one of 10 children. He grew up there and around Pittsburgh's Shadyside neighborhood on Morewood Avenue.

He was in the U.S. Army from 1944 to 1946 and then earned an electrical engineering degree from the University of Pittsburgh, Mrs. Shields said.

Mr. Thomas was hired by Westinghouse, and his roughly 35-year career working on nuclear power plants took him around the world to India, Cuba, Greece and Spain, where he met and married his wife, Maria, in the early 1960s. She died in 2006.

The family eventually returned to the Pittsburgh area, settling in Upper St. Clair. Mrs. Shields said even in "retirement" her father continued to work as a consultant to Westinghouse and then threw himself full-time into volunteering when he fully retired.

Mr. Thomas, who had repaired his children's bikes when they were young and maintained community softball fields on his own initiative, began working at St. Clair and the Jubilee Kitchen in the Hill District.

Mrs. Williams said she once ran into Mr. Thomas outside a supermarket. He was carrying a mountain of vegetables. After some prodding, he told her he made salads for the homeless.

Family and friends described Mr. Thomas as gruff on the outside but kind-hearted on the inside. He was modest and downplayed his good works. Mrs. Williams said she visited her friend in the intensive care unit and told him how much she admired him for helping others.

"You know what he said to me? He reached his hand out and held my hand. He said, 'Georgianne, don't destroy my reputation, that of an old grouch.' He said that with a twinkle in his eye."

Mr. Thomas would sometimes joke that his volunteer work had an ulterior motive -- it was a way to get him into Heaven.

"I hope his theory was right," Mr. Kraynick said.

In addition to his daughter, Mr. Thomas is survived by another daughter, Elena, of South Lyon, Mich; sons Willy, of Nashville, Tenn., and Michael, of Mt. Lebanon; and eight grandchildren.

Arrangements are being handled by Beinhauer Mortuary in Peters. There will be a viewing and service tomorrow at 5 p.m. at St. David Episcopal Church in Peters. Donations may be made to Girls Hope, 1020 State St., Baden, PA 15005.