“Long winters.”

That’s how lifelong resident Tom Bieleski explains the 13 noted bridges of the world he’s replicated with tiny “timbers” and eighth-inch dowels.

An exhibit of 11 of his bridges – including models of such famous spans as Oregon’s Bridge of the Gods and Australia’s Sydney Harbor bridge – is featured at the Sheldon Museum through May 15.

Bieleski, who has worked as a builder, bartender and fisherman in Haines, said the bridge-building itch struck 10 years ago, as an outgrowth of a model train hobby that started when he got his first train set at age 50.

But his fascination with bridge mechanics dates back to a college engineering class, he said.

“The professor was describing vectors and lines of compression and lines of tension, and he said, ‘If you can’t see those lines, you should drop out of the class.’ I could see them in my mind. I aced the course. That’s what got me interested in bridges,” Bieleski said.

Bieleski said he served with the Seabees in Vietnam and said he helped build bridges that were later blown up in the war there.

At Bieleski’s Piedad Road home, “HO” scale model trains recently ran through 11 of the displayed bridges on a 125-foot-long track circling his living room and kitchen. Two other bridges there include a suspension bridge resembling San Francisco’s Golden Gate and one with a V-shaped support of his own design.

Bieleski is planning an expansion into his bedroom and bathroom. “I want to add 125 more feet, including a section that goes through the shower in a clear tube.”

The museum display includes charts explaining different types of bridges and the tools Bieleski uses for the detail work, including a doll-sized table saw.

Displayed bridges include a historic trestle on the White Pass and Yukon Route Railway, the Victoria Falls Bridge linking Zambia and Zimbabwe and the Park Avenue Bridge, connecting Manhattan and the Bronx.

The Sydney Harbor bridge replica is 10 feet long and contains about 5,000 separate pieces, Bieleski said. It represents about 800 hours of work.

Museum operations coordinator Blythe Carter said the exhibit, “Bridges by Bieleski,” has been well-received. “People are just stunned by it. It’s so much more than they expect. It’s beautiful. It’s really an art form.”