C+S November 2022 Vol. 8 Issue 11

ASCE Alaska Section Historic Civil Engineering Landmark Designation

John O’Connell Memorial Bridge Sitka, Alaska By Aaron Unterreiner

SITKA, ALASKA – It’s difficult to distinguish the O’Connell Bridge from the Sitka Harbor shoreline, which is remarkable considering the bridge is 1,255 feet long and towers more than 150 feet over the Sitka Chan - nel. Among the vast commercial fishing fleet and hundreds of charter and recreational vessels berthed on the east side of the strait, the iconic cable-stayed bridge comfortably blends into its idyllic surroundings. The bridge’s harp design features a trio of cables suspended to the deck in each direction from high atop two sets of 100-foot twin towers. Run - ning parallel to each other at an angle as they cut across the Sitka sky- line, the bridge’s stayed cables can easily be mistaken at a distance for yet another series of stays hanging from the mast of a docked trawler. That’s partly what makes this bridge so appealing. It’s a beauti - ful bridge, but it’s not boastful. It’s a practical piece of thoughtfully designed infrastructure that has seamlessly woven itself into Sitka’s fabric. In many ways, the O’Connell Bridge represents the zeitgeist of Alaska’s economic development over the last 50 years. On Sunday, September 11, 2022, slightly more than a half-century after the bridge opened to vehicular traffic, the American Society of Civil Engineers (ASCE) Alaska Section designated the John O’Connell Memorial Bridge an Alaska Historic Civil Engineering Landmark. “We always seek through the national historic civil engineering landmark program to honor these projects and the engineers who make them happen, for their skills as innovators and risk-takers,” presenter Larry Magura, PE, the ASCE Region 8 Director, said during Sunday’s dedication in Sitka. “That’s honestly what it comes down to – no risk, no reward. “Engineers don’t do a particularly good job of blowing their own horn and acknowledging their accomplishments, and that’s really one of the reasons we’re here today. This is a beautiful bridge. It’s very iconic, very aesthetically pleasing. And we’re delighted to be here today to participate in putting a state historic landmark designation on the While some recognize the O’Connell Bridge as the first cable-stayed vehicular crossing in the United States, the Historic American Engi- neering Record among them, the bridge at the very least is the first of its kind in Alaska, “and that is a significant achievement,” said Magura, who cited a number of other cable-stayed crossings with close if not entirely discernible start dates, hence the ASCE’s hesitation toward christening the bridge a nationally historic landmark. O’Connell Bridge.” First Things First

If the Alaska Department of Highways bridge designers had their way in the 1960s, the “first” would’ve been undisputed. Roy Peratrovich, Jr. and Dennis Nottingham, the co-founders of PND Engineers, Inc. (PND) and key members of the O’Connell’s bridge design team, pitched the idea of cable-stayed crossings years earlier for both the Susitna River and Copper River crossings. “I had proposed the first one in 1962 when I had just come back to Juneau in ’61,” said Peratrovich, who was born in Southeast Alaska and earned his civil engineering degree in Washington State in the late 1950s. “That’s when I submitted the drawing of the Susitna River Bridge – 1,000 feet across, two twin towers, a 500-foot middle span. It would’ve worked, but it was way too early. My chief bridge engineer... he was sitting down at his table working over something. I came in with my drawing of the cable-stayed, and he looked at that and started shaking his head, looked up at me over his glasses and said, ‘Roy, it’s too early.’” Peratrovich stowed the cable-stayed bridge idea in his back pocket. He was eventually promoted from Department of Highways Bridge Design Section Squad Leader to Section Head in 1969. “Back in ’69, when we started looking at alternate crossings for Sitka – what type to use, where to put it, how would it fit in with existing situations and future improvement to harbor work and all that – I had this cable-stayed, and I said, ‘That would be ideal there.’” Peratrovich finally got his wish. As design squad chief, his bridge design team included Bill Gute as the design and plan preparation lead and Nottingham on design check and final structural analysis. Fred Kohls was the computer section lead, assisting Nottingham with one of the first computer-aided structural engineering designs in Alaska history. “We didn’t have the computer programs yet,” said Peratrovich, who deferred to Kohls, Nottingham, and the Department of Highways’ new IBM 1130 Computing System with the unfortunately titled STRESS acronym for its Structural Engineering System Solver software. “We had this paper-fed thing, you get this pile of responses and answers in this thing on folded paper that you’d pull out and spread all the way down to Seattle if you let it,” Peratrovich said. “It was just so much paperwork that you gotta go through; it just didn’t have the capabilities for doing structural work that was needed on this job. There was so



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