John O’Connell Memorial Bridge: How the iconic cable-stayed bridge supports Sitka

by Feb 20, 2023Engineering, Magazine

Roy Peratroviach Jr. | PND Engineers

In 2022, the American Society of Civil Engineers designated the John O’Connell memorial bridge as an Alaska Historic Civil Engineering Landmark.

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 Channel. 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. Running parallel to each other at an angle as they cut across the Sitka skyline, 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 beautiful 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 fifty 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, the ASCE Region 8 Director, said during the 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 O’Connell Bridge.”

bridge design team

From left to right: Bill Gute, Roy Peratrovich, Dennis Nottingham, and Department of Highways Commissioner Robert Beardsley—key members of the ‘60s bridge design team.

Alaska Department of Transportation & Public Facilities

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First Things First

While some recognize the O’Connell Bridge as the first cable-stayed vehicular crossing in the United States, the Historic American Engineering 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.

If the Alaska Department of Highways bridge designers had their way in the ‘60s, the “first” would’ve been undisputed. Roy Peratrovich Jr. and Dennis Nottingham, the co-founders of PND Engineers, Inc. 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 ‘50s. “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 unfortunately titled STRESS: an 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 much deflection analysis that had to be made because you had different deflection capabilities at different points where the cable was attached. It was pretty complicated, but Dennis figured out a way to do it.

“Later on, when the improvements were made on structural analysis, we went back and checked it again,” Peratrovich said, “and, sure enough, it was still working.”

The project was overseen by Department of Highways Commissioner Robert Beardsley. The winning bid for the project was $3.2 million in 1970; construction was completed in 1971. Beardsley was succeeded in 1972 by Commissioner Bruce Campbell, who presided over the O’Connell Bridge’s grand opening on August 19, 1972. None of the bridge design team members were present at September’s dedication. Peratrovich, who founded PND with Nottingham in 1979, spoke to PND about the O’Connell Bridge design in 2019 during the company’s 40th anniversary celebration.

“I’ve been with the department for twenty-two years, and I love these kinds of projects,” current Alaska Department of Transportation & Public Facilities (formerly known as the Department of Highways) Commissioner Ryan Anderson said at the ceremony. “There are so many stories. Whenever you work in the transportation industry, you look around at everything that was built, there are stories everywhere. This project in particular—with the innovative design and the way that people thought about this in 1972 when they built it—really is an example for us as a state, as the Department of Transportation, of how we want to move forward.”

“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 [drawing], and I said, ‘That would be ideal there.’”

—Roy Peratrovich Jr., Co-founder, PND Engineers

Historical Perspective

Alaska State Senator Bert Stedman, who has represented Southeast Alaska in the state legislature since 2003, graduated from Sitka High School in 1974. He was 16 years old when the bridge opened.

“When they built the bridge, it was pretty exciting in town,” Stedman recalled during the ceremony. “I happened to have [spent] that summer fishing out of Petersburg and bought a car when I got home. So, once it got shipped up here and I got to drive over this bridge—that was a couple of months after it was built, of course—but it was a big thing for the kids at the time to be able to drive over to Edgecumbe [on Japonski Island] and back. I think the police stayed over here [on Baranof Island], so we kind of enjoyed that until they figured it out.”

The resulting benefits of the bridge, however, were no laughing matter; its presence remains a boon to the City & Borough of Sitka today.

bridge

On September 11, 2022, the American Society of Civil Engineers Alaska Section designated the John O’Connell Memorial Bridge in Sitka as an Alaska Historic Civil Engineering Landmark.

Aaron Unterreiner | PND Engineers

“When we look at this economic development, once the bridge was done, there’s been construction over on Japonski for almost fifty years straight, and you can really see it today with the hospital going on and the expansion of the Coast Guard,” Stedman said. “Without the bridge, my guess is Mount Edgecumbe High School wouldn’t be there; the hospital would probably be in Juneau. The Coast Guard would probably still be there because they like the seclusion and the location, but it was really an anchor point in the economy to get this bridge built, and we’re reaping the benefits now.”

Sitka Mayor Steven Eisenbeisz echoed Stedman’s remarks: “We heard earlier about all of the economic activity that can happen on Japonski Island because of it, and that is on both sides of the island,” he said, referring to Baranof Island where the town center resides. “I don’t think it would be possible without this landmark here in Sitka.”

A Dedication Long Overdue

The dedication was two years overdue. Wheels were in motion for a 2020 dedication until the COVID-19 pandemic canceled all plans, travel and otherwise. The bridge’s merits were brought forth to the ASCE Alaska Section by Nottingham, who unfortunately didn’t live long enough to see the dedication come to fruition; Nottingham died March 6, 2022.

“I’m happy to be here to bring this recognition on his behalf,” said David Gamez, the event’s emcee and a past president of the ASCE Alaska Section.

The ceremony was held beneath the bridge’s composite steel reinforced concrete superstructure, between the substructure’s piers on the east side of the bridge. While the traffic busied itself at its usual pace overhead, the O’Connell Bridge Dock gently creaked and swayed in the background, rolling with the ocean waves. It was a gorgeous day—60°F, sunny, a light breeze. The roughly two dozen folding chairs set up for the event didn’t come close to accommodating the attendance, which numbered around fifty people. Over the crowd’s right shoulder was Crescent Bay; to the left, Castle Hill. It was fitting the ceremony took place in the shadow of the Baranof Castle State Historic Site, the national historic landmark where Russian Alaska was formally handed over to the United States in 1867.

Gamez was ticking off a number of the challenges the bridge design team faced in successfully completing this project—the high seismicity, climactic conditions, the technology at hand, and the bridge’s proximity to Castle Hill not the least among them. “In my opinion, it didn’t hurt Castle Hill,” Stedman said. “It’s just part of the community. The bridge blends in very well; the designers did an excellent job.”

The bridge is a bit of an enigma. Approach it from Japonski Island in the west, and the bridge presents itself as an imposing figure in front of its Sitka Harbor and Mount Verstovia backdrop. It’s one of the first things visitors see, a striking landmark welcoming them to Sitka. Approach it from Baranof Island in the east, and the bridge humbly defers to Castle Hill and Sitka’s rich history, content to rest in the shadows. The road slowly climbs and winds its way out of town, as the bridge says “thank you for coming”. It’s a hard phenomenon to explain, even for the locals.

“A couple things come to mind when I think of this bridge, one of them is obvious and one of them is not necessarily so obvious,” said Mayor Eisenbeisz, who spoke last with impromptu remarks. “The obvious one is this bridge is in just about everybody’s pictures. It’s in one or more drawings that you’ve done in the past. This bridge really is a landmark to Sitka, and Sitkans really do gather around the image of this bridge. So, I want to thank the people who spent the time designing it and thinking of the aesthetics of this, as well, because it does blend in so well with our community. In fact, it’s a focal point on our new city seal, which was recently redesigned. So, that’s how important this bridge is to Sitkans, whether or not they think about it every day.

“Which is my other less obvious point. I don’t know how many times a day you drive across this bridge, but you just really don’t think about it. It’s just there. It just happens to be there—you drive to the hospital, you drive to the airport, you drive to the harbor, whatever your business on the other side of the island, you just cross the bridge. No big deal.”

An enigma.

“I’m going to think about that a little bit more every time I drive across this bridge now,” he said, “what a convenience and what an asset it really is to Sitka.”

Aaron Unterreiner is the Marketing Manager for PND Engineers, a consulting engineering firm founded in 1979. He can be contacted at AUnterreiner@pndengineers.com.

 

“This bridge really is a landmark to Sitka, and Sitkans really do gather around the image of this bridge. So, I want to thank the people who spent the time designing it and thinking of the aesthetics of this, as well, because it does blend in so well with our community.”

—Steven Eisenbeisz, Mayor, City and Borough of Sitka

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