Few people can say their class prophecy in high school was that they'd spend their lives making bridges. Even fewer can say such a prophecy came true.

Jerry Nicholls, of Spokane Valley, has that distinction. Since his high school days in Phoenix, he has played a role—from designer to inspector—in the building or inspection of hundreds of bridges throughout Washington state during a career as a bridge engineer that has spanned four decades.

"It's my passion, more than anything. You can call it an obsession," Nicholls says.

Nicholls began his career in 1964 with the Washington state Department of Transportation, working in the agency's Eastern Region's bridge office here after earning a bachelor's degree in civil engineering from St. Martin's College, in Olympia. Since then, he estimates he's been involved in the design of at least 300 bridges, first with the DOT; then with Spokane County, during which time he earned a master's degree in engineering management from Washington State University; and, since 1992, with his company, Nicholls Engineering Inc., of Spokane Valley.

Nicholls Engineering has designed about 100 bridges and has worked for 21 of the 39 counties in Washington.

Nicholls employs two additional civil engineers in his firm, which operates out of the basement of his Spokane Valley home. In addition to designing bridge replacements and repairs, all three of the company's engineers are trained to conduct bridge inspections and to rate the strength of bridges.

One of the longest bridges Nicholls designed was about 5 miles long, to cross swampland near Everett, Wash., but he says that wasn't his most challenging project.

"It was basically the same design repeated over and over," he says.

Rather, Nicholls says, one of the more challenging bridges he has designed is the Hedlund Bridge, which carries a county road called Twin Bridge Road over the Kettle River near its confluence with the Columbia River in Stevens County. For that project, which was constructed recently, the county wanted to replace a 200-foot steel span there with a concrete bridge, using the concrete piers that already were in place. Designing such a structure was challenging given the length of the bridge, and because Stevens County wanted to build the bridge with concrete because it's much easier to maintain than steel, Nicholls says. Ultimately, Nicholls came up with the idea of splicing together three massive concrete girder sections that each weighed 150 tons, he says.

The bridge won the Washington Aggregate and Concrete Association's award for Excellence in Concrete Construction in the public works category for 2009.

Nicholls Engineering won a national award in 1995 for another Stevens County project. The Portland Cement Prestressed Concrete Institute named the Rockcut Bridge, which carries Rockcut Road over the Kettle/Colville River north of Orient, Wash., the Best Bridge built that year over 150 feet long, and also honored it for uniqueness of a single-span bridge, Nicholls says.

Nicholls designed award-winning bridges much earlier in his career. In 1976, he designed the Nine Mile Bridge, a concrete structure that carries Charles Road across the Spokane River just downstream from Nine Mile Dam. The bridge also won a national award for its design, which uses angled piers that jut out from the cliff on each side of the river, keeping them out of the water completely.

"That was designed with a slide rule," Nicholls jokes. He says that although the tools of the trade and design standards have changed over the years—he now uses computer software for bridge design—ultimately the goal remains the same. He seeks to design a bridge that will fit the situation.

In this region, that often takes the form of a concrete structure, Nicholls says.

"In Washington, we use a lot of concrete because we have exceptionally hard aggregates, and they are very durable," he says. "In the East, they are more crumbly." He says a typical strength for concrete would be 4,000 pounds per square inch, but on the Hedlund Bridge project, the construction team achieved a strength rating of 9,700 pounds per square inch, making the project viable, he says.

Also, the standards for bridge design have changed over the years in response to new threats to a bridge's lifespan, Nicholls says. For instance, now that salts are routinely used as deicers on roads here, more bridges are being designed with their steel rebar supports buried deeper below the deck surface to prevent them from being rusted by salt, which works its way down through small cracks in the surface. Rusting makes the rebar expand, causing concrete to "pop out" on the bridge surface, he says.

"The biggest enemy for bridges here is the salt," he says.

Current projects

Nicholls says his engineering firm experienced a slowdown at the beginning of the year, but business seems to be picking up a bit now. He says the firm designs about 10 bridges a year.

Nicholls Engineering's current pipeline of work includes contracts for bridges in Pend Oreille, Grant, Garfield, and Yakima counties.

The company has completed design work for a planned, $8.8 million replacement of the Freya Street Bridge, in east Spokane, which will be constructed by Garco Construction Inc., of Spokane, soon.

In addition to bridges for motor vehicles, Nicholls Engineering does projects that are pedestrian or bicycle oriented, including the recent redecking of three Expo '74-era pedestrian bridges in Riverfront Park, and it previously designed 34 bridges that carry parts of the 72-mile Trail of the Coeur d'Alenes project in North Idaho.

The bridges on that rails-to-trails project ranged in length from 15 feet long to a 3,400-foot-long span that carries the trail over Chatcolet Lake, in Coeur d'Alene.

To design a new or replacement bridge, the company first gets a site survey. Nicholls Engineering is small, so it typically contracts out that work, Nicholls says.

The site survey includes identifying where utilities are located, confirming the length and width of the bridge, noting elevations and the lay of the channel, and finding out where the right-of-way lines are. The company gets stream-flow information from the U.S. Geological Survey.

The company uses AutoCAD design systems to prepare drawings for bridge designs, but the engineers also use specialized spreadsheets the company developed, as well as computerized stress programs, in creating a design, Nicholls says.

Other work

In addition to designing bridges, Nicholls Engineering also rates the strength of bridges for their owners, he says. Washington state has standards for truck loads, and bridges typically are rated for what type of load they can take, based on the weight of a truck and how much weight is distributed over each axle of the vehicle, as well as what other traffic might be on the bridge at the same time.

The company often is contracted to determine the ratings for all of a county's bridges. It just completed such a project for Grant County, Nicholls says. The rating serves as one piece of a sufficiency formula that is used to determine when a bridge should be replaced, he says.

Sometimes, when a non-standard load is going to be carried over a bridge, a county or city will refer the commercial carrier to Nicholls Engineering. The carrier sends a layout of its load to the firm, which determines whether the bridge can handle the load in the proposed configuration.

Nicholls Engineering also performs bridge inspections. In Washington state, all bridges must be inspected every two years, and those that have load restrictions must be inspected annually, Nicholls says.

"Washington has been a leader in inspections," he says, adding that the state began the practice in the 1930s for bridges on state highways. In 1972, the federal government mandated inspections for all bridges, but Nicholls says that for the most part, cities and counties in Washington had been inspecting their bridges all along.

Among Nicholls Engineering's inspection clients are the cities of Pullman and Kennewick, as well as Spokane-based Potlatch Corp., which has about 80 bridges on its land, he says.

Also, when a bridge is first built, the company will do what Nicholls refers to as an inventory inspection, measuring everything to ensure that every aspect of the bridge has been constructed according to the plans. In regular inspections, it checks steel bridges for rust, bending, and missing bolts, for example.

Over his career, Nicholls has been involved as a consultant, designer, or inspector on many of the bridges in Spokane County, and throughout the region.

"I get involved with the bridges on one end or the other," he says.