One year into construction, Sherwood’s Bicycle and Pedestrian Bridge over Highway 99W came to life in a matter of weeks when the bridge spans were installed this spring.
Bridge Span Assembly
Each of the five bridge spans is simply supported. This means that they are structurally independent and self-supporting. The upright tied arches and inverted arch trusses are all biaxially symmetrical and can be lifted from four symmetrically located points. These trusses were assembled on site and in the Thompson Metal Fab shop in Vancouver, WA prior to erection to minimize road closures and traffic impacts.
The first arch is welded together outside of the YMCA pool.Steel framing for the span 5 bridge deck is assembled along Sunset Blvd.The first arch for span 5 is lifted into place on a temporary shoring tower.The steel deck edge assembly features a smooth exterior fascia articulated by alternating diagonal connection plates for the tension rods and vertical railing connection plates.The bridge scale suddenly becomes apparent when the first arch is placed vertically, revealing that it’s taller and longer than the adjacent YMCA pool façade.A large mobile crane wraps up assembly of the steel cross bracing holding the two arches together on span 5.Metal form decking is installed on span 5, offering the first glimpse of the future on-bridge experience. Welders attach the curved diagonal cross bracing to the arches on span 5.Span 5 assembly nears completion in its temporary home in the future footprint of the east approach ramps. Architectural stainless steel tension rods are woven between each arch and the bridge deck in a uniform diagonal grid.As the stainless steel rods are tensioned, span 5 becomes a self-supporting truss spanning 194 feet and ready to move into its final position over Highway 99W.Final painting touch ups wrap up ahead of the span 5 erection.All five bridge spans feature a five-degree outward tilt to the trusses, creating a unique and dynamic form viewed in the round.The curved cross bracing between the arches enables a delicately slender arch proportion on span 5 and reflects the woven tension rod patterning.The first arch for span 3 is lifted into place, with crews carefully threading a conduit through the structure to conceal electrical and low voltage systems. Span 3 continues assembly in the same sequence as span 5, in the contractor’s staging yard on the Elk’s Lodge hill overlooking the project site.Span 3 was assembled on axis with the angled end of the north wing of Sherwood High School.Span 4 was fully assembled in Thompson Metal Fab’s shop in Vancouver, WA. All of the steel for the project was fabricated and painted here, with final assembly of spans 1, 3, and 5 completed in the field.
Span 5 – March 8, 2025
The main bridge span over Highway 99W was first to be installed, on March 8, 2025. Extensive planning went into the highway closure and detour to Elwert Rd, beginning during the bridge design and continuing through the work in collaboration with ODOT, Washington County, the City of Sherwood police department, and other local partners. While the plans called for a full weekend closure from 9pm Friday through 5am Monday, crews completed the work and reopened the highway in just 24 hours. Span 5 is the largest on the bridge with a 194-foot span and 39-foot height at the work points. All spans have their trusses tilted outward at a 5-degree angle, creating a unique form with apparent shape-shifting across viewing angles.
Two cranes lift span 5 from its assembly bed onto transport dollies on Sunset Blvd.As span 5 is anchored to the transporters, the cranes prepare to move onto Highway 99W to set it into its final position.Span 5 inches toward its final destination as the completed bridge bents await arrival of the other four spans. The first crane is staged for the final span 5 pick over the highway.A final look across the highway from the future east approach before the bridge moves into place.The scale of span 5 becomes more apparent as it’s lifted incrementally higher from its assembly bed.Sherwood residents and their canines eagerly await span 5’s big move from Sunset onto Highway 99W.The sun emerges on Sunset, offering a first glimpse of the dramatic shadows that the bridge structure will cast.Around 10:30am, traffic controllers stop all traffic detouring from Hwy 99W onto Elwert Rd. and shift the closures barriers to make way for span 5.Span 5 begins its careful movement through the intersection on transportation dollies.The front transporter swings wide toward Elwert Rd as span 5 crosses the intersection.Span 5 begins to turn onto the southbound lanes of Highway 99W.At the tightest point along its journey, span 5 fills the full diagonal width of 99W/Elwert/Sunset intersection.Reality confirms the viability of the bridge movement path that was studied through extensive digital and physical 3D modeling.The rear transporter finally swings into the intersection to complete the turn onto the southbound highway lanes.Span 5 just clears the highway median traffic signals as it completes the turn.Span 5 parks on the southbound lanes of Highway 99W, allowing detoured traffic to resume onto Elwert Rd after just a 20-minute pause.The cranes prepare to pick span 5 into its final position, offering a pause in the process to observe the completed structure in a temporary position from various vantage points.This temporary slope is more extreme than the final condition, but clearly demonstrates how the existing highway grades are leveraged to increase clearance under the bridge and minimize pedestrian ramp lengths.This view from the west abutment shows the three roads that the completed bridge will cross. The detoured highway 99W traffic on Elwert Rd. is denser than typical, but not much worse than the daily peaks on school days.Utility lines along the highway were raised, undergrounded, and temporarily shifted with a shoefly to create clearance for the erection cranes.The tilted arches create dynamic oblique views along the structure.Crews wrap up a final safety meeting and move into position to lift span 5 into place.The first crane is attached to the east end of span 5.The east end of span 5 lifts off of the transportation dolly, which moves out of the way as the other transporter drives toward the second crane.The west end of span 5 crawls down the southbound lanes of Hwy 99W to be picked by the second crane. Span 5 swings carefully into place through a choregraphed effort of two cranes.Span 5 is set onto its bearings and welded into place atop the concrete bents.As welders permanently anchor span 5 into place, it can be observed from views across the surrounding area.Span 5 from the roundabout.Span 5 from Highway 99W Southbound, in a view that will reopen to drivers in a matter of hours.Span 5 from Highway 99W at Elwert. Span 5 from outside the YMCA gym.Span 5 from Sunset Blvd. at Hwy 99W. The bridge span was installed and the highway reopened more than a day early, with only a 24-hour road closure.
Spans 4 & 3 – March 22, 2025
With concurrent assembly work, the next two bridge spans were ready to be installed just two weeks later. This time, Highway 99W remained open while Kruger Rd, Elwert Rd, and the roundabout were closed to traffic.
With three bridge spans now on site, the bridge becomes a composition of tied arch shapes as they move toward their final arrangement.The 100-ft-long span 4 arrives on a truck that navigated from Vanouver, WA to Sherwood overnight.The underslung arch spans feature stainless steel compression struts to match the tension rods on the tied arch spans, in a vertical pattern that will follow the railing design.Span 3 turns from the construction staging yard onto Elwert Rd.A single crane will pick each of the remaining bridge spans.A southern view of the full alignment shows span 3 at distant perspective near the final position of span 1 and span 4 in close perspective near its imminent position.Crews begin attaching rigging to four symmetrical points on span 4 for hoisting.Span 3 drives into the roundabout from Elwert Rd. on transportation dollies similar to those used for span 5.Span 3, the second largest at 128ft long and 26 feet tall at the work points, traverses the roundabout.Span 4 lifts off over Elwert Rd. Span 4 swings into place in a remarkably simple maneuver compared to the two-crane operations for span 5.Span 4 is the smallest by a slight margin, at 100 feet long and 13 feet tall at the work points.Span 4 is slowly lowered onto its bearings alongside span 5, with highway traffic uninterrupted.With the first two spans in place, span 3 is staged near its final position over Elwert Rd.The arches of span 4 intersect the temporary placement of span 3 in this view down Elwert Rd.Spans 5 and 3 have the same aspect ratio and arch sizes, offering a play of scale and proportion from different angles.Span 3 prepares to continue the emerging undulating bridge form in this view from the west abutment.With 2/3 the height and length of span 5, span 3 feels slightly more muscular in its proportion of solid steel and void space.Span 3 waits in the roundabout while the crane is relocated.The joints between each span will be articulated with projecting belvedere features to complete the architectural form.The stainless steel struts on span 4 begin to sparkle in the sun for the first time.The crane rigging is stretched across the 128 foot length of span 3.The crane rigging is spread at a wide angle to pick span 3 from its four corners near the bearings.Span 3 lifts off of the transportation dollies along Elwert Rd. Span 3 slowly swings across Elwert Rd.Span 3 starts to touch down on its bearings to reveal the third bay of the undulating bridge form.The raw concrete walls of bent 1 frame a view of the first three bridge spans with the span 3 crane.The crane holds span 3 in place as crews bring to weld it onto the bearings at bent 2 across the stormwater pond.Spans 3 and 4 begin to curve the bridge alignment from the highway toward Sherwood High School.Span 3 joins the bridge in this view from the west abutment, leaving just two spans to complete the grade-separated path.Span 3 brings the bridge past the halfway point in length and features the highest elevation over the roadway at the peak of the bridge vertical profile.As the crane prepares to de-rig, the scale and alignment of the bridge project become much clearer to the public.
Spans 2 & 1 – May 17, 2025
Much of the work to fabricate the final two bridge spans was initiated following erection of spans 3 & 4, resulting in an eight week gap to this final step. This allowed onsite work to shift focus to pouring concrete decks and east approach retaining walls to maintain the overall schedule. With a similar roadway closure to the previous two spans, the bridge achieved its final form in a seamlessly choreographed effort.
The final two spans join the composition, meandering toward their final arrangement.Like span 4, span 2 was fully assembled at Thompson Metal Fab’s shop and shipped to site overnight.Span 1 begins to move from the site yard toward Elwert Rd. while span 2 is attached to the crane.Span 2 is rigged to the crane while span 1 turns onto Elwert Rd. in the distance.Construction on span 3 has progressed through bridge deck placement, offering a direct overhead view of spans 1 and 2 down Elwert.Span 1 caps span 2 in the distance under span 3. Span 2 is the second-shortest at 112 feet long, and the same height as span 4 at 13 feet tall to the work points.The crane prepares to lift span 2, closing the gap toward the west approach.Span 2 lifts off of its transport trailer in the roundabout.Span 2 spins over Elwert Rd. along span 3.Span 2 hovers over its home across the stormwater pond.The crane sets span 2 into place to complete the fourth section of the undulating bridge form.View across spans 3 and 2 from the bent 3 lantern.View across span 4 to spans 3 and 2.The bridge composition is nearly complete, with span 1 awaiting erection on the north side of the roundabout.Maturing landscaping in the stormwater pond offers a serene foreground for span 2. The underslung arches of span 2 float above landscaping in the stormwater pond. These arches are in tension and do not require the cross bracing found on the above-deck arches. The crane releases span 2 and prepares to relocate for the final pick of span 1, which will complete the connection to this vantage point.Bridge composition with span 1 foreground of its final position.Span 1 is the same length as span 3, at 128 feet, but has the same span-to-depth ratio as span 4 at 7.5:1 to shape the overall bridge form, resulting in a thicker proportion of structure to void.Span 1 makes its way down Elwert Rd. on transporters to join the rest of the bridge.Span 1 awaits erection in the roundabout.The crane prepares to pick span 1, viewed from the span 4 bridge deck.Span 1 lifts off from the transport dollies in the roundabout.Span 1 swing across the west approach walls viewed from the span 3 deck.Span 1 swings over the end of Kruger Rd.Span 1 spins into place above Kruger Rd.The crane prepares to set span 1 down into its final position.A first look across the completed bridge superstructure from span 5 over Highway 99W.Span 1 joins the composition with its conspicuous turn north toward Sherwood High School.The crane and span 1, with the other spans turning away in the background.All five bridge spans and the crane from the west approach ramps.The five bridge spans looking south from Elwert Rd.The five bridge spans, with the crane holding span 1, from the construction staging yard.The crane releases span 1 from the rigging.A first look across the future span 1 deck from the west abutment.The crane is dismantled, leaving the prominent horizontal bridge form.The completed bridge superstructure from Kruger Rd.The Sherwood High School baseball field’s berm offers broad views of the bridge galloping through the trees.Summary of the span lengths, heights, and aspect ratios of the bridge spans.
Timelapse Videos
ACMS NW is providing daily onsite inspection services for this project and collaborated with Stratoscape to produce aerial photography of the bridge span erections for all five spans.
Construction will continue with completion of the east and west approach ramps, concrete bridge decks, architectural and pathway lighting, railings, and landscaping in the coming months. The bridge is scheduled to open to bicycles and pedestrians this fall.
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