Metroparks Toledo recently completed construction of a new rustic style suspension bridge at the Brookwood Metropark in Toledo, Ohio. DGL was contracted to provide a full array of services for the new crossing including preliminary planning & conceptual design, surveying, hydrology and hydraulic study, alternatives analysis, and final design. The 90’ suspension bridge crossing Swan Creek links the existing special use venue with the preserve area on the west bank. The main suspension span is constructed of transverse wooden planks, deck cables, vertical suspenders, and a pair of 1” diameter overhead main cables.

The main cables connect timber towers on each creek bank with backstays that are secured to large concrete block anchors. The tower on the east bank is a simple timber A-frame supported by a helical pile. The cable support on the west bank is built into a nearly 40’ tall timber framed observation tower. Similar to the smaller tower on the east bank, the 40’ observation tower is also supported on helical pile. While not initially planned, the helical pile substructures were selected for this project due to the very soft soils present throughout the floodplain.

The final bridge location is north of the Brookwood Facility and was selected as the most efficient stream crossing site. Visitors can access the bridge by way of a new gravel pathway which connects the existing sidewalk with a new landscaped staircase down to the structure. The east approach includes a short two span timber boardwalk leading to the main suspension span. After crossing the bridge, the west bank transitions directly onto the lower platform of the observation tower. Visitors can then use the tower’s switch back staircase to enjoy a birds eye view of the floodplain from the upper platform or take the lower staircase down to the nature preserve area at grade.

The design of the bridge was based on a National Park Service bridge standard, but also included provisions from the AASHTO LRFD Guide Specifications for the Design of Pedestrian Bridges and the Ohio Building Code. The decisions behind the look of the bridge, as well as the inspiration behind the addition of the observation tower, are credited to Metroparks Toledo.