LOGAN — Hocking Hills State Park won the 2018 Outstanding Special Purpose Bridge Award from the Association for Bridge Construction and Design for their replica of the bridge featured in the movies “Indiana Jones and the Temple of Doom.”
The award was presednted in late February for the park’s unique Hemlock Pedestrian Bridge that has proved challenging to complete, but yet fun for park visitors.
The Outstanding Bridge Awards recognize owners, designers and contractors for deserving bridge projects within the state of Ohio. To earn the Outstanding Special Purpose Bridge Award the bridge must carry any type of facility other than highway, rail or transit; have a maximum span greater or equal to 20 feet; have new or rehabilitated main load carrying members; and new or rehabilitated substructure units.
The Hemlock Pedestrian Bridge is located at the beginning of Salt Creek where Clear Creek and Cedar Creek meet, which naturalist supervisor Pat Quackenbush says is notorious for flooding. After the flood of 1998 the state park swore they would never put a bridge down in the gorge, he noted.
“But we wanted to connect that whole section of gorge, it has not been connected in 40 years. The only way you can do it is, you’ve got to cross the stream to get over there,” noted Quackenbush.
That’s when Quackenbush had the realization while talking with co-workers that the only way you would be able to have a bridge in this location was if it was, “Indiana Jones style.” Quackenbush said they all laughed at him, not thinking he was serious.
“It’s right where those two (Cedar Creek and Clear Creek) come together. Which, another cool feature of it is, on the old trail you could not see the confluence, where those two came together to form the Salt Creek. When you’re standing on the bridge you can actually see where those two come together,” explained Quackenbush.
The Ohio Department of Natural Resources Road and Bridge Program Manager, Gus Smithhisler was the engineer behind the design with Woolpert, Inc. as the contractor for the project.
The idea was to allow the bridge to swing out of the way in case of big storms and the creek flooding the area. In fact, Smithhisler stated huge trees during a storm in the early 2000s came through there and wiped out most of the bridges through that area.
Logs can weigh tons and be extremely damaging, especially when they’re flowing downstream during a heavy rain. The force against a steel beam bridge or wood bridge would force it off the foundation, break the bridge in half or bend it, according to Smithhisler.
“So the idea behind a swinging bridge is the supports would be high up in the air, about 13 feet in the air, and the cable would swing down. Where the ends meet the ground we have them on styrofoam floats in those ramps so that they’ll float off their little stakes in the ground and swing out of the way if something were to hit it,” stated Smithhisler.
The original idea was a bridge that hung from trees to cross the stream, mentioned Smithhisler. Several 36-inch diameter trees were in the area that looked healthy enough to withstand the weight of the bridge and allow cables high up on their trunk to swing from there. However, after consultation with the Division of Forestry, folks decided it wasn’t worth the long term monitoring of health for the trees.
The remote location is central to the park and situated nearly a mile via trail from Old Man’s Cave, Cedar Falls and the former Hocking Hills Lodge site, which is also where the relatively new Whispering Cave trail connects.
The bridge is shaped in a “V” configuration, with the wooden portion of the bridge only 16 inches wide for a walking path. It’s 10 feet above the bottom of a stream, has a suspension length of 100 feet and a walkway length of 64 feet.
It took about four months to construct the bridge, but took roughly a year to complete it with the steel cable netting on the outside. It officially opened in early 2017.
The terrain in the area proved to be the most challenging and exciting portion of the project. There was no easy access to the location because of all the cliffs, so all the materials had to be hiked in about a mile to the location.
“We were able to get a road down close to the bridge to get some materials down on some ATVs and stuff, but there was no access for trucks. So everything had to be carried in. Then we had to pump the concrete a half-mile — we had a pumping company that was able to pump it the last half mile down for the foundations,” shared Smithhisler.
One thing’s for sure though, Smithhisler and Quackenbush said they’ve received a lot of positive feedback from the bridge.
“The visitors love it because of the style of bridge it is. It’s fun to go across, it swings and all that. It’s designed to have quite a bit of swing in it for that reason, because of the flooding,” concluded Quackenbush.