The newest footbridge in Long Beach, Calif., is unlike any suspension bridge ever built. Instead of using traditional construction methods, 10 men assembled the bridge by hand from 10,000 aluminum pieces in three weeks, with no bolts.
Just how does the 450-foot bridge stand? One of the project’s engineers, Glenn Reynolds, developed the new building method, which he calls “coaxial joint system.” In many ways, it’s like constructing a bridge out of tinkertoy sticks, only in much larger terms. The ends of 10-foot lengths of pipe are joined by connector points, which are machine-threaded so that grooved sleeves can be twisted to lock the pieces together. The bridge’s heavy-duty joints and pipes are screwed together like jars and lids. The only tool that was needed to put the bridge together was a hand-held wrench to tighten the connections.
The tinkertoy bridge now stands above Shoreline Drive at Long Beach’s Old Pike Park. During the first half of the century, the Pike served as the area’s amusement park, where visitors could ride “the steepest and fastest ride in the world,” the Cyclone Racer roller coaster. The Cyclone was demolished more than 30 years ago and the Pike is now under reconstruction. The area will feature shops and restaurants along the city’s waterfront.
Because Shoreline Drive is the roadway used for the Long Beach Grand Prix race and cuts through the development site, a pedestrian bridge was needed to connect the Pike’s two sides.
Originally, drawings of the Pike project plan included a traditional pedestrian bridge with adorned decorations to make it look like the old cyclone roller coaster. When Reynolds heard about the project, he and his partners, Gary Noble Curtis and Dean Hackbarth of Gossamer Space Frames, were able to convince the developers that a new kind of bridge, one that more resembled a roller coaster, could be built for less money than conventional construction.
Although there wasn’t any historical data on such a structure, the development team decided to try Reynold’s plan. When the $2.5-million structure was completed at the end of September, not even the project manager Michael Harness new if the project would work.
“I thought, ‘OK, this is different,'” Harness told the LA Times. “We took Glenn’s word on it that it would work.”
During the construction of the bridge, temporary support beams were set up to hold up the concrete-topped steel walkway deck. According to outside engineers, an unsupported steel span could not stretch across the 150-foot street below without sagging at dangerous levels. When the beams were removed, everyone stopped to watch. The 25-ton bridge stood, with a sag of only about an inch.
To complete the roller coaster look, pipes were painted white and the curving top rail is painted blue and will be lined with chaser lights, which will simulate roller coaster cars rising and dropping on the old Cyclone Racer roller coaster. The bridge will open to pedestrians in November, when some of the Pike’s first restaurants and movie theaters will open.
