The “long and narrow” wave sets damaged nearly a mile of Cleveland’s waterfront protective barrier, which had been repaired in 1979-80. Mohr said that the repair solution involved the application of massive concrete “dolosse” (plural of dolos, a geometrically shaped concrete block) that have been in use since the 1960s.
“Whenever you work with a breakwater, it’s like working with an iceberg,” he explained. “What you see above water is a very small portion of it. When you’re dealing with a breakwater, most of it is underwater. And it’s important to place these dolosse to get good density and good interlocking.”
We’ve been doing work for many other organizations, such as the Coast Guard, National Park Service, and even NASA.
Mohr said that the Cleveland waterfront repair includes placement of almost 16,000 dolosse. “Our construction contractor, Great Lakes Dock and Materials, selected the French company, Mesuris, which created the software and hardware that allows real-time 3-D visualization of each dolos placement. The dolosse arrive on-site by barge, with a special GPS tracking unit placed at the same location on each block.”
Mohr described the placement visualization system as “like a video game,” explaining, “the operator sees a dolos being picked up, going through the air, and getting placed underwater adjacent to the last one. He sees the full orientation and how it’s interlocking. As it begins approaching position, the dolos is depicted in blue. Then, as it gets closer to the proper location it turns yellow, then to green when it’s at the proper location.
“It’s working great with Cleveland,” he offered. “It seems that they are getting much faster placement than we had originally anticipated and this system is really helping them.”
Other little-known civil works activities support a surprising array of both USACE and non-USACE customers. Several examples of this can be found at the USACE Marine Design Center (MDC), which is collocated with the Philadelphia District.
“Whether it involves repair, repowering, vessel surveys, or brand-new vessel acquisitions within USACE or other government agencies, customers can come to the Marine Design Center for engineering, design, and procurement,” observed Nick Hirannet, a project manager at the center. “We’ve been doing work for many other organizations, such as the Coast Guard, National Park Service, and even NASA. And, as a project manager, I would be the main point of contact in handling all the finance, scheduling, and coordination for any given project.”
Hirannet offered some representative examples of recent MDC projects.
The first example involved NASA’s Pegasus barge, which was originally used to transport external fuel tanks during the space shuttle missions.
“NASA came to us and basically said, ‘For the new Space Launch System program, we have to transport a core stage rocket that is significantly larger and heavier and has different aspects than the external tanks that we were previously transporting,” Hirannet explained. “Essentially, we needed to add 50 feet of length to their existing vessel, strengthen the hull over a 165-foot section, upgrade the electrical systems to be able to support the new rocket, and bring the vessel back to working order, because it was out of service for some time.”
In another example, he pointed to the Olmsted Locks and Dam, a $3.5 billion project underway in the USACE Louisville District. MDC’s role included development of a “wicket lifter barge” for dam maintenance as well as raising and lowering the wickets to create larger upstream pools when necessary.
“We recently completed the design and actually just held the bid opening last week,” he said. “So now we’re waiting to find out what shipyard is going to build the vessel.”
This article first appeared in the U.S. Army Corps of Engineers Building Strong®: Serving the Nation and the Armed Forces 2016-2017 Edition.