The more the merrier.
That common saying could be the motto for an effort within the U.S. Army Corps of Engineers (USACE) to create a near real-time system that would track the safety and accessibility of our nation’s inland waterways.
Taking advantage of vessels already on the water, an effort in the works at the U.S. Army Engineer Research and Development Center (ERDC) will use those vessels’ depth finders and GPS to create a snapshot of a channel and any obstructions that may exist.
This information, crowdsourced for private and public vessels, would support USACE’s existing survey fleet and reduce the impact of any threats to navigation on the 25,000 miles of inland waterways USACE maintains.
“The Army Corps of Engineers has a fleet of surveyors that do highly accurate, precise surveys on a periodic schedule for all of the waterways,” said Dr. Brandan Scully, a research civil engineer with ERDC’s Coastal and Hydraulics Laboratory. “But given the nature of those surveys, cost, time, available vessels, etc., we do not have the ability to continuously monitor.
“In order for us to do that with traditional resources, it would cost millions of dollars.”
Scully said crowdsourcing bathymetry would use equipment that already exists on vessels, such as depth finders and GPS, and supplement it with a device that would transmit that data. Once collected in a cloud, the data would then be quickly analyzed and aggregated with data from other vessels in the same area to give a picture of that portion of the waterway.
“It’s relatively simple. It’s like plugging into a router at your home for the internet, and it aggregates the position and the depth observed by the vessel and sends it off to a cloud computing resource,” Scully said. “And because there are many more waterway users, because they’re working all the time, we can have a rolling picture of parts of the waterway based on who is in the crowd and how much they are moving around.”
Scully said this information – this picture – could then be used to prioritize the actions of the USACE survey fleet and its ability to capture accurate scans to better observe any concerns with navigation. It also provides the ability to watch the waterways between scheduled surveys.
As for the next step, Scully said ERDC is currently working with public and private organizations to determine the best device and setup to roll the program out on a larger scale for a proof of concept. In addition, he said there is still work to be done on where to best house the data and distribute the information.
In a discussion at the recent national meeting of the Association of the United States Army, Lt. Gen. Scott Spellmon, 55th Chief of Engineers and Commanding General of USACE, said he envisions the use of this crowdsourced bathymetry as a sort of digital traffic map for inland waterways, much in the same way as popular apps on cellphones provide updates on highway traffic. He also said a program such as this would help in USACE’s response to natural disasters, such as hurricanes.
“An example I would use is we just had Hurricane Idalia come through the state of Florida just a few weeks ago and the South Atlantic Division has five survey vessels that have to cover 12 ports in the state,” Spellmon said. “And that takes time after a storm. You have to get our survey crews there and work with the Coast Guard to reopen those ports.”
Spellmon said being able to pull data from public and private vessels already navigating in the area would provide “real-time processes of the federal navigation channel, and we would not have to put a survey vessel in that area right away.”
Scully said the analogy of a traffic app is a good one.
“Those apps tell you the speed of traffic and where the police might be and stuff like that,” he said. “But what this is telling us, essentially, is where are the potholes? Where are the speed bumps?”
The critical portions of this research are determining the technology to use to transmit and collect the data (whether that is a private or public solution), finding ways to aggregate and analyze it, and then figuring out how best to push out the information to those who need it, such as commercial operations and teams tasked with clearing any threats to navigation.
“That’s one of the nice things about ERDC … we filter the solutions and find the right answer, or we find the best available answer right now,” Scully said. “We have to have a good match between the Army’s mission and the provider’s capability.”
While the program continues to wait for additional funding to advance the technology, Scully said the exciting part is there is already buy-in from some Districts and Divisions, who believe such a technology would help their inland waterway operations.
“The Districts and Divisions really want this. I have been working with the Mississippi Valley Division and the Great Lakes and Ohio River Division. They want this as fast as they can,” Scully said. “They have shippers willing to go out and buy this on their own.”
Scully said this technology and idea are not novel -- similar technology is already being used by the National Oceanic and Atmospheric Administration for ocean and coastal operations, but it would be the first use of this technology on inland navigation.
“Mariners on our inland waterways are not necessarily going to benefit knowing the channel is in good shape,” Scully said. “They will benefit more knowing that there’s an obstruction and where that obstruction is.”
With more than 12,000 buoys already playing a critical role in our nation’s inland navigation system, the U.S. Army Corps of Engineers is researching a way to use patented technology to make those buoys even more valuable.
Relying on these water markers for marine navigation, hundreds of millions of goods are transported annually along our inland waterways. According to an annual report published by USACE, more than 280 million tons were transported in 2020, mostly grain and petroleum products.
Leveraging digital buoy technology developed and patented by Tung “Alex” Ly, a computer scientist with the U.S. Army Engineer Research and Development Center’s (ERDC) Geospatial Research Laboratory (GRL), USACE is now exploring the idea of turning buoys that are positioned and designed to mark shipping channels into critical components of an extensive inland waterways network.
Dr. Austin Davis, a technical director with GRL, said Ly’s research provided an example of an effective mesh network that could improve and expand the ability to share important navigation information along a waterway – a technology gap not covered by existing networks or cellular systems.
“Right now, the Lock Operation Management Application (LOMA) system has a network around locks and dam sites to pass information to mariners as they approach the structure, but once they get further down the waterway – away from that site – there is no network access,” Davis said. “The thought is this network could push important navigation information to the mariners along the entire waterway, not just around the locks and dam locations.
“Cell phone towers are just focused on cities and interstates, not so much on the waterways. There are gaps in the ability to get information. This would provide a way to get maritime information – which is important to navigation safety – to the people who need it.”
Developed in conjunction with the Inland Electronic Navigational Charts Program (IENC) and USACE Louisville District, the technology was first targeted at providing the U.S. Coast Guard with real-time locations of its buoys. The idea has now grown beyond that.
“I think the real value to USACE is there would be a network that could disseminate navigation information by augmenting the Coast Guard buoy itself,” Davis said. “At the same time, this would provide trackability to where buoys are and how they move in the waterway. They don’t sit still.”
According to Ly, USACE is responsible for planning and constructing improvements to inland water navigation and dredging and maintaining thousands of miles of inland waterways.
“Water navigation safety markers (buoys) are designated national critical data,” Ly said. “This system of maritime aids to navigation provides the lane markers, street signs, stop lights for the nautical rules of the water, much like the driving rules of the road.”
Initial water-based prototypes and small experimentations were done on the Occoquan River in Virginia. The final prototypes and larger experiments were created and tested on a 10-mile stretch of the Ohio River around the Louisville District.
While the COVID pandemic slowed the expansion of this initiative, Davis said interest and effort in the next steps for the program have increased.
“The ultimate goal is trying to be a stepping stone to start converting navigation on the rivers to a virtual buoys system, but that is several, several decades away … a far future,” Davis said. “The next step would be a large field trial. We have to prove the reliability of the technology. This is about how you make the aids to navigation a little bit smarter and give them more capabilities.”
Davis said a large field trial would try to answer questions about how to augment a Coast Guard buoy best, whether the system can be stretched over one river or multiple rivers, as well as questions about power, reliability, durability and costs.
“In the laboratory effort, we have provided a proof of concept, but there are a lot of things not considered in that effort,” Davis said. But if a larger field test proves successful, “if it makes sense, hopefully, we could scale it into a national digital buoy system.”
As the U.S. Army Corps of Engineers (USACE) works to modernize the nation’s infrastructure, it does so at a time when existing infrastructure components are operating well past their original lifespans. In the case of many of the locks supporting inland navigation, new techniques and technologies are critical to make sure lock facilities – some built in the 1930s – continue operating for another 100 years or more.
The key to that mission’s success may already exist in a material used consistently in military applications, private industry and in Europe, but one that has not yet been put to work in our nation’s civil works projects.
Ultra-High Performance Concrete (UHPC) is a class of concrete well known for its strength, durability and sustainability. It is also a material very well understood by engineers and scientists at the U.S. Army Engineer Research and Development Center (ERDC) and is at the center of what may be the future of new construction and rehabilitation of U.S. lock operations.
“We have been using UHPCs for a long time in military applications, such as hardening structures and force protection applications,” said Dr. Stephanie Wood, a research civil engineer at ERDC’s Geotechnical and Structures Laboratory. “Our experience with UHPCs goes back to even before we were ERDC, when the facility was known as the Waterways Experiment Station.
“We have been part of developing those concretes, testing them. Using our extreme weather facility at Treat Island, Maine, we have tested these concretes in that environment for decades. So, we are very confident in our capabilities, and in the performance of this strong and durable material.”
Thanks to years of ERDC research, engineers are now working with USACE to adopt the use of pre-cast UHPC panels for lock wall rehabilitation projects, replacing those made from traditional concrete and then covered with horizontal steel armor. Currently, the steel armor is cast into concrete panels in the precast manufacturing plant as horizontal strips.
The UHPC panels are not only stronger and more durable than those made with conventional concrete, but they do also not require steel armor.
Currently, damaged or deteriorated lock walls are repaired using traditional concrete with strengths ranging from 5,000 to 8,000 pounds per square inch (PSI). USACE District crews remove the damaged concrete down to the sound concrete. A pre-cast concrete is then placed over the sound concrete, and concrete is poured behind the panels to attach to the larger structure. “Those panels have been performing fairly well in the field, but sometimes we have issues with the steel armor,” Wood said. “Through normal operations of barge traffic, the armor and panels will get struck by barges. The metal will get caught, at times, and start pulling away from the concrete, creating a hazard, and in some cases, lock operators can no longer use that part of the lock chamber until repairs are made.”
In 2018, the Rock Island District issued a statement of need, asking if UHPC could be a substitute for current methods. Over the next three years, ERDC tested UHPC, discovering techniques that not only created a stronger and more resilient material, but also developed processes and guidance on how UHPC panels could be created using materials already on hand at concrete manufacturing facilities throughout the country.
During small-scale and large-scale testing, engineers also showed panels created with UHPC could be made thinner than those using conventional concrete.
“Panels using conventional concrete are traditionally 6-to-8 inches thick, which makes them pretty heavy and cumbersome. This requires USACE teams to have a very large crane on site to put them in place,” Wood said. “Not only does it take up a large footprint on site, but often times the crane requires just as many truck loads to haul it to the site as the panels themselves, which was the impetus of the statement of need from Rock Island.”
UHPC panels are no thicker than three inches and cure to a strength of 22,000 PSI in just 28 days. Using tests and data from more than three decades of research, ERDC tested the UHPC panels, including simulating what would happen if the panels were struck by a barge. The results validated the exceptional strength and durability of the UHPC panel.
“We have eliminated the coarse aggregate, or the rock, out of this mixture,” Wood said. “By eliminating the coarse aggregate, we have also eliminated the interfacial transition zone, which is where the cementitious paste meets the aggregate particle. This zone is typically the weakest location in conventional concrete, and we don’t have that in UHPC.”
Now that research proves the panels are stronger and more durable, the goal is to increase their usage in USACE projects.
“The biggest obstacles to overcome are the unfamiliarity with the product and with the technology, and the cost,” Wood said. “For most people, the only thing they do know about UHPC is that it is more costly up front.”
But that may no longer be an issue, Wood said.
The costs associated with the steel armor, along with the more complex logistics of casting it into the face of conventional concrete panels, increase project costs. The elimination of the steel, in addition to the fact you need less concrete to produce a much stronger panel, makes the use of UHPC more cost comparable.