Underwater drones dive deep to enhance efficiency and insight on Skanska construction sites

“In the next decade, due to climate changes we are going to witness a surge in waterfront and resiliency projects,” says Director, Emerging Technology and VDC Val Tzvetkov. “Today, we are building more structures not just on land, but in and below water. Innovation and technical capabilities will be paramount in overcoming challenges and creating new opportunities for our clients and project teams.”

Recently, several Skanska employees took to New York’s East River and Hudson River to pilot underwater drone technology. The event was a continuation of exploratory work that has been in the works for some time.

Over the past year, project teams have performed extensive research on utilizing underwater drone technology on our jobsites. During that time, numerous water drone models have been tested and reviewed. In the end, the list of drones was narrowed down to the top contenders for field testing.

Numerous drones were put in different water conditions including variation of currents and different bodies of waters like the East River, Hudson River and New York Harbor. At each site the team had different underwater structures and different goals for the inspections.

Together, they discovered numerous benefits to utilizing drones underwater—benefits that would intrigue any developer with waterfront work in their pipeline.

Minimizing project costs, enhancing worker safety and better understanding the landscape of a project’s context before and during construction are just a few of the perks that team members believe developers can expect if they take their drones underwater.

A case for utilizing drones underwater

For Skanska team members, several common challenges associated with building below sea level are reason enough to start thinking innovatively.

“Navigating unforeseen conditions is something we often have to deal with in waterfront construction,” says Assistant VDC Manager Julie-Ann Evans. “Whether it’s something within the mudline, or something that may have developed between the engineer inspection and the start of construction.”

Underwater drones have the potential to provide greater visibility into construction conditions before and during a project’s lifecycle.

Typically, companies send physical divers down to inspect underwater conditions before breaking ground. Or, issues are encountered underwater once construction has started. “Both of these scenarios add additional time and cost to a project,” says Julie-Ann.

In addition to increasing costs, Director, Emerging Technology Albert Zulps adds that “safety for diving operations and underwater inspections” can be a challenge. “We emphasize safety in everything we do, and underwater inspections requiring divers are often dangerous,” says Project Engineer Mike Loffredo. “By introducing water drones, we can eliminate that risk altogether by reducing divers on our projects.”

Transitioning from the sky to the sea

In their pilot, the team discovered similarities and differences between operating an aerial drone versus an underwater drone.

“The biggest difference is definitely the line of sight,” says Julie-Ann. “While controls and maneuverability are similar, you always have aerial drones in your line of sight. Underwater drones can only be seen on the surface of the water, especially with New York City’s murkier water conditions.”

“The latency and slow response of underwater drones versus their aerial counterparts, coupled with much-reduced visibility and situational awareness, can make operating them very difficult,” says Albert. “Underwater drones are also tethered by a cable that can be affected by currents, leading to it accidentally wrapping around objects.”

Looking ahead, utilizing autonomous water drone technology could address tether tangling, while introducing advanced capabilities, such as underwater mapping.

“Topographical mapping is something we already use for our aerial drones, so this would be equally helpful for our marine projects—for mapping out current conditions and unraveling more of the unknowns,” says Julie-Ann.

Initial takeaways from underwater testing

Challenges between operating drones in the air or the sea, or even an increased learning curve, aren’t too much of a hindrance in the eyes of Skanska team members. The immediate opportunities and potential future capabilities outweigh any upfront challenges.

For starters, the barrier to entry for operating drones underwater is technically lower than aerial drone operation. “Aerial drone usage requires an FAA license, whereas underwater drones do not,” says Julie-Ann. “We’re hopeful that this encourages more project teams to get comfortable with navigating drones.”

From their initial testing, despite operating in murky waters, the team walked away with clear takeaways.

“One of the biggest benefits of water drones is seeing conditions in real time and not relying on the conditions reported from a potentially outdated engineering report,” says Julie-Ann. “Drones can also go into conditions where it may be unsafe to send a diver, giving the project or design team invaluable visibility.”

“This exploratory activity established that there are multiple use cases where a water drone would be helpful. Going forward, we would use drones to view existing timber and sheet piles, look at installed work, check mudline conditions and see underneath piers,” continues Julie.

“We could also use drones to carry out pile or sea wall inspections more frequently, take progress photos and videos, and capture dimensions underwater,” says Mike.

In the future, utilizing drone attachments would further expand use cases for the technology. Robotic arms, sonar sounding systems, and metal detector and sample collection attachments are all enhancements that could make underwater drones as, if not more, advanced as aerial drones.

Bringing underwater drones to Skanska projects

Just as aerial drones propel Skanska project success across the U.S., it’s likely that underwater drones will become central to successfully executing projects going forward.

Several Skanska projects in the New York Metro region are already prime opportunities for the benefits of underwater drones to be further explored and realized.

Our East Midtown Waterfront Esplanade and East River Greenway project in Manhattan is a model example of how innovative technologies can aid project success. During the first phase of construction, several models of underwater drones equipped with cameras and sensors contributed to planning around safety concerns as it relates to underwater human operations in tight spaces, monitoring the work environment such as mudline elevation, and inspecting submerged structures for any defects and erosion.”

Additionally, when work begins on our Tompkinsville Esplanade and Pier Project in Staten Island, team members plan to leverage underwater drones. “Our pilot included testing the technology at Tompkinsville, and we believe drones used in this way would add value during construction,” says Julie-Ann.

After that, only time will tell where the technology will prove itself useful. “As word gets out that we are testing and beginning to use underwater drones within Skanska, we’re seeing keen interest, and new opportunities are revealing themselves,” says Albert.