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NEWS | July 17, 2023

Carderock Designs 3D-Printed Overboard Discharge Scupper Technology

By Todd Hurley, NSWC Carderock Division Public Affairs

Naval Surface Warfare Center, Carderock Division employees have collaborated with Mid-Atlantic Regional Maintenance Center (MARMC) in Norfolk to design and 3D print overboard discharge scupper technology using polymers to eliminate running rust stains from U.S. Navy ships. The project is funded by Naval Sea Systems Command’s Painting Center of Excellence (05P).

Carderock’s team consists of three members from the Integrated Manufacturing and Composite Materials Branch: Dr. Maureen Foley, composites team lead, and engineers Bill Manning and Brandon Newsome.

“These overboard discharge scuppers go below the discharge ports on the side of a Navy ship where water comes out — the current problem is that a lot of our ships have running rust from water that continuously dribbles out,” Manning said. “The whole idea is to reduce the amount of time our Sailors spend sanding and painting the ships by preventing that rust from occurring in the first place.”

The scuppers are attached after priming the surface of ship and scupper with an adhesion promoter, then, after waiting two minutes, applying Very High Bond (VHB) tape directly to the scupper and attaching to the ship, and finally using a sealant to prevent water from getting in between the tape and the surface of the ship.

“These resulting bond of the scuppers to the hull is pretty strong, and we have two different versions — a flexible one and rigid one,” Foley said. “The harder ones we are putting up higher, but ones that might get hit by a tug or something else we are using the flexible option. We are currently in our initial phases to see how long and how well they will last on the ship. To do this, we are simply attaching them to the ships before they go on deployment and observing the results when they return to homeport.”

For this effort, Carderock does all of the design work, which currently consists of 13 variations in sizing, while MARMC completes the 3D printing portion. The Integrated Manufacturing and Composite Materials Branch has been able to leverage previous interactions with Steven Peterson, MARMC Technology and Innovation Lab Manager, to finalize the designs and partner with their lab to print the scuppers to support our FY23 demonstrations. NSWCCD will provide MARMC with some installation materials for more ships to perform additional demonstrations.

“Manning and Newsome are both relatively new hires, having on boarded earlier this year,” Foley said. “But, they really hit the ground running with this project, going out to the ships and getting the surveys set up. They helped develop an entire laser-based setup that allows us to go out to the side of the ship and actually measure the size of the overboard discharge holes, since it can be difficult to get up close enough to physically measure them. They have been key in getting this project going.”

Currently, Foley and her team are actively working with five Navy destroyers on demonstrations of the 3D printed overboard discharge scuppers, including: USS Curtis Wilbur (DDG 54), USS Stout (DDG 55), USS Laboon (DDG 58), USS The Sullivans (DDG 68) and USS Kidd (DDG 100). The team completed the ship’s force training aboard Kidd in June and are in the process of scheduling the training for the four remaining destroyers later this year, with Stout at the end of July and Laboon scheduled for Aug. 23.

“For how small of a project this is, we have actually gotten a lot of attention from the fleet saying they want it — on average, there are roughly 200 overboard discharges on a Navy destroyer,” Foley said. “We have conducted full surveys of these five ships, and we are developing a standard kit based off our idea of what is most problematic with different sized holes. These kits will consist of the VHB tape, primer, 10-20 scuppers and demonstration guidelines for how to install them. We also provide initial training to the Sailors so they know exactly how to use it.”

Foley and her team have hopes of this product reaching the entire fleet, and are in talks with the Military Sealift Command and U.S. Coast Guard, who have also expressed an interest.

“This product really applies to every ship in the fleet,” Foley said. “They all have overboard discharges, and if this becomes a solution, it would easy for ships to print the product themselves since they are so low-risk items. The materials we have selected already have national stock numbers for the attachments, so that makes it much easier for the fleet to get the materials. We want to make it as easy as possible for everyone to use.”