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NEWS | April 3, 2020

NSWCPD’s HAMSTER Hammers Home Accuracy and Efficiencies

By Keegan Rammel, NSWCPD Public Affairs

Naval Surface Warfare Center, Philadelphia Division (NSWCPD) recently began delivering an advanced prototype tool to non-destructively test the bond between a coating and the hull of a vessel to several Navy shipyards.

NSWCPD’s Hammer Activated Measurement System for Testing and Evaluating Rubber (HAMSTER) allows a shipyard worker to use an impact hammer to rapidly and accurately determine the bonding condition of a hull coating.

“Prior to HAMSTER, there was no reliable and efficient technique or tool available to shipyards and shipbuilders for identifying a debonded coating; methods utilized are extremely subjective and prone to significant operator error or are too cumbersome for extended hand-held use,” NSWCPD’s Technical Director Tom Perotti explained. “This patent-pending innovation fueled by NISE internal investment funds has enormous potential in time and cost savings.”

NSWCPD, Naval Surface Warfare Center, Carderock Division (NSWCCD), and a commercial source used Naval Innovative Science & Engineering (NISE) funding to develop HAMSTER. The portable, battery powered hammer uses a unique algorithm to provide a real-time evaluation of the condition of the bond with each impact.

Previous methods included tapping the hull with a painter’s 5-in-1 tool to feel the vibration or hear the audible response and subjectively determining the quality of the interface bond. It is difficult to accurately identify debonded areas in a noisy dry dock environment or with varying hull structure configurations. An alternate test method relies on an impact device with multiple accelerometers that must be in contact with the hull; however, this technique is quite cumbersome for the user.

Mechanical engineer Jamie McDonnell and materials engineer Lisa Weiser are the Philadelphia Division leads for the development of HAMSTER. They have worked closely with their counterparts in naval shipyards to evaluate early prototypes, gathering feedback on the design and operation. NSWCPD’s Advanced Data Acquisition, Prototyping Technologies & Virtual Environments (ADAPT.VE) Lab used 3D printing to enable rapid prototyping which reduced development time and cost.

“The shipyards love the tool (as) it provides an objective method detecting debonds and allows them (the shipyards) to identify all debonds with certainty,” Weiser said. “HAMSTER provides confidence that they have identified all of the debonds, which is important when in a dry docking maintenance period.”

“So far we have performed more than 5,000 test hits and we have been proven 100 percent accurate,” McDonnell added.

HAMSTER will enable a shipyard to rapidly access the condition of a coating, accurately map areas of concern, and only replace or repair those areas requiring attention. This will contribute to greater shipyard efficiency, directly supporting the NAVSEA campaign plan to Expand the Advantage through the on-time delivery of ships and submarines.

“Shipyards are very excited to receive this tool,” McDonnell said. “There is a real appeal for a tool that provides a shipyard with a real solution.” HAMSTERs are being delivered to several shipyards and maintenance facilities.

NSWCPD employs approximately 2,700 civilian engineers, scientists, technicians, and support personnel doing research and development, test and evaluation, acquisition support, and in-service logistics engineering for Navy ships. NSWCPD is also the lead organization providing cybersecurity for all ship systems.

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