Advanced Metalworking Solutions for
Naval Systems that Go in Harm's Way

Inspection Under SHT

Advanced technologies that allow for inspection directly through special hull treatment could significantly reduce inspection costs. U.S. Navy photo


In Phase I of this project, NMC is evaluating the feasibility of these advanced inspection technologies for use in this application. Should one or more of these technologies prove to be feasible, their use could reduce the burden of SHT removal and reinstallation as well as the cost of the overall process.


The Navy Metalworking Center (NMC) is conducting a Navy ManTech project that will reduce the cost of the periodic inspection of submarine pressure hulls. The current processes, including visual and ultrasonic inspection, require the removal of significant amounts of special hull treatment (SHT) to access the hull structure underneath, followed by reinstallation of SHT after the inspection.
SHT removal, inspection and reinstallation are on the critical path for the schedule of a submarine availability. Technologies that can inspect directly through SHT, or minimize the amount of SHT that needs to be removed, will significantly reduce the cost of hull inspection. Technologies of significant interest include the use of ultra-wide band radar, phased array ultrasonic with reduced contact area, and terahertz imaging.


Reducing the amount of SHT that must be removed and reinstalled to accommodate hull integrity inspection during availability of the Virginia class submarine has the opportunity to reduce cost by as much as $1.2M per hull per inspection cycle, or $6M over a five-year period.


Phase II of this project will develop a prototype system to demonstrate/validate the technology. Successful project results will be transitioned to NAVSEA 05U7 for implementation at the Navy shipyards, including Norfolk Naval Shipyard, Pearl Harbor Naval Shipyard & Intermediate Maintenance Facility, Portsmouth Naval Shipyard, and Puget Sound Naval Shipyard & Intermediate Maintenance Facility.




Charles Stewart
PMS 392T


Applied Research Lab - Penn State
Naval Surface Warfare Center, Carderock Division
Naval Undersea Warfare Center- Newport
PMS 392 - Strategic/Attack Submarines