From weeks to hours: NRL's ISIS360 reduces inspection time shipboard tank inspections
The U.S. Naval Research Laboratory (NRL) has developed and fielded the next generation of its Insertable Stalk Inspection System (ISIS360), a nonhuman-entry inspection technology designed to improve the safety, speed, and accuracy of shipboard tank inspections across the U.S. Navy's Surface Fleet. The technology is collapsing inspection timelines from days or weeks to hours and enabling pre-assessment of tank condition, so only tanks requiring maintenance are opened during availability periods.
Tank inspections have historically been performed based on scheduled maintenance intervals, requiring tanks to be emptied, cleaned, and prepared for entry regardless of their actual condition. ISIS360 enables rapid, nonintrusive assessment of tank integrity, allowing maintenance teams to prioritize only those tanks that show signs of degradation, reducing unnecessary work and improving overall maintenance efficiency.
ISIS360 is a government-developed inspection capability that integrates select commercial off-the-shelf hardware with analytics and data processing software developed by NRL and industry partners.
Sailors and maintenance personnel have typically been required to physically enter confined spaces to assess corrosion and structural integrity, introducing significant safety risks and logistical complexity.
These inspections often required tanks to be certified gas-free, outfitted with temporary lighting, and supported by scaffolding, adding time, cost, and operational disruption.
ISIS360 eliminates the need for human entry by using a compact 360-degree imaging system capable of capturing detailed internal tank imagery, significantly reducing risk while streamlining the inspection process.
Beyond the initial imaging, the Corrosion Detection Algorithm (CDA) quantifies the percent of corrosion in the tank by analyzing the inspection imagery to identify and map corroded regions across the tank's internal structure, enabling inspectors to estimate the percentage of affected surface area and tank degradation.
During initial inspections conducted aboard USS America (LHA-6) in March 2025, 64 tanks were inspected, with 49 evaluated using ISIS360 technology.
In many cases, the system enabled inspections to be completed without gas-free certification or manual entry. Normally, fuel tanks must be emptied and purged before the atmosphere inside is safe for personnel to enter and conduct inspections.
ISIS360 includes a fuel-safe configuration that allows inspection of fuel-containing tanks without the need to empty and purge them, significantly reducing maintenance preparation time.
"That kind of time savings translates directly to increased maintenance efficiency and reduced ship downtime," said Ted Lemieux, head of the Center for Corrosion Science and Engineering Branch at NRL.
"The real savings come in improved planning. Advanced knowledge of tank condition allows better maintenance planning, limiting unnecessary maintenance and preventing surprises that turn into schedule delays."
CDA was developed by NRL in collaboration with Batenkill Technologies Inc. The data collected is hosted on a Digital Corrosion Inspection site in a Department of Defense-accredited cloud developmental environment.
The system enables inspectors to generate three-dimensional visualizations of tank interiors, archive inspection imagery, and export CDA results for delivery to the Surface Maintenance Engineering Planning Program (SURFMEPP). This capability allows maintenance personnel to move beyond one-time visual assessments and instead analyze inspection data over time to identify corrosion trends and inform long-term maintenance planning.
"With ISIS360, we're not only capturing images, but we're also building a digital record that supports predictive maintenance," Lemieux said. "That gives the Fleet a better understanding of how structures are aging and where intervention is needed."
The system's compact design and ability to operate without external AC power is an improvement over earlier versions, making ISIS360 easier to deploy in operational environments.
NRL is currently working in partnership with Commander, Navy Regional Maintenance Center and other Navy stakeholders to expand ISIS360 deployment to seven Regional Maintenance Centers in Fiscal Year 2026. Units have already been delivered to Norfolk, Virginia; San Diego, California; and Sasebo, Japan, supporting broader efforts to modernize fleet maintenance practices and improve long-term readiness.
"Ultimately, ISIS360 supports the Navy's goal of maintaining a ready and resilient force," Lemieux said. "By improving availability of condition data far in advance, we're helping ensure ships can return to operational status faster and remain mission capable."
Provided by Naval Research Laboratory
