US Navy engineers turn to additive manufacturing for obsolete boiler components
Philadelphia-based team redesigns wallbox using Inconel and 3D printing to address supply gaps on steam-powered warships
Engineers at Naval Surface Warfare Center, Philadelphia Division (NSWCPD) have turned to additive manufacturing to replace an obsolete component in the Boiler Combustion Monitoring System (BCMS) — safety-critical equipment used on Navy steam-powered ships to help crew members operate propulsion boilers safely.
The component in question, known as the wallbox, creates a protected channel that allows a furnace camera lens tube and inspection light to pass into a boiler furnace while keeping the camera and light source outside the casing, away from extreme heat.
Boiler operators rely on the system to check the furnace deck for unburned fuel before igniting burners — a step that prevents potentially explosive conditions caused by fuel oil pooling and vaporizing on the hot furnace floor.
The BCMS is installed on propulsion boilers aboard the Navy’s six Wasp-class amphibious assault ships and USS Blue Ridge (LCC 19), the US Seventh Fleet flagship. With the original wallbox no longer available through standard supply channels, the engineering team used additive manufacturing to produce a replacement rather than leave the fleet without a serviceable part.
“Additive manufacturing gives us the ability to solve supply challenges while improving system performance,” said Karen Dunlevy-Miller, Propulsion, Power & Auxiliary Machinery Systems Department Head at NSWCPD. “That combination is essential to sustaining legacy platforms and ensuring the fleet has reliable equipment when Sailors need it most.”
Redesigning for heat and airflow
The replacement program also presented an opportunity to correct a known design flaw. The legacy wallbox restricted the flow of cooling air through the assembly — airflow that protects both the furnace camera and the wallbox itself from heat damage.
“Because the wallbox is unavailable and obsolete, we decided to produce it via additive manufacturing,” said Ramazan Meta, Steam Systems In-Service Engineering Agent and Alteration Installation Team manager at NSWCPD.
“Using additive manufacturing for this project allows us to test various design changes and materials while keeping costs relatively low.”
Meta identified the airflow restriction as the primary design concern. “Currently, this path for cooling air is too small and restrictive, which reduces airflow and cooling,” he said. “The airflow is critical for cooling of the furnace camera and to minimize damage or warping of the wallbox.”
The redesigned component widens the cooling-air gap and will be produced in Inconel — a nickel-based alloy with greater heat resistance and structural strength than the carbon steel used in the original. Once testing concludes, the team will support installation during scheduled ship maintenance periods.
