Engineers at Naval Surface Warfare Center, Philadelphia Division (NSWCPD) are utilizing additive manufacturing to redesign and produce an upgraded component for the Boiler Combustion Monitoring System (BCMS) used on Navy steam-powered ships, enhancing reliability for equipment that helps Sailors operate propulsion boilers safely.
The component, known as the wallbox, allows a furnace camera lens tube and inspection light to pass into a boiler furnace while the camera and light source remain outside. Sailors use the system to monitor combustion conditions and inspect the furnace for unburned fuel before lighting burners.
The effort is led by NSWCPD’s In-Service Engineering Agents (ISEAs) in coordination with NSWCPD’s Advanced Machinery Systems Integration Branch.
Because the existing wallbox is obsolete and no longer available through traditional supply channels, engineers turned to additive manufacturing to produce a replacement while also improving the design.
“Additive manufacturing gives us the ability to solve supply challenges while improving system performance,” NSWCPD Propulsion, Power & Auxiliary Machinery Systems Department Head Karen Dunlevy-Miller said. “That combination is essential to sustaining legacy platforms and ensuring the fleet has reliable equipment when Sailors need it most.”
The BCMS is installed on propulsion boilers aboard the Navy’s six Wasp-class amphibious assault ships and USS Blue Ridge (LCC 19), the U.S. Seventh Fleet flagship. The system provides operators with video imaging and illumination inside the boiler furnace, enabling them to monitor combustion conditions and verify safe operating conditions before lighting burners.
Because a boiler furnace burns at high temperatures, the camera and inspection light must stay outside the furnace casing. The wallbox offers a protected path that allows the camera lens tube and inspection light to reach into the furnace while shielding the equipment from extreme heat.
Boiler operators depend on the system to inspect the furnace deck for unburned fuel before igniting the burners. If a burner flame goes out, fuel oil can build up on the hot furnace floor and vaporize, creating a potentially explosive situation. The BCMS camera and inspection light enable operators to visually verify that the furnace is clear before reigniting the burners.
“Because the wallbox is unavailable and obsolete, we decided to produce it via additive manufacturing,” said Ramazan Meta, Steam Systems ISEA and Alteration Installation Team (AIT) manager at NSWCPD. “Using additive manufacturing for this project allows us to test various design changes and materials while keeping costs relatively low.”
According to Meta, the legacy wallbox design restricts the flow of cooling air through the assembly. That airflow helps cool the furnace camera components and prevents damage to the wallbox itself in the high-temperature boiler environment.
“Currently, this path for cooling air is too small and restrictive, which reduces airflow and cooling,” Meta said. “The airflow is critical for cooling of the furnace camera and to minimize damage or warping of the wallbox.”
The redesigned wallbox increases the cooling-air gap to improve airflow and heat dissipation. Engineers also selected a new material for the upgraded component. The new design will be produced using Inconel, a nickel-based alloy widely used in high-temperature environments. Compared with the original carbon-steel construction, the material offers improved strength and heat resistance.
Meta said the design improvements and material selection are expected to increase durability and extend the component's service life. Once testing and production are complete, NSWCPD ISEAs will support installation of the upgraded wallboxes during ship maintenance availabilities.
By using additive manufacturing, NSWCPD engineers can replace an obsolete component while evaluating design improvements and supporting the continued operation of steam propulsion systems across the fleet.
NSWCPD employs about 2,700 civilian engineers, scientists, technicians, and support staff. The team focuses on research and development, testing and evaluation, acquisition support, and in-service and logistics engineering for non-nuclear machinery, ship machinery systems, and related equipment and materials for Navy surface ships and submarines. NSWCPD also serves as the primary organization responsible for cybersecurity across all ship systems.