IN Brief:
- L3Harris has received a $139 million modification for low-profile submarine photonics mast production.
- The award covers both new-construction and in-service submarines, alongside spares and engineering support.
- Production and support will continue at Northampton, Massachusetts, through September 2030.
L3Harris Technologies has received a $139 million US Navy contract modification for production of low-profile photonics masts for new-construction and in-service submarines, together with associated spares and engineering support through September 2030.
The modification combines cost-plus-fixed-fee, cost-plus-incentive-fee, and firm-fixed-price elements under an existing Naval Sea Systems Command contract. All work will be performed at L3Harris’ Northampton operation in Massachusetts.
Funding is drawn from several Navy accounts and programme years, including shipbuilding and conversion, other procurement, and national sea-based deterrent money. That mix reflects a contract serving both submarines under construction and equipment already operating within the fleet.
Photonics masts perform the observation and imaging role once associated exclusively with an optical periscope, but they do so through electronic sensors rather than requiring a direct optical path from the mast head to an operator inside the submarine.
L3Harris says its submarine optronic systems can combine high-resolution visible, short-wave infrared, mid-wave infrared, and low-light sensors. Integrated mast packages can also accommodate electronic-support, direction-finding, GPS, communications, and other antenna functions depending on the required configuration.
The September contract does not disclose the sensor fit for individual masts being ordered, so the company’s full catalogue should not be treated as the specification of every system funded by the $139 million modification. The confirmed scope is production of low-profile photonics masts plus spares and engineering support.
Replacing a traditional optical path with electronic imaging changes the internal architecture of a submarine. Sensor information can be processed and displayed within the control room rather than requiring an operator to stand directly beneath a penetrating periscope tube, giving designers more flexibility over equipment placement and allowing imagery to be shared with multiple users or systems.
That benefit comes with a different integration burden. The mast becomes part of a network of sensors, processors, displays, software, power supplies, cooling systems, cabling, and combat-system interfaces whose configuration has to remain controlled through both construction and service.
The equipment must also work in an unusually demanding environment. A mast is repeatedly raised into saltwater and weather exposure, experiences mechanical loads during deployment and retraction, and has to maintain stable imaging and sensor alignment while contributing as little as possible to the submarine’s observable signature.
The low-profile design addresses part of that physical problem, but production quality remains critical across the complete assembly. Mechanical tolerances, seals, actuators, optics, electronics, connectors, software, and internal interfaces all have to perform reliably before the mast can be accepted for installation.
L3Harris states that it supplies the US Navy’s next-generation Low Profile Photonics Mast and describes itself as the sole designer and manufacturer of US submarine optronic mast systems. The Northampton production base therefore supports a specialised capability with relatively few alternative industrial sources.
The new contract spans both construction and fleet sustainment. New submarines need masts delivered in sequence with shipyard integration, while boats already in service require spares, replacement equipment, engineering assistance, and configuration support during maintenance and modernisation periods.
Serving both groups creates a more complicated production environment than repeatedly building one fixed configuration. Individual submarine classes and hulls can carry different equipment baselines as technology evolves, meaning software, electronics, interfaces, documentation, and replacement parts have to remain matched to the boat receiving them.
Engineering support is therefore a substantial part of the programme rather than an administrative extra. Components become obsolete, software changes, sensor technology evolves, and faults found in operating equipment can require design or manufacturing action that must then be incorporated into later production and spares.
The contract notice does not identify the submarine classes receiving the masts, and none should be inferred from other L3Harris programmes. It states only that the modification covers new-construction and in-service submarines, which is sufficient to establish a fleet-wide production and sustainment role without assigning hardware to particular hulls.
The September 2030 completion date gives Northampton another four years of production and engineering work. In a submarine industrial base already dependent on a narrow set of qualified suppliers, preserving that continuity can be as important as the individual mast deliveries because the design authority, tooling, test processes, and specialist workforce have to remain available when the next boat or maintenance period requires them.
The $139 million modification consequently links production and sustainment rather than treating them as separate markets. L3Harris will build new mast hardware, support equipment already in service, supply spares, and retain the engineering capability required to keep those configurations aligned through the end of the decade.
