The US Navy has ordered new thin-lined towed array motor assemblies for its Virginia-class nuclear-powered fast attack submarine (SSN) fleet.
L3 Technologies, doing business as L3-KEO, was selected as a sole-source supplier to deliver these subcomponents to the Navy by August 2026 in a stand-alone contract worth $20m according to the US Department of Defense at the end of May 2024.
The submarine’s ‘towed array sonar’ system comprise a collection of hydrophones – or sound sensors – that straddle behind the boat along a long thin line. Its detachment from the boat means that the submarine’s noise will not interfere with its detection of other sounds beneath the surface.
Naturally, the details of these subcomponents are not disclosed for security. However, according to the supplier is the prime contractor delivering the US Navy’s next-generation thin line towed array, the TB-29C. This is a thin line towed array passive sonar receiver that has the same form factor to the TB-29A with improved reliability.
Notably, this latest contract order for 22 towed array motor assemblies matches the same number of Virginia boats that the Navy have commissioned so far. In addition, there is no option for any more of these subcomponents.
Sustainment and procurement
In mid-May, the Department of the Navy (DoN) laid bare its ambition to deliver an “historic level of throughput” in submarine construction after years of underperformance, which was met with healthy scepticism by the Senate Armed Services Committee.
With new funds amounting to $11bn allocated to the submarine industrial base in the fiscal year 2025 Budget, the Assistant Secretary of the Navy for Research, Development and Acquisition Nickolas Guertin was steadfast in his belief that the DoN could deliver more submarines.
At the moment, industry are already struggling to deliver just 1.2 boats per year.
Already under pressure to deliver on the Navy’s growing importance in a decade of rivalry with China on the world stage, which now requires a new ‘Maritime Statecraft’, sustainment will also continue to take time and resources as industry push to deliver all they can.
