The U.S. Navy successfully loaded a vertical launching system cell on an underway cruiser this week in the first-ever test of a new reloading mechanism that the service claims will be a “game-changing” capability to keep warships in the fight without returning to port.
USS Chosin (CG-65) and USNS Washington Chambers (T-AKE 11) held the test off San Diego on Friday. The trial saw the loading of an instrumented test canister into the Ticonderoga-class guided-missile cruiser’s Mk.41 vertical launching systems (VLS) using the Transferrable Rearming Mechanism (TRAM), a new reloading system based on older concepts from the late Marvin Miller that appears to address the relative motion issues of the former strike down cranes. Secretary of the Navy Carlos Del Toro deemed the development of TRAM to be a priority, highlighting its necessity and progress since early 2023 as the service looked to match increasingly capable near-peer adversaries.
“The ability to rearm at sea will be critical to any future conflict in the Pacific or elsewhere. Our surface combatants’ exemplary performance in the Red Sea and the eastern Mediterranean over the past year only further reinforces the tremendous value TRAM will bring the Fleet,” said Del Toro to reporters following the test.
The ability to reload and sustain combat operations without U.S. naval bases or friendly facilities has been an increasing concern as the service faces down adversaries in the Red Sea and plans for contingencies in the Indo-Pacific region. In the Western Pacific, many U.S. naval bases are within range of long-range Chinese missiles, which could deny their use to resupply and replenish warships during a conflict. Meanwhile, bases that aren’t under active threat are outside of the theater, something that Tim Barnard, director of the NAVSEA technology office, highlighted following the TRAM test:
“Deploying TRAM into the Military Sealift Command logistics fleet would enable combatants to remain in theater while reloading their VLS missile launchers instead of having to travel long distances to a port, greatly expanding the volume and tempo of long-range fires—and the U.S. Navy’s advantage over adversaries.”
According to a Naval Sea Systems Command (NAVSEA) press release, the missile canister was transferred to Chosin from Washington Chambers using the already existing underway replenishment process in Sea State Four. Once onboard the missile cruiser, the canister reached the VLS cell using rails attached directly to the Mk.41 system. From there, TRAM vertically tilted the canister and lowered it into the cell.
NAVSEA further claimed that as TRAM was designed to be done during underway replenishment, the receiving warship could also be refueled and restocked with provisions at the same time as its VLS cells were reloaded. “The combatant can stay near the fight to be rearmed, refueled and resupplied all at the same time,” said Richard Hadley, UNREP division manager at NSWC PHD, in the press release.
Further details on the test such as how long the reloading took, what would happen with used missile canisters, and if TRAM sped up the tedious and lengthy VLS reloading process, were not mentioned by the Navy. However, Del Toro and NAVSEA highlighted that this test was the first of many to refine and develop TRAM for operations. Del Toro said:
“This demonstration marks a key milestone on the path to perfecting this capability and fielding it for sustained operations at sea,”
Reloading the Mk.41 pier side has been known to be a lengthy process, with the loading of a single missile cell taking up to half an hour. For reference, the U.S. Navy’s primary surface combatant, the Arleigh Burke-class guided-missile destroyer, has up to 96 missile cells. It is unclear if this process is sped up with TRAM or remains the same at sea.
Before this at-sea test, TRAM was previously ground trialed by Naval Surface Warfare Center, Port Hueneme Division and sailors from Chosin at Naval Base Ventura County in July. Chief of Naval Operations Lisa Franchetti also observed the system in late 2023 during her tour of the facility.
The Navy aims to field TRAM into the fleet by 2026 or 2027. Del Toro stressed that once the new reloading mechanism was fielded, the service’s warships would be able to stay at sea and target “any adversary with an overwhelming tempo and volume of long range strikes.”
“By enabling our combatants to refill their magazines underway, TRAM offers us a powerful near-term deterrent that will disrupt the strategic calculus of those who would do us harm. By investing in innovations like TRAM, we are ensuring that the United States remains the world’s preeminent maritime power,” said Del Toro.