U.S. Navy's Expeditionary Sea Bases might become drone motherships

General Dynamics has said that plans are in the works to turn the huge Expeditionary Sea Bases (ESBs) of the U.S. Navy into drone motherships.
Christopher McFadden
The Expeditionary Sea Base (ESB) ship
The Expeditionary Sea Base (ESB) ship

The U.S. Navy 

General Dynamics NASSCO (GE NASSCO) has made several big changes to its line of Expeditionary Sea Bases (ESB) to meet the needs of the U.S. Navy and Marine Corps. Because the ESB started in business as an oil tanker of the Alaska class, NASSCO has said that the class has "infinite" potential.

In case you didn't know, GD's ESBs are a class of mobile offshore platforms designed by the United States Navy. They are based on commercial semi-submersible drilling rigs. They are intended to provide a flexible, multi-mission platform for various operations, including mine countermeasures, special operations, intelligence, surveillance, and reconnaissance.

The ESBs also have a helicopter operation flight deck and a large mission bay for storing equipment and vehicles. They are designed to be rapidly deployable and able to operate in hostile environments.

Proposals have been made to change ESBs into ships that help with aviation or even "motherships" for drones. GE NASSCO presented these future upgrades again at the Surface Navy Association National Symposium this year after debuting them during the Sea Air Space Exposition 2022.

Jim Strock, a freelance consultant who collaborated with NASSCO on the ESB, described how NASSCO tailored these ideas and capabilities to the force's future needs:

“We did two things. We looked at emerging operational concepts. We looked at Expeditionary Advanced Base Operations, Distributed Maritime Operations, and Littoral Operations in a contested environment. We looked at future operating concepts. And then we wrote papers on how the ships could support accomplishment missions within those concepts.”

To this end, GE NASSCO has developed several changes to support these proposed operational changes of its ESBs. A new aft flight deck, the addition of repair facilities, and the capacity to do replenishment at sea with other boats are a few examples of these upgrades.

The two most notable and extensive changes to the ESB are the unmanned underwater vehicle (UUV) bay installation and what appears to be the embarkation of marine aircraft, including F-35Bs, on the ESB.

Strock said that an ESB could hold different UUVs, like the Lockheed Orca Extra-Large UUV, because it had a unique launch mechanism built into it, "we call it the Rotary UUV Launch and Recovery System, the RULARS. So we talked about how that could be engineered into the ship. This (referring to the document) shows just a moon pool. Then we went on to look at the counter-rotating system.” 

NASSCO looked into a spinning system because they were worried that a launch and recovery process like a lunar pool would make the ship less stable at sea.

“It is much better in mitigating the effects of sea state surge and water coming up. It stabilizes the vehicle and keeps it in the upright position as it rotates down into the water. So the moon pool would work, but you get a lot of wave action and surface action that could become problematic. It’s hard to see here (referring to document), but it goes in, rotates around, and goes out,” Strock said.

Strock emphasized that one of the reasons the ships may be converted into uncrewed motherships is the ESB's already substantial command and control facilities.

“We’ve got nearly 40 seats for operational planners, so the C4I spaces are very extensive on this ship that can be collectively used in a variety of fashions to include unmanned systems information integration,” said Strock.  

When asked how and why these upgrades would assist F-35Bs, Strock explained how the F-35B would operate on the ESB.

“So I want to be very, very clear. This ship was not designed to operate F-35s. Could it transit F-35 airframes into theaters that could be transferred to amphibious ships and aircraft carriers? Yes. Could an F-35 with a small amount of fuel and no armament hopscotch from one ship to the next? Potentially, yes. It would involve modifications to the flight deck for deck heating modifications for the jet blast reflection,” he explained.

In light of this, the proposed changes to ESB will not be able to support F-35B missions in the same way that more conventional amphibious assault ships like the America class can. Instead, a NASSCO brochure says that the idea is to add more Marine aircraft, like V-22 Ospreys and CH-53K King Stallions, and give them full support so that amphibious assault ships with the F-35B can "be converted into F-35 carriers."

The ESB At-Sea Precision Lift idea makes it possible to reload VLS while at sea. Photo courtesy of General Dynamics NASSCO, which was scanned from a brochure.

NASSCO also looked into the use of At-Sea Precision Lift (ASPL), which would let ESB transfer supplies and equipment to other ships while they were at sea. When asked if this change could make it possible to reload Vertical Launch Systems (VLS) at sea, Strock said that the Office of Naval Research is already using all of the technologies described in the ESB's ASPL modification idea.

“ONR took all three (technologies), and they’re now integrating that, and generically they’re calling it At-Sea Precision Lift, but they’re using the integration of these technologies for VLS reload,” Strock explained.

ASPL meets current and future requests from the U.S. Navy, as it did with earlier upgrades. Carlos del Toro, who is in charge of the navy, has asked many times that VLS be able to be reloaded at sea instead of in port.

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