Leidos Gibbs and Cox is looking to deliver enhanced logistical capabilities and faster vertical launch cell reloading through its Mobile Depot Platform, a concept that converts surplus civilian semi-submersible oil rigs into relocatable resupply hubs.
Developed with supply chain and operational considerations, such as the American commercial offshore industry, logistical necessities west of the international date line, and the defense of Guam, the naval architecture and marine engineering firm claimed that their proposal aims to “bring a lot more capability into the U.S. Navy” within a short period of time.
Since its debut last April at Sea Air Space 2024, the company surveyed 10-12 surplus semi-submersible offshore oil and gas rigs for conversion and expanded MODEP’s mission profiles to include submarine tending, logistics and hospital roles. Engineering analysis has also looked into the modification of the semi-submersible’s pontoons that would allow the massive platforms to cruise at 8-11 knots, an increase from the originally envisioned 5-8 knots. “We can do all of this without touching the current U.S. Navy industrial base,” Ray Sheldon, President of Leidos Gibbs and Cox, told Naval News in an interview.
“That’s an important point. As great as these platforms would be, if it means delaying a submarine, delaying an Arleigh Burke, or heavens forbid delaying Constellation, it’s maybe not a good trade off. But we can bring all this capability and tap the most capable and most productive parts of our maritime industrial base, which is the offshore world.”
Company officials further highlighted how the MODEP concept could address ongoing challenges and programs, such as the defense of Guam against air and missile threats as well as the Navy’s AS(X) Submarine Tender Recapitalization Program.
David Zook, a Solution Architect and Combat Systems/C4I Department Manager with Ledios Gibbs and Cox, also told Naval News that work on a drone mothership variant is underway. According to Zook and provided infographics this platform would not only support the deployment of unmanned underwater and surface vessels, but also employ additive manufacturing facilities to produce them while underway.
“The platforms are so large and flexible that most of these missions can coexist, although we have done somewhat tailored versions of each. These are shallow draft, they’re variable draft, which means that we can do what the U.S. Navy did in World War Two for refit and repair. Which is to pull back to Pacific Atolls with their internal sheltered harbors. Despite the massive size of this thing, it can ballast up, go through the channel, ballast down if it needs to, and then conduct missions like submarine repairs, logistics, reloading at-sea, a key thing.”
Another aspect of the supply hub variant of MODEP that Leidos Gibbs and Cox shared with Naval News is their new Speed Reloader, an in-development system that aims to increase the reloading times of the fleet’s VLS cells from one cell every 40-60 minutes to six to eight within the same period at sea state four conditions. Sheldon explained that the “principle bottleneck” identified by the company was loading missiles one at a time.
“The idea is very simple, a frame with the appropriate mechanical systems and control systems that allow us to plug into the storage bays on MODEP or ashore for that matter, pull up a very significant number of missiles, and then pull across to the receiving vessel, and then drop them in.”
Reloading at-sea was deemed a priority by the previous Secretary of the Navy, Carlos Del Toro in 2023. While the U.S. Navy debuted at-sea reloading with the Transferrable Reloading Mechanism last year on USS Chosin (CG-65), the system still re-arms VLS one at a time. Compared to the TRAM concept and existing methods, which require a lengthy time in-port to reload the 96 cells of the Arleigh Burke-class destroyers and 112 cells of the Ticonderoga-class cruisers, Speed Reloader utilizes a frame to drop multiple new canisters and remove used canisters within the same period. “We see that as a force multiplier. MODEP doesn’t need to have the speed loader to be effective but it becomes far more effective if we can do that logistics and reload mission quickly,” said Sheldon.
MODEP’s resupply hub concept can support the reloading of 384-446 VLS canisters depending on a vertical or horizontal storage across 16 magazines, which can fully restock the missile banks of 4.5 Arleigh Burke-class destroyers. Large gantry cranes already installed on the semi-submersible platforms would then transfer the missiles on the Speed Reloader to the nearby vessels.
