The U.S. Navy is moving closer to construction of a new class of ships to augment its combat logistics force (CLF). The T-AOL, previously called the Next Generation Logistics Ship, is intended as a smaller oiler capable of supporting dispersed formations of ships and Marines. It is critical to make the right design decisions that will make this class a valuable asset for future naval warfare.
The Navy intends to begin building the new class in two years. These light replenishment oilers will supplement the current CLF inventory of T-AOEs (fast-combat support ships), T-AOs (fleet replenishment oilers), and T-AKEs (dry cargo/ammunition ships). The Shipbuilding Plan for Fiscal Years (FY) 2025–29 shows the Navy building three T-AOLs—one each in FY 2027, 2028, and 2029—at a cost of $453 million per ship.1 The Navy anticipates eventually procuring 13 T-AOLs.
Build to Accomplish the Mission
The ship’s stated missions include supporting the refueling, rearming, and resupply of naval assets afloat and ashore near contested environments. Its ship-to-ship and ship-to-port missions will support distributed maritime operations (DMO), littoral operations in a contested environment (LOCE), and expeditionary advanced base operations (EABO). It will support surface action groups (SAGs) afloat and EABs ashore.2
The top-level requirements and proposed design solutions are conceptual for now, and the Navy envisions the T-AOL as a family of ships. The Office of the Chief of Naval Operations has indicated the Navy might build two variants: a platform-supply vessel and a fast-supply vessel. The variants would perform the same missions, but the fast-supply vessel might be smaller and faster.3
Versatility is important. Different characteristics and capabilities are required to refuel, rearm, and resupply dispersed SAGs during DMO compared with ashore and littoral-support requirements. The fast-supply vessel design may be useful as an adjunct in supporting missions for DMO—depending on its size, features, and capabilities—while the platform-supply vessel may be better suited to support EABO and LOCE. But the Navy risks building two different ships with the capabilities of a light oiler, neither of which can independently support DMO.
A T-AOL supporting DMO will require significant space to hold multiple commodities, likely necessitating a large size and a deep draft. Ships supporting EABO/LOCE may not carry the same variety or quantity of products, and they might need access to ports that will not accommodate a deeper-draft vessel. DMO support also will require at-sea connected replenishment (ConRep) transfer rigs, whereas EABO/LOCE support may require a ramp offload capability. The platforms as proposed are likelier to meet EABO/LOCE requirements. Different capabilities—and hence a different T-AOL design—will be needed to effectively support DMO. What matters most is that the ship can supplement and fulfill the same missions as the rest of the combat logistics force—namely that it can refuel, rearm, and resupply naval assets at sea.
What the Navy Needs the T-AOL to Be
One of the principal afloat missions for the T-AOL will be supporting guided-missile destroyers (DDGs), frigates (FFGs), or cruisers (CGs) deployed independently or as part of SAGs and most likely located some distance from primary strike groups and other, larger CLF assets.
Looking at the prospect for prolonged conflict in the vast western Pacific, the current inventory of 34 CLF ships split almost equally among coasts and fleets is clearly not enough.4 There are only two T-AOEs in the CLF inventory. In a high-end conflict supporting multiple strike groups, T-AKEs and T-AOs will need to pair together to act as a T-AOE station ship to support larger formations, in addition to their role as shuttle ships. There will not be enough remaining T-AKEs or T-AOs to support ships or SAGs operating independently. Hence the need for more and cheaper replenishment ships.
A look at historical operations helps clarify the capabilities the new oiler needs. Commander Task Force 63 (CTF-63) in the early 1990s developed the “mini-multi” concept for CLF ships, specifically relating to the Henry J. Kaiser–class T-AOs. These ships primarily carried fuel, but they also could deliver small amounts (“mini”) of other stores such as provisions, high-usage load list (HULL) items, and AO-deckload material (“multi”).5 This capability was a critical part of the logistics-delivery system and still is. When a force does not have enough CLF ships, the ones it has must be able to do it all.
A T-AOE can deliver all three major commodities. It carries large quantities of fuel and ammunition, but also a good-sized load of other stores and provisions. But a T-AOE usually is tied to an aircraft carrier. It stays in the vicinity of the carrier and its escorts and is unavailable for other tasking. With only one of the older AFS/T-AFS ships in theater, it alone could not cover all the remaining replenishments. To fill the gap, CTF-63 turned to the T-AOs. Although they carry no ammunition, T-AOs deployed with eight refrigerated 20-foot military-owned demountable containers (Milvans), which gave them the flexibility to replenish outlier surface combatants with fuel, stores, and provisions.
Under the mini-multi operating concept, the T-AO would link up with an AFS/T-AFS and receive as fleet freight all stores and provisions that the AFS/T-AFS could not deliver directly to combatant ships, then detach to replenish customers. A T-AO used in this way could add 128 pallets of Milvan refrigerated capacity to approximately 450 pallets of deck/cargo stowage capacity—enough to replenish at least four surface combatants. For operations in the Sixth Fleet area of responsibility, T-AOs so equipped were in strong demand.
A ship that can conduct mini-multi-type replenishment operations is an indispensable CLF asset to the fleet. In fact, the older Henry J. Kaiser-class T-AOs now have 10 refrigerated Milvans, and the newer John Lewis-class T-AOs are designed with 500-600 pallets of storage capacity in three configurable storerooms for freeze/chill/dry provisions.
The shortcoming of the mini-multi concept is that the T-AO is only a two-commodity CLF ship—it cannot carry ammunition. The T-AKE solved this problem for major combatant formations (carrier strike groups and amphibious ready groups), because it is a three-commodity CLF ship, even though the cargo fuel capacity is only 25,000 barrels. But dispersed formations still require a true three-commodity CLF platform. What the Navy really needs is for the T-AOL to be that ship—a new mini-multi oiler that can steam over the horizon and replenish several major combatants with fuel, ammunition, stores, and provisions, whether the combatants are deployed independently or as part of a SAG.
T-AOL Minimum Capabilities
With this operational perspective as background and based on the stated missions, the below capabilities and characteristics are the bare minimum the Navy needs from the new T-AOL for any future high-end conflict.
• Fuel: Diesel fuel marine (DFM) and JP-5 jet fuel would be the primary commodities. The T-AOL should carry a minimum of 30,000 barrels of cargo fuel appropriately split—maybe 90 percent DFM. The average daily burn rate for a CG/DDG is about 710 to 725 barrels of DFM, or about 5 percent of total capacity.6 Keeping these ships 70 percent fueled means refueling about 4,000 barrels every five to six days. (Wartime steaming may require more.) A T-AOL with a 30,000-barrel capacity could replenish four or five surface combatants before reaching 30 percent cargo fuel on board, at which point the T-AOL would need to refuel itself. Further, depending on the DFM/JP-5 split, the T-AOL could easily replenish fuel to a three-ship amphibious ready group, as well as providing some JP-5 to a carrier’s airwing if a T-AO or T-AOE is not available.
• Provisions: Capacity must be enough to resupply three to four surface combatants—basically, a SAG. To reduce construction costs, the T-AOL could be designed to use 20-foot refrigerated Milvans on deck, such as those used on the Henry J. Kaiser-class T-AOs, rather than storerooms built inside the ship such as in the John Lewis class. The ship can configure each container for either frozen or chilled provisions, based on requirements. At CTF-63 during Operation Desert Storm, a one-month resupply of provisions for a combatant-class ship was about 25 to 30 pallets of dry provisions and 15 to 20 pallets of frozen and chilled provisions. One 20-foot refrigerated container on a T-AO can handle approximately 16 pallets of refrigerated provisions, stacked two high. A T-AOL would therefore require three refrigerated containers, although four would be better if deck space allowed. The dry provisions and other cargo such as fleet freight material could be deck-stowed depending on outside temperatures, but a separate internal storage area that could handle 100-150 pallets of material would be beneficial. All provisions would be carried as fleet freight, not as part of the T-AOL ship’s load.
• HULL, AO deckload material: These two commodities are standard ship loads carried by any oiler-class CLF ship (T-AOEs and T-AOs). The T-AOL also should stock these items, requiring additional storerooms. Load quantities would be less than the larger oilers, gearing the T-AOL to support smaller groups of DDGs/FFGs/CGs.
• Ammunition: The T-AOL should be able to carry 200 tons in a certified ammo storage space. Ammunition would be carried as fleet freight, not a part of the T-AOL ship’s load. Cargo would include five-inch ammunition, torpedoes, helicopter weapons, close-in weapon system ammunition, and small-arms ammunition. It would not include anything that requires a crane for reload, such as vertical-launch-system missiles.
• Number of stations and manning: The T-AOL will require one cargo ConRep station per side, similar to the current T-AO configuration. Four fueling ConRep stations would be optimal—two starboard and two port. Having two stations per side would cut refueling time in half if the receiving ship were configured to accept them. This could be critical in forward-deployed areas where refueling speed and reduced time alongside are critical. T-AKEs and T-AOs are manned to simultaneously provide five ConRep stations, or three ConRep stations and a vertical replenishment (VertRep) station. For the T-AOL, manning should accommodate three ConRep stations, or one ConRep and a VertRep.
• Flight deck (no hangar): A smaller flight deck able to accommodate and refuel an H-60 would have to suffice. No hangar means no organically embarked helicopter detachment. Vertical replenishment will rely on the customer ship’s embarked detachment, if it has one. This is the same as the current T-AO configuration and method of operations. To save space, the flight deck could be configured forward instead of aft.
• Cranes: There should be two cranes for loading and unloading cargo, one port and one starboard, rated at 5 to 10 tons.
• Speed: The T-AOL should be able to steam at speeds up to 20 knots, as most CLF ships can. A slower speed would make it hard to reach outlier ships in a reasonable amount of time or to keep pace with moving combatant formations. However, a faster ship would likely cost too much to build and operate.
RightSizing the T-AOL
With these capabilities in mind, it is possible to consider size/displacement and cost.
As one of three commercial shipyards awarded industry studies contracts, Austal’s initial design comments for the T-AOL stated it would likely be close in size and displacement to the Russian Navy’s new Project 03182-class tankers, which have a full-load displacement of 3,500 tons and are approximately 260 feet long, with a beam of 50 feet and a draft of 16 feet.7 This is not enough tonnage to properly support naval assets and SAGs, and there is no indication of transfer rigs for any of the commodities, much less a flight deck. If the T-AOL carries 30,000 barrels of cargo fuel to fulfill its mission, at 300 pounds per barrel, that alone weighs 4,500 tons. Given that assumption, a vessel in the 10,000-ton range would be more appropriate.8
The T-AOL’s budget of $453 million per ship is about half the cost of a John Lewis–class T-AO, which exceeds $800 million per ship. Extensive cost analysis is beyond the scope of this article, but fiscal austerity must not compromise operational effectiveness. The concept of the T-AOL is sound. In the three-commodity mini-multi role it would be able to support the CLF, the fleet, and DMO. So if the Navy is going to build the T-AOL, it must build it right. It is time to begin shifting the balance between efficiency and effectiveness in the direction of the latter.9
1. Office of the Chief of Naval Operations, OPNAV N9: Report to Congress on the Annual Long-Range Plan for Construction of Naval Vessels for Fiscal Year 2025, March 2024. Appendix 1: PB2025 Shipbuilding Plan (FY2025-FY2029), page 16.
2. Ronald O’Rourke, “Navy Light Replenishment Oiler (T-AOL) Program: Background and Issues for Congress,” Congressional Research Service, updated 5 August 2024.
3. Ronald O’Rourke, CRS, “Light Replenishment Oiler Program.”
4. Military Sealift Command, “Ship Inventory.”
5. Naval Supply Shipping Command, Consolidated Afloat Requisitioning Guide – Overseas, NAVSUP Publication 4998.
6. Global Security Manual, Combat Logistics Force, 7 July 2011.
7. Xavier Vavasseur, “Austal USA To Design U.S. Navy’s Next Generation Logistics Ship NGLS,” Naval News, 22 December 2021.
8. Just based on commodity weight, 10,000 tons is about one-fifth the full load displacement of a John Lewis T-AO at 49,850 tons.
9. Sam LaGrone, “PACFLEET CO Paparo Talks Combat Logistics, Chinese Coercion,” USNI News, 14 February 2023.