In February of this year, the US Navy commissioned the John L. Cantley expeditionary naval base ship. So far, the country's navy has deployed four Lewis B. Puller class expeditionary naval base ships. So, what is an expeditionary naval base ship? Why did the United States choose to develop and build such ships? What is its overall performance? Please refer to the relevant interpretation. The USS John L. Canley, an expeditionary naval base ship of the United States. The Lewis B. Puller expeditionary naval base ship. Striving to 'move military bases to the sea', as the name suggests, expeditionary naval base ships are ships that can be used as military bases in distant seas. According to the relevant plans of the United States, this type of ship is mainly used to ensure that its armed forces operate under low-intensity military conflict conditions. This idea began in 1983. At that time, the US Marine Corps' military camp in Beirut was attacked, causing serious casualties. In the complex international context at that time, the US Department of Defense began to discuss the topic of building mobile offshore bases. Afterwards, after several changes, the expeditionary naval base ship project began to be implemented. Simply put, an expeditionary naval base ship is a large vessel equipped with necessary infrastructure that can "move military bases to the sea". Its hull is huge, with not only ammunition depots, fuel depots, repair shops, mission planning rooms, but also a large number of personnel living quarters. Unlike other ships, it has huge loading and unloading platforms, and some cabins can be merged or split for functional conversion, making it relatively easy to "switch" to a cargo dock and achieve loading and unloading of large or even super large cargo at sea. The emergence of expeditionary naval base ships means that as long as the conditions are met, expeditionary naval base ships can be deployed to many sea areas, reducing dependence on foreign ports and shore based logistics bases. However, the construction standards for this type of ship are not high, and low-cost civilian ships are usually used for retrofitting, which makes it difficult to resist damage despite its short construction period and ease of mass production. The US Navy has high expectations for this type of ship, requiring it to provide support for various combat vessels and ensure that they have the conditions to complete related tasks. Therefore, for the US Navy, an expeditionary naval base ship is a combat support vessel that can be used as a sea transit station. The initial idea of the US military, which originated from the development of expeditionary transfer dock ships, was to build an expeditionary transfer dock ship whose main task was to temporarily store and timely send large quantities of materials. And these materials are transported by large medium speed roll on/roll off supply ships and ammunition transport ships that are pre positioned at sea. The expeditionary transfer dock ship can quickly unload the materials transported by the above-mentioned preset ships with the help of professional supporting facilities on board, and then transfer these equipment and supply materials ashore through air cushion landing craft or other ships. Two of these expeditionary transfer dock ships were built in total. The first ship is the Cape Montefort, and the second ship is the John Glenn, delivered in 2013 and 2014 respectively. The expeditionary naval base ship is transformed from this type of expeditionary transfer dock ship. In 2015, there were new changes to the Lewis B. Puller, the third ship under construction for the expeditionary transfer dock. According to the new positioning of the US military, it was converted into an expeditionary naval base ship, becoming the first ship of its class and entering service in 2017. Later, the second ship of the class, Herschel Woody Williams, and the third ship, Miguel Keith, were commissioned in 2020 and 2021, respectively. The fourth ship, the John L. Canley, was commissioned at the beginning of this year. The fifth ship, Robert Simanek, and the sixth ship, Hector Cabrata, are still under construction. Some common features of this class of expeditionary naval base ships can be seen from the Lewis B. Puller. The Lewis B. Puller is a "civilian to military" ship, whose hull comes from an Alaska class oil tanker. The tanker has a sturdy structure and can navigate in polar ice regions. The ship was launched in 2014, joined the US auxiliary fleet in 2017, and was incorporated into the US Navy combat sequence in August of the same year. The Lewis B. Puller expeditionary naval base had a captain of 233 meters, and subsequent ships of this class were also large in size, second only to the Nimitz and Ford aircraft carriers in terms of tonnage. The maximum speed of this class of ship is 15 knots, and it can travel 17600 kilometers with one full tank of fuel. The ship is designed with a flight deck, combat deck, and hangar. There are four heavy helicopter landing platforms on the flight deck. The ship is designed with ammunition depots, ship storage compartments, etc. In addition, the ship can also accommodate 300 special forces personnel inside. The four expeditionary naval base ships that have been put into service successively have to some extent enhanced the material supply capability of the US military. Based on this, the US military began to accelerate the construction of other ships of this type. In the early days, the US Navy believed that expeditionary naval base ships should be primarily used for anti mine operations, serving as minesweepers to carry minesweepers, clear mines and other explosives in mission areas. The currently built expeditionary naval base ships do possess this capability. To cope with the threat of mines, this class of ships not only has acoustic systems for detecting mines, mechanical and magnetic mine clearance systems, but can also carry four magnetic minesweepers. With the passage of time, the mission and tasks of this class of expeditionary naval base ships have expanded, and their "uses" have also increased. In addition to serving as a transfer station for maritime supplies, expeditionary naval base ships, due to their large size, can also be used as command ships, used for mooring other ships, and serve as helicopter landing platforms. When needed, it can also carry out tasks such as humanitarian rescue and disaster relief. But overall, expeditionary naval base ships exist for the purpose of deploying and using forces and equipment in the global oceans. Since their deployment, they have become an important part of the US military's efforts to enhance its military power in key areas of interest. In July 2017, the first ship of the expeditionary naval base, the Lewis B. Puller, made its first operational deployment to the Middle East region. Afterwards, the ship sailed in the Middle East related waters for a long time. Since the beginning of this year, as the new round of Israeli Palestinian conflict continues to escalate, the US Navy's combat vessels have increased their operations in the region, further highlighting the role of the Lewis B. Puller. The second ship of the expeditionary naval base, the Herschel Woody Williams, is deployed at the Suda Bay Naval Base in Crete, Greece, mainly providing support for US Navy vessels operating in the Mediterranean and Black Sea. In recent years, with the increasing attention of the United States to the African continent, this ship has also frequently appeared in the waters near Africa. Shortly after entering service, the third ship, the Miguel Keith, was dispatched to Saipan Island in the Western Pacific region and is now deployed in Okinawa, Japan. The ship has conducted joint exercises with Japanese Maritime Self Defense Force ships multiple times, and in February 2022, it also provided ammunition and other supplies to naval formations, including the USS Lincoln aircraft carrier. From the actual performance of expeditionary naval base ships, it can be seen that this type of ship indeed provides support for the US military's large-scale deployment and flexible deployment of troops in certain situations. However, the shortcomings of the ship are also evident. After all, expeditionary naval base ships are built to provide supplies under low-intensity military conflict conditions. Their large size, slow speed, and weak self-defense capabilities make them easy targets on the sea surface. In a highly competitive combat environment, it requires heavy protection to survive and function at sea. Or it may also serve as the future "mother ship" of unmanned equipment. From the current situation, the manufacturer of this class of ship is still on the road to transforming the expeditionary naval base ship. According to the plan, there are various modification options for expeditionary naval base ships to meet the constantly emerging new demands of users. It is reported that the relevant research and development manufacturers have conducted research on the possible usage scenarios of this class of ship in the future, and have proposed some targeted new modification plans, including creating a stern flight deck for unmanned aerial vehicles to fly, and adding maintenance ship capabilities. Among them, serving as the future "mother ship" of unmanned equipment is one option. According to the modification plan, in addition to commanding unmanned aerial vehicles, this class of ship will also be equipped with unmanned underwater vehicle compartments and launch and recovery systems for unmanned underwater vehicles. With these new systems, expeditionary naval base ships can support the operation of various unmanned equipment, including super large unmanned underwater vehicles. At present, expeditionary naval base ships are unable to take off and land F-35B fighter jets, and can only carry the Marine Corps' V-22 "Osprey" transport aircraft and CH-53K "Stallion King" helicopter. Therefore, the modification plan also includes further expanding the ship's capabilities to enable it to take off and land multiple types of naval aircraft, including the F-35B. In addition, the ship will further improve and provide related support equipment. As for how this class of ships will develop in the future and whether they can truly play the role of an "expeditionary maritime base" as their name suggests, time will give the answer. (New Society)