Expeditionary Transfer Dock

The Expeditionary Transfer Dock (ESD), formerly Mobile Landing Platform (MLP), is a type of amphibious assault ship being constructed for the United States Navy, with the first ship due to enter service in 2013. ESD ships are to serve as floating bases for amphibious operations, and operate as a transfer point between large ships and small landing craft. Proof-of-concept testing began in 2005, with heavy lift ships serving as substitutes for the ESDs. General Dynamics' National Steel and Shipbuilding Company was awarded a contract to design and build the first ship in late 2010, with construction beginning in July 2011. The United States Navy initially plans to acquire three vessels (with a possible fourth proposed in 2012, and fifth in 2014), which will be designated the Montford Point class. The ships are expected to have a 40-year service life.

In September 2015, the Navy decided to redesignate the MLP as the Expeditionary Transfer Dock (ESD) and the AFSB as the Expeditionary Mobile Base (ESB).

Design


The Expeditionary Transfer Dock concept calls for a large auxiliary support ship to facilitate the 'seabasing' of an amphibious landing force by acting as a floating base or transfer station that can be prepositioned off the target area. Troops, equipment, and cargo would be transferred to the MLP by large-draft ships, from where it can be moved ashore by shallower-draft vessels, landing craft like the Landing Craft Air Cushion (LCAC), or helicopters. In order to transfer vehicles from the larger ships to the ESD, the vessels were originally to be fitted with a Vehicle Transfer System; a ramp connecting the two ships alongside, and able to compensate for the movements of both vessels while underway.

A preliminary design by General Dynamics envisioned a ship that carried six LCACs, with the ability to turn around (dock, unload or load, then launch) two landing craft simultaneously from the stern. The ESDs were to host a brigade-size force, sail at 20 kn, and have a maximum range of 9000 nmi. Each ship was to cost US$1.5 billion to build. However, cutbacks to defense spending planned for the fiscal year 2011 budget forced the downscaling of the design in mid-2009.

General Dynamics identified the civilian Alaska-class oil tanker (built by the subsidiary National Steel and Shipbuilding Company) as a suitable basis for an "ESD 'Lite'", with the design modified into a float-on/float-off vessel that could be built for US$500 million per ship. As part of the cost trade-off, the Vehicle Transfer System was scrapped in favor of skin-to-skin mooring of a host ship alongside the ESD, and the LCAC complement was reduced to three. The new design is 785 ft long, with a beam of 164 ft, a top speed of over 15 kn, and a maximum range of 9500 nmi. Converteam supply an integrated power system and vessel automation system for the ESD.

USS Ponce
In March 2013 CNO Jonathan Greenert showed Powerpoint of the ESD-Expeditionary Mobile Base (ESD-ESB), a proposed variant of the ESD with increased accommodation, a hangar and large flightdeck on piers above the semi-submersible deck, This was first proposed in January 2012, around the time of the sudden announcement that the USS Ponce would be converted as an interim AFSB(I) (ESB). The ESD-ESB could be used to support special forces and intelligence gathering as a base for helicopters, MV-22 Osprey tiltrotors, and even the F-35B stealth fighter, but the main role of the Ponce will be operating minesweeping MH-53E Sea Dragon helicopters. "a number of variations" of the ESD were being considered; the ESB can fulfil many of the roles of a $2.5bn "big deck" amphibious ship at a quarter of the price.

Expeditionary Mobile Base (ESB) ESD variants


Unlike the first two Expeditionary Transfer Dock, T-ESB-3 and T-ESB-4 will serve as Expeditionary Mobile Base (ESB) vessels to support special forces missions, counter-piracy/smuggling operations, maritime security operations, and mine clearance, as well as humanitarian aid and disaster relief missions. In order to support these extended roles, the ESBs will have military detachments in addition to the civil service mariners.

ESB vessels are designed to support low-intensity missions, allowing more expensive, high-value amphibious warfare ships and surface combatant warships to be re-tasked for more demanding operational missions for the U.S. Navy. These ESB variants are slated to operate in the Middle East and the Pacific Ocean.

Like the first two Expeditionary Transfer Dock, the overall design of the T-ESB-3 and T-ESB-4 is based on the hull of the civilian Alaska-class oil tanker. Both ESB variants will be outfitted with support facilities for its mine-sweeping, special operations, and other expeditionary missions. An accommodation barge will also be carried to support up to 298 additional mission-related personnel. Their aviation facilities include a flight deck with landing spots for two heavy-lift transport CH-53 helicopters, as well as additional deck space for two more CH-53s. The Lewis B.Puller will also have a helicopter hangar, an ordnance storage magazine, underway replenishment facilities, and deck space for mission-related equipment storage. The addition of a flight deck makes the ship more top-heavy, and so less stable in heavy seas. The deck is made with two operating spots and two parking spots, plus room to store two in the hangar. The mission deck's ability to submerge to launch landing craft was disabled and instead a crane, capable of carrying 11 metric tons (12 short tons) and moving a 41 ft boat in up to sea state 3, carries watercraft, towed arrays, and unmanned vehicles into the water.

The United States Navy ordered T-ESB-3 in February 2012 as part of the Fiscal Year 2013 appropriation for the U.S. Department of Defense via the National Defense Sealift Fund (NDSF). The keel-laying ceremony for MKP-3 took place at the General Dynamics NASSCO shipyard in San Diego, California, on 5 November 2013.

On 16 January 2014, at the Surface Naval Association's national symposium, the head of NAVSEA's Strategic and Theater Sealift program, Captain Henry Stevens, announced that the Bell-Boeing MV-22 Osprey tilt-rotor aircraft (pictured) will be evaluated for potential operations on board the Expeditionary Mobile Base ESD variant. Currently, the testing and certification of MH-53E helicopters for minesweeping operations from ESB support ships are slated to begin during fiscal year 2016. Additionally, Captain Stevens noted that the F-35B STOVL strike fighter was not currently being considered for ESB operations because of exhaust heat from F-35B damaging the flight decks of U.S. Navy amphibious assault ships. Some outfitting and specialized equipment specific to the V-22 would be needed to support it, but little engineering work or modifications to the ship would have to be done.

On 19 December 2014, U.S. Navy's Naval Sea Systems Command awarded a $498M USD contract to General Dynamics NASSCO for the construction of second ESB variant, the as-yet unnamed T-ESB-4. This vessel will be built at the NASSCO shipyard in San Diego, California, with a scheduled completion date of 2018.

While the USN intends to procure a fifth ship, the T-ESD-5, it has not yet submitted a funding request for advance procurement funding.

Concept testing


In September 2005, the United States Navy approved trials of the ESD concept, to test the feasibility of seabasing for an amphibious operation. The heavy lift ship MV Mighty Servant 1 served as the substitute for the ESD, while the Roll-on/roll-off vessel USNS Watkins (T-AKR-315) played the role of a planned type of transport ship for the United States Maritime Prepositioning Force. The first part of the trial consisted of the two ships transferring cargo between themselves while anchored in Puget Sound. After successfully completing this, the vessels sailed to San Diego, where cargo was transferred from Watkins to Mighty Servant 1, then taken ashore by LCACs; slightly submerging the deck of the heavy lift ship allowed the hovercraft to "'fly' aboard".

A second series of tests was conducted off Norfolk, Virginia in September and October 2006, with USNS Red Cloud (T-AKR-313) and MV Mighty Servant 3. This time, the ships were moored together while underway, during which vehicles drove from Red Cloud onto Mighty Servant 3, then embarked aboard LCACs. In February 2010, Mighty Servant 3 joined USNS Soderman (T-AKR-317) for further trials in the Gulf of Mexico. During these, personnel and a wide range of vehicles, from Humvees to M1 Abrams tanks, were transferred to, then launched from Mighty Servant 3, in conditions up to Sea State 4.

Construction


In August 2010, the National Steel and Shipbuilding Company in San Diego was awarded a US$115 million contract to design the Mobile Landing Platform, and build the first ship. Construction on the first vessel began in July 2011.

By January 2016, the names for the four ships were announced:
 * USNS Montford Point (T-ESD-1)
 * USNS John Glenn (T-ESD-2)
 * USNS Lewis B. Puller (T-ESB-3)
 * USNS Hershel "Woody" Williams (T-ESB-4)

Orders for the second and third vessels are expected to be made in the 2013 and 2015 fiscal years. The keel for the first Montford Point-class Expeditionary Transfer Dock was laid on 19 January 2012. Construction of John Glenn begin on 17 April 2012, by which time the Montford Point was 48% complete. The Montford Point was christened in San Diego on March 2, 2013. The first ship is to be operational by 2015, with the third in service by 2018. The Montford Point completed final contract trials on 13 September 2013; the John Glenn was floated off on 15 September and construction began on the Lewis B. Puller on 19 September 2013.

In March 2012 the USN requested a fourth ship in the FY14 budget of the National Defense Sealift Fund, and proposed that both T-ESB-3 and T-ESB-4 would be ESD-ESB variants. Congress rejected both requests on the grounds that the Ponce could do the job and ESB's should in any case be funded out of the main Navy account. the Chief of Naval Operations is still planning to buy two ESD and two ESD-ESB variants despite the uncertainty caused by the sequester, in fact the late-2012 "Vision for the 2025 Surface Fleet" by the head of Naval Surface Forces envisages buying more MLP variants as a cheap alternative to traditional amphibious ships.

On 19 December 2014, U.S. Navy's Naval Sea Systems Command announced the construction of the second ESB variant, the as-yet unnamed T-ESB-4. This vessel will be built at the NASSCO shipyard in San Diego, California, with a scheduled completion date of 2018. It is anticipated that T-ESB-4 will be assigned to the Pacific Ocean, and like the other ESD ships, will be operated by the Military Sealift Command.

Ship re-designation
Effective 4 September 2015, U.S. Secretary of the Navy Ray Mabus officially announced the creation of a new ship designation, "E" for expeditionary support. Joint High Speed Vessel (JHSV) will be called Expeditionary Fast Transport, or EPF; the Mobile Landing Platform (MLP) will be called Expeditionary Transfer Dock, or ESD; and the Afloat Forward Staging Base (AFSB) variant of the MLP will be called Expeditionary Mobile Base, or ESB. The new designation was pursuant to a memorandum sent to Secretary Mabus from Chief of Naval Operations Admiral Jonathan Greenert dated 31 August 2015.