- 4 * MAN/B&W medium speed diesels
- 24MW diesel electric plant, twin screws
- 2MW azimuth bow thruster
An Expeditionary Transfer Dock (ESD), (formerly the Mobile Landing Platform (MLP)), are designed to be a semi-submersible, flexible, modular platform providing the US Navy with the capability to perform large-scale logistics movements such as the transfer of vehicles and equipment from sea to shore. These ships significantly reduce the dependency on foreign ports and provide support in the absence of port availability.
The ESD and ESB (Expeditionary Mobile Base) and are part of a new ship class added in 2015 with an E as a new designator, similar to the L-class amphibious ships, S-class submarines, A-class auxiliaries and more. These three E-class ships were previously listed as seabasing ships in the Naval Vessel Register.
The first ship of the ESD program, USNS Montford Point (ESD-1) was delivered in May 2013, and the second ship, USNS John Glenn (ESD-2), was delivered May 20, 2013.
The Navy plans to procure six Expeditionary Mobile Bases (ESBs) in total.
The Expeditionary Transfer Dock concept is 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.