, with helicopter The EPF is able to transport
U.S. Army and
U.S. Marine Corps company-sized units with their vehicles, or can be reconfigured to become a
troop transport for an
infantry battalion. Vehicles and cargo are loaded and unloaded by a ramp that can support up to 100 tons of weight. Although designed for a military crew of 46, the ships usually have a crew of 26. The passenger room contains reclining seats with overhead televisions and racks for weapons and equipment. Each vessel has 104 permanent berthing spaces. Without resupply, it can support 312 embarked personnel for four days, or 104 personnel for 14 days. The EPF has a greater level of comfort for the crew than larger Navy ships. The stateroom-style berthing areas for the ship's crew have private features including toilet stalls, outlets, air conditioning, and thermostats. People being transported are less well catered for. They may live in "
hot racking"-style living arrangements of available berthing bunks if necessary. There is no ship's store in the typical Navy sense of the term, but the ship's captain may unlock the "slop chest" and sell ship's coins and other ship-specific paraphernalia on a case-by-case basis. The ship is unstable in rough seas and at high speeds. At 10 knots in calm sea states the hull can roll up to four degrees to each side, while conventional ships would roll very little. This increases if the ship goes faster or in rougher conditions, raising the possibility of
seasickness. , an EPF costs $180 million to build and has an annual operating cost of $26 million.
Chief of Naval Operations Jonathan Greenert has suggested using the ships as a cheaper way to perform counter-piracy missions to free up blue-water combatants. Offensive armament and defensive measures against pirates would be handled by a security team on board, and an EPF's speed would also be a good defense against an attack by pirates. After various tests to explore the EPF's suitability to perform different missions, the ship was found to perform its primary role of intra-theater transport effectively, but had extreme difficulty in carrying out other suggested missions. When performing at-sea transfers of equipment with a
Mobile Landing Platform (MLP), the EPF ramp used for vehicle transfers could not effectively operate with it in open ocean sea states of 2–3, and was determined to only be able to work in calm sea states found in protected harbors, an unacceptable constraint for operational deployment. The Navy has been aware of the current ramp's limitations and is developing one for use in up to sea states 3–4. When deploying a
SEAL Delivery Vehicle (SDV), the EPF's stern-mounted crane could launch it in up to sea state 3 conditions, but support surface craft were needed to get divers into the underwater vehicle, which could only be launched in sea state 2. The same General Dynamics OPEN CI is used on the , also built by
Austal USA.
Amphibious assault Marine Corps General
John M. Paxton, Jr. called the EPF "a very capable ship" for certain missions, but cites several deficiencies as a substitute amphibious assault ship, including inability to operate in difficult sea states, survivability in contested waters, lack of a
well deck to launch amphibious vehicles, and lack of "splash capability" to drive vehicles off the ramp into the sea. The ship has been rejected as a platform on which to base
MV-22 Ospreys due to its weight, and potential flight deck damage from engines during take-off and landing. The USMC is investigating changes to the EPF ramp to enable the "splash capability" for placing
Amphibious Combat Vehicles into the water near the shore. A single EPF could carry and deploy 20 to 30 ACVs.
Expeditionary Medical Ship Beginning with EPF-14, the ships will be designated as EPF Flight II, with increased health services capabilities while still maintaining most of the original mission of the ship. The Flight II variant is designed to bring enhanced medical capabilities at the request of Combatant Commanders, and allows patients to recover onboard rather than in a higher-level facility. They can respond faster, and to more places than the Navy's larger, slower and unarmed
hospital ships. The EPF Flight II design includes upgrades to the medical facilities for resuscitation and surgery, enhanced support of V-22 flight operations, and enhanced launch and recovery of 11-meter rigid inflatable boats. In January 2023, the Navy announced that three Expeditionary Medical Ships (EMS) had been approved in the
2023 military budget. They will be
Bethesda,
Balboa, and
Portsmouth. These are planned to be about versus the earlier ships , and have a
draft of for operations in "austere ports". The EMS will have four operating rooms and 124 medical beds, separated into acute care, acute isolation,
ICU, and ICU isolation spaces. Two 11-meter
rigid-hulled inflatable boats allow for the transfer of patients from other ships or water rescue; the flight deck has room for a single
V-22, or an
H-53 or
H-60 helicopter. is planned for delivery by December 2026. ==Program==