The U.S. Navy plans to buy a third hospital ship to provide support for smaller amphibious operations and rapid assistance to coastal emergencies or natural disasters. The two existing hospitals are large (70,000 tons) and slow (30 kilometers an hour). The navy wants to build a smaller, faster EMS (Expeditionary Medical Ship) based on the high-speed EPFs (Expeditionary Fast Transports) it has been using for nearly a decade.
The U.S. Navy currently has twelve Spearhead class EPFs, which are high speed catamaran transports. Three more are under construction and one more is planned. These ships cost about $180 million to build and $28 million a year to operate. The EMS would be EPF 17 and the navy wants to have it in service by 2029 or earlier. Austal, the designer and builder of the EPFs and similar ships already advertises a medical ship variant of their EPF design. This ship is a bit longer and heavier, at 3,100 tons than the current 2,400-ton EPF upgrade design used for the last three EPFs the navy has ordered. This “Flight II” design responds to use requests, including expanded sick bay (medical facilities) that make possible simple surgical procedures and facilities for injured sailors to recuperate on board rather than be taken off the ship for that.
The EMS ship has a crew of 28 and fifty medical personnel. There would be three operating rooms and 56 patient recovery beds (six intensive care, 20 intermediate care and 30 light care) in addition to 170 seats for other passengers. The two larger hospital ships have a thousand hospital beds and 950 medical personnel. The EMS is needed for situations where you need some medical help quickly and in places that a 70,000-ton ship cannot reach. EMS top speed is nearly three times that of larger hospital ships and the shallow four-meter (13 feet) draft of EMS means this faster ship can get closer to shore and up rivers and estuaries. Another EMS advantage is that it is an active duty-ship while the two larger hospital ships are in reserve status most of the time because most of their medical personnel are reservists. It takes about a week for the larger hospital ships to be ready and since they are based in the United States, often travel farther to where needed than the EMS, which will move around to potential hot spots. The EMS landing pad can handle the V-22 tilt-rotor aircraft and there is a hangar for a smaller conventional helicopter. EMS can receive or transfer patients via small boats up to 12 meters (40 feet) long.
Until 2015 EPFs were known as JHSV (Joint High Speed Vessels) type ships. The U.S. Navy wanted to have 22 Spearhead EPFs but had to settle for 16. The Spearhead class are twin hulled catamaran that displace 2,100-tons fully loaded, EPF can carry 545 tons of cargo or vehicles in a 1,900 square meter (20,000 square foot) cargo bay. Cargo gets on and off via a ramp that can handle up to 100 tons at a time. That means tanks can be loaded and transported. Up to 312 passengers (troops or civilians) can be carried on another deck in airline type seats. These passengers can be carried for four days. As many as 104 passengers can be carried for up to 14 days. Top speed is 80 kilometers an hour and max range is to 2,200 kilometers on internal fuel. One shortcoming of the catamaran design is that it cannot handle rough seas as well as single hull ship, which can move as fast or faster than a catamaran design in rough seas.
The minimum crew size is 26 but up to 45 are needed for some types of missions. There is a helicopter pad that can handle heavy (up to 30 ton) helicopters. There is also storage space for a smaller (12 ton UH-60 class) helicopter.
The U.S. Navy first ordered ten Spearhead class EPFs in 2008 (for $160 million each) and received the first one in 2013 and the rest arrived by 2018. One advantage of these ships is that they are based on successful and heavily used commercial designs, thus the price per ship went down. This commercial success is what led the U.S. Navy to using leased commercial versions in 2001 for use in the Pacific. The U.S. Army also tested the design and after 2003 these tests extended to the Persian Gulf. All this eventually led to the EPF and EMS.