The Kilauea class of ammunition ship's mission is transport and deliver of bombs, bullets, missiles, mines, projectiles, powder, torpedoes, and various other explosive devices and incendiaries, as well as associated ordnance cargo to the various ships in United States Navy, while underway.
This type of support is necessary in order to achieve and maintain the United States Navy's requirement for a high degree of logistical independence. These efforts enable the Navy to more effectively perform its functions of sea control and projection of power ashore. Their Secondary Mission involves providing limited quantities of fuel, water, and combat store products, in addition limited ship repair and maintenance services, as well as special project services. To get their Job done they utilize CH-46 Sea Knight Helicopters for vertical replenishment (VERTREP), as well as the conventional connected replenishment (CONREP) abilities using seven CONREP Stations.
The eight ships were initially outfitted with four twin 3"/50 gun mounts, but these were eventually removed and replaced with two CIWS point-defense systems except for USS Mount Hood, which never received her CIWS. Upon transfer to the Military Sealift Command these were removed as well.
The ships have four cargo holds, which break down into 14 magazines. A magazine is the level within the cargo hold, and is defined as a magazine due to the stowage of ammunition and the requisite fire detecting and fire fighting items found on each level. The four cargo holds are serviced by six high speed cargo weapons elevators. The ships have a certified helicopter flight deck and can handle almost any US military helicopter as well as most commercial and allied helicopters. There are 7 unrep cargo transfer stations and 1 fuel delivery station. The ships can receive fuel at sea from any of 4 stations and are also self-sufficient in the loading and discharge of ammunition or cargo from the ship to a pier or barge. There are four cargo booms which allow shore or barge transfer.
Modern Underway Replenishment (UNREP) facilities include the capability to support and operate two assigned medium-lift "Sea Knight" Helicopters. This added dimension of logistic support capability allows for the Vertical Replenishment (VERTREP) of ordnance cargo and combat stores. Fleet units requiring resupply inside, or even somewhat outside, the immediate horizon of the support ship can now be served by VERTREP utilizing these helicopters. They also maintain the capability for Connected Replenishment (CONREP). This can be accomplished simultaneously with VERTREP. There are seven CONREP stations - four stations to port and three to starboard. They can all be rigged for the Standard Tension Replenishment Alongside Method (STREAM) System. The STREAM System employs a specially designed trolley riding on a constant high-tension span wire. As dictated by the operational situation and resupply requirements, any or all of the station can be utilized concurrently. One ship can be replenished underway alongside to port, while another ship is being serviced alongside to starboard.
Ammunition ships operated by Military Sealift Command provide logistic support to US Navy ships at sea. was the first ship of the class and the first to be transferred to Military Sealift Command, on 1 October 1980. was transferred in August 1995, in June 1996, in August 1996 and Mount Baker in December 1996. was transferred 1 October 1997. transferred to MSC operation on 30 September 1998, and the final ship, , has not been transferred, and sits in reserve at Suisun Bay, California. Ships undergo a civilian modification overhaul during which accommodations are improved, main armament taken out and ships outfitted for reduced crewing by MSC.
The ships are outfitted with a Fleet satellite communication system. In comparison to other systems, this modern and efficient system is less likely to suffer processing delays due to radio frequency interference or message traffic backlogs. Command and control directives and operation orders can be processed on a near real-time basis, as can logistic requirement requests from other Fleet units.
The ships are equipped with an automated propulsion system. This system permits personnel in the Pilot House to control the ship's speed directly, as the propulsion plant responds to their orders. The system also features a mode that allows personnel in the engineering operation station to light-off boilers and operate the propulsion plant by remote control. The ships have three oil-fired Foster-Wheeler D-Type boilers, each capable of full power of producing 87,900 pounds of steam-per-hour, at a pressure of 615 pounds-per-square-inch. The main propulsion plant consists of a high pressure steam turbine to a low-pressure steam turbine geared-drive combination which can develop up to 22,000 shaft horsepower. This drives a single shaft, with a six-bladed propeller, in diameter. The ships have a speed capability in excess of twenty knots, which is enhanced by their bulbous bow. This also improves their sea-keeping ability in rough seas and enables her to keep pace with fast-moving Task Forces at sea.
The five ships of the improved Kilauea class were to be slightly larger, with gas-turbine propulsion.
The new Lewis and Clark class of dry cargo ships will replace aging ammunition ships and dry cargo ships in the Navy's Combat Logistics Force (CLF), including the Kilauea class, beginning in the 2007 timeframe.