USS Frederick (LST-1184)

USS Frederick with its bow ramp down

USS Frederick (LST-1184) was a which replaced the traditional bow door-design tank landing ships (LSTs) of the United States Navy. The ship was named after the city of Frederick, Maryland and Frederick County, Maryland. The vessel entered service in 1970 with the United States Pacific Fleet and saw service during the Vietnam War, and the Persian Gulf War earning three battle stars. The ship was decommissioned in 2002 and put up for sale.

Frederick was acquired by the Mexican Navy the same year as part of the Security Assistance Program and entered service in December 2002 renamed ARM Usumacinta. Usumacinta has since taken part in three RIMPAC multi-national naval exercises as well as provide humanitarian support following earthquakes in Oaxaca and Chiapas.

Design and description

Frederick was a which were designed to meet the goal put forward by the United States amphibious forces to have a tank landing ship (LST) capable of over . However, the traditional bow door form for LSTs would not be capable. Therefore, the designers of the Newport class came up with a design of a traditional ship hull with a aluminum ramp slung over the bow supported by two derrick arms. The ramp was capable of sustaining loads up to . This made the Newport class the first to depart from the standard LST design that had been developed in early World War II.Template:SfnTemplate:SfnTemplate:Sfn

Frederick had a displacement of when light and at full load. The LST was long overall and over the derrick arms which protruded past the bow.Template:SfnTemplate:Sfn The vessel had a beam of , a draft forward of and at the stern at full load.Template:Sfn

Frederick was fitted with six Alco 251-C diesel engines turning two shafts, three to each shaft. The system was rated at and gave the ship a maximum speed of for short periods and could only sustain for an extended length of time. The LST carried of diesel fuel for a range of at the cruising speed of . The ship was also equipped with a bow thruster to allow for better maneuvering near causeways and to hold position while offshore during the unloading of amphibious vehicles.Template:SfnTemplate:Sfn

The Newport class were larger and faster than previous LSTs and were able to transport tanks, heavy vehicles and engineer groups and supplies that were too large for helicopters or smaller landing craft to carry.Template:Sfn The LSTs have a ramp forward of the superstructure that connects the lower tank deck with the main deck and a passage large enough to allow access to the parking area amidships. The vessels are also equipped with a stern gate to allow the unloading of amphibious vehicles directly into the water or to unload onto a utility landing craft (LCU) or pier. At either end of the tank deck there is a turntable that permits vehicles to turn around without having to reverse.Template:SfnTemplate:Sfn The Newport class has the capacity for of vehicles, of cargo area and could carry up to 431 troops.Template:SfnTemplate:Sfn The vessels also have davits for four vehicle and personnel landing craft (LCVPs) and could carry four pontoon causeway sections along the sides of the hull.Template:SfnTemplate:Sfn

Frederick was initially armed with four Mark 33 /50 caliber guns in two twin turrets. The vessel was equipped with two Mk 63 gun control fire systems (GCFS) for the 3-inch guns, but these were removed in 1977–1978.Template:Sfn The ship also had SPS-10 surface search radar.Template:Sfn Atop the stern gate, the vessels mounted a helicopter deck. They had a maximum complement of 213 including 11 officers.Template:Sfn

Construction and career

United States Navy service

The ship was ordered as part of a group of eight ships in Fiscal Year 1966.Template:Sfn The LST was laid down on 13 April 1968 at San Diego, California, by the National Steel and Shipbuilding Company. Named for a city of city and county in Maryland, the vessel was launched on 8 March 1969, sponsored by Mrs. Kleber S. Masterson. Frederick was commissioned into the United States Navy on 11 April 1970.Template:Sfn

Following shakedown, Frederick was assigned to the Amphibious Force, Pacific Fleet, and was homeported at San Diego. She made over thirteen major deployments to the Western Pacific and Far East. Frederick earned one award of the Meritorious Unit Commendation and three battle stars for Vietnam service.Template:Sfn Frederick was decommissioned on 5 October 2002.

Mexican Navy service

File:US Navy 030723-N-3228G-001 Mexican Navy ship Usumacinta (A-412), formerly USS Frederick (LST-1184), arrives in Pearl Harbor for a 10-day port visit.jpg

ARM Usumacinta in 2003

Frederick was sold to Mexico as part of the Security Assistance Program on 9 December 2002 and was commissioned into the Mexican Navy as ARM Usumacinta (A 412) the same day.Template:Sfn The ship was struck from the United States Naval Vessel Register on 6 November 2002.

In 2012 ARM Usumacinta, along with a Naval Infantry detachment, took part in the large multi-national naval exercise RIMPAC 2012 off the coast of the Hawaiian Islands. The ship also took part in RIMPAC 2016 and RIMPAC 2018. In 2017, following earthquakes in Oaxaca and Chiapas, the ship was used to transport of supplies to the stricken areas.

External links

• united-states-navy.com: USS Frederick