USNS Mizar

For other ships with the same name, see USS Mizar.

History
United States
Name	Mizar
Namesake	star Mizar
Builder	Avondale Marine Ways, Inc.
Laid down	1 January 1957
Launched	7 October 1957
In service	7 March 1958
Stricken	16 February 1990
Identification	IMO number: 8834873
Fate	Sold for scrap
General characteristics As AGOR-11
Displacement	3,886t loaded 2,036t light
Length	266 ft 2 in (81.13 m) LOA 250 ft (76 m) Design waterline (DWL)
Beam	51 ft 6 in (15.70 m)
Draft	17 ft 6 in (5.33 m) 20 ft (6.1 m) to hydrophones 2 ft 6 in (0.76 m) below keel
Propulsion	2 X diesels, 1,600 hp each 2 X propulsion motors 27 hp at 150 rpm 2 X 4 blade propellers
Speed	12 kn (14 mph; 22 km/h)
Range	20,000 nmi (23,000 mi; 37,000 km)
Endurance	60 days
Crew	11 officers, 30 crew (civil service marine personnel) 19 scientific personnel (accommodations for)
Notes	Double hull, ice strengthened, ice breaker bow

USNS Mizar (MA-48/T-AGOR-11/T-AK-272) was a vessel of the United States Navy. She was named after the star Mizar.

Cargo ship

Mizar was built as a small ice-strengthened, double hull, cargo ship of the Eltanin class on a Maritime Administration type (C1-ME2-13a) hull, by Avondale Marine Ways, Inc. from January 1957. She entered service on March 7, 1958 and served as part of the Military Sea Transportation Service (MSTS), working around Canada and Greenland, with a single voyage to Antarctica in 1961.

Naval Research Laboratory

Mizar circa 1966 with ice conning tower.

The loss of the USS Thresher (SSN-593) on April 10, 1963 and problems handling heavy search equipment over the side from James M. Gilliss in 1963 drove the Naval Research Laboratory (NRL) requirement for a larger, more capable ship than the usual oceanographic research type. A search for a candidate ship, capable of being modified for an inboard center well, led to selection of Mizar in late 1963.

In 1964 Mizar's successful search for the sunken submarine, before modification for the desired center well, further demonstrated the need for a sheltered work space with heavy lift and towing capability.

Center well

The location of the 34 ft (10.4 m) number two hatch straddling the ship's center section made a center well through even the double bottom feasible. A well 23 ft (7.0 m) long and 10 ft (3.0 m) wide with curved fore and aft ends to reduce wave pounding within was installed. The keel level opening was reduced to one of 21 ft (6.4 m) long and 8 ft (2.4 m) wide. A flush mounted, water tight hydraulic door or two parts, one fore and one aft, closed the well at the main deck level. Three 24 in (61.0 cm) diameter cable sheaves installed in a carriage, within which towed devices would be contained for lowering and raising, and extending below the keel allowed towing of heavy equipment without exposure on open decks. The system had a capacity of 12 tons. Large "breather" ducts from the well relieved air pressure caused by wave action within when the doors were closed. All was enclosed by a housing allowing all weather protection for operators. Mizar went into the Philadelphia Naval Shipyard in late 1965 with the installation of the well being a priority.

On April 15, 1964 Mizar was reclassified AGOR-11, designed for deep oceanographic search and research, and to be operated by MSTS for NRL. The ship was fitted with a deepsea vehicle (fish), equipped with strobe lights, cameras, sonar, and magnetometer. Her major tasks were to be ocean floor study and service as a floating base for underwater acoustic, chemical, and biological research. The search for Thresher had paused with advent of bad weather in September 1963. Mizar was assigned to the successor search task group, TG 168.1, when it formed May 18, 1974. Mizar's "fish" located the wreckage of the submarine withing a few hours of searching.

Acoustic navigation system

The only means of subsurface navigation locating a search vehicle or other sensors relative to the ship and bottom is by acoustic navigation. Towed deep vehicles may be half a mile from the towing ship and respond to the ship's movements as much as half an hour after that movement. A capability developed at the University of Washington Applied Physics Laboratory was implemented for Mizar. The system is composed of a triangular array of hydrophones on the ship's hull, a transponder on the towed vehicle with an acoustic pulse triggered by a signal over the towing cable, and a sea floor transponder triggered by an acoustic signal from the ship. By using travel times of the signals distances can be computed. A response from the vehicle can be computed for relative position with regard to the ship and that from the bottom transponder is used to find its relative position. The towed vehicles relative position to the ship and bottom is then computed.

Research

The ship was fitted to perform extensively in ocean science and technology with acoustics an important specialty. Mizar supported scientists from three NRL divisions. The Acoustics Division supported undersea surveillance, fleet sonar systems and studied undersea sound propagation. The Ocean Sciences Division worked in the classical oceanography fields of chemical, physical and biological oceanography and atmospheric studies. Research and development regarding materials and ocean engineering and the ship's searches were under the Ocean Technology Division.

As an example of extensive acoustic research with general oceanographic observations included was the ship's work in Operation NORLANT, an acoustic propagation and noise experiment that involved aircraft as well as NRL ships Mizar and Hayes and the Norwegian research vessel Sverdrup in the Greenland, Norwegian and Barents seas. In one instance Mizar penetrated the ice pack while Hayes remained in the open sea. The closure of the ice and mechanical problems led to Mizar becoming stuck in the ice pack along with her icebreaker escort USCGC Edisto which also suffered from mechanical problems. Both were freed by USCGC Southwind after some days.

One of the NRL developments deployed on Mizar was the Light Behind Camera (LIBEC) that extended the coverage of deep sea cameras significantly. That system was used to photograph portions of the Mid-Atlantic Ridge during Project FAMOUS.

Searches

Often more public attention was drawn to the ship's searches for sunken ships than to routine research.

Mizar took part in the search operations for Thresher, the Palomares Incident in which nuclear weapons were lost off Palomares, Spain. The ship was engaged in the extended search for USS Scorpion (SSN-589) – which was found in October, 1968. She also took part in searches for foreign wrecks, including Eurydice. In 1969 Mizar was called on to locate the Woods Hole Oceanographic Institute deep submersible Alvin, fellow searcher off Palomares, had sunk in 5,000 ft (1,524.0 m). Mizar lifted the submersible to shallow water. Mizar was not involved, despite speculation, in the search for the Soviet submarines K-129 as the ship was well known to the Soviets and could not operate clandestinely.

Addition of water sampling capability to the search vehicle allowed environmental monitoring as well as location and photography. One example is the ship's monitoring of the scuttled, nerve agent laden, LeBaron Russell Briggs five times between 1970 and 1974. The entire hulk could be photographed and water samples taken close to its deck.

Assignment to undersea surveillance

The Naval Research Laboratory was forced by increasing ship costs to choose between Mizar and the newer Hayes and chose to retain Hayes. In 1975 Mizar came under the technical control of the Naval Electronic Systems Command (NAVELEX) to become part of the "Caesar fleet" supporting the Sound Surveillance System (SOSUS) installation under the unclassified name Project Caesar. A footnote to a table of ships in The Federal Ocean Program dated April 1974 notes that Mizar is funded and operated by NAVELEX and no longer funded as an oceanographic ship.

The ship was assigned to Military Sealift Command Pacific in 1975 and underwent another major modification in 1980.

Disposal

Mizar was withdrawn from active service entering the James River National Defense Reserve Fleet on December 17, 1989. The ship was withdrawn October 24, 1991 for stripping before retruning December 18 awaiting disposal. Bay Bridge Enterprizes, LLC of Chesapeake, Virginia was awarded a $243,900 contract for the dismantling and recycling of Mizar on 21 July 2005.

Biblography

• Bundage, Walter (November 29, 1988). NRL's Deep Sea Floor Search Era (Report). p. 48. Retrieved 23 February 2020.{{cite report}}: CS1 maint: ref duplicates default (link)
• Jones, W. L. (September 17, 1970). USNS Mizar 1979. Washington, D.C.: Naval Research Laboratory. Retrieved 23 February 2020.{{cite book}}: CS1 maint: ref duplicates default (link)
•  This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.
•  This article includes information collected from the Naval Vessel Register, which, as a U.S. government publication, is in the public domain. The entry can be found here.

External links

• USNS Mizar (T-AGOR-11), NavSource Online: Service Ship Photo Archive
• AGOR Numeric List
• USNS Mizar (T-AGOR 11)
• Side view of the towed sled used by the Navy research ship Mizar in the search for the nuclear submarine USS Scorpion (SSN-589).