The contract for the first four Powhatan-class tugs was awarded to Marinette Marine Co. on 12 September 1975. The contract price for the four ships was $30.5 million.[1]Navajo was the fourth ship built under this initial contract award. The ship was laid down on 14 December 1977 at the company's Marinette, Wisconsin shipyard. Navajo was launched on 20 December 1979, and delivered to the Navy on 13 June 1980.[2]
Her hull was built of welded steel plates. She was 225 feet 11 inches (68.86 m) long at the waterline and 240 feet 1 inch (73.18 m) overall, with a beam of 42 feet (13 m), and a draft of 15 feet (4.6 m). She displaced 2,260 tons fully loaded.[3]
As originally built, Navajo had two controllable-pitchKort-nozzle propellers for propulsion. She had two 20-cylinder Diesel engines, GM EMD 20-645F7B,[4] which provided 4,500 shaft horsepower. These would drive the ships at 15 knots. She also had a 300-horsepower bow thruster to improve maneuverability.[3][5]
Electrical power aboard the ship was provided by three 400 Kw generators. These were powered by four Detroit Diesel 8v-71 engines.[4]
Powhatan-class tugs had global range in order to support the U.S. fleet across oceans. Navajo's tankage was consequently large. She could carry 206,714 U.S. gallons (782,500 L) of Diesel oil, 6,100 U.S. gallons (23,000 L) of lube oil, and 6,000 U.S. gallons (23,000 L) of drinking water.[4] Her unrefueled range at 13 knots was 10,000 miles (16,000 km)[3]
Navajo's aft deck was largely open to accommodate a number of different roles. It had 4,000 square feet (370 m2) of working space.[6] One of the missions of a fleet tug was to tow damaged warships back to port. She was equipped with a SMATCO 66 DTS-200 towing winch for service as a towboat.[4] The towing system could accommodate either wire rope or synthetic-fiber hawsers and produce as much as 90 short tons of bollard pull.[7][8][6] She had a 10-ton capacity crane for moving loads on the aft deck.[5] There were connections to bolt down shipping containers and other equipment.
Like all MSC ships, Navajo was crewed by civilian mariners. At launch, her complement was 16 civilian crew and a 4-person military detachment of communications specialists. The ships could accommodate an additional 16 people aboard for transient, mission-specific roles.[3][5]
All the ships of the Powhatan-class were named after Native American tribes.[8]Navajo was named after the Navajo people, of the United States southwest.
Service history
Navajo tows ex-Belleau Wood from Pearl Harbor for RIMPAC 2006
An engine room fire disabled USNS Taluga northwest of San Diego in April 1981. Navajo was dispatched to bring her back to port.[9] On 10 June 1981, Navajo, took USNS Hudson under tow. She was dead in the water off San Nicholas Island at the time.[10]
The large, open aft deck of the Powhatan-class tugs, combined with the 10-ton crane made them capable platforms for salvage missions. Navajo was called upon several times in this role. In July 1988 she assisted in the recovery of a MH-53E Sea Dragon helicopter which crashed off San Francisco.[11] In 2016 she assisted USNS Salvor in recovering the wreckage of two MH-53E helicopters that crashed off Hawaii.[12]
Navajo was used as a dive platform in a joint US Navy/Indian Navy salvage exercise, SALVEX 2009, in November 2009.[16]
In December 2010 and January 2011, the Navy's deep-ocean recovery system CURV-21 was embarked on Navajo. She was able to determine that a deep water sensor was not stuck on its anchor on the sea bottom at more than 16,000 feet (4,900 m) deep. In a second mission, she was unable to locate an Air Force asset.[17]
On 28 July 2012 the ship was conducting training near the entrance to Pearl Harbor, Hawaii when a parted mooring line caused the ship to dump 8,000 pounds of expensive anchor, chain, and heavy rope on the ocean floor 150 feet below. The equipment was recovered on 9 August 2012.[19]
In May 2016, Navajo towed the missile tracking barge Mobile Area Targeting Support System (IX524) into Pearl Harbor.[20]
Decommissioned ship tows
Vessels which are retired from Navy service are often towed to various inactive ship maintenance facilities where they are held in reserve. Ultimately, they are towed on to their final fate. These decommissioned ships do not have full crews and cannot sail under their own power. Navajo was frequently employed to tow decommissioned ships.
"Rim of the Pacific" (RIMPAC) is a multinational naval exercise hosted every two years in Hawaiian waters. It typically includes a live-fire exercise during which a decommissioned ship is sunk. Navajo towed several of these vessels on their final voyage, and has participated in other RIMPAC exercises as well.
RIMPAC 2012: She towed ex-Kilauea from San Francisco to Hawaiian waters where she was sunk. She also served as a dive platform for Royal Australian Navy divers.[38]
USNS Navajo was deactivated and stricken from the naval vessel register on 1 October 2016.[2] After deactivation Navajo was moored at Pearl Harbor pending final disposition.[42]
^ abcdPolmar, Norman (1997). Ships and Aircraft of the United States Fleet (16th ed.). Annapolis, Maryland: Naval Institute Press. p. 252. ISBN1-55750-686-8.
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