Natick class
| Natick- class | |
|---|---|
_bow_view.jpg) USS Muskegon (YTB-763) |
|
| Overview | |
| Type | tractor |
| units | 77 built, 19 in service |
| Namesake | Natick , Massachusetts |
| Technical specifications | |
| displacement |
356 ts |
| length |
33.2 meters |
| width |
8.8 meters |
| Draft |
3.95 meters |
| crew |
12 men |
| drive |
1 diesel engine, 1 screw, 2000 hp |
| speed |
12 knots |
The Natick-class , even YTB-760 class called, is a class of tugs (yard tug boats) of the United States Navy . The ships were used in all major bases of the US Navy from 1961, currently the ships are being decommissioned, their tasks are being taken over by civilian tugs. The US Navy only uses its own tugs at a few bases.
history
Development and construction
The Natick-class tugs were designed in the late 1950s to replace the obsolete port tugs used by the Navy, most of which dated back to WWII . The old tugs were overwhelmed with the larger ships, so the Navy designed a class of new harbor tugs. The plans were completed on June 16, 1960, the construction contract for the first ship, the USS Natick (YTB-760) , was issued on June 29, 1960 to the Jakobson Shipyard in Oyster Bay , New York . A total of six shipyards were commissioned to build the 77 ships, most of the tugs were built at Marinette Marine Shipyard in Marinette and Peterson Shipbuilders in Sturgeon Bay , Wisconsin . The last ship of the class, the USS Pokagon (YTB-836) , launched at Marinette Marine on April 9, 1975.
designation
The ships of the class were named after locations in the United States and after various Indian tribes. The type ship was named after the place Natick in Massachusetts .
Present and Future
Because of the high operating costs, which result mainly from the large crew of the tugs, the US Navy has been awarding the contracts for tug operations in its bases to private operators since 1998, resulting in savings in the millions. The tenders made many of the tugs redundant; 17 ships are currently still active, most of them on the west coast and on the Pacific bases of the United States. However, these ships are also to be decommissioned in the future and their tasks will be taken over by civilian tugs. Most of the decommissioned ships were either sold or scrapped, with a few remaining in the reserve fleet.
technology
Hull and superstructure
The hull of a Natick-class tug is 33.2 meters long and 8.8 meters wide. The draft is 3.95 meters, the displacement is 356 ts when loaded . The bow stem is raised and reinforced, and it is also provided with fenders . The front half of the ship is occupied by the deckhouse, which houses the crew quarters including the washroom and galley. The wheelhouse is on the deckhouse, the chimney is behind the wheelhouse. The mast on which the navigation radar and position lights are located can be folded down to the rear. There are several bollards and rope guides on the flat aft deck.
drive
It is driven by a single diesel engine with 2200 hp , which transfers its power to a single screw with a diameter of 3.65 meters via a reduction gear. The maximum speed is 12 knots , the pulling force is 45 tons. It is controlled by a single, electrically controlled rudder. Two 60 kW generators generate electricity for the tractor's 12V / 24V electrical system.
_spraying_water.jpg)
Equipment and crew
On the aft deck of the tug there is a capstan with an electro-hydraulic drive and a load capacity of four tons for the towing gear. There are also two winches and hoists for rescue operations on board. On some ships, a small crane was also attached to the chimney.
The ships also have an extinguishing pump with a pumping capacity of 7570 liters per minute, which feeds two extinguishing monitors in front of and behind the bridge with a pressure of 10 bar. In addition, there are two tanks on board, each with 2800 liters of foam concentrate for generating fire-fighting foam . Another pump with a capacity of 7570 liters per minute can be used to pump out seawater that has penetrated. Two compressors generate compressed air with a pressure of 17 bar.
The crew, which consists of four officers and eight crew ranks, has a fully equipped galley with freezer, a cabin with bunks for each crew member and a wet room with shower and toilet. In the first ships, the cabin was heated by means of an oil boiler, and from 1972 the ships were equipped with electrical heating.
_out_of_drydock.jpg)
commitment
The Natick-class tugs were used on all major US Navy bases around the world. They accompanied ships in and out of the harbor, helped with mooring and maneuvering in the narrow waters.
The tugs were also used in salvage and rescue operations in the port area and in coastal waters, and in some cases they were also used on the high seas for towing and maneuvering unpowered or damaged ships. Most of the time, however, the ships stayed in their traditional home ports.
Web links
- Natick class at globalsecurity.org
- Pictures, mission data and crew lists of all tugs at navysite.de (English)
Individual evidence
- ↑ a b globalsecurity.org , as of January 25, 2007
- ↑ navysite.de ship list, as of April 9, 2012