USNS Walter S. Diehl

USNS Walter S. Diehl (T-AO-193) is a Henry J. Kaiser-class replenishment oiler of the United States Navy. She was named after Captain Walter Stuart Diehl, USN, a career naval officer and aeronautical engineer.

USNS Walter S. Diehl (T-AO-193) in 2019
History
United States
Name	USNS Walter S. Diehl
Namesake	Walter Stuart Diehl (1893–1976), a U.S. Navy officer and American pioneer of aerodynamics and aircraft design
Ordered	28 June 1985
Builder	Avondale Shipyard, Inc., New Orleans, Louisiana
Laid down	7 August 1986
Launched	2 October 1987
Christened	10 October 1987
In service	13 September 1988
Out of service	1 October 2022
Identification	IMO number: 8511495 MMSI number: 367222000 Callsign: NWSD
Status	out of service, in reserve
General characteristics
Class and type	Henry J. Kaiser-class replenishment oiler
Type	Fleet replenishment oiler
Tonnage	31,200 deadweight tons
Displacement	9,500 tons light Full load variously reported as 42,382 tons and 40,700 long tons (41,353 metric tons)
Length	677 ft (206 m)
Beam	97 ft 5 in (29.69 m)
Draft	35 ft (11 m) maximum
Installed power	16,000 hp (11.9 MW) per shaft 34,442 hp (25.7 MW) total sustained
Propulsion	Two medium-speed Colt-Pielstick PC4-2/2 10V-570 diesel engines, two shafts, controllable-pitch propellers
Speed	20 knots (37 km/h; 23 mph)
Capacity	178,000 to 180,000 barrels (29,000 m3) of fuel oil and jet fuel 7,400 square feet (690 m2) dry cargo space; eight 20-foot (6.1 m) refrigerated containers with room for 128 pallets
Complement	103 (18 civilian officers, 1 U.S. Navy officer, 64 merchant seamen, 20 U.S. Navy enlisted personnel)
Armament	Peacetime: .30 cal GPMG & .50 cal heavy machine guns Wartime: ×1 (or more) 20-mm Phalanx CIWS
Aircraft carried	None
Aviation facilities	Helicopter landing platform
Notes	Five refueling stations Two dry cargo transfer rigs

Design

The Henry J. Kaiser-class replenishment oilers were preceded by the shorter Cimarron-class fleet replenishment oilers. Walter S. Diehl has an overall length of 206.5 metres (677 ft 6 in) and a beam of 29.7 metres (97 ft), with a draft of 11 metres (36 ft). The oiler has a displacement of 41,353 tonnes (40,700 long tons; 45,584 short tons) at full load. It has a capacity of 180,000 imperial barrels (29,000,000 L; 6,500,000 imp gal; 7,800,000 US gal) of aviation fuel or fuel oil. She can carry a dry load of 690 square metres (7,400 sq ft) and can refrigerate 128 pallets of food. The ship is powered by two 10 PC4.2 V 570 Colt-Pielstick diesel engines that drive two shafts; this gives a power of 25.6 megawatts (34,800 PS; 34,300 shp).

The Henry J. Kaiser-class oilers have maximum speeds of 20 knots (37 km/h; 23 mph). They were initially built without armaments, but are equipped with small arms and can be fitted with close-in weapon systems if required. The ship has a helicopter platform but not any maintenance facilities. Walter S. Diehl is fitted with five fuelling stations; these can fill two ships at the same time and the ship is capable of pumping 900,000 US gallons (3,400,000 L; 750,000 imp gal) of diesel or 540,000 US gallons (2,000,000 L; 450,000 imp gal) of jet fuel per hour. She has a complement of 89 civilians (nineteen officers), 29 spare crew, and 6 United States Navy crew.

Construction and delivery

Walter S. Diehl, the seventh ship of the Henry J. Kaiser-class, was laid down at Avondale Shipyard, Inc., at New Orleans, Louisiana, on 7 August 1986 and launched on 2 October 1987. She entered non-commissioned U.S. Navy service under the control of the Military Sealift Command with a primarily civilian crew on 13 September 1988.

Service history

Walter S. Diehl was assigned to the United States Pacific Fleet, serving in the Pacific Ocean, Indian Ocean, and Persian Gulf regions.

On 23 April 2008, Walter S. Diehl was passing through the Strait of Hormuz when six small motorboats sped alongside in an aggressive and threatening manner. Walter S. Diehl fired flares to warn the boats off, but they did not move away. She then opened fire with a .50-caliber (12.7-mm) machine gun and the boats sped off.

On 20 November 2014, Walter S. Diehl collided with the USNS Amelia Earhart (T-AKE-6) during an underway replenishment operation. No injuries were reported.

She was taken out of service and placed in reserve on 1 October 2022.

References

•  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

• NavSource Online: Service Ship Photo Archive: USNS Walter S. Diehl (T-AO-193)
• USNS Walter S. Diehl (T-AO 193)
• Wildenberg, Thomas (1996). Gray Steel and Black Oil: Fast Tankers and Replenishment at Sea in the U.S. Navy, 1912–1995. Annapolis, Maryland: Naval Institute Press. Retrieved 28 April 2009.