(United States)

Notes: Originally three (possibly four) of these submarines were to be transferred as part of the Shah’s naval buildup, to be joined by German-built Type 209 units. At the time of the revolution, Kousseh had recommissioned (but not yet departed the United States), Nahang was nearing her turnover date, and the unnamed ex-Tang’s crew was in training. On the morning of 12 March 1979, a USN shore patrol at New London Submarine Base, CT, found the Kousseh abandoned and the crews’ Imperial Iranian uniforms in a dumpster on the pier. The entire crew was Royalist politically, and apparently feared returning to Iran. They melted into the American population. Kouseeh was technically Iranian property but the United States had no intention of giving it to the Islamic government, and it was held up in court for a number of years, meanwhile sitting in limbo at NISMF Philadelphia. Eventually a settlement was reached and the sub was repossessed by the USN. Nahang was cannibalized to support the Italian and Turkish Tang-class units.

IINS Kousseh’s wardroom silver service is quietly displayed in a hallway at the Naval Submarine School in New London; perhaps the last tangible reminder of this interesting bit of submarine history.

Notes: Transferred by lease.

Notes: These subs were originally transferred by lease and then sold outright in 1987.

General Notes: Although they were not the final diesel-powered submarines in the USN, the Tang class is often considered the finest. They incorporated all the lessons learned from the GUPPY class conversions and captured German WWII U-boats. They were streamlined, quiet, and optimized for deep-ocean warfare (In 1952, USS Tang became the first USN sub to exceed 700‘). They could also use their batteries in the “DC series” mode, enhancing their underwater performance.

The Tangs were to be centered on the “pancake engine”; a stacking of four diesels arranged radially (as in aircraft engines) turning a common vertical crankshaft. The entire “pancake” weighed 34 tons and the vertical arrangement freed up an entire compartment in the submarine. Unfortunately the “pancake” arrangement was a failure and in 1956-1958 the first four units were sent into drydock, cut in half, and re-engined with traditional diesels in a 9‘-long hull extension. The final pair were built longer with the new arrangement from the start. This basic hullform would later be used on the Sailfish class submarines.

(above: USS Trout with the original sail and before the hull extension and engine change out.)

The forward tubes utilized an experimental “water slug” launching method; which was safer than swim-out method, and, did not leave a telltale bubble after firing like the old air-impulse method. This method was extremely successful and every single USN submarine built thereafter has utilized it. (The stern tubes were of the old swim-out variety.) In 1971, USS Trigger became the first sub in the fleet to carry the then-new Mk48 torpedo.

(Top: The AN/BQS-4 console on USS Tang, next to the twin reels of the AN/UNQ-7 recorder. Bottom: The aft torpedo room of TCG Pirireis in 2004; by this time the aft tubes had been deactivated and the space used for crew storage.)

In 1959, USS Trout set a USN diesel sub record by sailing 268NM submerged under the arctic ice (the snorkel deicer used on this mission later became standard for USN submarines). Trout had an interesting story later on; she was slated to be transferred to Iran, which never happened (see above). After being repossessed by the USN, she sat at NISMF Philadelphia for many years before being transferred to NAS Key West, FL for conversion into an unmanned ASW target. In the end, funding was never found for the conversion and ex-Trout was towed back to Philadelphia were a group of submarine veterans tried to restore her. The restoration fell through and many websites in 2007 stated that the USN had Trout scheduled for scrapping/SINKEX; however as of April 2008 she is still listed as “available for museum donation” on the Naval Vessels Register.

(ex-USS Trout under tow.)

In 1967, the Tangs underwent a final major overhaul which saw the installation of a taller, streamlined fibre-glass sail, a revised internal arrangement, battery replacement, and new sensors including the three PUFFS “shark-fin” arrays. To accommodate the aft PUFFS array, the external (non-pressure) hulls were slightly elongated.

COMBAT USAGE: USS Wahoo earned three battle stars during the Vietnam War and USS Tang four, although neither is known to have actually engaged in combat.

Displacement: originally: 1560t surfaced, 2260t submerged later: 2050t surfaced, 2700t submerged Dimensions: originally: 268’x27’17’ later: 302’x27’x17’1” Machinery: Diesel-electric: originally: 4 General Motors 16-338 diesels, 2 2530H electric motors (+ 4 36PS11B 126-cell lead-acid batteries), 2 shafts later: 3 Fairbanks-Morse 38D8 diesels, 2 2530H electric motors (+ 4 36PS11B 126-cell lead-acid batteries), 2 shafts Max speed: 15.5kts surfaced, 8kts snorkeling, 18.3kts submerged Range: 10,000NM @ 10kts surfaced, 19NM @ 17kts submerged on battery Diving depth: 700’ test, 900’ crush Complement: 83 (8 officers, 75 enlisted)

(above: a battery cell from USS Tang)

x8 (x6 fwd, x2 aft) 21” tubes for twenty-two total weapons:

Fwd tubes: Mk14, Mk18, Mk35, Mk37, Mk45 ASTOR, Mk48 torpedoes, or, Mk49 and Mk57 mines

Aft tubes: Mk27, Mk28, Mk37 torpedoes