USS Aspro (SS-309)

USS Aspro (SS-309) during World War II
Overview
Shipyard	Portsmouth Naval Shipyard , Kittery , Maine
Keel laying	December 27, 1942
Launch	April 7, 1943
1. Period of service
period of service	July 31, 1943-30. January 1946 and September 23, 1951-30. April 1954
Whereabouts	in reserve until 1962; deleted on September 1, 1962; sunk on November 16, 1962 (as a target for the USS Pomodon (SS 486) )
Technical specifications
displacement	1526  ts surfaced 2424 ts surfaced
length	95.0 meters
width	8.3 meters
Draft	5.1 meters (maximum)
Diving depth	120 meters
crew	10 officers , 70 NCOs and men
drive	4 × 1350 PS diesel engines (total 5400 PS) 4 × electric motors (total 2740 PS)
speed	Surfaced 20.25 knots surfaced 8.75 knots
Range	11,000  nautical miles at 10 knots
Armament	10 × 53.3 cm torpedo tubes (6 in the bow; 4 in the stern) 1 × 12.7 cm (5 inches) gun (1945: 2 × 12.7 cm (5 inches)) 1 × 4.0 cm Bofors FlaK 1 -2 x 20 mm Oerlikon MK

The USS Aspro (SS / AGSS-309) was a US Navy submarine . It belonged to the Balao class and, like all other boats in the class, was named after a fish. Aspro is the English name for the genus of the spindle perch ( Zingel ).

Technology and armament

The Aspro was a diesel-electric patrol submarine of the Balao class, which was only slightly improved compared to the Gato class . In particular, the diving depth has been increased and the interior has been improved based on experiences during the war against Japan . Outwardly and in their dimensions, the boats of both classes were largely the same.

technology

The Aspro was 95 meters long and 8.3 meters wide, the maximum draft was 5.1 meters. When surfaced it displaced 1526 ts , and when submerged it displaced  2424 ts. The drive was carried out by four nine-cylinder diesel - opposed piston engines of Fairbanks-Morse , Model 38D8-1 / 8, which generated an output of 1000 kW. Under water, the submarine was powered by four electric motors with a total of 2740 hp, which obtained their energy from two 126-cell accumulators . The motors gave their power via a gearbox on two shafts with one screw each. The maximum surfaced speed was 20.25 knots , submerged the Aspro managed 8.75 knots. The maximum possible diving time was 48 hours, the construction diving depth was around 120 meters. 440 cubic meters of diesel fuel could be stored in the fuel tanks , giving the boat a range of 11,000 nautical miles at 10 knots.

Armament

The main armament of the Aspro consisted of ten 533 mm torpedo tubes , six of them in the bow and four aft, for which 24 torpedoes were on board, during the war usually Mk-14 torpedoes, from summer 1944 also increasingly Mark 18- and Mk-23 torpedoes. Behind the turret was a 12.7 cm deck gun , 25 caliber long. A 40 mm anti -aircraft gun was mounted in front of the turret and a 20 mm MK behind the turret. In addition, two to three 7.62 or 12.7 mm machine guns were carried, but their installation and use for this boat has not been proven. If necessary, these light weapons could be flexibly mounted at several points - especially on the tower (submarine) or the winter garden - and were otherwise stowed in the boat.

During a stay in the shipyard in 1945, a 12.7 cm gun was installed in front of the tower to strengthen the combat strength. In addition, the 20 mm MK was replaced by a double mount of the same caliber.

To locate enemy ships ordered the Aspro a JK / QC - and a QB - sonar under the bow, on deck were JP - hydrophones installed. On extendable electronics mast was a SD - radar with 20 mile range reconnaissance to locate enemy aircraft attached, in addition, the submarine had a SJ -Oberflächensuchradar with about twelve nautical miles range. When submerged, enemy ships could also be located using the ST radar attached to the periscope with a range of eight nautical miles.

history

The Aspro was launched on April 7, 1943 and christened by Mrs. William L. Freseman . It was commissioned on July 31, 1943. The commandant of the Aspro was Harry Clinton Stevenson , at the time of commissioning he held the rank of Lieutenant Commander .

Second World War

After sea trials and the first training runs off the coast of New England , the Aspro was commanded to Pearl Harbor , where she entered on October 18. After further training trips off Pearl Harbor, the boat left for the first patrol on November 24th.

First patrol (November 24, 1943 - January 1, 1944)

The area of ​​operation of the USS Aspro during the first war patrol were the waters off Formosa and the Sakishima Islands , southwest of the main Japanese islands . On the march into the operational area, the boat stopped briefly at Midway to replenish fuel and supplies.

The patrol was immediately resumed and, after the destruction of a floating Japanese sea mine on December 4, the Aspro was the first to attack on December 15 when it sighted a convoy consisting of a tanker and two freighters accompanied by two warships . The attack was carried out with four torpedoes from the bow tubes and resulted in a hit and damage to the tanker. There were no further attacks or successes.

On the night of December 17-18, the Aspro sighted a large Japanese convoy, consisting of 15 ships, which the submarine attacked twice. In the first attempt, Aspro fired five torpedoes which, according to the crew, hit a tanker and a freighter. On the second attempt some time later, four more torpedoes were fired, which hit two other ships. In total, the crew of the Aspro claimed three sinks and another heavily damaged ship that was towed. Subsequent counterattacks by the Japanese destroyer Shiokaze survived the Aspro unscathed.

On December 27, the Aspro unsuccessfully attacked a Japanese cargo ship with four torpedoes. With only one torpedo left on board, the commander decided to return to Midway, where the submarine's first combat mission ended on January 1, 1944.

The three sinks claimed by the Apogon's crew could not be verified when analyzing Japanese documents after the war.

The previous commander, Lieutenant Commander Harry Clinton Stevenson, was declared unsuitable for use on a submarine during an examination of his eyes after the end of the first mission and was forced to relinquish command of the Aspro . He himself proposed his brother Lieutenant Commander William A. Stevenson as his successor. He was appointed the new commander of the USS Aspro by the Admiralty .

Second patrol (February 3, 1944 - March 28, 1944)

With the new commander, the Aspro first sailed from Midway in the direction of Pearl Harbor on January 15 , where a short training phase followed. On February 3, the Aspro ran out for the second patrol, which took her first to Midway and from there to the operational area in the sea area north of Truk , where the boat was operating as part of Operation Hailstone . On February 15, 1944, after a long pursuit, she was able to attack the Japanese submarine I-43 with four torpedoes. Two hits led to the sinking of the Japanese submarine, with which the Aspro achieved its first confirmed success.

On February 17, the Aspro was attacked by Japanese units with depth charges, but suffered no damage and continued the patrol. After two uneventful weeks, another opportunity arose on March 4 for the Aspro to attack a Japanese freighter. Of six torpedoes fired, only one hit the target and caused an explosion. However, the ship hit was able to continue its voyage. The Aspro remained in the area of ​​operation for some time and ended its mission in Pearl Harbor on March 28th after 54 days.

Third patrol (April 22, 1944 - June 16, 1944)

On April 22nd, the submarine left for the third patrol. The area of ​​application was the sea area around Palau . After a short stop on Midway, the Aspro reached Palau. A convoy consisting of two freighters and three warships was sighted there on May 13th. The sister ship USS Balao (SS-285) , which operates in the same sea area, was also in contact with this convoy, but was initially prevented from a successful attack by the escorts. However, this distracted the guards and so the Aspro launched the first attack with four torpedoes. This remained inconclusive. At dawn, the second attack took place again with four torpedoes, one of which hit one of the two freighters in the convoy. The ship sank slowly and went out of sight after about two hours. The sinking of the Bisan Maru (4,667 ts) was not officially confirmed by the Joint Army-Navy Assessment Committee after the war . The Aspro chased the convoy until late the following night and was again in a favorable attack position on the night of May 15. The following attack was aimed at the transporter Jokuja Maru (6440 ts). Two out of four torpedoes fired hit the target. Four more torpedoes were later fired and the Jokuja Maru was finally sunk. After another month in the operational area, this war patrol ended on June 16, 1944 in Fremantle , on the west coast of Australia .

Ultimately, the Aspro was awarded a sinking and participation in a further sinking with a total of 8,650 ts.

Fourth patrol (July 9, 1944 - August 18, 1944)

On July 9, 1944, the next patrol began, that of Fremantle first to Darwin and from there on to the area of ​​operations in the South China Sea . West of Luzon , Philippines , the Aspro made out a Japanese convoy on July 19, consisting of four medium-sized transport ships and five escort ships . At dawn, the boat attacked and fired a total of 10 torpedoes at three ships. Explosions were heard. A sinking and a damaged ship were claimed. There was no official confirmation.

The following day (July 18), the Aspro attacked another convoy of three ships. No hits could be achieved. On July 28th, the Aspro had more success when she successfully torpedoed a Japanese ship lying aground. All three torpedoes hit and destroyed the armed transport ship Peking Maru (2,288 ts).

On August 6, the handle Aspro two without escort of driving Japanese freighter, one of which was hit with a 15 ° list could go on. The following day, August 7th, a convoy of twelve ships came into view and was also attacked. Another freighter was torpedoed. A sinking could not be confirmed in either case. The Aspro then returned to the Fremantle base, where it arrived on August 18 and was then prepared for its next mission.

Fifth patrol (September 10, 1944 - October 14, 1944)

On September 10, 1944, the Aspro ran out on its fifth war patrol . From Fremantle it led its way past the Dutch East Indies and the Philippines into the South China Sea. Shortly before reaching the operational area, the Aspro located a convoy of seven or eight transport ships and four escort ships northeast of Luzon on September 30 . Aspro attacked while driving and fired six torpedoes at the convoy. The crew claimed two hits as well as the severe damage to the torpedoed Japanese freighter. The west-facing convoy was pursued for two days and on October 2, the Aspro attacked again west of Luzon. The target of the four torpedoes fired was a tanker that was hit and, after a few minutes, protruded with the stern under water and the bow up. However, the sinking of the tanker was not officially confirmed. The Japanese passenger cargo ship Azuchisan Maru (6886 ts), torpedoed and subsequently sunk about an hour later , was not able to verify its sinking.

In the period that followed, the Aspro formed a coordinated submarine group with the sister ship Cabrilla and half-sister Hoe , known in English as the Wolfpack . This submarine group sighted a larger convoy with at least twelve ships on October 7th, of which the Aspro attacked a freighter with four torpedoes using radar at dawn on October 7th and inflicted three hits. The Macassar Maru (4026 ts) sank as a result of the hit. The day before on October 6th, the Aspro launched an attack on a cargo ship, during which a hit was observed from three torpedoes fired. The hit damaged the enemy ship.

The successful patrol ended when we reached the base on Saipan on October 14, 1944. From there the boat then drove to Pearl Harbor, where it entered on October 25. Of the four claimed sinkings, only one ( Azuchisan Maru on October 2) could be confirmed.

Sixth patrol (December 13, 1944 - February 11, 1945)

On November 21, the Aspro started on a transfer trip to Saipan, from where the sixth patrol was to be undertaken. On November 28, however, one of the ship's generators was damaged, the repair of which made it necessary to return to Pearl Harbor. After a week the repairs were done and the boat was ready for use again, so that it could leave for the sixth patrol on December 13th. The main task was to take up a position from January 3rd west of the island of Formosa to support the air forces of the US Navy aircraft carriers operating there . While the Aspro was taking position, she attacked Japanese ships that were sighted on January 2nd, 5th and 6th, 1945. Of ten torpedoes fired in the process, only three found their target, damaged a Japanese ship on October 2 - Shinshu Maru (8170 ts), sunk the following day by carrier aircraft from Task Force 38 - and also claimed the sinking of a previously damaged tanker. The latter could not be verified.

The Aspro fulfilled its main task during the mission, rescuing crashed aircraft crews , by rescuing a total of four naval aviators from the sea. The mission ended without any further enemy contact on February 11, 1945 in Pearl Harbor. Following this mission, the Aspro continued to the west coast of the United States, where it was overhauled in the Hunter's Point Naval Shipyard . Meanwhile, the Aspro was equipped with a second 12.7 cm L / 25 on-board gun to increase combat effectiveness in surface combat. With the end of the work on May 31, the Aspro moved back to Pearl Harbor, from where she sailed under a new commander for her last war patrol.

Seventh patrol (June 25, 1945 - August 13, 1945)

Under the new commander, Lieutenant Commander James H. Ashley, Jr. , the submarine left the Pearl Harbor base on June 25, 1945, heading for the sea area south of the main Japanese islands . Once again, the boat was primarily intended to rescue aircraft crews who had been shot down or crashed at sea. For this purpose, Aspro, initially patrolling south of Japan , took up position not far from the Japanese main islands from July 8, while US Air Force aircraft operated from Okinawa against targets in Japan. From July 20, the Aspro repositioned itself in order to support and secure air strikes by carrier-based aircraft of the US Navy on targets in the south of the island of Honshu in the same way . On August 3, in a daring operation, accompanied by repeated Japanese air strikes, the Aspro rescued a US Navy pilot from Sagami Bay about 40 km southwest of Tokyo , approaching within a few kilometers of the Japanese coast.

Only one opportunity to attack a Japanese ship arose during the Aspro's last patrol in the Pacific . On July 25, the Aspro reported the sinking of a tug from a torpedo hit. After the war, this could not be verified by Japanese sources.

On August 13, 1945, the last military mission of the USS Aspro ended in Midway. On September 1, the submarine left Midway for California , where it reached San Francisco on September 11 and the boat was prepared for decommissioning. On January 30, 1946, the boat was officially handed over to the Pacific Reserve Fleet in Mare Island , where it was mothballed with about 50 other submarines.

post war period

Since the end of January 1946, the USS Aspro was mothballed as part of the reserve fleet in Mare Island, California, where it was maintained so that it could be reactivated and used again if necessary.

Korean War

On July 6, 1951, the USS Aspro was put back into service due to the Korean War and operated off the west coast of the United States for the next two years, performing routine tasks before moving back to Mare Island on November 9, 1953, where it was relocated to Mare Island on November 30, 1953 April 1954 was decommissioned again and transferred to the reserve fleet.

Cold War

On May 5, 1957, the USS Aspro was reactivated and incorporated into the Pacific Fleet on June 8. Again she took on routine duties off the west coast of the United States. In January 1960, the Aspro was overhauled in San Diego and on July 1, 1960, the Aspro was reclassified as an auxiliary submarine (AGSS), which also resulted in a change in its official name from SS-309 to AGSS-309 . After two more years of service in the Pacific Fleet, the Aspro was decommissioned on September 19, 1962 and deleted from the US Navy shipping register on October 9.

Awards

For its missions during the Second World War, the USS Aspro was awarded a total of seven Battle Stars .

Use as a film set

For the feature film Battle of the Coral Sea , the Aspro interrupted its routine tasks for some time in 1959. Some scenes of the film were shot on board the submarine. To do this, the submarine moved again to the western Pacific for a few weeks.

Whereabouts

On November 16, 1962, the sunken Pomodon as part of a weapons testing by an improved Mark-37 torpedoes the Aspro as a target ship off the coast of California.

Web links

• Aspro at uboat.net (engl.)
• Aspro in the Dictionary of American Naval Fighting Ships (DANFS )
• The Balao class on fleetsubmarine.com
• Aspro in the World War II Database
• History of Aspro I (SS-309) in the Dictionary of American Naval Fighting Ships (English)
• JANAC list verified success of submarines of the US Navy (ed. By the Joint Army-Navy Assessment Committee (JANAC)) (Engl.)
• Attack data of Submarine Operations Research Group (SORG) for Aspro (Engl.)
• Submarine armament on fleetsubmarine.com (engl.)
• US Navy History 1943 (Engl.)
• Confirmed sinkings of Aspro (Engl.)

Footnotes

1. ^ ^{A b c d e} Norman Friedman: US Submarines Through 1945: An Illustrated Design History . United States Naval Institute, Annapolis, Maryland 1995, ISBN 1-55750-263-3 , pp. 285-304.
2. ↑ ^{a b c d e f g} K. Jack Bauer, Roberts, Stephen S .: Register of Ships of the US Navy, 1775–1990: Major Combatants . Greenwood Press, Westport, Connecticut 1991, ISBN 0-313-26202-0 , pp. 275-280.
3. ^ ^{A b c d e} Norman Friedman: US Submarines Through 1945: An Illustrated Design History . United States Naval Institute, Annapolis, Maryland 1995, ISBN 1-55750-263-3 , pp. 305-312.
4. ↑ ^{a b c d e f} USS Apogon at navsource.org.
5. ^ Lenton, HT, American Submarines. Garden City, New York: Doubleday, 1973, passim.
6. ↑ ^{a b c d e f g} USS Aspro at uboat.net.
7. ↑ ^{a b c d e f g h i j k l m n o p q r s t u v w} USS Aspro in the Dictionary of American Naval Fighting Ships
8. ↑ Submarine armament on fleetsubmarine.com
9. ↑ The Balao Class on fleetsubmarine.com
10. ↑ ^{a b c d e f g h i j k l m n} Attack data from the Submarine Operations Research Group (SORG) for USS Aspro .
11. ^ Robert Cressman: Chapter V: 1943 . In: The official chronology of the US Navy in World War II . Naval Institute Press, Annapolis, Maryland 2000, ISBN 978-1-55750-149-3 , OCLC 41977179 (Retrieved December 18, 2012).
12. ↑ ^{a b c d e f g h i j k} JANAC list verified success of submarines the US Navy (ed. By the joint Army-Navy Assessment Committee ).
13. ↑ Blair, Clay, Jr. Silent Victory . Bantam, 1976, p. 647.
14. ↑ Bob Hackett, Kingsepp, Sander: HIJMS Submarine I-43 : Tabular Record of Movement . In: Sensuikan! . Combinedfleet.com. 2009. Retrieved July 22, 2009.
15. ↑ ^{a b c d e f g} USS Aspro at fleetsubmarine.com.