Story prepared from the statements of Augusto Zimmermann Zavala and others, appears on the website:
http://boletinmaritimo.blogspot.com/2018/09/efemerides-maritimas-y-navales_75.html
It is basically the same account as Vice Admiral A.P. Federico Espinosa Espinosa but with the following peculiarities:
First.- The incident places him in the year 1971; that is, a year later.
Second.- The incident places it further south, at the height of the port of Ilo.
Conclusion: The story provides data that complements the story of Vice Admiral A.P. Federico Espinosa. In historical research the fact that slightly different dates and/or places are found for the same event does not invalidate the story; however, first source/eyewitness testimony is considered has more weight.
Ilo Naval Combat (1971)
Peruvian Navy severely damages a Chilean Navy submarine
In the 70's (1970-1979) Peru and Chile were experiencing a time of tension, a kind of cold war where the first serious incident occurred in 1971, when a Chilean submarine entered Peruvian territorial waters between the towns of Ilo and Matarani.
Indeed, in 1971, the Destroyer/Destroyer Escort D-2/DE-62 B.A.P. Aguirre (ex USS Waterman DE-740) [B.A.P. Aguirre 1st (1951–1974) Cannon class] and the DD-71 Destroyers B.A.P. Villar (Fletcher-class) (ex-USS Benham DD-796 ) and DD-72 B.A.P. Admiral Guise (Fletcher-class) (ex USS Isherwood DD-520 ), They were on an (Anti-Submarine Warfare) ASW operation in the south of the country, with three submarines from the squadron off the port of San Juan. The exercise was carried out between 0900 and 1030 hours. Once finished, returning to the port the oldest Officer of the surface fleet aboard the B.A.P. Guise recounts the actions with the commanders of the participating ships, in which he reports that three submarines were detected detailing their position, but it was further reported that one of which did not acknowledge receipt of impact during the simulated attacks.
B.A.P. Almirante Guise (DD-72)
© wikipedia
The positions were compared with the participating submarines, and they found that one of the submarines in the squadron was never detected because it was in a position north of the area where the operations were carried out, that is, specifically, there were four submarines in the area of the exercise.
The commander of the exercise ordered to head south in search of the strange submarine, for which they arranged different search sectors for the ships in order to find it, meanwhile, the admiral in charge of the exercise informed Lima of what had happened, requesting authorization. for the use of depth charges against the submarine in case it was found. The order did not take long to arrive and it was so that almost at the height of the port of Ilo, the B.A.P. Villar detected an unidentified ship and reported to the group commander "effective submarine contact under the ship".
B.A.P. Villar (DD-71)
© wikipedia
They proceeded according to international conventions urging them to emerge, however the submarine ignored them. A depth charge was launched as a warning for the submarine to surface, but the submarine again declined the invitation.
There being no response, the B.A.P. Villar proceeded to drop depth charges at different depths with the intention of bringing him down, the actions did not stop until oil slicks were observed and some supplies emerged from the depth. The officers reported the incident and ended the fight.
During the withdrawal the B.A.P. Aguirre detects a submarine again (the B.A.P. Aguirre had a search area one quadrant further south than the B.A.P. Villar), this time the submarine showed a different bearing than the one obtained initially, which indicated that the ship had moved towards the south. The ship proceeded to get into attack position launching the first charge that shook the stern of the ship, then came a second that did not detonate and after the third charge no more noise was reported on the sonar.
The presence of a merchant ship that was stopped a few kilometers from the combat zone was strange, a fact that caused suspicions that it was acting as a support for the submarine, which motivated the B.A.P. Villar goes to intercept him. It was the Oil Tanker AO-52 "Almirante Montt" 1st (1956–1978), which when intervened reported a fault in one of its engines but the problem was almost solved , and after a few minutes they resumed their march south.
B.A.P. Aguirre (DE-62)
© wikipedia
As the ships of the squadron withdrew towards the San Juan naval base, a message was intercepted on the radio that said: "Mom, mom, Isabel is seriously injured".
Shortly after the event, intelligence from the Peruvian Navy obtained information about the submarine that had managed to enter the Talcahuano shipyards, which was reported as an extremely seriously damaged submarine, with serious damage and a number missing crew members, it also transpired that two of them were Officers.
Regarding the chilean submarine, it was a Balao Class, a design of ocean submarines used during World War II that are a variation of the Gato class, basically the difference was the use of more reinforced steel in the pressurized hull which increased its maximum depth to 122 meters, they had 10 torpedo tubes (6 in the bow and 4 in the stern).
The Chilean Navy had two of this type at that time, one of them is the SS-20 Thomson* (former SS-414 USS Springer) incorporated into the Navy in 1961 (April 3) and the other was the SS-21 Simpson (former SS-413 USS Spot) incorporated in 1962. The present story involves the first of them.
* "It was loaned to Chile in 1960 together with its twin, the Simpson, definitively acquired in 1972, and served until 1981"
http://repositorioarchivohistorico.armada.cl/handle/1/11382
The SS-21 Simpson was taken out of service in 1982. The Thomson is listed in the Navy registries as discharged by Resolution D.G.S.A. N° 4281/6 on December 15, 1981, however SS-20 Thomson was scrapped before 1978, according to accounts of the Beagle crisis by Captain A.Ch. (r) Rubén Scheihing**.
** "At the beginning of 1978, the Navy had four submarines, but only three available. The "Thomson", twin of the "Simpson", was scrapped, and the newcomers "Hyatt" and "O'Brien" were among the most modern in the region"
https://www.elsnorkel.com/2009/01/la-fuerza-de-submarinos-de-la-armada-de.html
The Balao Class submarines (Thomson and Simpson) were leased by the Chilean Navy to the North American Navy, after the incidents of 1971, in 1972 the US Navy required Chile to purchase the Thomson.
The Thomson remained in activity for another 10 years according to the Chilean Navy (1972–1981) but without any fuel budget item in that entire period. Years after the incident, General Juan Velasco Alvarado's Press Secretary, Mr. Augusto Zimmermann, published a story in the newspaper 'La República' about a serious incident with Chile that occurred in 1971, when a Chilean submarine entered territorial waters between Ilo and Matarani, The incursion was detected by the Navy, which after failing to get the ship to leave the territory, ordered patrol boats to drop depth charges on it, which severely damaged it. After being chased, it moved away without coming to the surface.
Velasco was informed of the incident, and sent the Secretary General of the Presidency to Santiago to explain to [Salvador] Allende the reasons why the naval authorities had used depth charges.
[President] Allende apologized after explaining that the incursion of the submarine was caused by a navigation error, with which Velasco considered the case closed. The incident was quickly overcome and kept as a state secret, without the slightest knowledge of the press in both nations.
B.A.P. Castilla (DE-61)
© wikipedia
Iván Illanes Mendoza
