r/submarines

Project 09851 Khabarovsk-class SSAN/SSDN set sail from Severodvinsk for the first time, heading for the White Sea to undergo sea trials. A. Mikheev (Aug. 16)

u/No-Adeptness-8986 — 1 day ago

The Peruvian Navy submarine BAP Antofagasta (SS-32) is nearing its re-entry into the water at the SIMA Callao shipyards after undergoing an extensive modernization program to extend its operational service life.

u/defender838383 — 2 days ago
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The French Cruiser Submarine "Surcouf" (1929)

Among the efforts to curtail an arms race following World War One, the 1922 Washington Naval Treaty - signed by the British Empire, France, Italy, Japan and the United States - limited the construction of warships among its signatories, specifically for battleships, battlecruisers and aircraft carriers (which were an emerging concept at the time).

However, the first version of that treaty did not explicitely limit the construction of submarines (save for a maximum displacement of 10000 tons) and soon enough the French authorities ordered the construction of a "submarine cruiser", as a way to circumvent some of those limitations (and mostly because French shipbuilders were already quite experienced with designing cutting-edge submarines).

The "Surcouf" was designed following the requirements that it should be able to carry provisions for 90 continuous days of high-seas deployment, and feature firepower comparable to that of a battlecruiser. Indeed, the submarine was built around a turret sporting two 203mm guns - which were the largest caliber allowed by the Washington Naval Treaty. According to the specifications, it could fire up to a distance of 16 kilometers with its own instruments, and 26 kilometers with aircraft support. To this end, the Surcouf was also the first submarine to carry a reconnaissance aircraft. Initially an improved version of the Besson MB.35 floatplane designated MB.411 was chosen for that task {images 3 and 4}, but a bespoke gyroplane was later devised to replace it in the form of the Dorand G.20 {image 5} - although development for it never came to fruition with the fall of France in 1940.

Launched in 1929 and commissionned in 1934, the Surcouf would remain the largest submarine in the world until the launch of the Japanese I-400 class in 1944 - namely because the 1930 London Naval Treaty specifically regulated submarine warfare in order to address the topics that the Washington Naval Treaty did not cover. In particular, submarines were now limited to 2000 tons - with each major nation allowed to operate three units of up to 2800 tons. However, the Surcouf and its 3250 tons of displacement was exempted by the terms of this treaty as the sole exception, mostly on the basis that it was already operational at this point.

At the time of the Battle of France in 1940, Surcouf was being refitted in France and managed to escape to the United Kingdom and ultimately remained under the control of the Free French forces. In February 1942, the submarine departed Halifax, Canada, with the intent of rallying Australia and was sunk on the way to the Panama Canal during the night of the 18th to 19th of the same month. The circumstances of her sinking are unclear, although the most likely scenario points towards American forces being responsible after confusing her with an enemy ship.

Sources :

- Covert Shores : Surcouf, The Ultimate Interwar Cruiser Submarine

- Drachinifel : MN Surcouf - Guide 136 (Extended)

Images :

- (1) Marine & Océans : Chronique Navale du 18 Février

- (2) Aviation Navale Française 1939 - 1940 : Sous-Marin Surcouf

- (3) & (4) Aviation Navale Française 1939 - 1940 : Besson MB.411 "Petrel"

- (5) Old Machine Press : Dorand Gyroplane G.20 (G.II)

u/Serendipitian — 3 days ago
▲ 301 r/submarines+1 crossposts

The new Russian Project 09851 special purpose submarine Khabarovsk leaving Severodvinsk for sea trials

u/Vepr157 — 3 days ago

Two unique Victor (671) submarines

K-147 and K-438 were fitted with SOKS system in late 1970s; K-438 also featured an "Akula-style" sail after modernization.

The SOKS array position on K-438 was higher than that on K-147.

pic source:VK

u/Pitiful-Practice-966 — 3 days ago

China's third Kilo‑class submarine has been decommissioned and may be converted into a tourist attraction in the future.

u/Low-Career3769 — 3 days ago
▲ 118 r/submarines+1 crossposts

Plan of the Day, 6/15/1974

Dug this up from some recently discovered boxes. It’s pretty cool how things are different and other things remain the same.

u/BunBunChow — 4 days ago
▲ 173 r/submarines+1 crossposts

USS Annapolis (SSN 760) transits Apra Harbor, Naval Base Guam. Aug 13, 2026 [7300 x 5436]

u/Saturnax1 — 4 days ago

Navy STS

I was just wondering if STS is a good rate and how hard is the school for it and are the test multiple choice or fill in the blank like nuke school.

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u/Crazyrunner2 — 4 days ago
▲ 508 r/submarines+1 crossposts

Royal Navy HMS Otus(1024x734), an Oberon Class submarine. This very successful and long lived class of submarine would be on the shortlist of the best ever designed. Known for their quiet during operation, they served in five navies. The last being retired in 2000.

u/Grahamthicke — 5 days ago
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The thickness of the steel hull of the Kursk submarine. Taken while cutting off the torpedo section during salvage.

u/JimBean — 7 days ago

Stephen Biesty's illustrations of the Type VIIC and the Trieste

It's been almost 35 years since I begged my parents to buy me a copy of the original Incredible Cross-Sections, and yet I still find myself becoming hopelessly obsessed with this guy's work for a couple of weeks every 18 months or so. As an adult, I find myself cringing at some of the technical errors and simplifications, but then again, he was producing books for the 9-12 age group, so I can kinda forgive him. It probably says a lot about Biesty's skills as an artist, and his impact on me at a young age, that I'm still unhealthily obsessed with a lot of the subjects he illustrated.

u/MrSubnuts — 5 days ago

WWII Sub Warfare

**USS Tinosa** contributed the barbecue sauce — the standalone master, the machinery behind every rib and chicken card in the file. She earned her place in history through failure: in July 1943 she caught the giant tanker *Tonan Maru No. 3* dead in the water and fired **fifteen perfect torpedoes that did not explode.** Her captain saved the last dud as evidence and slammed it on Admiral Lockwood's desk at Pearl — and the Tinosa's heartbreak finally broke open the Mark 14 torpedo scandal. The tests that followed fixed the exploders, and every kill in this chapter made after late 1943 was made with torpedoes that worked *because hers hadn't*. She ended at Bikini, expended in the atomic tests. From dud torpedoes to Operation Crossroads.

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u/No_University7832 — 4 days ago
▲ 164 r/submarines+1 crossposts

A 637-class SSN nuclear-powered fast attack submarine at Naval Submarine Base Charleston, South Carolina in 1986. [2944x2096]

u/Saturnax1 — 6 days ago