Thread by @Saturnax1

#SubmarinesSaturday #Submarines #Accidents
Another #nuclear bedtime story, short 🧵:
1. Russian ROSATOM agency recently announced a plan to recover two sunken nuclear submarines: K-159 (Project 627A/November class SSN) & K-27 (Project 645/November class SSN).

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 2. K-159 was one of 12 Project 627A class SSNs - a slightly modified Project 627 Kit, that produced the first Soviet nuclear submarine Leninskiy Komsomol K-3.
Assigned to the Northern Fleet, K-159 was laid down at SEVMASH shipyard in 1962 & commissioned a year later.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 3. K-159 was finally decommissioned in 1989 & laid up in Gremikha naval base with both of her VM-A reactors not defuelled for the next 14 years, awaiting disposal, with little to no maintenance whatsoever. The hull of the submarine deteriorated extremely over the years...

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 4. raising major safety concerns in the neighbouring Baltic & Scandinavian nations. Shortly after a multimillion $ donation for the decommissioning activities from the aforementioned states was announced, Northern Fleet's command decided to tow several hulls out of Gremikha...

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 5. and one of those was the K-159. Her hull was so corroded & breached at so many places, that to keep her afloat 4 pairs of pontoons were spot-welded under the hull. These pontoons, however, were of extremely poor quality & nowhere near watertight.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 6. On 28/08/2003, with ten crewmembers aboard, towing operation to the Nerpa Shipyard began. Two days later, during a storm, two pairs of pontoons detached from the hull & with very little positive buoyancy left, K-159 quickly sank northwest of the Kildin Island, Barents Sea.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 7. K-159 with her top hatch open, came to a rest at a depth of approx. 250m. Only one crewmember was saved by the tow tug SB-406. Two bodies were later recovered by the rescue forces, rest of the crew still rests with their unfortunate boat.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 8. The second actor of the story, K-27 of the Project 645/November, was truly a unique boat. She was the first Soviet submarine to use lead/bismuth liquid metal-cooled reactor (LMR) - a technology later deployed on the famous Project 705 Lira/Alfa class fast interceptor SSNs.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 9. K-27 was laid down in 1958 & commissioned in 1963. Apart from exotic nuclear reactors, she also better antimagnetic steel alloys & a fire control system "Toriy" allowing quick torpedo tubes reload.
In May 1968, during a combat training in the Barents Sea, a disaster struck.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 10. On May 24 at 11:30, the reactor power output reading suddenly began to decline. Trying to understand the situation, operators increased the power of the reactor, but with no effect. At approx. 12:00, gamma activity readings in the reactor compartment increased to 150 R/h...

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 11. accompanied with a release of radioactive gases. Roughly 20% of the reactor core elements were destroyed in this accident. Boat was forced to surface, ventilate & began way back home, using power from her starboard reactor.
As a result the whole crew was exposed to radiation.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 12. and suffered from acute radiation sickness. 20 sailors received doses ranging from 600 to 1000R. 9 crewmembers died, one sailor suffocated in a gas mask aboard, eight died later in the Leningrad Naval hospital from high radiation doses.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 13. K-27 was written off in 1979 and in 1981 at the Zvezdochka Shipyard in Severodvinsk both reactors were sealed off with 270t of bitumen. A year later she was towed out & scuttled in the Kara Sea off the northeast coast of the Novaya Zemlya archipelago at a depth of 30m.

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 14. Worth noting is that this wasn't K-27's only accident - in 1967 another leak occurred on the starboard reactor, causing partial solidification of the coolant. No wonder this unfortunate boat earned her nickname "Nagasaki".

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one 15. End of thread, hope you enjoyed it.
RIP sailors🕯️
FYI @Aviation_Intel @vcdgf555 @CislakJaroslaw @GrangerE04117 @KrastavacKonst1 @KaptainLOMA @militaryhistori @EmbersOfSuns @FPSchazly @Aeroengineer1 @_LOAC_lawyer @JOStrumillo

@CovertShores @SubBrief @USN_Submariner @TayfunOzberk @FORONAVAL @Capt_Navy @RSS_40 @HMUboff @The_Lookout_N @R_P_one @Aviation_Intel @vcdgf555 @CislakJaroslaw @GrangerE04117 @KrastavacKonst1 @KaptainLOMA @militaryhistori @EmbersOfSuns @FPSchazly @Aeroengineer1 @_LOAC_lawyer @JOStrumillo + my previous nuclear bedtime story:

https://twitter.com/Saturnax1/status/1593358212589305856?s=20&t=3_Z3_DrniAjo4nxNKHkTqQ