Consider this a military curiosity and oddity? A heavily modified Soviet era Romeo class submarine the mission of which not made entirely clear. At least to myself. I think I understand but am not sure.
Thanks to the Internet web site English/Russian. As is normal click on all images to see an enlarged view.
"RUSSIAN TWO-BARREL SUBMARINE"
"A Russian submarine with two torpedo tubes, with two HUGE torpedo tubes, was produced in the 1950s by Russian Navy engineers. A truly weird creation of Soviet engineering thought – partly beautiful, partly awkward and in many senses unique. It could carry nuclear loads, too."
Heavily modified Soviet era submarine Project 633 Romeo class RV.
Another perspective of the heavily modified Soviet era submarine Project 633 Romeo class RV. Look at the size of those torpedo tubes!!
"This submarine carried special underwater rockets, 'Vodopad' – 'waterfall'. It was 533 mm caliber and could carry a nuclear load."
Current mission of the Project 633 Romeo class submarine RV as an ELECTRIC CHARGING STATION? That apparently is a modern Russian Kilo class diesel/electric boat moored alongside the Romeo sub. Recharging batteries of the Kilo. That is what this is?
Regarding the modified section of the Romeo 633 RV class submarine:
"Project 633RV – 2 units: S-11 in 30.05.1978- and S-49 in 09.1970-1972 For trials a anti-submarine missile complex «Veter» and «Vodopad»"
Romeo class RV submarine as modified used for testing of anti-ship, anti-submarine missiles. Missiles as can be launched from a torpedo tube of either a submarine [submerged or surfaced] or a conventional surface warship. There you have it.