This has Nothing to do with the Philadelphia Experiment at all, as the various Fake News articles say. It’s actually hard to find info online about this and that helps spread the mystery but here is a translation from a Russian site;
“Russian: The bow of the minesweeper, a memorable sign to the marines of the OVR (military unit 10678). Its opening was timed to the 30th anniversary of the capture of the port of Liinahamari (1974).”
https://www.tracesofwar.com/sights/26151/Memorial-Soviet-Seamen-Liinakhamari.htm