On the Baltic Sea to White Sea Canal, ~20km from Belomorsk.
More info later. If anybody is real hot about Sosnovets, write and I’ll do a compilation on it.
A review of the history of Sosnovets on the Pomor Cultural Center’s site: http://pomorskibereg.ru/sosnovec. In Russian but really well written and, as texts that make sense, should easily submit to online translation. The Pomor Culture Center is in Belomorsk, the end point of the Baltic to White Sea Canal.