The Soviet Zvenigovo ship repair yard according to a CIA report dated September 1967

An item reported the fenced and road served Soviet Zvenigovo ship repair yard with as geographic coordinates 55.58.40 north and 47.59.40 east on the west border of Zvenigovo on the east bank of the Volga which seemed to be used for repairing river craft, The shipyard possessed a side-haul marine railway with minimal 1 transverse repair way and 1 shop and 10 support buildings.

Source
The report was published on www.archive.org, document number CIA-RDP78T04759A007300010035-9