Russian floating dock leaving Kronstadt, Russia according to a CIA report dated 15 March 1957

An item reporting the departure from Kronstadt of floating dock with as dimensions 250-300 x 80 feet towed by an icebreaker [called ?epecbet] on westerly course.

Source
The report was published on www.archive.org, document number CIA-RDP80T00246A033200070001-5