The Russian BOR-450 inland screw steam tug according to a CIA report dating from the 1950s

An item referred to the publication Susa Novykh Tipoc dlya Bol’shoy Volgi, written by A.P. Strakhov, Moscow 1954 dealing with new kind of ships to serve on the Volga. The river channel would in the future be changed caused by constructing of hydroelectric power projects and corresponding attendant reservoirs. So in this manner were new types of river ships needed including several types of screw steam and diesel tugs. The new tugs were be stronger and their propulsion more economical despite it were vertical steam engines or internal combustion diesel engines.

One type was the BOR-450 hp screw steam tug with 2x225 ihp steam engines with a towing capacity at hook of 6.000 kilo with a speed if 8 kilometres and without a tow a speed of 19,0 kilometres. The dimensions were 41,0 (between perpendiculars)-43,3 (over all) x 8,0 (moulded) x 3,2 (depth amidships) x 2,2 (mean draught with full fuel load) metres. The first series were fitted out with 2 TM2 200-250 ihp/200rpm vertical triple expansion steam engines with sliding valve steam distribution and link gear. One engine was working port and the other star board. There was one coal fuelled KV5 water tube boiler with a heating surface of 160 square metres, Twin screws (diameter 1,8 metres) in directional cowls. Welded frame transverse framing with floors at each fame. USS Register Division Ma demands. The prototype Georgiy Sedov executed with success her trials on the Rybinsk Reservoir. With 475 ihp was the pull capacity of the hook with 9 kilometres speed 6.080 kil0. Net pull with 8 kilometres speed was 12,8 kilo/ihp in stead od the designed pull of 12,5 kilo. The second tug named Semen Dezhnev even had 13 kilo pull with 8 kilometres speed. For the later series were the triple expansion steam engines to be replaced by the new MP10 engines resulting in 35% increase of the horsepower in fact a conversion into the BOR-600 tug. Further more were the boilers to be replaced by the new KV-5M steam boilers resulting in increasing steam pressure and more horsepower resulting in maximum 800 ihp still without changing the hull and dimensions and enlarging the crew.

Source

The report was published on www.archive.org, document number CIA-RDP81-00280R000200210013-9