G-5 boats were divided into 5 Series with small differences between them. From Series 7, 8 and 9 a total of 152 boats were completed between 1934-36, from Series 10, 20 were built in 1937, and from Series 11, 120 units were manufactured in 1945.G-5 had a “whaleback” design type that gave them a very particular appearance, similar to a catamaran seen from the front. The two engines were installed in the front, inside the hull, and each engine had its own transmission that moved a propeller.G-5 Series 7 and 8 mounted two GAM-34 gasoline engines with 675 hp each and reached 45 knots of maximum speed. The Series 9 mounted the GAM-34B of 800 hp each and reached 49 knots. Series 10 mounted the GAM-34BS of 850 hp each and reached 53 knots. Finally, the Series 11 had the GAM-34BSF engines of 1,000 hp each and reached 56 knots of maximum speed.The hull of G-5 boats was made of aluminum that tended easily to corrosion by sea water. In fact there are reports that indicate that in summer period, anti-corrosion treatments should be applied every 7 days of navigation and in winter it should be done every 15 days.When the USSR entered the WWII there were 42 boats in the Baltic Fleet, 77 with the Black Sea Fleet and 135 with the Pacific Fleet. During the war 104 units of this type were destroyed or decommissioned for different reasons. Finland captured 3 of them that were returned to the USSR after the armistice. G-5 boats made few torpedo attacks and were used for escort missions, transports or even as landing craft. The torpedoes release system was quite complicated, similar to the British method used in WWI’s MTBs and required a lot of skill to be effective.
