Russian patrol ship Ivan Susanin

Ivan Susanin (Иван Сусанин) is a Soviet and later Russian Navy icebreaking patrol ship. It was the first of eight Project 97P patrol ships built by Admiralty Shipyard in Leningrad in 1973–1981.

Description
In the mid-1950s, the Soviet Union began developing a new diesel-electric icebreaker design based on the 1942-built steam-powered icebreaker Eisbär to meet the needs of both civilian and naval operators. Built in various configurations until the early 1980s, the Project 97 icebreakers and their derivatives became the largest and longest-running class of icebreakers and icebreaking vessels built in the world.

The patrol ship variant, Project 97P (97П), was developed as a response to the renewed interest of the Soviet Navy and Soviet Border Troops on icebreaking patrol vessels after United States Coast Guard and Canadian Coast Guard icebreakers began appearing more frequently near the country's northern maritime borders. New icebreaking patrol vessels were needed because existing Soviet naval vessels could not operate in ice-covered waters and large icebreakers, in addition to being unarmed and operated by civilians, could not be distracted from their primary mission of escorting merchant ships.

Project 97P patrol ships are 70 m long overall and have a beam of 18.1 m. Fully laden, the vessels draw 6.5 m of water and have a displacement of 3710 t. Their three 1800 hp 10-cylinder 13D100 two-stroke opposed-piston diesel engines are coupled to generators that power electric propulsion motors driving two propellers in the stern. In addition to being slightly bigger than the icebreakers they are based on, Project 97P lacks the bow propeller and features a bigger deckhouse built of aluminum-magnesium alloy to reduce weight as well as a helideck capable of receiving Kamov Ka-25 or Ka-27 helicopters.

Project 97P patrol ships were initially armed with a twin 76 mm AK-726 deck gun and two 30 mm AK-630 close-in weapon systems, but the ships operated by the navy were later disarmed.

History
The first of eight Project 97P patrol ships was laid down at Admiralty Shipyard in Leningrad on 31 July 1972, launched on 28 February 1973, and delivered on 30 December 1973. The ship was named after Ivan Osipovich Susanin, an early 17th century Russian national hero and martyr and joined the Soviet Navy Red Banner Pacific Fleet.

Following the dissolution of the Soviet Union, Ivan Susanin was passed over to the Russian Navy. The vessel remains in service.