The Ugra class was the NATO reporting name for a group of seven submarine tenders built for the Soviet Navy in the late 1960s.
[2] The class, named Project 1886 by the Soviets, designated the type of ship as Russian: Plavuchaya Baza meaning "Floating Base".
[4] The vessels were powered by a diesel-electric system composed of four Kolomna 2D 42 diesel engines and two electric motors turning two shafts, creating 6,000 kilowatts (8,000 bhp).
[4] The Ugra class were armed with two quad launchers for sixteen 9K32 Strela-2 (NATO reporting name: SA-N-5 "Grail") surface-to-air missiles and four twin-mounted 57-millimetre (2.2 in)/80 anti-aircraft guns.
[2] They were also equipped with four "Watch Dog" electronic warfare/jamming radar, two "Square Head" and one "High Pole B" identification friend or foe antenna.
[2][4] Two ships, Ivan Kucherenko and Volga, were equipped with lattice masts for "Vee Cone" HF communications antenna.
Amba was armed with two 76.2 mm (3.00 in) anti-aircraft guns and equipped with one "Slim Net", two "Hawk Screech" and one "Don-2" radars.