Vladimir Grigor’yevich Yermolayev worked on Stal-6 and -7, seized opportunity when Bartini arrested and became leading member of special KB to continue Stal-7 and produce bomber version. Stalin’s interest January 1939 meant immediate large OKB, resulting in DB-240 (June 1940) leading to outstanding Yer-2 long-range bomber, 128 produced at Voronezh before evacuation, terrible difficulties but 300 more 1943, numerous prototypes and experimental engine installations, including 300 series Yer-2ACh-30B diesel-engined 1944, range over 3,110 miles (5,000 km) with 6,614-lb (3,000 kg) bomb. OKB run down after Yermolayev’s death from illness 31 December 1944, taken over by P.O. Sukhoi.