Konstantin Fyodorovich Chelpan (Russian: Константин Фёдорович Челпан; 27 May 1899 – 10 March 1938) was a prominent Soviet engineer of Greek background. Head of the Engineering Design Bureau of the Kharkiv Locomotive Factory, chief designer of the T-34 tank engine. Awarded the Order of Lenin, he was politically repressed and executed under a mass persecution ordered by Joseph Stalin, but politically rehabilitated after death.

Born on 27 May 1899 in Cherdakly, Yekaterinoslav Governorate, Russian Empire (now Kremenivka, Donetsk Oblast, Ukraine),^[1] to Fyodor Myhailovich Chelpan and Elizaveta Khalangot.^[2] Both parents were Greeks.^[1]

After graduating from Mariupol Realschule in 1919, took part in the Russian Civil War.^[2] In 1924, he graduated with honors from Kharkiv Technological Institute with a major in internal combustion engines.^[2][3]

From 1924 to 1937 Chelpan worked at the Kharkiv Locomotive Factory^[3] as a Designer, Head of the Diesel Department, Lead Designer, and Head of the Engineering Design Bureau.^[4][5] In 1928–1929 he received practical training in Germany, Switzerland, and the UK.^[2]

Konstantin Chelpan was the head designer of the famous T-34 tank diesel engine V-2,^[6] for which he was awarded the Order of Lenin.^[7] The engine consisted of lightweight aluminum alloy.^{[8][9][10][11]}

From 1927, he was a senior lecturer at Kharkiv Technological Institute.^[12]

Konstantin Chelpan was arrested on 15 December 1937 during the first days of the Greek Operation of NKVD.^[1][2][11] He was charged with leading a Greek nationalist counter-revolutionary organization, as well as conspiring to sabotage the Kharkiv Locomotive Factory.^[1][11] After being interrogated and tortured, he confessed to being a spy.^[2] On 4 February 1938, he was sentenced to execution by shooting.^[2][3][11] The sentence was carried out in Kharkiv prison on 10 March 1938^[2] and covered up.^[1] In a few years his wife received a death certificate, indicating that Konstantin Chelpan died on 16 May 1942 from congestive heart failure.^[1]

On 6 August 1956, Konstantin Chelpan was rehabilitated by the Military Collegium of the Supreme Court of the USSR.^[2][3] However, only in 1988 was his true cause of death revealed.^[1][11]

• In 1994 one of the streets in the village of Cherdakly was named after Konstantin Chelpan.^[2]
• In 2000 a book entitled Life story of famous Ukrainian Greeks. The case of Konstantin Chelpan by G. Zakharova was published.^[2]
• In 2001 a commemorative plaque was placed on the house, where Konstantin Chelpan had spent his last years.^[2]