T-18 was a development of the T-16 and came into production in the spring of 1927. It was lengthened, one road wheel was added, and stronger engine. Production from 1928. Modern-ized in 1929-30 with better speed, mobility and armor. In service from 1930. Production stop: end of 1931. End of service: 1938. Some units said to have been into battle in 1941-42.