1T (zero T) or 0-T may refer to: * 0t, or Zero temperature, alternate term for absolute zero * One of several Whyte notations for steam locomotive classifications * 0-4-0T, variant of 0-4-0 * 0-6-0T, variant of 0-6-0 * Bristol and Exeter Railway 0-6-0T locomotives * List of preserved Hunslet Austerity 0-6-0ST locomotives * LMS Fowler Class 3F * GWR Sir Watkin Class * 0-10-0T, variant of 0-10-0 * 2-4-0T, variant of 2-4-0 * South Devon Railway 2-4-0 locomotives * Highland Railway O Class * 2-6-0T, variant of 2-6-0 * 2-8-0T, variant of 2-8-0 * 4-4-0T, variant of 4-4-0 * Bristol and Exeter Railway 4-4-0T locomotives * 4-8-0T, variant of 4-8-0 * South African Class 13 4-8-0T+T