(rail transport,UK) Storage of a train taken out of service temporarily, which is kept powered and maintained.
2020 April 8, “Network News: COVID-19: Questions and Answers”, in Rail, page 10:
However, operators including LNER, Chiltern Railways and East Midlands Railway have already indicated that some of their fleets will be temporarily placed into warm storage until the Coronavirus crisis is over. What does warm storage mean? Warm storage means that trains are maintained and kept powered at all times in order to keep all systems working.
