Triple bubbles in the snow! 55023 (L123), 55020 (L120) & 55029 (L129) pass South Moreton on 9 February 1991 with the 2C23 09:15 Banbury to Reading Network SouthEast service. Class 121s often substituted for one of the driving vehicles of Class 101s, 117s, etc, and sometimes ran in pairs, or with their dedicated trailers, but to have three Class 121 DMBS vehicles running together is slightly different. Much the same capacity as the more normal Class 117 three car unit, but of course with no connection between the coaches. Plenty of power though, with 900hp available from the six Leyland engines.