It's Whit Saturday, 19th. May, 1956 and Old Oak Common's 6012 has worked down to Plymouth on the 11.a.m. relief from Paddington, running behind the "Cornish Riviera" by 30 minutes or so.
On Laira's coaling line 6012 is having the smokbox and tubes cleared, is being re coaled and has already had its fire "dropped", the ash seen on the cabside indicating that this has been done.