With a train of track panels

3813 seen here at Hayes and Harlington on the main line from Paddington was one of twenty of her class to be modified to burn fuel oil during the post war years when coal was in short supply , this particular engine being so modified in 1949 and being renumbered as 4855 .
The engines so treated were renumbered with a series of numbers taken from the little " 4800 " class of Mr. Collett's branch line engines , which were accordingly thereafter themselves renumbered in the " 1400 " series .
Sister engine 2834 was the last to run as an oil burner , being converted back to coal in January of 1950 as the experiment was short lived with the modified examples suffering from an increase in weight .