LCDR M3 4-4-0 No 474 on shed c1910.
The very similar Gillingham shed had three arched entrances and decorative brickwork on the gable end.
This is Deal shed which was extended to three roads around 1881. It closed around 1930 with the opening of Ramsgate depot.
The Historical Survey of Southern Sheds has a photo with the distinctive wooden shed door on the left.

Photo: L.E. Brailsford/Rail Archive Stephenson