Great Western Railway class 3600

Instead of purchasing another series of the now obsolete "Metro Tanks", William Dean had a 2-4-2T tank locomotive built in 1900 with the number 11. With a driving wheel diameter of 5 ft 2 in (1,575 mm), it was ideal for fast suburban traffic. There were also water scoops in both directions to replenish water supplies.

In 1902 and 1903, 20 and ten more of the now known as class 3600 locomotives were built. About half each were deployed in the London area and the Birmingham area. Although they could be used in a variety of tasks and performed these tasks well, it was recognized that there were already suitable locomotives for all of their tasks. Their withdrawals took place between 1930 and 1934.