Based on the Duke class, William Dean developed another 4-4-0 locomotive with larger wheels to be used on flatter routes with express trains. It can be described as a smaller-wheeled sister model to the Bulldog class and shared some commonalities with it. As with the Duke class, the outer frames of both were curved upwards in the area of the cranks of the coupling rods. 

The initial 20 pieces were initially numbered 3292 to 3311 and given names that did not follow the same pattern. Among them were country houses of the British nobility, after which the first example “Badminton” was named. Others were named after cities and historical figures.

No. 3373 “Atbara”, later No. 4120

collection Colin Howley

The Badminton class featured a boiler that was the first of the GWR to feature a copper Belpaire firebox. Like the prototype of the Bulldog class, it was a so-called “parallel” boiler, which did not taper towards the front and also had a steam dome. The steam dome was only left out on the last production example, No. 3310 “Waterford”. Later, most of the locomotives in the class were fitted with one of the new “tapered boilers”, i.e. boilers tapered towards the front without a steam dome. 

Another innovation was the arrangement of the valve body, which was based on the ideas of LB&SCR chief engineer William Stroudley and mounted below the inside cylinders. Since the cylinder and valve bodies no longer had to be accommodated next to each other between the wheels, the valve body could have a larger diameter. The precise location of the piston and orifices also reduced internal resistance when the regulator was closed, which reduced wear.

No. 4120 “Stephanotis”, Flower class, later No. 4168

Locomotive Magazine, October 1908

From 1900 a total of 40 engines followed in another class which combined the new Bulldog class boiler with coupled wheels half an inch larger than those of the Badminton class. They also received the straight-top outer frame, which featured greater stability. They were mostly named after the locations of important battles, famous generals and Commonwealth cities. The first locomotive was No. 3373 “Atbara”, named after a river where a battle took place in 1898 in present-day Sudan during the Mahdi uprising.

In the years 1902 and 1907 to 1909 a total of ten engines from the Atbara class were converted into the City class. The remaining enignes were given new, tapered boilers as early as 1904 under Dean's successor Churchward. From 1909 superheaters were also installed. Locomotives that were not converted to the City Class were retired between 1927 and 1931.

Side view of the Badminton class

Railway an Locomotive Engineering, February 1900

Just as the Bird class was developed from the Bulldog class locomotives, the Flower class was developed from the Atbara class. As the name suggests, these 20 engines were named after types of flowers used in horticulture. Like the Bird class, they had outer frames with a greater height and a new design of the lead bogie from France. From 1910 they were all converted to superheated steam. Like the Atbara class, they were all retired between 1927 and 1931, with No. 4102 “Begonia” being the last.

The locomotives achieved impressive performance for their weight class and were also able to cover longer distances at high speeds. The locomotives initially shared the operating numbers with their small-wheeled relatives, so that the Badminton, Atbara and Flower numbers did not form a common, uninterrupted number range. This led to a renumbering in 1912, in which the three classes were given consecutive company numbers from 4100, 4120 and 4149.

However, the locomotives reached their limits on inclines due to their large coupling wheels, as the Cornish Main Line in particular showed. This section between Plymouth and Penzance winds through the Cornish hill country and features a succession of short, steep climbs and descents. This eventually led to Dean developing the Bulldog class with smaller wheels. Although the large-wheeled types also proved themselves on flatter routes, the era of the ten-wheelers soon began at the GWR.