London & North Western Jubilee class

As a successor to the unconventional Teutonic class with a very large low-pressure cylinder and uncoupled driving axles, Francis William Webb developed the more conventional Jubilee class. The leading axle was replaced by a bogie and a total of four cylinders were installed. All cylinders now acted on the front driving axle and the rear one was coupled as usual.

When comparing the cylinder dimensions with other compound locomotives, it is noticeable that the piston area of the low-pressure cylinders was less than twice that of the high-pressure cylinders, while this ratio is ideally around 2.4. This meant that the high-pressure cylinders were already consuming a large part of the steam and the low-pressure cylinders were no longer being fully utilized. In addition, the volume of the cylinders was very large in relation to the boiler, which could lead to the boiler being exhausted more quickly.

Nevertheless, the 40 locomotives of this class were considered successful because they performed well in the hands of experienced drivers. Trains weighing almost 350 tons covered the hilly 157 miles non-stop from London to Crewe in three hours and four minutes, an average of 51 mph. Trains with up to 20 cars have also been reported.