The standard class 4 tank locomotive was developed to replace older tank locomotives for use with fast commuter and suburban trains. It was based on the LMS Fairburn 2-6-4T and had a similar driving wheel diameter of five feet eight inches. For a wider range of uses, the loading gauge was reduced by slightly rounding off the driver's cab and the water tanks. The smaller cylinders, which were compensated for with a higher boiler pressure, also contributed to this.

Most of the locomotives were made in Brighton, where a total of 130 were built. Another 15 were from Derby and ten from Doncaster. Another order for 15 locomotives was canceled in view of the dieselisation. The fact that only small detail changes were made to the locomotives during the period of operation shows that the design itself was successful. It also served as the basis for the standard class 4 4-6-0 tender locomotive. 

The locomotives were used almost all over the country. Only in the Western Region was the GWR's Large Prairie available in sufficient numbers to be able to dispense with the 2-6-4T. The first machine was scrapped in 1962 after it suffered a broken frame. Since older classes were phased out first, the 2-6-4T was only phased out between 1964 and 1967. A total of 15 have survived to this day, some of which are used regularly.