The BR Standard Class refers to a series of steam locomotives built by the British Railways (BR) between 1951 and 1960. These locomotives were designed to replace older models and standardize the fleet, featuring a range of types including Class 4, Class 5, and Class 7. They were known for their reliability and efficiency, serving both passenger and freight services across the UK. The design of the BR Standard Class locomotives was influenced by earlier British designs, incorporating modern engineering techniques. They were built in various configurations, with some models capable of high speeds, making them suitable for express services. The series played a significant role in the transition from steam to diesel and electric trains in Britain.