This was designated H&BR Class L, and later became LNER Class J28. Matthew Stirling's locomotive designs often incorporated the design traditions established by his father, including domeless boilers.
The locomotive in question was initially classified as H&BR Class L, and eventually became LNER Class J28. The designs of Matthew Stirling's locomotives often reflected the traditional approaches to engineering that he had learned from his father, which included the use of domeless boilers.