One hundred and ninety five engines were built by the LMS, adding to the 45 Midland Railway 1000 Class, to which they were almost identical. The most obvious difference is that the driving wheel diameter was reduced from 7' 0" on the Midland locomotive to 6' 9" on the LMS version. They were given the power classification 4P.
The LMS continued the Midland numbering from 1045 to 1199 and then started in the lower block of 900-39. After nationalisation in 1948, BR added 40000 to their numbers so they became 40900-39 and 41045-199.
None has survived to preservation, though the first of the Midland 1000 Class engines has.
For terminology, see Steam locomotive components