The London and North Western Railway (LNWR) Precursor Tank Class was a class of 4-4-2 tank steam locomotives. Fifty were built to the design of George Whale between 1906 and 1909, being a tank engine version of his Precursor Class. All fifty passed into LMS ownership in 1923. The LMS gave them the power classification 2P. The LMS also renumbered them into solid block of numbers: 6780–6809 for the 3 ft 9 in engines and 6810–6829 for the 3 ft 3 in engines, in the order given above. They were withdrawn between 1927 and 1940. None were preserved.