The London and North Western Railway (LNWR) Precursor class was a class of forty 2-4-0 steam locomotives designed by F. W. Webb and built at the railway's Crewe Works between 1874 and 1879.
The Precursor class was the first locomotive class to be designed wholly by F. W. Webb. He had previously ordered further examples of his predecessor's Samson and Newton classes.
The class featured enclosed wheel splashers and cabs from new, but no brakes were initially fitted; some received steam brakes and others vacuum brakes.
They were fitted with 1,500-imperial-gallon (6,800 L; 1,800 US gal) tenders.