LNWR Precursor class (Webb)
LNWR engine No. 680 'Giffard'
Type and origin Power type Steam Designer F. W. Webb Builder Crewe Works Serial number 1902–1821, 2229–2238, 2249–2258 Build date 1874–1879 Total produced 40
Specifications Configuration: ​  • Whyte 2-4-0  • UIC 1B n2 Gauge 4 ft 8+1⁄2 in (1,435 mm) Leading dia. 3 ft 6 in (1.067 m) Driver dia. 5 ft 6 in (1.676 m) Wheelbase 7 ft 5 in (2.261 m) + 8 ft 3 in (2.515 m) Loco weight 32 long tons (33 t) Boiler: ​  • Diameter 4 ft 2 in (1.27 m)  • Tube plates 9 ft 10 in (3.00 m) Boiler pressure 140 lbf/in2 (0.97 MPa) Heating surface 1,074.6 sq ft (99.83 m2) Cylinder size 17 in × 24 in (432 mm × 610 mm) Valve gear Allan
Career Operators London and North Western Railway Scrapped 1892–1895 Disposition All scrapped

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.

• Baxter, Bertram (1979). Baxter, David (ed.). British Locomotive Catalogue 1825–1923, Volume 2B: London and North Western Railway and its constituent companies. Ashbourne, Derbyshire: Moorland Publishing Company. ISBN 0-903485-84-2.