In the early 1900s, to provide for the growing demand for passenger services to and from the Manchester and Birmingham areas, the LNWR created rakes of carriages which collectively became known as the Manchester and Birmingham Exchange Sets. For the Manchester sets the traffic was centred on services to and from Manchester primarily to the Leeds & Huddersfield areas in Yorkshire, Bolton & Wigan to the north of Manchester and Liverpool & St Helens to the West of Manchester. The rakes were often used on excursion services from Manchester, particularly to the Fylde & North Wales coast.
51L produce the following vehicles for these trains:
Diagram 110: 7 compartment first class carriages, 24 built between 1903 & 1904.
Diagram 182: 7 compartment composite carriage, 29 built between 1904 & 1907.
Diagram 285: 8 compartment third carriage, 73 built between 1903 & 1906.
Diagram 336: 6 compartment brake third, 33 built between 1903 & 1904.
Diagram 338: 5 compartment brake third, 82 built between 1904 & 1907.