Chief Mechanical Engineer Richard Maunsell set about providing the merged SECR system with a range of modern and highly serviceable locomotives and rolling stock. Aided by Lionel Lynes, one of a number of talented engineers recruited from Swindon, as Chief Draftsman for the Carriage & Wagon section a modern steel wagon underframe was designed and used as the basis for a range of new standard wagons. Ordered towards the end of WW1 the first wagons entered service before the 1922 grouping of the railways, however the Southern Railway selected Maunsell to continue in his role as CME and more batches of the modern SECR wagons were ordered as the Southern Railway standard types.
Although the Southern later changed a number of details to better suit traffic across the entire system the familiar lines of the Southern Railway wagons built up to nationalisation, including the triple-arc 'Lynes' roof of the vans, are evident in these SECR vehicles.
Being of modern construction and using robust steel underframes the majority of these wagons passed to British Railways ownership in 1948, though by then accumulating 30 years in service were beginning to be assigned to departmental and engineering service.