class class type steam locomotive designed constructed immediately prior second world war use medium distance freight trains network locomotives built successor design relatively old fashioned class soon eclipsed powerful class locomotives performed adequately reliably tasks designed withdrawal survived preserved railway background primarily passenger carrying railway resources extend electrified lines continuing need steam freight locomotives preferred mixed traffic designs haul passenger trains remaining non electrified lines peak periods late 1930s adequately served powerful mixed traffic locomotives classes need smaller freight locomotive high route availability undertake light passenger duties role performed jubilee approaching end useful lives year chief mechanical engineer decided inside cylinder tender locomotive undertake role class relatively old fashioned design late 1930s britain major railways built locomotives pattern 1940s class contained modern features widow cab southern steam locomotive design second world war represented final design career retired ill health construction history successor oversaw building members class railway works january september reported found class having manufactured traditional victorian principles locomotive design said stated order class cancelled appointed earlier ample opportunity cancel order build test single prototype expense building members class case class performed adequately reliably tasks designed versatile hoped requirement modern freight locomotives southern increased second world war faced options continuing production class design completely new locomotive taking option designed highly class locomotives modifications common designs class locomotives reliable complaints poor steaming main line trains designed fitted member class blast pipe attempt improve efficiency proved successful remainder class fitted 1950s experiments carried fitting british railways standard class plain blast pipe small chimney resulting improvements steaming fuel consumption received blast pipe standard class chimney operational details preservation locomotives adequate reliable secondary services working lives utility compounded light weight steady handling disappointing main line traffic improved war fitted steam carriage heating despite primarily freight design periodically duty british railways responsible class gave power classification denoting freight locomotive power class service began completed preservation class considered sufficiently important official preservation barry examples survived number rescued operated railway sussex operational black returning service april numbering primary role freight locomotive class carried locomotive number southern located tender painted numbering locomotives ranged built tenure locomotives followed adaptation classification system refers number leading trailing driving case system class prefix numbers event form numbering granted class locomotives early included temporary retention southern number remained black certain cases british railways applied tender place southern british railways class granted power classification immediately class given temporary prefix original number class eventually numbered british railways standard numbering system changed british railways goods plain black crest tender numbering cab locomotive numbers ranged locomotive summary
SR Q class