class class type steam locomotive constructed second world war class designed use intensive freight turns experienced wartime network total locomotives built incorporated innovations weight saving concepts produce highly functional design class lasted service july member class number preserved highly unusual controversial design represents ultimate development british freight engine capable hauling trains usually allocated larger locomotives railways nicknames class included ugly coffee background late primarily high density commuter railway serving london electrified rail pick found british line second world war severe lack modern freight handling capability newest freight design class locomotive designed built essentially victorian era principles designed replacements older inherited entered service january having retired end october replaced southern railway essential strategic war asset proximity continental europe needed equip adequate freight handling capability transport vast quantities supplies troops required conflict brief stipulated high route availability high effort construction history answer problem came drawing board innovative chief mechanical engineer shape minimum raw materials features stripped away produced powerful steam locomotive run britain railways locomotives constructed brighton works remaining powerful light formed backbone southern heavy freight capability engine weighed tons tonnes route mileage design class built wartime regime stressed pure functionality considerations style decoration approach design explains functional appearance aspect shape like merchant navy class classes simply driven coach cleaning time manpower time consuming spared unusual shape dictated use materials glass material known cheap plentiful war years support weight separate required followed seen merchant navy class locomotives boiler rings adapted lend support needed copper steel utilised unlike wheels smaller adaptations brown type utilised locomotive cylinders link outside admission having travel gear steam lap provided blast pipe boiler design based lord nelson class boiler barrel measured length area heating surface tubes giving total heating surface heating surface operational details represented final development british main line steam locomotive later designs medium powered freight locomotives class class wheel arrangement wheel arrangement standard designs locomotive classified class power classification represented rarity exceeded classification notable exceptions class class class route availability meant primarily freight locomotives frequently secondary passenger services class gained reputation poor braking freight trains light construction tender braking system intended duties world war class proved addition southern locomotive fleet achieved extent remained service 1960s long intended cease operation design began implementation plan saw end steam operations britain railways example class withdrawn numbering numbering system class plain freight black numbering southern lettering tender shaded green advocated continental style locomotive nomenclature based experiences french branch world war tenure rail operating department conflict number followed adaptation classification system refers number coupled driving case locomotives carried numbers started followed individual original southern continued use british railways tender onwards remained plain guise british railways freight black lining description british railways crest located tender given british railways power classification locomotives renumbered british railways standard numbering system preservation locomotive class survived preservation class preserved resides york carries original number return york locomotive worked railway fiction locomotive thomas friends children television series based class
SR Q1 class