Th LNR Clss 4 s clss f strmlnd 4-6-2 stm lcmtv dsgnd by Ngl Grsly fr th Lndn nd Nrth strn Rlwy n 1935. Thr strmlnd dsgn gv thm hgh-spd cpblty s wll s mkng thm nstntly rcgnsbl, nd n f th clss, 4468 Mllrd, hlds th rcrd s th wrld's fstst stm lcmtv. Thrty-fv f th clss wr blt t hl xprss pssngr trns n th st Cst Mn Ln rt frm Lndn Kngs Crss v Yrk t Nwcstl, nd ltr v Nwcstl t dnbrgh, Sctlnd. Thy rmnd n srvc n th st Cst Mn Ln ntl th rly 1960s whn thy wr rplcd by Dltc dsl lcmtvs; thy thmslvs prvng t b wrthy sccssrs t th 4s. Svrl 4s sw t thr rmnng dys ntl 1966 n Sctlnd, prtclrly n th brdn – Glsgw xprss trns, fr whch thy wr sd t mprv th tmng frm 3.5 t 3 hrs.