Àwọn wo ni àwọn ilé-iṣẹ́ ojú irin "Big Four" ní UK kí ìjọba tó sọ wọ́n di ti orílẹ̀èdè
Awọn mẹrin nla ni London, Midland ati Scotland (LMS), London ati North Eastern Railway (LNER), Great Western Railway (GWR) ati Southern Railway (SR)