Circle line (London Underground) Circle Stock, at first painted red and cream, later painted red all over to reduce costs. These trains included first-class accommodation, but this was downgraded in 1940. From 1947 these were replaced by 5-car trains of O and P Stock, with doors remotely operated by the guard, released by the transfer of F Stock to the Uxbridge line. The 1933 London Underground Beck map shows a Metropolitan line north of and stations and a District line south of these points. On the 1947 map the Metropolitan and District lines were shown together in the same colour and two years later
London Underground S7 and S8 Stock The DMIs show destination and line, and can display other messages such as safety notices. There are also DMIs on the exterior, with text alternating between destination and line, and on S8 stock the type of service, i.e. fast, semi-fast or all stations. Another new feature is that to prevent accidental pressing of emergency alarms there are flaps over the alarm buttons where the wheelchair spaces are. The air-conditioning system, the first on London Underground trains, is supplied by Mitsubishi and has two circuits so that if one fails there is still 50% capacity. Through gangways from car to car