allocated to its film department. Despite early GPO films primarily educating and promoting the public about its services, as with The Coming of the Dial (1933), they were also largely intended to ward off privatisation and promote a positive impression of the post office and its employees. Night Mail originated from the desire to produce a film that would serve as the public face of a modern, trustworthy postal system, in addition to boosting the low morale of postal workers at the time. The postal sector had seen an increase in profits in the late 1920s, but by 1936 wages had fallen 3% for the mostly working class GPO employees. The Trade Disputes and Trade Unions Act 1927 had seriously curtailed postal union power, and the Great Depression fostered a general mood of pessimism. The liberal-minded Watt, Wright, Grierson, and other GPO film unit members, therefore, wanted Night Mail to focus not only on the efficiency of the postal system but its reliance on its honest and industrious employees. Pre-production In 1935, directors Harry Watt and Basil Wright were called into Grierson's office who informed them of the GPO's decision to make a documentary film about the postal train that travels overnight from London Euston to Glasgow, operated by the London, Midland and Scottish Railway (LMS). Watt had no knowledge of the service, and claimed the idea was originally instigated by Wright. Wright prepared a rough shooting outline and script by travelling on the railway and used conversations picked up by a stenographer to write the dialogue, all of which was used in the film. Watt then used the rough version to write a full script as the outline had lacked enough detail, "but there was a shape". He contacted the LMS and was amazed to find the railway had its own film director who offered assistance. Watt described the research process as "reasonably straightforward", which included multiple trips along the railway, and soon completed a full treatment. Wright later said that Watt changed his dialogue towards "a more human and down-to-earth" style which he praised him for doing. Early into development, however, Wright had to dedicate more time to other projects and left Watt in charge as director, yet both are credited as the film's two writers, directors, and producers. Initially, Grierson sent his team to observe the postal train staff at work with the aim of producing an