Guildford shed’s No.33019, an Oliver Bulleid designed Q1 class loco rumbles past the camera with what appears to be a Redhill to Reading service. Though the head code might suggest otherwise.
As we all know, these ‘austerity’ locos were designed during WW2. To take up less space in storage or a ship’s hold, the various section of the boiler collapse in upon themselves until almost flat, apart from the tender to a fraction of its normal length. There were plans to build a collapsing tender, but that never manifested due to wartime budget restrictions.
To open it up after disuse, steam pressure build up slowly extends the loco back to its operational length.