British Railways / British Transport Commission instruction book "Instructions and Diagrams for Loading and Securing Long, Projecting and otherwise exceptional Loads, also Procedure regarding Acceptance and Conveyance of Out-of-Gauge and otherwise exceptional Loads", published 1 November 1956. 59pp. Publication no. B.R. 20426 3. Instructions and Diagrams for Loading and Securing Long, Projecting and otherwise exceptional Loads, also Procedure regarding Acceptance and Conveyance of Out-of-Gauge and otherwise exceptional Loads