The paper commences with an explanation of the need for reliable bulk-mail elevators in multi-storey sorting offices; it continues with a brief description of the Langton riser. There follows an historical review of Post Office experience with such machines, including references to the first scale model, early operational experience, and the design changes subsequently introduced. Mention is then made of the improved reliability of the redesigned risers. In conclusion, brief descriptions are given of the steps being taken to overcome the remaining shortcomings.
