This paper gives details of a fully engineered single-mode route between Liverpool and Preston, England. The installation of the cable was completed in late 1983 and the full cable sub-system will be completed in early 1984 with the line equipment following shortly afterwards. This is a 140 Mbit/s system which will operate over 50 km. Details are given of the cable subsystem, the optoelectronic devices and the line terminal equipment. Consideration is given to the systems budget in terms of attenuation.