The Plessey BICC 140 Mb/s multimode London-Birmingham long wavelength route is one system meeting BT trunk network requirements. This 205 km route is divided into 25 sections and comprises Terminal and Intermediate Station Equipment in TEP1E equipment practice and buried and in-station regenerators. The system employs LED sources and PINFET receiver modules. A microprocessor based fault locating supervisory system is provided. The cable sub-system uses loosely tubed fibres jointed using a 3-Rod splice. There are also a number of conductors to provide for ancilliary services. The overal cable joint closure uses an injection welding technique. The fibre has a nominal minimum bandwidth specification of 800 MHz-km and a nominal maximum attenuation of 1.6 dB/km.