Developments in UK cable-installation techniques to take account of environmental thermal resistivities

Accounts are given of the authoritative and novel recommendations concerning the current ratings of distribution cables which were promulgated by the ERA in 1969, and of the manner in which long-established rating and installation practices for transmission cables were transformed during the period 1962¿1968. The second of those two accounts is preceded by a description of the evolution, composition and characteristics of the special backfills introduced during that period, provision of which is now obligatory for all buried CEGB transmission circuits. Attention is drawn to the dearth of information on the extent to which the latest ERA recommendations are being implemented; it is suggested that consideration should now be given to the possibility of wider application of some techniques now peculiar to one or other of the two main fields.