HC Deb 04 February 1959 vol 599 c98W
Sir A. Bossom

asked the Paymaster-General, in view of his responsibilities concerning schemes for putting major electric cables underground, what is now the difference in cost between putting them underground or carrying them on pylons across the countryside as is now the custom.

Sir I. Horobin

The comparison is as follows:

Overhead line: Cost per mile Underground cable: Cost per mile
£ £
275 kV Standard Super Grid Line. 25,000 300,000 to
400,000
132 kV Standard Grid Line. 10,000 50,000 to
80,000

Costs vary according to the sizes of conductors and types of construction used. Underground cable laying costs are particularly affected by different local conditions. In the case of the super-grid, where the cost shown is an estimate, undergrounding would also present serious technical difficulties.