[1] The system originated in the construction during 1962–3 of the 200-mile (320 km) high-pressure methane pipeline from Canvey Island (on the Essex coast) to Leeds.
The pipeline had 150 miles (240 km) of spur lines, supplying gas to area boards.
[4] The Gas Council was responsible for this £10 million co-operative scheme and the construction details were a joint effort of the distribution engineers of the area boards.
LNG had first been imported to Canvey from Louisiana in February 1959, and piped to Romford gasworks as feedstock to a reforming plant.
[10] Gas from the West Sole field was first dispatched from the Easington terminal on the Yorkshire coast in July 1967, via Feeder No.
[14] North Sea gas first reached Scotland in Spring 1970 at Coldstream via an extension of the Leeds-Newcastle pipeline.
11) were laid via Bathgate to Partington and Bishop Auckland to connect to the NTS in England, a total pipeline length of 595 miles (950 km).
Initially they carried gas from southern England into Scotland until the Frigg field began production via St Fergus in September 1977.
North Wales was also connected in 1969 via a 24-inch/18-inch pipeline from Audley Cheshire to Maelor near Wrexham (an extension to Feeder No.
[14] In addition to these distribution pipelines, in 1971 the area boards began to supply natural gas directly to major consumers.
6), and the West Midlands Gas Board laid six similar 'spine' mains into industrial districts of Birmingham and the Black Country.
[16] Later (post-1983) feeder mains not described above include:[17] The NTS now comprises over 7,600 km of welded steel gas pipelines.
[18] These were peak-shaving facilities used to support the NTS at times of high demand, and to ensure security of gas supplies at strategic locations.
When demand was high, liquefied natural gas was pumped from storage tanks, heated in vapourisers to a gaseous state and delivered into the NTS.
When demand was low, gas was withdrawn from the NTS and liquefied by cryogenic cooling to minus 162 °C to replenish the storage tanks.
[34] The decline of supply from the UK continental shelf since 2000[35] and the sharp increase in LNG imports during the 2021 natural gas supplier crisis have made the composition more variable, though still within the calorific value limits.
[36] This facility, owned by Centrica, was closed in 2017 due to maintenance costs[36] but about 20% of its capacity was reopened in October 2022.
This was followed by inserting metal tubes into the holes and filling the annulus with cement to create a leak-tight seal.
Water was injected into the wells to dissolve the salt and create brine which was supplied to local industry for the production of bulk chemicals, such as soda ash and chlorine.
It also ensures that the temperature rise across the compressors is not high enough to require after-coolers to prevent damage to the pipeline protective coatings.
Financial transactions between gas transporters are managed by Xoserve, based in Solihull, which was a department of National Grid before it became an independent company.