The Southwick Hill Tunnel is a 490-metre twin-bore road tunnel to the north of Southwick,

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

. The tunnel was opened in early 1996 as part of the A27 Brighton bypass and carries the road under Southwick Hill. The border between

West Sussex West Sussex is a county in South East England on the English Channel coast. The ceremonial county comprises the shire districts of Adur, Arun, Chichester, Horsham, and Mid Sussex, and the boroughs of Crawley and Worthing. Covering an ...

and the unitary authority of

Brighton and Hove Brighton and Hove () is a city and unitary authority in East Sussex, England. It consists primarily of the settlements of Brighton and Hove, alongside neighbouring villages. Often referred to synonymously as Brighton, the City of Brighton and H ...

is close to the eastern entrance of the tunnel. Non-motorised traffic (e.g. pedestrians, cyclists) and mopeds under 50 cc are prohibited from using the tunnel, with a warning sign indicating an alternative route.

Engineering

The tunnel was built through the Newhaven Chalk layer using the

New Austrian Tunnelling method The New Austrian tunneling method (NATM), also known as the sequential excavation method (SEM) or sprayed concrete lining method (SCL), is a method of modern tunnel design and construction employing sophisticated monitoring to optimize various wa ...

. The structure uses

shotcrete Shotcrete, gunite (), or sprayed concrete is concrete or mortar conveyed through a hose and pneumatically projected at high velocity onto a surface, as a construction technique, first used in 1907 invented by Carl Akeley. It is typically ...

and untensioned bolts.Bowden 2013 https://qjegh.lyellcollection.org/content/46/2/203

References

Road tunnels in England Adur District Transport in West Sussex Buildings and structures in West Sussex

{{Europe-tunnel-stub

Engineering

See also

References