Retaining wall

Masonry flying arches strutting the retaining walls in Chorley cutting, Manchester-Blackpool line, L.M.S.R.

The viaduct is joined to the embankment by retaining walls, which have been strengthened since they were constructed by the addition of stay bolts extending right through the embankment and fastened outside each retaining wall.

In order to accommodate the new platform 4 and the reversibly signalled slow line, a deep cutting had to be cut back and held up in places with a concrete retaining wall.

Biddle even notes how Brunel, after observing how one retaining wall had part-collapsed during the construction of one of the GWR's Bristol tunnels during heavy rains, "decided to leave it like that and planted it with ivy to represent a ruined medieval gateway".