Duckbill mechanical ground anchors supplied by WT Anchor Systems are securing rock fall netting on the newly stabilised Merstham Cutting near Croydon in Surrey, on the main London to Brighton railway line.
The cutting is up to 25m high.
The 146 MR3 Duckbills were installed on the 120m long section by WT Anchors' sister company WT Specialist Contracts. Operatives abseiled down the steep slope and installed the anchors using handheld breakers. The 3m long anchors with 12mm diameter stainless steel bar were driven through the surface soils and into the underlying chalk before being set with a working load of 30kN.
Sheffield based HRS Services then suspended and stitched the protective blanket of Maccaferri rockfall geogrid netting that will allow vegetation to grow and reduce the risk of anything falling onto the tracks below.
Work was carried out for Laing Railtrack Partnership and its contractor Fondedile, which installed vertical and horizontal reinforced concrete beams tied into the chalk using mini piles in tension and compression to stabilise the slope (GE November 2001).