A large stabilisation project near Tain has now been completed. Preparation work began in September with night-time line occupations and ended in February. Victorian era railway embankments were often built at a much steeper angle than is allowed nowadays, and this section of cutting was affected by what's known as 'translational failure' when sections of the top layer break contact with a more stable layer below and begin to slide downwards (see diagram).
There are three other kinds of landslip and each requires different remediation. A translational failure is stabilised by using 'soil nails' to attach a high tensile mesh facing incorporating erosion-control matting.
This cutting is around 600m long and up to 10.5m high. Rope access operatives using bespoke drilling equipment installed 1,800 nails, up to 6m in length. At this stage this is not the prettiest look, but in time vegetation will probably grow through the mesh. Network Rail contracted the work to specialist company QTS Group.