Simon Dunbar

Said the following about Dover Sea Wall:

“On the morning of 24th December 2015 part of the Sea Wall, supporting the railway line between Dover Priory and Folkestone Central stations, adjacent to Shakespeare Tunnel cracked and collapsed following a severe overnight storm. The rail lines were immediately closed to rail traffic with the consequent effect on both passenger and freight services.

Network Rail instigated emergency action over the Christmas and New Year period through the Framework Contractor Costain to prevent further failure of the Sea Wall. The emergency works comprised placement of available rock to the toe of the wall as a buttress to the section of wall considered to be at risk.

Early in the New Year 2016 it was determined that a 250m length of Sea Wall varying in height between 8m and 10m would require remediation before the rail line could be reopened. Costain’s were instructed to complete the emergency works as necessary whilst also drafting remedial options to provide a further life span of 120 years to the solution within the earliest possible date for reopening the route.

The remedial options were drafted, with the design process being handled by Tony Gee & Partners, together with the necessary cost and programme implications and the selected option agreed with Network Rail by the end of February 2016.

On agreement of the selected option Costain were instructed to continue with the works under a cost reimbursable interim contract whilst more detailed design, fully integrated programme and proper estimated cost enabled a target price to be agreed with the cost reimbursable element being included within the overall contract sum. The target price was agreed at a figure that was less than the initial cost implications provided in the early optioneering.

The works comprised the construction of a fully independent viaduct supported on 132 number 900 dia. piles behind the failed sea wall. To achieve this objective significant major plant had to operate in a narrow corridor of the width of two railway lines. This construction provided the remedial track bed whilst rock armour placed in front of the existing sea wall dissipated wave action against the sea wall to prevent further deterioration. The design allowed the rail line to be reopened on the viaduct support prior to the rock armour being completed providing the earliest possible date for reopening the rail line.

During the initial optioneering the programme date for reopening the rail line was given as the 5th September 2016 on the basis of 24/7 working. The site was fully set up for 24/7 working including a full catering facility 24/7 and irrespective of the vagaries of any detailed works programme the first train ran on the line at 04.30 on Monday 5th September 2016. Currently the rock armour works are progressing, after finalisation of all necessary statutory processes and finalisation of the complete works is anticipated during the early part of 2017.“