Firth-of-Tay-Brücke
Soon after the opening of the wet (floating) dock at Silloth, the "Carlisle Patriot" had reported both an inward bulge of the dock's west wall and bubbling at the dock sill. The company (and its supporters) had responded that neither effect was as severe or as significant as the "Patriot" was suggesting. However, in April 1879, the wall failed, dislodging one of the dock gates, and blocking the entrance to the dock with fallen masonry. The Silloth steamers ran temporarily from Maryport, whilst the failed gate and masonry were removed, after which Silloth returned to operation, but as a tidal harbour. Informed that the repair of the existing dock would mean the closure of the harbour for two years, the North British board decided to instead build a new and larger wet dock behind the old dock, which would then serve as a tidal entrance basin. The Silloth and Port Carlisle companies were amalgamated with the NBR by an Act of Parliament of 12 August 1880 and construction of the new wet dock began in 1882. The work (and financing) of this was carried out in parallel with the construction of the second Tay Rail Bridge, the NBR concentrating its efforts on these two projects. The replacement dock, 50% larger (six-acre rather than four) and costing about £90,000 opened in July 1885.