River Tay River Tay The River Tay () is the longest river in Scotland and the seventh-longest in the United Kingdom. The Tay originates in western Scotland on the slopes of Ben Lui (), then flows easterly across the Highlands, through Loch Dochart, Loch Iubhair and Loch Tay, then continues east through Strathtay (see Strath), in the centre of Scotland, then southeasterly through Perth, where it becomes tidal, to its mouth at the Firth of Tay, south of Dundee. It is the largest river in the UK by measured discharge. Its catchment is approximately , the Tweed's is and the Spey's is
Tay Bridge disaster anomalously high because of peculiarities of the site (one of the highest points on the Wirral.<ref name="The Wirral Hundred/The Wirral Peninsula"></ref>): a wind pressure of would overturn railway carriages and such events were a rarity. (To give a subsequent, well documented example, in 1903 a stationary train "was" overturned on the Levens viaduct but this was by a 'terrific gale' measured at Barrow in Furness to have an average velocity of , estimated to be gusting up to .) A new double-track Tay Bridge was built by the NBR, designed by Barlow and built by William Arrol & Co. of