Tay Bridge disaster warned of their unreliability, and declined to estimate conditions at Dundee from readings taken elsewhere. One modern interpretation of available information suggests winds were gusting to . Usage of the bridge was restricted to one train at a time by a signalling block system using a baton as a token. At 7:13 p.m. a train from the south (consisting of a 4-4-0 locomotive, its tender, five passenger carriages, and a luggage van (brake van) slowed to pick up the baton from the signal cabin at the south end of the bridge, then headed out onto the bridge, picking up speed.
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