passenger train was derailed and crashed down the embankment. The investigation led by Yolland established the root causes very quickly, and further details emerged at the public enquiry set up by the Board of Trade. By tracing the marks on the sleepers behind the derailed train, Yolland established that the small 4 wheel carriage behind the locomotive had suffered a broken wheel rim, which disintegrated and caused the derailment. The driver braked hard and the carriages behind cannonaded into the 4 wheeler, crushing it entirely, as well as themselves running off the track. The accident occurred near to a small bridge crossing the Oxford canal and 34 passengers died from their injuries. Tay bridge disaster (1879) He was a member of the Board of Inquiry into the Tay Bridge disaster, with fellow members Henry Cadogan Rothery and William Henry Barlow. A train was lost on the night of 28 December 1879 while crossing the Tay estuary just south of Dundee. The centre section of the 2-mile-long bridge collapsed during a storm, with the loss of all on board the train. The inquiry sat initially in Dundee to hear eyewitness accounts of the accident, and then in London for expert evidence. They produced their final report in June 1880, and concluded that the bridge was "badly designed, badly built and badly maintained". Yolland went on to report on the state of other Bouch bridges, especially a very similar structure at Montrose, the South Esk Viaduct. Yolland found that the bridge was in such a dire state, with the piers not perpendicular, that it failed under test and needed to be demolished and replaced by a more stable double-track structure. The directors of the owning company, the North British Railway, did not "feel free to adopt this suggestion" and the Board of Trade allowed the company to build a less expensive replacement, retaining their narrower and less stable single-track design. Honours and awards Fellow of the Royal Astronomical Society 1840 Fellow of the Royal Society 1859 Fellow of the Royal Society of Arts 1860 Companion of the Order of the Bath 1881 Notes References Further reading Vetch, R. H., revised Matthew, C. G. (2004): Oxford Dictionary of National Biography. Oxford University Press. 1810 births 1885 deaths 19th-century British astronomers 19th-century British engineers Companions of the Order of the Bath Fellows of the Royal Society Royal Engineers officers People from Atherstone People from