Nine Years Later, the Quebec Bridge Fell Again

On August 29, 1907, the Quebec Bridge, planned as the longest bridge span in the world, collapsed into the St. Lawrence River during construction. Seventy-five men were killed. Nine years later, in 1916, the rebuilt bridge failed again, this time while its centre span was being lifted into place. This documentary follows both disasters through the 1908 Royal Commission report and contemporary records, and explains why the two failures were completely different. What the investigators found: in 1907 the bridge itself was wrong. Its dead load was underestimated and never rechecked, and the latticed lower chords of the anchor arm beside the main pier were too weak; warnings were not acted on in time. In 1916 the design was sound: one cast-steel piece in the temporary lifting gear at a corner of the span failed, and the span fell into the river. In 1917 a new span was raised, and the Quebec Bridge still has the longest cantilever span in the world. CHAPTERS 0:00 August 29, 1907 0:28 The record span 0:57 The engineer in New York 1:32 The weight problem 2:05 The hidden weakness 2:39 The warning signs 3:11 Two and a quarter inches 3:42 The telegram 4:14 Fifteen seconds 4:47 Kahnawake 5:04 The verdict 5:42 No one in charge 6:16 Starting again 6:44 The lift 7:31 One piece of steel 8:06 Two failures, one bridge SOURCES & ARCHIVES Primary report Royal Commission, Quebec Bridge Inquiry Report, Sessional Paper No. 154, 1908 (Government of Canada Publications): https://publications.gc.ca/collection... Pages shown on screen: title page; findings (pp. 7–8 of the PDF); letters of N. R. McLure (Aug 6, 1907) and Theodore Cooper (Aug 9, 1907); the telegram of Aug 29, 1907; Appendix 12, "A Description of the Fallen Structure". Contemporary accounts of the 1916 failure and the completed bridge St. Lawrence Bridge Company, The Quebec Bridge, 1918: https://archive.org/details/cihm_77289 Canadian Government Railways, The Quebec Bridge, 1919: https://archive.org/details/cihm_79290 Photographs Wm. Notman & Son, 1916–1917, McCord Stewart Museum, Montreal (public domain): VIEW-5668, VIEW-5670, VIEW-5672, VIEW-5674, VIEW-6071, VIEW-6075, VIEW-6079, VIEW-6081, VIEW-6082 — https://collections.musee-mccord-stew... Neurdein Frères, 1907 postcards, McCord Stewart Museum (public domain): MP-0000.1154.3, MP-0000.1154.9 F. E. Cudworth, 1907, British Library, HS85/10/18815 and HS85/10/18817 (public domain; British Library "Picturing Canada" project) Sidney Jack Hayward, 1921, British Library, HS85/10/39076 (public domain) A. A. Chesterfield, 1916, Library and Archives Canada, C-003623 (CC BY 2.0, https://creativecommons.org/licenses/... https://www.flickr.com/photos/lac-bac... ; high-resolution scan e011196377 About the visuals Archival photographs and documents are credited on screen and above. Diagrams, maps and animations, including the animated reconstruction of the 1907 failure, are schematic and approximate and are labelled as such. The 1907 failure is shown as a schematic animation of the sequence described by the Royal Commission, followed by photographs of the real wreckage. Figures: the Royal Commission counted 86 men on the work, of whom 11 survived (75 deaths); some later sources give 76. Thirteen men were killed in 1916. English subtitles are available. #QuebecBridge #EngineeringDisaster #History #Documentary Image adaptations: archival photographs are cropped and tonally adjusted for presentation. Narration uses a synthetic voice.