The Tay Bridge in Dundee, Scotland collapsed during a violent storm, sending a passenger train and 75 people into the Firth of Tay. It had been open for less than two years.

The bridge was designed by Thomas Bouch, who was knighted after its completion. The knighthood aged poorly.

The Court of Inquiry found the bridge was "badly designed, badly constructed, and badly maintained." A rare hat trick of failure. Some of the key issues:

1. Wind loading was essentially ignored in the design. Bouch later claimed he had used 10 psf for wind pressure, but evidence suggested even that was applied inconsistently or not at all. For context, the Board of Trade recommended 56 psf after the disaster. The bridge's tall "high girder" spans were particularly vulnerable since they acted like sails.

2. The cast iron columns had serious quality problems. Many had blowholes and defects from the foundry, and rather than being rejected, they were filled with a putty called "Beaumont egg" and painted over. Inspectors either missed or ignored this.

3. The bracing was inadequate. The diagonal tie bars connecting the columns were secured with cotters and gibs that were found loose throughout the standing portions of the bridge after the collapse. Maintenance was basically nonexistent.

4. The lugs cast into the columns for bracing connections were undersized and brittle. Several fractured lugs were found, and the design placed critical tensile loads through cast iron, which is notoriously weak in tension.

5. There were warning signs. The bridge had been observed swaying and vibrating during normal train crossings. Passengers reported unease. A speed limit was imposed but poorly enforced. Bouch apparently dismissed the oscillations as acceptable.

What makes this one stick with me is how many people had to look the other way for it to happen. The designer, the foundry, the inspectors, the railway company. Everyone had a reason to keep moving forward and nobody wanted to be the one to stop the train, literally.

Modern engineering was still in its infancy at this time. So it’s a littler easier to mark some of this up as teething problems in modern industrial society, …. Maybe. I made a calendar project with events like these every month. Check my bio.

Source of the pictures here, here, here and here

"A man slips out of his seat and he turns sideways and he's flipping in the air, he comes down and he slams down on our cart...We felt his thud. People reached trying to grab him...we couldn't." Horrified riders who were on the Goliath roller coaster at a Six Flags in Georgia say they will never be able to forget what they witnessed.

The ro-ro ferry left harbour with her bow doors open. Water came onto the car deck and she capsized within minutes. 193 people died.

Documentary built from the Formal Investigation (Report of Court No. 8074): https://youtu.be/sebnQLbXwIQ

Happened Thursday last week. The truck is still stuck.

The bridge was rated for 74 tons (per vehicle), but was given special permission crossing the bridge with centric driving, even though the total weight was about 100 tons. They had already cross 79 other bridges with the exact same weight rating.

The bridge was recently under maintenance, but apparently the bearing(s) that broke wasn't included in this operation.

Edit: specify limit was per vehicle

The canal is located just outside what is now Hamilton, Ontario, Canada. In 1857, ten years before Confederation, Ontario was known as Canada West, when Canada was a British colony known as the Province of Canada.

The train was heading from Toronto to Hamilton and was passing over the Desjardins canal when it derailed. The engine's front axle broke, throwing the engine off the tracks, gouging apart the wooden ties before the engine smashed through the wooden structure of the bridges and fell onto the frozen creek below, with one passenger car leaning almost vertically against the stone wall. Moments later, the ice broke and the wrecked train sank into the freezing water. Of 90 onboard the train, 59 were killed and 18 were injured. Almost 170 years year, it still remains one of Canada's worst rail accidents.