Cover image: https://pixabay.com/photos/bridge-collapse-damage-312873/
Failure is Integral to Engineering
By examining failures, we can prevent them from happening again.
The Titanic was believed to be an unsinkable ship. It was made of 25mm thick steel plates fastened together with rivets. The steel was thought to be impenetrable.
But what the ship’s engineers didn’t know at the time was that under low temperatures and high impact loading, combined with the high sulphur content of the steel, the plates would become brittle. So much so, that when the ship struck an iceberg on its way across the Atlantic, they ripped open like a tin can.
Engineering failures like the Titanic are embarrassing and costly, but they are integral to the profession. Henry Petronski, an American engineer specialising in failure analysis once said “Failure is central to engineering. Every single calculation that an engineer makes is a failure calculation. Successful engineering is all about understanding how things break and fail.”
When an engineer begins their design, they often start with a series of assumptions based on the intended usage, applicable codes and past experience. These assumptions could be how much weight a bridge could support, how much water the occupants in a building intend to use, or the size of a product.
As the design takes shape and more information becomes available, the assumptions are replaced with calculated data. At several stages throughout this process, engineers run extensive tests on their designs to see how and where they might fail. Then they strengthen the failed portion and re-test it again, over and over, until the design no longer fails.
Engineering as a profession has only been regulated in Canada for around 125 years. Nowadays, engineers have several tools at their disposal to test their designs before they are put into production. There are decades of data on construction materials, climate and how humans interact with design. Engineers also have computer simulated models that can be used to test designs under both normal and extreme conditions, before they are constructed.
But this wasn’t always the case. Early engineers saw a lot of advancements with respect to available materials, manufacturing processes and how people use infrastructure. These advancements were exciting and necessary, but also provided several unknowns about how the new materials and designs would react under changing conditions.
Several of the codes, standards and governing bodies that we have today are borne out of engineering failures. After the Titanic sank, for example, the SOLAS (Safety Of Life At Sea) treaty was formed in 1914 to address all aspects of ship design, construction and navigation at sea.
The Quebec Bridge collapsed during construction on August 29, 1907 due to underestimated design capacity and a lack of engineering oversight during construction. A segment of the replacement bridge also collapsed on September 11, 1916 due to a material flaw in one of the temporary supports used to transport and hoist the segment.
The aftermath of these collapses saw the creation of the American Association of State Highway and Transportation Officials in 1914—which publishes transportation standards and policies throughout the United States—and the American Institute for Steel Construction in 1921—which develops specifications and design guides for structural steel construction. Both of these standards were created as a means to fund research that was too difficult and expensive for manufacturer’s to do themselves, and are still in use today.
Fire safety standards have also been created as a result of engineering failures. A scrap bin in the Triangle Shirtwaist Factory caught fire on March 25, 1911 and the fire spread quickly throughout the factory. It was located on the upper three floors of a 10-storey building in New York City. Due to crowded floors, locked doors, and inadequate exiting—both via stairwell and fire escape—nearly 150 workers died.
This disastrous fire led the National Fire Protection Association to publish their first safety bulletin outlining the importance of evacuation drills in public spaces. Today, the National Fire Protection Association has over 300 codes and standards, ranging from fire prevention to extinguishing, intending to minimise the possibility and effects of fire on occupants and infrastructure.
More recently, we saw the devastating collapse of Champlain Towers in Surfside Florida in 2021 which is still under investigation. This failure caused building owners and operators around the world to take a good hard look at their infrastructure and prioritise the critical repairs they had been putting off.
Engineers design to the best of their ability, using all of the tools at their disposal. Sometimes, failures slip through the cracks—whether due to changing materials, innovative designs, unforeseen site conditions or even a lack of peer review. But only by learning from the engineers and failures that have already occurred can we prevent them from happening again. It’s unclear how much of the Titanic’s design issues were negligence or just unknowns at the time, but it has made a lasting impression on the development and oversight of ships worldwide.
Nicole Imeson is a mechanical engineer in Calgary, Alberta. She has spent her career overseeing the construction of plumbing, HVAC and fire protection systems in various facilities across Western Canada. In her spare time, Nicole hosts a podcast about engineering failures called Failurology.