#structural failure

On July 17, 1981, the Hyatt Regency Hotel in Kansas City, Missouri, suffered the structural collapse of two overhead walkways. Loaded with partygoers, the concrete and glass platforms cascaded down, crashing onto a tea dance in the lobby, killing 114 and injuring 216. Kansas City society was affected for years, with the collapse resulting in billions of dollars of insurance claims, legal investigations and city government reforms.

The Hyatt had been built just a few years before, during a nationwide pattern of fast-tracked large construction with reduced oversight and major failures. Its roof had partially collapsed during construction, and the ill-conceived skywalk design progressively degraded due to a miscommunication loop of corporate neglect and irresponsibility. An investigation concluded that it would have failed even under one-third of the weight it held that night. Convicted of gross negligence, misconduct and unprofessional conduct, the engineering company lost its national affiliation and all engineering licenses in four states, but was acquitted of criminal charges. Company owner and engineer of record Jack D. Gillum eventually claimed full responsibility for the collapse and its obvious but unchecked design flaws, and he became an engineering disaster lecturer.

Sometimes crisis appear suddenly. Other times they sneak up on you like a deadly disease. I think the second type is worse as it gives you time to think and worry and get all twisted up. I have had a few.

One thing about me is I take on things that have never been done before. I invent stuff to solve problems. There is risk in that, but I love the challenge too much to say no. If the numbers support me I keep going.

Several years ago I did a design for a strange cover system to go on top of a large water treatment facility. This involved a fabricated truss made from composite materials so as to be corrosion proof. I had gobs of numbers and gigabytes of FEA studies. There was one particular detail that was key to it working. This was how the very end which sat on a concrete edge was shaped to carry the weight. The problem was nobody could see it once it was made.

The parts were to be built in China. Our company owned the factory so generally we have great control over what is built. The owner of our company was from Hong Kong originally but his family was from China proper in the nearby region. He traveled back and forth between our office in North America and the factory. He was very clever and a true entrepreneur. But not clever enough.

The detail I mentioned was tricky to build. And once the part was closed in you would never see it. Tricky means expensive. I had a meeting with our owner before he left for the factory and discussed this detail and told him how important it was. He made no objections.

The parts were fabricated and shipped to the site in California. Installation went well with only a few minor questions about fit and order of assembly. All was well.

After almost a year the contractor got in touch about these cracks that were appearing in the ends. At first I was not concerned as there were only a few places, and I knew that inside this box shape was this detail that was actually carrying the load. We hired a local shop to go and patch the cracks. Everything was fine for a while longer.

More cracks appeared. This time I got a photo that was able to see inside the box and it was empty. The internal frame part was missing. I contacted the factory. Are there any photos of the fabrication? No we have no pictures. They always have pictures. Actually I should have suspected something as the factory did weekly reports that always had photos, except this project. I was busy with other things so did not ask back then.

As best as I can figure our owner wanted to save money on the job so told the factory to not follow the drawings. It would be fine. Nobody can see. He is the boss. Oh and don't tell the engineer. After pushing very hard I got them to admit that all the parts had been made that way. They did have photos.

At this point there is little choice as to what to do. But it is scary as this kind of issue can cripple a company. If all these parts did not have this internal feature it would not survive the loads it was intended to. If we fixed it by replacing all these parts our company might not survive. The units on site did not fail, these were only cracks so far. There were other secondary load paths and my FEA on the "missing" configuration showed that the safety factors were far less, and not right, but no so dangerous people could not work on the cover area in the interim.

I agonized over this. It was a weekend with little sleep as I really had no choice. I knew what was wrong. What happened was not my fault, but I was responsible now. This is an OH Shit moment. Wonder I do not have an ulcer.

I informed the contractor who informed the owner. I informed our management. Our old boss had passed away so he could not offer resistance. The contractor sent me a nice letter appreciating my candor and honesty. I know some professions where you hide behind a phalanx of lawyers and let the courts deal with it years later. I am not that kind of person.

Eventually our company took it on to fix the pieces. New sections of the ends were fabricated in China with photos showing all the details. I redesigned the ends to let me see inside the critical area. We shipped the new ends to our shop and had all the defective units shipped there too. We cut off all the bad ends and spliced on all the new ones. We shipped them back.

I am sure it cost far more than the original job to do the fix. I was proud and a bit surprised we did not go bankrupt.

May 1, 1913: Collapse of a Large Steel Pipe

May 1, 1913:  Engineering News article. Collapse of a Large Steel Pipe. “A steel pipe, 14 ft. in diameter, connecting two reservoirs of the Balleville Hydroelectric Co., near Fremont, Ohio, recently collapsed, while being filled with water. The views herewith show the nature of the failure and give some idea of the construction and arrangement of the pipe. Examination of the design shows that the…

May 1, 1913: Collapse of a Large Steel Pipe

May 1, 1913:  Engineering Newsarticle. Collapse of a Large Steel Pipe. “A steel pipe, 14 ft. in diameter, connecting two reservoirs of the Balleville Hydroelectric Co., near Fremont, Ohio, recently collapsed, while being filled with water. The views herewith show the nature of the failure and give some idea of the construction and arrangement of the pipe. Examination of the design shows that the…