6 fatal errors
We all didn’t like school very much and thought that the majority of the knowledge gained there would never be useful to us. Indeed - much of what was learned in the school curriculum is often a dead weight. But sometimes it turns out that ignorance of trifles can lead to tragedy. Like for example, in these six cases, when tiny mistakes, unaccounted trifles, became fatal.
1. The collapse of the passenger liner due to square windows
Jet aircraft in the 1950s was just beginning. The first ship was the "Comet" - the brainchild of de Havilland. It was an ultramodern jet passenger aircraft with unique technical characteristics for that time and an airtight cabin. Unfortunately, in 1954, two “Comets” collapsed right in flight, ditching a total of 56 people.
The reason is ridiculously simple:
Square portholes. It was one of those annoying little things that are easy to miss when designing; but as soon as something happens, they become apparent even to the child.
Here is a bar of chocolate.What do you think, in which place it will break, if you press it?
Right along these grooves.
So, the square window consists of four 90-degree grooves, and therefore, it has four weak points. If your house was pressed, the crack would surely pass through the corner of some window:
Have you noticed that the windows in all planes are round? This is not done for beauty - the round shape does not allow the plane to be torn to pieces. The pressure is distributed over the entire curve, instead of going through the cracks in the corners (as it turned out) and tearing the plane to shreds.
Believe me, it was not easy to find out. Experts had no idea why the design of the aircraft was falling apart, until they tested the structure by repeatedly simulating the pressure on the cabin. Of course, the fuselage, in the end, burst, and the gap began exactly from these notorious angles. Since then, the windows of all aircraft are only round.
2. The angle of the runway causes the fighter to crash
You do not need to be a pilot to understand - to land an aircraft on an aircraft carrier is extremely difficult. This runway in miniature, stuffed with other planes, in addition also swings on the waves. But there was another problem ... ridiculously simple.
The first aircraft carriers looked like this:
Floating runway. What else could she be?
On the one hand - the aircraft waiting for takeoff, on the other hand you are trying to land. If you don’t stop on time, there will be one big ball of hellfire. And to stop on time, it didn’t bother you; the capture of the brake cable required a serious skill. In the end, the aircraft carriers went according to a logic logic and installed networks that could stop the aircraft that did not catch the brake cable. However, the aircraft missed the brake cable sometimes managed to jump even through the network.
And what was the brilliant innovation that made the landing much safer?
They turned the runway about 9 degrees.
Just something! But with a crooked angle the plane, which did not catch the cable, could give full gas, go off again, and make another attempt. And other planes quietly waited outside the runway from harm's way.
3. The huge gallery collapsed due to (seemingly) a minor design change.
The owners of the Hyatt Regency, a new hotel in Kansas City, dreamed that they would have everything with all sorts of snoops and whistles. The architectural firm responsible for the design of the building proposed to make several galleries that would be fixed to the ceiling. The idea was very elegant.That's just the embodiment led to the death of more than a hundred people.
The project’s flaw was ridiculously simple: One long rod was replaced by two short ones.
If there is a principle that is the same for all human beings, it is that we always prefer the path of least resistance. The original plan was to place two galleries one above the other, both of which had to be supported by one long rod attached to the ceiling. Like this:
Looks pretty simple, right? The whole structure hangs on one long rod, which makes it as strong as it is difficult to assemble - the rod must pass through both galleries. The thing is that with large details it is difficult to manage - dragging a table into the house is much easier when disassembled. In addition, the rod must have a thread along the entire length - so that you can tighten the nut to the upper gallery.
The steel company responsible for manufacturing the rod introduced one small change into the structure - replacing one long rod with two short ones. Like this:
This small change killed 114 people, crippled 216, and cost the company $ 140 million in lawsuits.
One rod, two nuts.Each nut was supposed to carry the weight of only its own platform. What is good, because each nut (and a welded beam to which it is screwed) can withstand the weight of only one gallery. After changing the design, it turned out that the top nut was supposed to carry the weight of the two galleries. The tragedy was inevitable. However, despite the evidence, none of the engineers and builders did not notice this error. And so, one night during a dance competition, the carrier nut could not stand it, and both galleries collapsed. During subsequent trials, it turned out that neither the steel company, nor the engineering firms responsible for the construction, had even bothered to make a calculation that would reveal this glaring flaw.
4. The hinges of the nightclub became the cause of the death of several hundred people.
In Boston, the thirties and forties, the most fashionable place was the nightclub Cocoanut Grove. Life was always in full swing, local celebrities gathered. Well, of course, it was often not overcrowded. Sometimes the people gathered nearly twice the official capacity of the institution, which was 460 people. Neither the owners nor the visitors did not bother.Until 1942, when a fire killed 492 people. The paradox is that the cause of most deaths was not fire at all, but ... door hinges. The reason is ridiculously simple:
The waiter’s assistant in the dark could not find an electrical outlet. To look around, he lit a match and accidentally burned some flammable interior detail. The guy did not even have time to blink an eye as the fire spread to the bright scenery imitating the rainforest, and soon the whole club was in smoke and flame. It all happened so lightning that the bodies of some of the victims were later found sitting with glasses in their hands.
Among the numerous safety violations - from the number of visitors to the use of dry needles in the design of the club - there was one fatal flaw that no one could even think about: all the doors of the restaurant opened to the inside. Firefighters calculated that if the doors were opened outside, the list of victims would have been reduced to three hundred names.
5. The Tacoma-Narrows Bridge collapsed due to being too solid.
The Tacoma-Narrows Bridge (One of the largest suspension bridges in the United States; approx. Mixednews) was considered a engineering marvel until it collapsed into the Tacoma-Narrows Strait, killing the dog left in the car.Its owner safely reached the safe place (while prudently taking the camera with him, with which he shot unique, sensational shots). Now, on the example of this bridge, future physicists and engineers are explained how not to do it.
The reason for what happened is ridiculously simple: The bridge was too solid, without cavities.
Have you noticed how fragile the largest bridges look? They literally translucent:
If you think that this is done for the beauty or economy of metal, you are deeply mistaken. The real purpose of all this openwork - to pass air. You can strengthen the bridge as firmly as desired - and it will still swing in the wind. This can not be ignored. The designers of the bridge across the Tacoma Strait decided not to bother with such nonsense. They decided that there was already enough space for the wind:
They were wrong.
From the very beginning it was clear that there was something wrong with the bridge. As soon as the wind rose, the canvas began to bend, shake, and get out, for which, during the construction, the bridge received the nickname “Galloping Gertie” among the people. One fine day, the oscillation frequency of the wind flow coincided with the natural frequency of oscillation of the bridge structures.The central span of the bridge fluttered like an autumn leaf, convulsed and collapsed into the strait.
Construction of the new bridge was completed only in 1943. This time, open trusses, stiffenders, expansion joints and vibration damping systems were introduced into the structure.
Here is what it looks like now:
6. Titanic sank because the central screw could not change the direction of movement
Theories on how to prevent the death of Titanic - a lot. Some believe that the iceberg had to be rammed into the forehead and not bypassed, others did not have to anger God with boastful statements about the ship’s unsinkability ... Creative with creative, but most critics still sin on the insufficient attention that the creators of Titanic paid to security measures.
The real cause of the tragedy turned out to be ridiculously simple: the central screw of the steering mechanism could not change the direction of movement.
On the Titanic was installed three screws. Two external, which were driven by piston engines, and the central - driven by a steam turbine. Steam turbines have a significant advantage compared to their piston counterparts - a combination of smaller size and greater efficiency. But there is a drawback - they can only rotate in one direction.The steam cannot change direction, and therefore the shaft, driven by steam, will only spin in one direction.
Therefore, when the senior mate, Murdoch, tried to give a “full back” to avoid colliding with an iceberg, the outer screws spun in the opposite direction, while the central one just stopped. However, the central screw was directly in front of the steering pen. After it was turned off, less water fell on the steering feather, making it extremely difficult to steer the vessel.