Lifts, Trains and Information Technology
Reading the blog of Ivan Sagalayev, I found a reference to an article that seemed to me an interesting and worthy translation.
George Westinghouse was not a theorist, but one of the great inventors of the 19th century. Perhaps his most famous invention was the air brake for a train in 1869. A little later more.
Today I would like to talk about the synthesis of Westinghouse’s ideas and the role they can play in information technology.
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The first trains were called Trolleys (Wagonsway) and were used in Germany as early as the 1550s. They rode on horseback until 1804, when Richard Trevithick , funded by Samuel Homfray, used a steam engine to pull 10 tons of iron and 70 people for 9 miles. This was the beginning of modern trains.
Immediately an important problem arose: how to stop the train? Just drowning the locomotive is not enough, because the trains were long and moving fast. The inertia is too great for the locomotive to stop the train by itself. The first method used was simple: the operator was assigned to each car, and pulled the handbrake, at the signal of the driver. Pretty soon, the direct air system came to replace the direct air system — when the driver wants to stop the train, he opens a valve that sends compressed air to each car. The air forces the brake to press on the wheel. The train stops. Very simple.
And here another problem appears: how to stop the train safely. Direct air brakes worked well if they worked. But if the compressed air tank is empty, or the pressure is not enough, or there is a leak on the line, the brake will not work. The train won't stop. And this is a problem.
The genius of Vestnighaus was in the invention of reverse air brakes. His great idea was to use compressed air for the train to travel, not stop. Here is how his system worked: The brakes in each car were pressed against the wheels with a strong spring. In this state, the train could not move. If the driver wanted to move, he let in the compressed air, which depressed the brakes from the wheels, which allowed the train to start moving.
This, I think, was very clever. Notice, if the tank with compressed air was empty, or the pressure was not enough, or there were some leaks, then the train stopped. The brakes could not fail, as they are always pressed to the wheels by springs.
This system is used today. One day, I was on the Amtrac train (Amtrac) going from DC to Princeton, when we stopped in the middle of the road. It was late at night, and everyone wanted to go home, and someone would ask the conductor when he passed by, what happened? He answered us in technical jargon: “The train does not want to go” (“The choo-choo she no go”)
We later learned that the air line was broken and the brakes were released. We stood for about an hour before we installed a new hose and restored the integrity of the air duct system.
Lifts are even older than trains. They existed in immemorial times. But it was not until the middle of the 19th century that tall buildings appeared, so that the reliability of elevators became quite an important task. As long as the buildings were 6 floors or less, security was not so critical, although I wouldn’t enter an unsafe elevator, even at such a small height. Anyway, as the construction of high-rise buildings, elevators should not only be safe, but also look like that. Otherwise, people will be afraid to use them.
In 1865, Elisha Otis solved the problem of elevator safety. He invented the mechanism that will stop the falling lift, even if the supporting cable breaks. The solution was that the cable pulled the elevator brakes inward, but as soon as the cable weakened, the brakes were released and prevented the fall.
Otis's brilliant insight had no immediate success. He realized that he needed a visual demonstration of the brake mechanism to give the public a sense of security. During the first world exhibition in 1854 in America, Otis built an open elevator shaft. Several times a day, he climbed into the elevator, and cut the cable from the inside. Since the mine was open from the front, all viewers saw it. As soon as the elevator began to fall, the mechanism immediately safely blocked it. What they said every time: "Everything is in order, gentlemen, everything is in order"
This multi-thousand, visual demonstration ultimately led his company to success and made high-rise buildings possible.
I think there is a powerful principle used in the security system of both the train and the elevator. Both are designed, so no active action is required. Instead, security is built into the system:
The key principle should be this: do not rely on the action, but on the properties of the system. Make a default state, a passive state, a safe state, so that when the system crashes, it will fall into security.
I always liked such systems. I often wondered if we could use similar passive methods to create better computing systems. Can we, for example, create a system safe from viruses using passive methods? Is there a formal model of a passive or active system that we can use as an argument that such a system is possible in principle?
Is it possible to use the power of passive methods used by Westinghuz and Otis to solve computer problems?
Lifts, Trains and Information Technology
Possible methods for creating secure systems.
George Westinghouse was not a theorist, but one of the great inventors of the 19th century. Perhaps his most famous invention was the air brake for a train in 1869. A little later more.
Today I would like to talk about the synthesis of Westinghouse’s ideas and the role they can play in information technology.
')
Train brake:
The first trains were called Trolleys (Wagonsway) and were used in Germany as early as the 1550s. They rode on horseback until 1804, when Richard Trevithick , funded by Samuel Homfray, used a steam engine to pull 10 tons of iron and 70 people for 9 miles. This was the beginning of modern trains.
Immediately an important problem arose: how to stop the train? Just drowning the locomotive is not enough, because the trains were long and moving fast. The inertia is too great for the locomotive to stop the train by itself. The first method used was simple: the operator was assigned to each car, and pulled the handbrake, at the signal of the driver. Pretty soon, the direct air system came to replace the direct air system — when the driver wants to stop the train, he opens a valve that sends compressed air to each car. The air forces the brake to press on the wheel. The train stops. Very simple.
And here another problem appears: how to stop the train safely. Direct air brakes worked well if they worked. But if the compressed air tank is empty, or the pressure is not enough, or there is a leak on the line, the brake will not work. The train won't stop. And this is a problem.
The genius of Vestnighaus was in the invention of reverse air brakes. His great idea was to use compressed air for the train to travel, not stop. Here is how his system worked: The brakes in each car were pressed against the wheels with a strong spring. In this state, the train could not move. If the driver wanted to move, he let in the compressed air, which depressed the brakes from the wheels, which allowed the train to start moving.
This, I think, was very clever. Notice, if the tank with compressed air was empty, or the pressure was not enough, or there were some leaks, then the train stopped. The brakes could not fail, as they are always pressed to the wheels by springs.
This system is used today. One day, I was on the Amtrac train (Amtrac) going from DC to Princeton, when we stopped in the middle of the road. It was late at night, and everyone wanted to go home, and someone would ask the conductor when he passed by, what happened? He answered us in technical jargon: “The train does not want to go” (“The choo-choo she no go”)
We later learned that the air line was broken and the brakes were released. We stood for about an hour before we installed a new hose and restored the integrity of the air duct system.
Lifts
Lifts are even older than trains. They existed in immemorial times. But it was not until the middle of the 19th century that tall buildings appeared, so that the reliability of elevators became quite an important task. As long as the buildings were 6 floors or less, security was not so critical, although I wouldn’t enter an unsafe elevator, even at such a small height. Anyway, as the construction of high-rise buildings, elevators should not only be safe, but also look like that. Otherwise, people will be afraid to use them.
In 1865, Elisha Otis solved the problem of elevator safety. He invented the mechanism that will stop the falling lift, even if the supporting cable breaks. The solution was that the cable pulled the elevator brakes inward, but as soon as the cable weakened, the brakes were released and prevented the fall.
Otis's brilliant insight had no immediate success. He realized that he needed a visual demonstration of the brake mechanism to give the public a sense of security. During the first world exhibition in 1854 in America, Otis built an open elevator shaft. Several times a day, he climbed into the elevator, and cut the cable from the inside. Since the mine was open from the front, all viewers saw it. As soon as the elevator began to fall, the mechanism immediately safely blocked it. What they said every time: "Everything is in order, gentlemen, everything is in order"
This multi-thousand, visual demonstration ultimately led his company to success and made high-rise buildings possible.
The main principle.
I think there is a powerful principle used in the security system of both the train and the elevator. Both are designed, so no active action is required. Instead, security is built into the system:
- In the case of a train: there is no pressure in the system, the brake will stop the train.
- In the case of an elevator: there is no cable supporting the elevator, the latch will be released and prevent a fall.
The key principle should be this: do not rely on the action, but on the properties of the system. Make a default state, a passive state, a safe state, so that when the system crashes, it will fall into security.
I always liked such systems. I often wondered if we could use similar passive methods to create better computing systems. Can we, for example, create a system safe from viruses using passive methods? Is there a formal model of a passive or active system that we can use as an argument that such a system is possible in principle?
Question for discussion:
Is it possible to use the power of passive methods used by Westinghuz and Otis to solve computer problems?
Source: https://habr.com/ru/post/84459/
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