This viaduct is monumental and extraordinary bridge. Record Breaking.
The lightning, The frying pan, The nuclear submarine,
1. Plasma Cutting
2. Wedges mechanism & Teflon
3. GPS
4. Cable changeable.
The road in not straight, it bent across the valley that kept drivers alert. The curve viaduct made engineers not to build simply.
This is the tunnel inside the deck. So the road is above and nothing below. You can see how clever it is. The sturdy and light structure made of thousands of steel fit together precisely like a colossal jigsaw puzzle which made the curve. Each piece of steel must be made individually.
How to cut thousands of pieces steel with incredible precision and phenomenal fast ??
Traditional cutting is not fast enough.
Someone wanted to harness lightning. It produced new state of metal that is the the key to cut the steel quickly.
Controlled Lightning.
The metal suit would be like the cage that allowed lightning to flow around me rather than through me. That's the theory.
You can see birds standing on high voltage overhead wires without getting hurt. Because the current passing through the bird is extremely small compared with that in the transmission wire. Let as think of the situation as two resistors connected in parallel : one resistor is the body of the bird itself (the resistance between the two legs), and the other resistor is the small segment of the wire on which the birds stands. (The above picture). Since the wire segment is very short, the bird's body is almost an insulator having a very high resistance. When a potential difference " V " is applied to a resistance " R " , the current " I " is given by " I = V/R ".
Since both the bird and the wire segment are subject to the same potential difference
(resistors in parallel), the current passing through the bird (very large resistance R). In other words, the bird doesn't get hurt because the current flowing through its body is extremely small.
How does lightning help engineers cut the steel fast and precisely ??
Huge electricity turned the air into the full state. Plasma Water, Ice, Gas. One state to another. Heat the solid ice becomes the water and then gas. But if you heat the gas with huge electricity, you would get plasma.
This is slow motion shown of man-made plasma. When it was controlled, its heat can be used to
cut the metal.
Just like lightning charged the air to turn into plasma. The electrical current is the same to charge
the air that turned into the jet plasma that what is going to melt the metal quickly.
Staggering speed !!
Put the gargantuan steel in the place without toppling the colossal towers and then fit them together.
There are two main ways to put the deck on the piers.Option 1.
You can build the whole deck and push it to the piers. Option 2
The valley is too deep to lift the deck to the piers. Option 2. Build the deck and push it. But, the pier is extremely high, the slight force of the deck would cause the pier to collapse.
Bending Moment.
Solution. Reverse.
It used two giant wedges to slide across each other and move the steel deck over the piers.
Using the wedges means the deck is lifted and slid forward at moving. Avoid any pushing
against the piers.
And than, the second wedge (Blue) is pulled out.
The deck is lowed and sat back on the top of the piers. The red wedge would move forward.
Both wedges would re-set and start the cycle again.
It is incredibly simple, but extremely clever.
The engineers must manufacture sliders over one another. The most slippery substance.
Polytetrafluoroethylene (PTFE)
Non-stick pan. Teflon.
The piers must be built precisely.
Submarine Navigation.
The gyroscope system is designed to record every movement of the submarine. But time error
would cause the problem. If the nuclear ballistic submarine didn't know where it was, it would be
the problem for the nuclear weapon.
Transit (satellite). it was the first satellite navigation system to be used operationally. The system was used primarily by the U.S Navy to provide accurate position information to its
Ballistic Missile Submarine. Initially for the military purpose and later for civil use as well.
Global Position System or GPS. { From Wikipedia }
By walking away from the truck, and then stopping and played the note. We can measure the delay between the sound leaving the speakers on the truck and reaching to us. Using the time difference to calculate the distance.
The more distance, the more delay obviously.
Doppler Effect.
We can use the signal to measure the distance, no matter what the signal is. If you know how fast the signal traveling, and how long you get from one point to another.
The more satellites you have, the more precision you can locate your position.
The chain can take much load than the same size rope, but it breaks catastrophically without warning.
Wire Rope.
How to replace the old cables to new one without the bridge falling down ??
Each cable can be replaced, if it corroded.
This bridge built by the metal which had the drawback. The hotter it gets, the more it expanded.
Expansion Joint
Expansion would push outward on the vertical piers. The concrete is notoriously unbending material.
The top of the column is split into two thin pillars.
This design would overcome the potential fatal failure.
The timber of the keel must be sturdy and flexible.
[Highlights]
Wedge mechanism
[Questions]
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