For the first, I would have to say yes. It's 300 feet.
For the second question, Giant Drop cars need to know where to stop on top, and needs to brake before it reaches the bottom again. It probably also needs a sensor for that thing that picks it up for when it comes down. It needs to know how far away it has to reach the cars.
"I've been staring at the world, waiting. All the trouble and all the pain we're facing. Too much light to be livin' in the dark. Why waste time? We only got one life. Together we can be the CHANGE. So go and let your heart burn bright"
No idea on Sky Trek. PRobably close to a million (have to take into account inflation, so it'd be quite alot more than what the park actually paid for it)
As for Giant Drop, part of that is Single Sensors dont always work right so they are always groups of 2, so that automatically doubles the number of sensors. Also a majority of the sensors are inside the ride tracking the counterweights. I've never understood it.
Fabbri Mega Drops basically have 3 sensors on the entire ride, one at the bottom, and two at the top. One at the bottom when activated allows the restraints to be opened and one up top that slows the catchwagon/car when it's right near the top/release point and one at the very top that tells the system to stop the catch wagon after the car has dropped. Figure times that by 6 and Giant Drop is 6 seperate systems and they could technically get away with a total of 18 sensors(or 36 for doubles)
Favorite Wood Coasters: The Voyage, Ravine Flyer II, Thunderhead, Balder Favorite Steel: Voltron Nevera, Steel Vengeance, Expedition GeForce, Olympia Looping Parks visited: 239, Coasters Ridden: Steel: 937, Wood: 179, Total: 1116
The green sensors are for proximity so that the computer tracks where the car is at all times, this disables to train to dispatch before the safe interval or if theres a unlocked restraint (on modern steel coasters).
If you want to see some of these green sensors, V2 has two of them on the side facing waiting to ride the ride. The front wheel of the train stops in between the the two green sensors..
"I've been staring at the world, waiting. All the trouble and all the pain we're facing. Too much light to be livin' in the dark. Why waste time? We only got one life. Together we can be the CHANGE. So go and let your heart burn bright"
Yep, those are called Proximity Sensors. Basically all they do is detect the presence of an object, without physically touching it. There's also what are called Inductive Proximity Sensors, which is the same but senses only a metallic object. It can do this because of the change in magnetic field when the object enters the sensor's range.