Light Curtain?

I have seen this term used around this forum a few times, but now I want to know what everyone is talking about. What exactly is a light curtain? And what does it do?

There are strips which are mounted to the steel supports on either side of the station between the people and the train - Basically, it uses infared(I assume?) beams. When they 'activate' the light curtain, these IR beams turn on creating an invisible curtain on each side of the platform of the train between the people and the train - if anything were to break this 'beam', the ride would e-stop.

Next time you are at the point, look for the yellow strips on the steel support beams in the station a little over an arms reach toward the train while standing in one of the queue lines waiting to board. You'll see them.

bholcomb is right on. Light curtains are very common where I work.

MrScott

Oh, so thats what they are. I thought that they were some safety device for LIM's or something.

Thanks for clearing that up!

Well, they are a safety device for them. Since the train comes rocketing through the station, MUCH quicker than a regular train does. These make sure that the train stops if anything tries to step out into the path of the train.

Now, obviously, if the train is on the back spike, and you run out there, you're dead.

I remember hearing stories back in 02 that birds were tripping the light curtain by flying through the station. Did they add anything to the station to scare them away and keep them from flying through?

I've seen it e-stop twice because of someone in line crossing the curtain, apparently with their hand. A very stern lecture by whoever was on the mic followed....

If it was the same person, removal from the line should have happened the second time. If I remember right, the curtain is outside normal reach isn't it? I mean you'd have to really stretch out your arm to get there, and that would make it pretty obvious.

Jugga you're correct the curtain would be a stretch to reach. If I had to guess I think it was a bunch of people who were mad because their group got split up and they all couldn't ride the same train together. The first time was accidental, and the second time was on purpose.

Are you sure youd be a gonner if it was on a back spike? Or is there something that they thought of that would prevent accident too?

There is not much you can do the track curls almost right into the station it would attempt to stop. Say someone/something went out in the line of track in the back of station and train was in back spike...*splat* i would imagine the train would be able to stop about halfway into the station.

During my senior year in college, I constructed a project that featured a light curtain. It's a pretty cool device. Typically, most of them can be found in industrial environments.

jonisneo said:
There is not much you can do the track curls almost right into the station it would attempt to stop. Say someone/something went out in the line of track in the back of station and train was in back spike...*splat* i would imagine the train would be able to stop about halfway into the station.

Picturing that in my mind, that seems like a really violent E-stop.

Well, there's no brakes in the station. So if it was to e-stop on the back spike, it wouldn't stop until it's out in the brakes, which are in the straightaway beyond the station. So, no, the train wouldn't be able to stop halfway into the station.

WT brakes the same way no matter what. Well, with the exception of normally in reverse but possibly forward.

It would probably suck to stop at the far end of the launch area. I bet the inverters would overheat quickly. Possibly not allowing the train to return completely to the station.

The train can not stop coming down from the back spike untill it hits the actuall brakes out on the launch track. The station is basically a kill zone if the train has cleared it and is on the back spike.

That is probably why the plating was added to the top of the gates. To make it that much harder to get into the ride area.

I wonder if the gates have some kind of a lock. Most gates can be opened fairly easily. If the signal to the PLC doesn't matter, then something else probably should be in place. I would imagine a lock of some sort such as an electromagnet, or increasing the pressure to the pneumatic cylinder operating the gates. Using a higher pressure to operate the gates is not safe. When confirmed that they are closed via sensors mounted on the cylinder, it can increase pressure holding them tight. Better yet, a magnet could be activated holding them. Once the flux builds up in those, it takes tens of thousands of pounds of force to open them. I've heard of the bolt holding the core plate ripping in half before pulling away from the magnet.

The employee gates and the exit gates are magnetized. There are magnet assemblies provided by Securitron, a leader in magnetic locks.

This is the page for the product that's installed

http://www.securitron.com/Class.asp?SubCatagoryID=68

It takes 1200 lbs of force for the lock to give way. The bolts would shear well before that.

In addition, below the strike plate is a green proximity sensor (look for it on the exit gates next time you ride). If the gate somehow opened while the train was going, the ride would shut itself off. Same thing would happen if the platform gates were pushed open. The train won't launch with the gates open.

right. and if the proxies sense that the platform gates have been opened, the ride will e-stop. and they're really sensitive. it can happen just from kids shaking the gates really hard for no reason. that's why ride ops can seem so mean when they yell at you to please "take two giant steps back from the platform gates"

while at the po!nt saturday I was in line for Wicked Twister standing in line, right before getting in station, the ride launched and i seen a group of younger kids in line and one of them had put arms on the gate, now i don't know how much wieght they were putting on the gate or if that even coused it but im pretty sure, but the ride E-stoped. I started to laugh because i thought about this thread and I was talking about it with a friend while waiting in line.

I have a question though this was the 2nd trip to the po!nt this summer (yes it's sad but reality hit when i got a fulltime job) and i noticed there are now 2 support bars on the top of each tower, did they recently add the 2nd one or have i just not payed attention the first time they put the first ones in?

Those were new for the 2003 season.