Red Train

ForgottenEE said:

The train has to arrive before it can be unloaded

I read that and just chuckled a little bit. I sure hope the train arrives before you guys start trying to unload me.

Though that was intentional, I have slipped a couple times before. Always, it's around the people that catch it right on the spot. For example I once said. "My keys were in the last place I looked." I sure would hope so... "find your keys yet?" "I found them 15 minutes ago, but I'm still looking for them"

Forgotten E your idea is good and you seem to know more than the average person about how the trains move throughout the station, however there are some problems with your idea. First of all 9 times out of 10 unload is ready to dispatch before load so the unload 2 spot is parked and unloaded before the 2 loading trains are ready. Waiting for unload 2 to arrive and unload isn't really an issue.
Also I don't really follow Purdue's idea about making brake a true block. It's a declined section of track there and without putting in some kind of friction brakes like most coasters I don't see how a train would fully stop without entering Hold 2, even with the drive wheels stopped and the magnetic brakes up the train still slowly rolls down the decline and eventually enteres Hold 2. But I don't know, Patrick is A LOT smarter than I am so maybe it would work.
Its hard to justify stating the 6 trains in dry mode is better capacity than 5 trains anything because its never been tried. At least not long enough without breakdowns to see what kind of numbers it can produce.
Dry mode would be nice but for the number of problems it itself can cause, I don't see it as a high priority to fix. I would love to have dry mode work, we would probably be able to push a lot of people through that line, but I have my doubts whether or not it will happen.

I'm sorry about my post. I didn't realize them putting the trains back on was already discussed.

Feeling stupid :) .

Did they not take the red train off this winter because it did not have to be rehabbed because it did not have enough hours on the track

The assembly to the last drive tire pair would have to be replaced. This will allow a much greater force to be used between the tires and the train. Basically it would need to be able to hold the train in position without the brakes being there. Remember, eddy brakes produce no braking force when the train is not moving. The goal is to be able to stop the train when the tires are iced over. (worst case scenerio)

6 train operation is slighly better than 5 trains operation if dry mode actually worked without other modification. 5 train op was actually improved in May 2003 because they didn't have the 6th train at the time. It used to ghost a train as it was working in 6 train operation. The biggest point of improvement is if you effectivly turn the brake area into a block, you are also cutting over 5 seconds off the launch interval. The actual time is the interval between the brake clearing and the hold 2 clearing. This will improve both 5 train operation and 6 train operation. The improvement running 6 train in dry mode or even 5 trains in dry mode at that point is having a longer loading time.

It's quite hard to explain how the trains will move in dry mode in words, let alone how it can be improved. The best you can do without dry mode is maintain slighly more than a block between the two trains. There is two routes that dry mode could take. A conditional setup and a timer setup. A conditional setup looks at the sesnors and determines how far the trains are apart. If they are too close, it reacts by either slowing the second train and the rest behind it. If they get too close then activate an alarm (trouble light) and stop the trains or activate an Estop. The problem with this is the ride can't tell how fast the trains are going. If the first train were to stop then the second train would have to get close enough, slow down, and then finally stop. There needs to be a large gap between trains or they will hit. This doesn't allow the trains to have much of an improvement over wet mode. This is where timer based dry mode comes in. It requires one timer per pair of sensors in the station, plus some. Basically it sets up an interval for each train to be in. It must be within that interval or it changes modes. There is also speed setup so the sensors have to be activated sequentially within a specific timeframe for it to continue as is. The timing has to be tight so it would take some testing to get the ride to that point. Also it could be a one shot. If it doesn't work within the limits, it slows the trains down and reverts back to a much slower conditional dry mode. If it continues to deviate from the operational limit or the trains come too close, an alarm will be set.

If the mod is made to the brake block, then dry mode won't need to be integrated at full scale. A lot of the problems that came from dry mode operation was the trains abilty to stall in unload when running at reduced speeds. That can be more easily worked around it you don't need to move up the train in hold 2 a block before you can launch.

The biggest problem with dry mode is the sheer complexity of it. That makes it not the easiest thing in the world to improve. Each factor effects others so a minor change can be a bit of a battle. I've personally programmed and optimized several PLCs but I can't say I've done anything as ambitious as TTD's program.

I heard from a ride op that Dry Mode works works for a little bit then everything goes crazy and shuts down.

I've seen websites do the same thing. lol I haven't personally seen TTD's program, but I'm sure that particular problem is caused by the feedbacks in the program. They are able to slightly alter the program for each run. The feedbacks should be confined with limits or negative feedback. If not it can runoff. If the program is ouside of the normal operation, an alarm could be set and shut the ride down. The prefered option is to easily be able to revert back to a safe operational mode if the program begins to run off. It the program continues to run off, an alarm can be set to shut down the ride.

At first the ride won't be able to get out of the safe op mode. As the program timings are tweaked, the ride will be able to run in dry mode more and more. If the brake area is turned into a block or 5 train operation is used, a partial dry mode can be integrated to get the safe operation of wet mode and the long load times of dry mode.

Has anybody noticed that the red train is now by the tree?

What the heck is dry mode????

Dry mode is where the trains are able to move in pairs at the same time. Currently TTD has been moving one train at a time. Dry mode makes it where both trains will pull into the load station at one time and dispatch into the staging area at the same time. It has been tried but has never been able to work correctly.

Nope, thats not dry mode sorry. Dry mode is when the trains move through the station from block to block faster than normal.
As for moving in pairs at the same time it happens, nearly all the time, just not how you're probably imagining in your head. Moving in pairs how you described it cannot happen. You cannot have 2 trains in 1 block at the same time, hence the point of a Block. Thats about the most basic and common multi-train coaster concept. Unload 1 block has to be completely clear in order for the train in Unload 2 to move forward.

Then whats the other mode? wet mode? haha that was irony.

I thought Dragster has many prox sensors in each block, so that each block is actually divided into many smaller blocks, which would make simultaneous train movement possible.
*** Edited 2/28/2005 2:57:46 PM UTC by Pete***

The idea is to have a rolling block. Each block must be able to stop a train before entering the block ahead. Each rolling block is made up of many microblocks. The rolling block is from the tip of the rear bumper and extends past the front bumper far enough so the train can completely stop before exiting the rolling block. Basically the rolling block moves with the train.

Dry mode takes this a step futher by calculating the speed of each train. Depending how long the sensors are on. In a worst case scenario each train can slow down before the first train can stop. This mean you can have some interference on the "true rolling block." In the worst case scenario the trains will take slighly longer to start slowing down. From the point where the first train can completely stop, there must be a buffer area to make sure the trains behind it can also stop. The buffer is all that is needed between trains so they can stop without bumping. This distance plus the length of the train is the pseudo rolling block.

If you look at the complexity of a true block, a rolling block and a pseudo rolling blocl. A true block a very simple, a rolling block is slighly complex and a pseudo rolling block a very complex.

As for the terms dry and wet mode. It really is the condition of the tires and their ability to stop trains. If they are wet, it takes much longer distance to stop the trains than if it's dry out. As long as the tires are wet, the ride needs to be in wet mode. This could even come from water used while cleaning up someones lunch. The reason for the switch is not playing pinball with very expensive trains and riders when the tires are wet.

I think that's what we all thought (were hoping) was going to happen since they did it on Millennium Force, but it never has. Ohio State is right - dry mode just lets the trains move faster. They still don't move "in pairs."

I always thought that. It seems silly to build a ride that runs trains in pairs, but they can't move together. MF can pull it off and it doesn't even need it that bad.

The modes are move, multi move, dry.

Thanks ForgottenEE for that explanation. Going by the modes that CPfan200 described, I'm assuming "move" means individual train movement, "multi move" means a rolling block and "dry" means a pseudo rolling block. Do they ever use anything other than "move"? Whenever I've been on dragster the train motion was never in rolling block mode.

TTD was designed to run trains much closer than MF. The trains in load are far enough apart that they could start them simultaneously wait a couple of seconds start the unload trains slightly apart and wait a couple more and start the holding trains again slightly apart.

MF needs it's rolling block more than you think. From the time the waiting area is clear untill the ride will initiate a block stop is about 5 seconds. It takes much longer than 5 seconds more to move the train in unload forward untill it clears unload then move the train in waiting untill clears waiting.

Even then they wouldn't be able clear the waiting area before the ride initiates a block stop. The lift speed was limited to 4.5 m/s while waiting is occupied and allowed to go 6 m/s when it's clear. When running with 3 trains, the train on the lift runs at 4.5 m/s untill waiting is clear and then speeds up. If the train hits the prox that initiates block stop before the waiting clears, the train will stop. As soon as waiting clears, the train accelerates to full speed. This will happen when running 2 trains also. Most of the time waiting will be clear before the train accelerates up the lift; therefor the trains usually run full speed the entire distance of the lift.