Lift Hills

[rileybrands]

Thanks gravitywolf and CoasterBP. That makes sense after reading your responses.

 

I did see Iron Dragon's wheel do that when watching a train engage the lift and I was thinking, "What in the world is happening to that wheel?!"

[b&mforever]

I have felt this a lot on Loch ness monster but Great American Scream Machine did not do that.

[abc2001]

it's maybe some sort of feedback loop system to keep the chain at constant speed, but is not very accurate (as other rides)

[RaptorBoyASU]

The pulsing is probably best explained above, however if you're talking about the fact that Iron Dragon starts each lift hill fairly fast then slows down to a snail's crawl, it's because of the blocking.

 

Ever notice as you're going up the first lift, that the 2nd train is going up the 2nd lift? The first lift will slow down until the other train crests the 2nd lift. The only time the 2nd lift slows down is if a train is stacked outside the station.

[rileybrands]

Thanks. I did notice a gradual slowing of the lift, but also a pulsing.

[eddie200330]

I was just about to say the same thing that RaptorBoy just said. Have you ever seen the speed of the Phantom's Revenge chain when they add the second train to the track? It slows drastically. When CP runs 2 trains on Iron Dragon, there is usally no change in the lift speed. It is all about the blocks.......

[Fallen Heretic]

Yeah, it been answered already. The 'rocking' can be a result of several things on different coasters. The block issue tends not to cause it. Yes they slow the train down, but they tend to do it only once, until they don't need to anymore, and stop it if they have to, rather than slow down and speed up repeatedly.

 

The counterweight/piston/springed tension wheels do sometimes bounce and this can cause the effect your talking about. the rocking is usually pretty quick, depending on how much movement is in the tensioner. It can range from a small vibration, to the train almost coming to a halt, then hitting a fast speed repeatedly. How varied the effect is depends on the individual tensioner and how well it has been maintained. Old wooden coasters with an old spring tensioner that should have been replaced do this alot.

 

Motors being put under a very sudden load (such as suddenly having the train's weight to deal with) can also cause a very similar feeling effect, although the surges will usually be further apart and feel a little smoother (if you get my meaning). Think of a learner driver pulling away and letting the clutch out too fast. It puts the engine under too much load to quickly at too low a power level, and it will bounce or 'kangaroo' along the road. The same can happen with electric motors to a degree.

[Tyrant]

*EDIT*

 

Didn't even notice the 3 other pages of comments

 

Already been explained well.