TTD Overspeed

[TTD03]

I have never seen a train go over this fast before.
Just thought it would be interesting to share.
The over-speed is at 1:17.
As a bonus this video also includes a rollback.

Link
http://www.youtube.com/watch?v=R-tZCHlYcsI

To me, it doesn't seem too much faster than a normal cycle. But, if that train is the launch right after the rollback, then it is a clear example of the new(ish) system they implemented on the ride. The rollback was REALLY short of clearing the hill, so on the next launch, the system automatically adjusted the launch parameters to ensure that the train would crest the tower. In this case, it may have gone over at a somewhat faster speed than usual because of how notably short the rollback was.

[gouldy]

I actually think that looked insanely fast. I've definitely never seen it go over that quickly before. Looked like it would actually be a little painful, to me.

Was the train empty?

[yoshifreak]

Was the video taken yesterday? I was at the park and it honestly seemed like dragster was running fast. So much so that on the down spiral I banged my head on the headrest, which I've never had happen before.

I had a similar ride on kk during the travel channel filming for insane coaster wars. My dad caught it on video and it was going even faster than that. Not that it's a competition or anything.. In fact it was incredibly painful and I could only ride El Toro once after that because my legs were sore, and I was sick.

Holy poop, that was fast!

[Mikey]

Looks a little fast... how you have to look at the logic.

Launch
if Launch = Fail
Increase Speed
Launch
if Launch = Fail
Increase Speed
If Launch = Fail
Move to max default
Launch
If Launch = Fail
Trouble Light

[TTD03]

I approve of this logic chart.

Faster than normal but still not the fastest I've seen.

[Mikey]

If it's anything like the rides I work on it has a couple of mainteance modes which are great fun:

Warm Up Mode AKA Short Launch Mode - Used to warm up the catapult / sled and bring it to operating temperature. Allows for fractional launches and short launches with very little recovery time.

Sure Shot Mode - Even if the train is loaded down with 500lbs per seat, the friction values for the wheels are set to high by a grease monkey with a torque gun, and the bearings are warn out so bad the trains scream when they roll the train will make it through the circuit. (Or the ride will destroy itself or rip the train apart.)


Sequential Launch Calibration Mode - This launch mode is typically used at the start of the season or mid-season to calibrate the launch controller.

What this mode does is launch the train at below V1 speed and slowly increases the launch speed until it exceeds V1 speed and clears the circuit.

You run the same test with maximum load and then it averages it out to find the average values that it uses for guestimation purposes.

At the start of the season I typically set launch speeds high, then lower them mid season, then raise them towards the end of the life cycle of the road wheels. Only exception is Saturdays because we need more cycles per hour, and on ACE day because we know there will be more guest of extra ordinary size and thus a more likely event of a roll back.

Edit: Should mention that there is usually a 25 MPH window that the equipment will support. So if we tell the guest it goes 0-70, we can launch it as low 62 on the low end and as high as 87 for maintenance purposes.

Yeah, Kingda Ka flies over the hill for the first 40 mins or so of the day, from what I've seen. Still always end up at El Toro first...need to switch it up, because it looks awesome. Maybe next week

[TTD03]

Yea, I was just at SFGAdv and Kingda Ka does always start the day flying over the top.
Then about 15 minutes later it was already creeping slowly over the top.
I always think to myself, does SF send the trains up slower to save on operating costs? Because if they did, I would really be surprised. Anyways, 4-5 hours later, once I was leaving the park, KK had a rollback. I clearly knew this wasn't a weather issue because it had been sunny all day with no clouds at all and I knew this wasn't a maintenance issue because the train came so close to making it over the top. So on the re-launch 5 minutes later the train flew over the top. So my guess is that SF cut the power a little too short and that is what caused the rollback? So to then redeem themselves they sent the re-launch with extra power to make sure it would make it over?
I don't really know and this could all be wrong. But what do you all think?

I expect it's a maintenance thing. The train is cold early (more friction in the wheel lubrication and such), so they make sure it gets over by launching significantly faster. Once it's going over reliably, they don't have much of a reason to keep the speed up and create a greater chance for a breakdown. There's always fatigue with moving parts, and increasing forces on these parts will decrease their life.

[TTD03]

Hmm interesting, I never thought of it like that but I guess your reason sounds a lot better than mine.

Somewhat unrelated, does KK have kicker wheels at the top? I definitely experienced negative accel g hangtime. And when watching it, it seemed like the train got to cresting, then remained a constant speed for a few seconds, and then was released as the last car got to about -30 degree slope.

it doesnt have tires (i dont think) but it does have the fins on the downside of the crest

Originally posted by A.S.C.

it doesnt have tires (i dont think) but it does have the fins on the downside of the crest

I believe the fins are to actually slow down the train in case it's travelling too fast.

Oh. Duh. So I did experience hangtime lol, thanks guys. It definitely wasn't going too fast though, we barely crested like minimal floater air and it still kept us going slow for a while on those fins. Reason #3 why TTD is better than KK, lol.

^^yeah that's what i thought, probably shouldve specified what it was in my original post

Where did you sit tiepilot35? I pretty much always sit in the front car, and I've never experienced only "minimal floater air." Physics says the highest forces after the twist are 0G, and to pull over the top from 90* it has to go below that.

I can't remember, probably third row. Minimal floater was exaggeration; basically, it didn't feel nearly as strong as TTD lol. I feel like because of those fins slowing the train down, the forces were >0.0 gs for the second half of the tophat. I could be wrong though.

Yeah on average launches, the forces are >0G until you near vertical. With that said, on most any drop, if you sit near the front the forces will be positive for most if not all of the crest, so it's not a huge deal to me. I do wish I had tried Dragster in the back when I was there in 2003...only rode row 3 then 1.