Pull through or just let it rip?

Watching Diamondbacks progress and now it's test runs I got to thinking about something.......
Why do certain coasters require a pull through as opposed to just letting the coaster run and see what happens?

I remember in 2000 MF had a pull through, can't remember if Maverick did or not but was wondering if it is a coaster manufacturer's policy or requirement and what would a pull through really prove?

Can NOT wait to ride Diamondback!! Since it's a B&M I am confident we will be without any 1st year drama (*cough* TTD)

Jo

Maverick did have a pull-through (see PC video #3). I can't imagine that not doing one would be anything less than ridiculously careless, not to mention potentially expensive.

They do whatever the manufacturer mandates. Tells you something about the confidence in engineering between Intamin and B&M, doesn't it?

Shouldn't every manufacturer require it? Wouldn't it be more of a safety precaution than a "confidence" level? I think it would fall along the lines of "measure twice, cut once."

Yeah, the more "confident" (arrogant?) a group of engineers is, the more I'd be concerned, especially when their confidence precludes clearance testing.

If you did the math up front, why would you have to do clearance testing? That would be like designing a car, building it, and finding it's not tall enough to seat grandma. Yeah, obviously Intamin sucks at that (see: Millennium Force, first turn). But when has a B&M required modifications like that?

Jeff I agree with you. B&M are so precise in their engineering why would they have to do a pull through. A couple of years ago I saw a Travel Chanel show on the building of Kingda Ka. I was shocked when they showed the crew pulling a device made out scrap plywood around the track of a 25 million dollar coaster to make sure the riders had clearance. Wouldn't the computer modeling show any issues way before it was built. Shouldn't the designers have enough confidence in their work to know that the train with water dummies would make it around the track without ripping part of a dummy off?

Jeff said:
They do whatever the manufacturer mandates. Tells you something about the confidence in engineering between Intamin and B&M, doesn't it?

Yes it does! :)

Jo

I don't know, I guess it just makes more sense to me to err on the side of caution. I mean, you can look up and go, "Yep! That looks about right!" Or you can actually ensure that you've done your job correctly by pulling the vehicle through slowly with the clearance board (or whatever its official name is).

I'm pretty sure that B&M has a "clearance" test board that they'll hang on the track if they think it's close.

I saw it on Patriot and then on some recent Manta shots.

Yep here is a picture of the thing that is (was?) being used for Manta.
Manta pull through picture

Then again those clearance devices on a B&M could be more about making sure the ground work is correct in relation to the coaster which would rely on precise construction from whoever's building. Unlike, for instance, the issue with MF's first turn which was between one part of the coaster and another.

I recall seeing a clearance indicator on SFOT's Batman between the track and the troughs toward the end of the ride.

That contraption used on Manta and other B&Ms (I've seen pics of a the one used on Kumba) is to check that the train and it's riders do not come in contact with nearby objects.

Yeah, that's not a pull-through at all, and as Matt indicated, I'm certain it's to make sure that they don't screw up the ground work. B&M can't know what people pushing dirt around are going to do, which is why it makes sense to check those clearances on inverts and flying rides.

But again, that's something completely different than what Intamin has been doing it, and we've seen them get it wrong more than once.

On MF...did they cut out a piece of the support or something? I can't really recall, but it seems like there was even a picture showing it somewheres.

Yes, Millennium Force had a section of support that was cut out. I don't think it was after the pull-through test. I think it was a while into the first season.

Did anyone else think that this thread was going to be a fart joke?

robotfactory said:
Yes, Millennium Force had a section of support that was cut out. I don't think it was after the pull-through test. I think it was a while into the first season.

Part of one of the supports had to be cut out because riders hanging out with longer arms managed to hit it with their fingers more than once. Something about hearing "ping" then feeling bad pain.

I've often been surprised knowing how anal CP is they've never done anything about how close the supports are on Gemini coming around the final turn I know you could easily smack those without even really trying that hard.

Jo

You don't need long arms to touch it even today.

Mine Ride is even worse!

Speaking of Diamondback testing, I can't remember the last time I saw a B&M exit a mid-course with that much speed. Let's hope it's not clamped too much.