Alpengeist Pilot Coach??

I think I remember reading in Rollercoaster that the Zero Car has something to do with reducing the noise on Alpengeist. I don't remember how, I guess I should start digging through some old copies of RCM.

I have always heard something close to the "first two fixed rows" theory.

Look at the gap between the first two rows in this picture compared to all the others.

http://pictures.rcdb.com/picmax/six-flags-ohio/batman-knight-flight9.jpg

You can see it a little better in this pic...

http://rcdb.com/ig5.htm?picture=11

Notice how the first 2 rows are parallel.

Not to advocate one theory over the other, and it is possible that it's either fixed or at least some sort of limited movement in the first 2 cars. My first question is, what makes those 2 cars different than the others that they have to be fixed/limited? Also, regarding that photograph, is it just coincidental from the point it happens to be at in the loop? I'd be interested in seeing similar photographs from when the train is exactly 1 car further in the loop. If you look at http://rcdb.com/ig5.htm?picture=10 (same coaster, picture right before it) you can see that cars 1 and 2 are not parallel. (Although, in contrast, http://rcdb.com/ig5.htm?picture=2 looks like it's in a different position in the loop, and cars 1 and 2 are clearly parallel).

Just food for thought, that's all. :)

They can rotate, but not turn. The best place I've seen this is on Raptor when the train is disengaging from the lift how each car "kicks" forward. The first two rows "kick" together.

The wheel carriers will rotate separately... but if you were to arbitrarily define the first row's wheels of having a pitch of 180 degrees, the second row's, while facing a different direction laterally, would also be pitched at 180 degrees.

On a similar principal, the wheel carriers within the same car will always rotate at the same degree. The two wheel carriers in each car are linked with a Rod (As seen in this photo, the green bar in the back of each Hydra car http://www.coasterbuzz.com/rollercoasterphoto.htm?i=3118)
which causes the carriers to rotate in tandem. I would assume the same principal could be applied to describe the motion of the first and second row's pitch.
*** Edited 11/30/2005 7:39:58 AM UTC by Fun***

Ah, I think I understand..

But that still leaves the other question - why is this so, and not on any of the other cars? (Or has it been mentioned before and I just can't find it?)

^I believe it's because the single row cars of B&M's have only 2 wheel assemblies (one on each side) and cannot properly balance themselves, therefore they need to link the first 2 cars together to create a 4 wheeled "car" that will then tow the rest of the train properly.

As far as I know this is only for the Floorless and Inverted models, as the Hypers and Looping trains have that extra little front car that allows them to gain a 4 wheel base without linking the 1st and 2nd rows. The little front car you see on the hypers and loopers is actually very similar to the "zero car" on Alpengeist, so my guess is that they just wanted to see if there was any benefits to having a zero car on the Inverted trains. (obviously we would never see that with a floorless because it would get in the way of the view) *** Edited 12/2/2005 3:26:15 AM UTC by MrX***

Just think of it as a car pulling a trailor. The car needs 4 wheels in order to keep itself in balance, the trailor then is supported by the car because it is balanced. Just like in this picture, http://www.coasterbuzz.com/rollercoasterphoto.htm?i=3120

Think of the first two cars as a car, they need four wheels right. Then think of the following cars each as a tiny trailor getting pulled by the 'car'.

Another way to think of it is Dominoe's (just follow me on this, and no not the pizza place ;)) If you were to connect the first two dominoes they wouldn't fall over, but if none of them were connected they would all fall over. Make any sence. I'm trying my best people. :)

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Michael Darling said:
If anything lengthening the train like that would give you a longer train with a center of mass more toward the rear. In a low-speed situation if the CoM doesn't crest the hill, the train won't. All you're doing by back-loading the train like that is making it more likely to roll back in a low-speed situation.

*** Edited 11/27/2005 10:58:20 PM UTC by Michael Darling***

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Warning: Long Post.

Someone needs to do a simple Center of Mass calculation. Oh thats right I just did. Now I can't give the exact position because I don't know the differences in mass between the zero car and the other cars but using the formula for position of Center of Mass: [m1(L1)+m2(L2)+...]/[m1+m2+...] one can determine quite easily the real postion of the center of mass.

It should be noted that the value for the mass of the car doesn't effect the position (ie. further forward or back) from the "center" of the train(directly between rows 4 and 5, which was used as the origin for the calculations) which is where it is on a normal 8 seater.

The final result places the center mass of the train w/ a zero car, contrary to your statement, further toward the front of the train.

I used a value of 1/8 the mass(m) of a regular car for the zero car and made the assumption that all the distances (L) between the centers of mass of the cars, this would most likely be right below and between the wheels to ease design, are equal. The final value I got for my calculation is that it would be [(1/8m*5L)/(8&1/8m)]meters(if L is in meters) from the center of mass of an 8 seater train. Because this number is positive, it will be a distance in the positive direction (in my case positive was chosen towards the front of the train for my calculations).

This means it actually will do the opposite of what you stated it will make the train less likely to roll back. It is in fact identical to your TTD example add more weight to the front of the train ( ie add a zero car) the center of mass moves with it. Too bad you were so busy with your incorrect idea to realize you just nullified your own argument.

Also for the information of you doubters who are thinking to yourselves right now what makes him think he knows so much, I am a Mechanical Engineering Major at the top Engineering School in the state of California and we did a very similar problem in our physics class not very long ago.

Note: sorry for all the technical mumbo jumbo but it's the only way that I can ensure someone replicating my experiment won't use different directions for positive and negative etc. and therefore get a "different" answer. The edit was to fix a few minor gramatical errors and and the paragraphs to make this long post easier to read. Once again sorry for the long post but it was necessary to properly display the way I came about my answer. *** Edited 12/2/2005 4:46:46 AM UTC by coaster_freak00***

Why do people feel the need to pull rank, as if their arguments stand better because they say "top engineering school"?

I have no idea where Dave Althoff went to school, but I trust his thoughts on these matters way more than anyone else, regardless of where they went to school.

I also love when engineers make grammatical errors. (i.e. effect vs. affect) For some reason it just seems like cosmic justice at work. *** Edited 12/2/2005 4:52:04 PM UTC by ApolloAndy***

Last week at work, I was expecting to see some B+M guys. I had only one question for them when they arrived and it was going to be what is the purpose of the lead ?

Unfortunatley the schedule must have been wrong . They did not show on that day.

I wanted to hear the answer so bad directly from them!

I did have the pleasure of meeting other ride manufacturer reps though. They were all awesome.

I wated to see B+M though! Place curse words here.

Thanks, Andy. 8-) I graduated from Capital University in 1992 with a BA degree in Communication and no formal training whatsoever in engineering. No secret there!

I've stayed out of this thread thus far, largely because I don't have the answer to what is going on with Alpengeist. But there is one thing...

As someone else has noted, the lead axle on any B&M inverted coaster is connected to the rest of the train by means of a roll-axis pivot. The lead axle wheel sets can pitch and yaw, just like all of the other wheel sets, but the axle cannot pitch and yaw relative to the second axle. All of the other car connections are made with a universal joint that can pitch, roll, and yaw...and is located right between the wheels. I believe the main issue is to NOT allow the lead axle to pitch relative to the second axle, thus insuring that the lead car (the beam between the first two axles) runs parallel to the track. Once the second axle is set, the rest of the train will follow.

On most inverted coasters, the first row of seats is on the lead axle. Alpengeist is the exception. The most plausible explanation is that Alpengeist is the only inverted coaster that has a straight drop on it, and the rollover into a straight drop will tend to scrunch the cars together. That kind of makes sense, except for one thing: the train scrunching described will NOT happen on the lead car, because of the pitch control in the lead axle, but will happen on all of the other cars. So while it's a plausible explanation, it is demonstrably false, unless of course I am missing something... :)

I think it would make for a more consistent ride, as all of the seats would be mechanically similar to the configuration of all the other seats. But how important is that, anyway? I can also report that when it is raining, it makes the front seat on Alpengeist an unpleasant place to sit. While all the other cars have drain hoses that run from the wheel cover down to a point below the seat, the pilot car just has a pair of openings on the outer edges of the wheel covers, and rainwater drains from these drain holes and hits the outboard seat passengers square in the face. In an effort to avoid that, you could sit in the inboard seats, but there you will find that rain water kicked off the wheels is aimed directly at the two inboard seats.

(On that same trip I learned that Big Bad Wolf includes on-board drink service when it is raining... :( )

--Dave Althoff, Jr.

Maybe there was some kind of element that would make it unsafe to make the first rows attachted (as in hitting the row infront of you) so they added this..?

This thread is really fascinating, and I mean that with no sarcasm whatsoever. Do the skis factor into any of this? If it was weight related couldn't they have made the skis heavier? ;) It seems like someone should email Busch or B&M......
P.S. I love Alpengeist!