IAAPA 2001: X train modification to smooth out ride

Well, this is certainly more news than I know of...and I work at the park! I guess now all they have to do is rebuild the station!

Where is the link? I can't find it. When I click on that it sends me directly to the same page. How's about a direct link.
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Hey, I got more snow cones!

-The Abdominal Snowman in Monsters, inc.

The link comes tomorrow. I'm a bit surprised that he's willing to talk about X's problems publically, not that I'm complaining. I guess with all the mis-information spreading round the net, it was time to set a few things straight.
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Work like you've just gotten paid, Love like you've never been hurt, and dance like no one's watching!

I am glad to see everyone being patient. You will be rewarded, trust me! IAAPA couldn't have happened at a better time, since this gives the world it's well deserved X update.

Phil, I do models too, and would LOVE to see a pic or stats of your creation! Sounds great.
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Moxie: Not quite Cola, not quite Root Beer, not quite Asphalt!
Model coasters and rides: www.angelfire.com/oh4/tk173

Great news, I knew they would get it figured out eventually.
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"Why does S:UE only have one train?!?!"-Andy Byington 2001"

Wait, now that Arrow has the 4D coaster figured out, do think there's a possibilty that one of Six Flag's two new 4D will open as the Superman coaster at SFoG?  Just think about it! It's supposed to be a coaster witha unique flying experience, could this be it?

 

(Please don't take this post to seriously, just a quick thought, don't start another arguement.) 

Nope. No doubt about it, SFOG's new ride is pure B&M.

Thats why there is a lot of testing before it actualy opens to the public. Some coasters open sooner others may take time to open.

If youve seen X in person, you know that there was stress fractures on the track.  I was there today taking care of business, strolling around backstage, and checking out X (among other things) and they are welding the stress fractures as we speak...

Cool news maybe ill get over to California sometime next year to ride it, but I wish they would bring one to SFGAm it would cost me a little less money.
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Amazing how many structural engineers we have here...

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

More quality designs from Arrow Dynamics folks.
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.:| Brandon Rodriguez |:.
http://www.coasters2k.com

So Jeff, what then do you call these?

http://www.americacoasters.com/Photos/welds.jpg

Presuming that the X track is extremely durable (and not all of it, apparently), being able to withstand some of the stress from empty X trains, how is this problem going to be fixed, making it so that it will completely withstand the stress of a full train of passengers, weighing in upwards of at least 1 ton total weight? I really cannot see this happening. I know the ride is supposed to deliver thrills, and it guarantee will, but I wouldn't like to sit on the outside seats for fear of the seat completely breaking away from the train itself. That is more likely to happen now, right?

That's what the test of the sand bags and dummies are for! If suspended coaster could run without flying of the track, I think Arrow could fix this one. Or mabye this will be The Bat all over again...hmmm... *** This post was edited by Acrophobia on 11/15/2001. ***

OK, first things first.  The term stress crack has no real meaning in engineering.  All cracks are caused by stess.  Without stress there would be no reason for a material to crack.  The only place other than this board that I have heard the term used is medically to describe a bone which is cracked by excesive stress from exercise, heavy lifting, etc. rather than by a blow.

General note:  I'm a mechanical engineer with an background in materials.  I also spent 18 months as a welding inspector at one point.

I blew up the photo the photo supplied by PxPxPunKrAwKeR, and here is what I see:

There a what appear to be numerous weld repairs in the photo.  The distribution of these repairs is more or less random.  They don't seem to be confined to any particular areas of high stress.  If the weld failures were caused by stresses being too high, I would expect to see the same weld on each cross piece have a problem.  Instead there are weld repairs more or less randomly distributed on the track rails, on the main spine tube and in several positions on the cross members.  This would lead me to believe that the need for repair was caused by faulty welding not by any type of design error.

The need for repairs could have been caused by cracks in the welds,  but these would have been cracks caused by residual stresses and/or inclusions from faulty welding, not from excessive stresses on the track.

Jim,

I'm no engineer but I am facinated by mechanical/structural engineering in relation to roller coasters. With that said I went back and reviewed the picture. You stated                 " The distribution of these repairs is more or less random.  They don't seem to be confined to any particular areas of high stress. If the weld failures were caused by stresses being too high, I would expect to see the same weld on each cross piece have a problem." It appears that 3 major ties (larger ties in the middle of the spine) and 1 minor tie (smaller ties at the end of each section of track) have welds in the same area. This would not appear to be random. What is your feeling on this? Also take into account we are only seeing one side of the track. This same situation may also be taking place on the side of the track not visible to us. I will agree that some of the other welds appear to be ramdom but two have me wondering. They are located in the center of the photo, one on the spine the other on the track itself. The track weld is right above the spine weld. It appears as if this may be a joint of some kind that had been factory welded. With all this said I would like to know what you meant by "The need for repairs could have been caused by cracks in the welds,  but these would have been cracks caused by residual stresses and/or inclusions from faulty welding, not from excessive stresses on the track." What do you mean by residual stresses and or inclusions from faulty welding? Also I would like to know how it is determine when a crack was caused by one type of stress over the other (residual vs. excessive).

Phil:

Cataloging the weld repairs circled, and a couple that aren't circled, here's what I see.
1 - butt weld on the yellow rail
1 - weld on cross tie near, possibly par of attachment to the yellow rail
1 - weld attaching cross tie to spine
4 - welds on the inside of cross ties on the far side of the track
3 - welds on the outside of the cross tie at the top (some not circled)
1 - circled something on the spine that I'm not quite sure what it is.  It doesn't look like a weld repair in the photo unless it is just being started or is a small repair that has been ground in preparation for painting.

This gives us definate weld failures in 5 different types locations, not counting the one that I can't be sure is a weld repair.  If the welds were trully overstressed I would expect to see all of the initial failures occurring in the same location on the track,  ie the same weld on each cross tie, with possible later failures at secondary failure point on cross ties that have already had the primary failure.

Weld failures are determined most frequently by visual inspection, X-ray, or dye penetrant testing. I guess visual inspection and X-ray are pretty obvious.  Dye penetrant testing involves applying a dye that sinks into any cracks or porosity in the welds.  The residual dye is then thoroughly cleaned off the outer surface of the metal. Finally a developer is sprayed on the surface.  This developer is very absorbant and absorbes any dye left in cracks or porosity turning the color of the dye where the problem is.

Determination of the cause of a weld failure may involve the use of many other techniques after a chunk of the failed weld is cut out for examination.  However, usually the cause is pretty obvious.

Residual stresses are stresses that are produced during the welding process.  As the weld metal freezes and cools it shrinks causing stress in the metal.  Just run a weld bead down a flat piece of metal and it will bend from the shrinkage of the weld.  Residual stresses a minimized by proper welding procedures and a skilled welder.

Inclusions are simply things that are in the weld that don't belong there.  These can be dirt, oxidized metal, or other contaminants.  A weld can also be just plain porous.  The inclusions don't just weaken the weld buy reducing the amount of sound metal present, they also provide a place for cracks to start.

I think that we can feel pretty confident that any weld that is not painted was made in the field.

Does anybody know anything about X's capacity?  Can the trains be loaded and unloaded quickly?  How many trains will run?

Rows of 4, outside seats set back from center 2, rows look like about 16, and figure the intensity of the ride, most likely one will take off after one on track is almost finished, so 2 cars at a time.