Mine Ride Construction Update

[Pixiedustmaker]

Setting anchor bolts correctly is literally one of the most difficult tasks in a construction project. Many trades will argue that fact, but being a G.C. I've seen every task completed....and getting anchor bolts in the exact correct location while pouring hundreds of yards of concrete around them is very difficult.

You make the plywood template, and draw an exact set of crosshairs on it, in addition to drilling the holes and double-nutting the bolts through the plywood. In low-budget operations, you'll pour the concrete then "wallow" the set of bolts down into the concrete while it's still wet, and vibrate the concrete around them to fill in any voids. You use string lines and live surveying to align the drawn crosshairs in the X an Y directions.

In high-end jobs (like this one), you build a complete wooden form around each footing, and build some supports across the top of the forms that the bolt template suspends from. That way they're sighted in well in advance, using precision surveying instruments, and you just have to be sure not to bump them when pouring in the concrete. You still give them a second check after you pour that footing, before it sets up.

Changes in code in the last several years prevent steel base plates from being torched during installation to adjust for an out-of-place bolt...without a professional engineer being on site to supervise the modification. They don't really get to do that with a coaster, so if a bolt is off, they likely tear out the footing and start over, or drill out the bad bolt(s) and then epoxy in a new set.

Awesome, thanks for the details!

A big question I have with this coaster is the strain that the swinging ride vehicle while have on the track. Sure, coasters get a lot of pounding, but the whole swinging thing . . . with perhaps 400 lbs of guests. Obviously, they designed the track with this in mind, and it looks very sturdy, but it is a new ride mechanism.

I know that if you're carrying a 5 gallon bucket full of rocks/heavy stuff . . . if you start swinging it back and forth you really get some shearing effect on your hand . . . no doubt they'll want tons of sensors on the track to monitor for deformations. Maybe they'll be OK with the track lasting half as long as similar tracks . . .

 

[unkadug]

I'm not seeing the conduit bender.

But I did just notice the welder leads connected to the track and draped over the concrete wall.

To the right of the RCES guy leaning vertically against the track.

 

[Tom]

Leaning against the track in the first picture that started this discussion.

Argh! I feel like I'm playing Where's Waldo

Which pic? Red Cart pic or ERMCO/RCES dudes pic? And are we talking PVC heater or EMT pipe bender?

 

[Tom]

To the right of the RCES guy leaning vertically against the track.

Oh! I kept writing that off as a stick of PVC sticking up with a piece of tape on the top.

 

[Tom]

Awesome, thanks for the details!

A big question I have with this coaster is the strain that the swinging ride vehicle while have on the track. Sure, coasters get a lot of pounding, but the whole swinging thing . . . with perhaps 400 lbs of guests. Obviously, they designed the track with this in mind, and it looks very sturdy, but it is a new ride mechanism.

I know that if you're carrying a 5 gallon bucket full of rocks/heavy stuff . . . if you start swinging it back and forth you really get some shearing effect on your hand . . . no doubt they'll want tons of sensors on the track to monitor for deformations. Maybe they'll be OK with the track lasting half as long as similar tracks . . .

I would enjoy hearing about the unique design parameters they took into consideration on this one. No just the lateral and centripital forces of the loaded vehicle, but also the additional live load of the swaying buckets of guests. That will most certainly factor into the design of the steel and support system.

 

[Pixiedustmaker]

I would enjoy hearing about the unique design parameters they took into consideration on this one.

It sure would be interesting. If anything, the 7DMT track appears to have much closer spacing of the pylons than Expedition Everest, though of course Everest had to contend with the fact that the rockwork mountain supports don't touch the track. I believe with 7DMT no such requirement was necessary, probably in part because of the slower velocity of 7DMT, but perhaps also because with closer pylon spacing excessive sway is constricted.

The sections going inside 7DMT's mountain appear to have extra reinforcement to prevent excessive movement inside this structure.

The track itself is a much wider gauge that even BTMRR

Even though 7DMT probably won't be as fast as BTMRR, looks like they had to engineer a much studier track. Perhaps even studier that the spinning coasters like Crush:



While the spinning coasters spin, one issue with 7DMT is that the whole train jerks to the side at once, instead of rotating around an axis.

 

[danlb_2000]

It's amazing that the anchor bolts are installed before the tracks as they need to be dead-on with very little margin for error . . . I would think that would be a lot of precision survey work. I guess for the cement to cure they need to obviously do this work first.

I was at Hershey Park a couple years ago when Skyrush was being built, before the track was installed. I remember looking at the footers scattered about the landscape, some of them even in the stream bed, and wondering how they manage to very every one of those perfectly positioned.

 

[danlb_2000]

It sure would be interesting. If anything, the 7DMT track appears to have much closer spacing of the pylons than Expedition Everest, though of course Everest had to contend with the fact that the rockwork mountain supports don't touch the track. I believe with 7DMT no such requirement was necessary, probably in part because of the slower velocity of 7DMT, but perhaps also because with closer pylon spacing excessive sway is constricted.

Good observation, I didn't even notice the high number of pylons on this curve. I'm still trying to get my head around the swinging car physics. As the car is going around this curve which way will it swing?

.[/quote]

 

[phi2134]

Im wondering if they high number of pylons have something to do with how far they could put them in the ground and how much concrete they sit on. Maybe the expedition everest pylons go deeper and have more stability. If I remember correctly they didnt go down all too far when constructing the base of the mountain, but that might be because of how small this ride is compared to everest.

 

[RandomPrincess]

Good observation, I didn't even notice the high number of pylons on this curve. I'm still trying to get my head around the swinging car physics. As the car is going around this curve which way will it swing?


.

[/quote]

The cars would swing out making the curve seem steeper if they are just using centrifugal force to make the cars swing.

 

[danlb_2000]

Ah yes...that's probably it...and everyone seems to think Parks Blog will have a pic of a mine train car tomorrow that has arrived on-site somewhere...

Yep...

http://www.wdwmagic.com/attractions...-mine-train-ride-vehicle-delivered-to-wdi.htm

 

[Victor Kelly]

Yes.

The red trolley is used to check clearances, while also ensuring that the track doesn't become deformed during construction. They traverse it around the entire track system to make sure the rails remain EXACTLY the correct distance apart, and aren't compromised by surrounding construction, loads or equipment.

Correct! Railroads use them when laying track. Model railroaders use the track gauges to build their own tracks. It also most likely serve the purpose of scenery clearance as many have already speculated.

 

[Scuttle]

The cars would swing out making the curve seem steeper if they are just using centrifugal force to make the cars swing.[/quote]

Physics would say yes this is correct, but the CGI videos of the 7DMT show it the opposite. It's confused me forever now.

 

[G00fyDad]

The cars would swing out making the curve seem steeper if they are just using centrifugal force to make the cars swing.

Physics would say yes this is correct, but the CGI videos of the 7DMT show it the opposite. It's confused me forever now.[/quote]



The car has to be moving fast enough to cause the g-forces to swing the car outward. If it is moving slow enough then gravity will hold the car upright even around a corner. With heavy cars like these the speed wouldn't have to be too slow for that to happen either.

 

[Victor Kelly]

I cannot wait to get on this ride. I know it is just a kiddie coaster but it looks and sounds to be a blast

 

[lazyboy97o]

Physics would say yes this is correct, but the CGI videos of the 7DMT show it the opposite. It's confused me forever now.

The whole reason a mine car swings is so that the load stays as level as possible and doesn't fall out. We're going to sway a little, but extreme banking doesn't make sense as the load would fall out along the way.

 

[danlb_2000]

The whole reason a mine car swings is so that the load stays as level as possible and doesn't fall out. We're going to sway a little, but extreme banking doesn't make sense as the load would fall out along the way.

A real mine car swings so that if can dump it's load when it reaches it's destination. They don't swing as they are moving.

 

[lazyboy97o]

A real mine car swings so that if can dump it's load when it reaches it's destination. They don't swing as they are moving.

True, but you don't still want to dump anywhere except where desired so over-banking isn't a positive.

 

[Victor Kelly]

I think over banking will not be an issue. If the motion is on hydraulic pistons or shocks that will limit the range of motion to a maximum point. As I understand it, the range of sway will be partially influenced by weight. Much the same as when you come down the last hill on Splash. More weight in the front and it digs into the water more and you get more splash.

The restraint system will also be very secure as well. I expect them to have a lengthy testing period as well as long soft opening.

 

[DrewmanS]

Physics would say yes this is correct, but the CGI videos of the 7DMT show it the opposite. It's confused me forever now.

The car has to be moving fast enough to cause the g-forces to swing the car outward. If it is moving slow enough then gravity will hold the car upright even around a corner. With heavy cars like these the speed wouldn't have to be too slow for that to happen either.[/quote]

It is all dependent on the center of gravity of the swinging car relative to the pivot point and angle of the track. Think about a gimbaled drink holder (on a boat for instance). If you put a can filled with liquid into the drink holder, the can will remain relatively still compared to the horizon as the boat rocks back and forth. So, as the "train" enters a high bank corner the wheels base will move more toward vertical than the swinging car. It will actually have a dampening effect. The g-forces felt by the riders will be relative to the position of the car, not the track. This can cause additional torque on the track. Now, if the track was flat in a turn, the car would swing out based on centrifugal forces. This may happen as the cars come out of a turn.