RMC track construction

Hi All, it's my first time posting here, great to meet you all!

Does anyone know how RMC manufactures their track. Specifically I'm trying to figure out how they "flex" or "bend" the top/bottom portions of the track. As far as I understand the top/bottom sections are solid steel plates, and there are several references that say they don't do any mechanical or heat bending of the track - so how do they get it to twist so much?

In the image below you can see the "top" and "bottom" portions I highlighted on the blue cross section of track. As I understand, all other pieces are cut into the right shape out of steel plate but the highlighted top/bottom sections are essentially solid. The second picture with the red track (trex or raptor) shows how the top piece of solid steel is all twisted up.

I know they use stands/jigs that are welded to the floor to hold the track while they assemble it, but nothing I can find explains what they do to bend/flex the solid steel into the twisted shape it becomes. Does anyone know or have guesses?

Thanks!!

Nice try, Ron Toomer...

Lol, I have no idea what that means?

If its a trade-secret or something I understand, but they give tours of their factory - in fact watching youtube videos of their factory tour is what got me curious about this in the first place

Ron Toomer was one of the original minds at Arrow and was famous/infamous for designing curves with coat hangers in the era before CAD.

Actually it was welding wire.

But steel plate is not inflexible, and while the twists can be rather extreme, they are spread out over a long enough distance that a whole lot of flex in the Z axis and a little bit of roll twisting is possible, and to shift it around Y you just cut a curved piece of steel.

This is exactly how GCI's Titan Track work, except that theirs isn't welded...in part because the heat generated by the welding process can deform the finished track. But generating twists and curves works in the same way: lateral radii are cut, vertical radii and rolls are easily bent. The exact positions of those manually bent pitches and rolls are determined by the precisely-cut curves of the connecting parts.

For a compound curve like the one RollerDad showed us, the top and bottom steel plates will be cut in a flat curve, so it will look like a flat, shallow right hand bend. Over that distance the plate steel will be quite flexible. Likewise the undersides of the flanges...essentially the same shape but smaller. And not identical because the turn radii are different for the inside and outside flanges. Here's the trickery: The side plates are also cut as curved pieces. Again, all four of the side plates are similar. The curve cut into the side plate sets the bend of the top and bottom plates, while the curve cut into the top and bottom plates determines the bend of the side plates.

The fabrication is straightforward, but it requires precision cutting of the steel webs. You can see why simply roll-forming a piece of steel tube (circular in cross-section so that ultimately you don't care which way is "up") is a whole lot easier in the absence of CNC laser cutting. You can also see how CNC laser cut parts will produce a finished product that lines up more accurately with the CAD drawing than the hand-rolled tubing ever will.

--Dave Althoff, Jr.

Going a bit O.T.

Ron Toomer was the guest speaker at one of the Coastermainia's I attended.

He said he both a BS and MS in Mechanical Engineering.

BUT, never did the actual design (calculations) for coasters.

He said he'd he would take the now famous piece of wire, bend it into the shape he wanted, then give it to a jr. engineer.

He said he'd tell them, the rest is your job.

Engineers gotta calculate

rpbobcat:

He said he'd tell them, the rest is your job.

And that's how we all ended up with brain damage from riding Steel Phantom.

I caught a lap on Tennessee Tornado yesterday. Evidence that Arrow could build coasters that did not hurt.

Yep, the glimmer of hope for Arrow's continued success. Then they built a couple mice, filed for Chapter 11 while building X, and got sold to S&S all within 3 years.

Sucks.

Given that it is pushing 25 years, it's kind of amazing how well TT still runs.

I first rode it in 2002 when it was fairly new. I just rode it again last year (20 years later) and I agree, it was still nearly as smooth as I remembered it.

I rode it Wednesday and it was as good as ever.
But I wonder if there are any enthusiasts among us who haven’t figured in their heads how to add another 1000 feet or so to it.

I am guessing that was part of your conversation with the maintenance guy.

I honestly don't mind the short duration. Inversions destroy me in my old age...but if I wanted it to be longer, I could just queue up again since I've never seen much of a line for it.

Vater:
Then they built a couple mice, filed for Chapter 11 while building X, and got sold to S&S all within 3 years.

I have to wonder, at least in the domestic market, how much the failure of Drachen Fire may have hurt them. Other than the Mice, almost everything built after that was smaller or a mouse. Yes, Kings Island had Top Gun / Bat / etc., and SDC had Thunderation, but for the most part, Arrow completely lost out on the Y2K craze of the day.

They built quite a few hypers in the mid-90s, albeit most of them outside the US. I would pin it on the fact that they failed to keep up with the emerging competition at the time (i.e. the B&Ms and Intamins with their much smoother transitions) until it was too late vs. the failure of one coaster. Arrow seemed to really kick the so-called "coaster wars" into overdrive with Magnum, and then other companies flourished with better tech while Arrow stagnated.

I remember talking to Arrow's last CEO (there's probably an interview on here somewhere). Young guy, ambitious, but X really screwed them because it was so expensive to make. That's probably at the to of the list of things that killed it off.

Shades:
I am guessing that was part of your conversation with the maintenance guy.

Don’t be a jealous hater. I do these things for you.
And also, I didn’t think of it.

RCMAC:

But I wonder if there are any enthusiasts among us who haven’t figured in their heads how to add another 1000 feet or so to it.

Another 1000 feet or so is the path to the dark side.

Length leads to smaller inversions.

Smaller inversions lead to head bangers

Head bangers lead to hate.

Hate leads to suffering.

...or something like that. TT is great because it was built with larger, smoother inversions and ends before it has to start using their older style, small and painful ones.