I spent this past weekend doing something that I haven't done much of, lately: riding roller coasters. Yes, I'm a card-carrying member of American Coaster Enthusiasts, but I haven't kept up with most of the new coasters that have been built in recent years. I get motion sickness, and I always worry that I'm building up an immunity to Dramamine. Maybe that's part of it, but for whatever reason I just haven't made the time.

But when some friends asked my wife and me if we wanted to join them for the opening weekend at Cedar Point in Ohio, we jumped on a plane bound for Detroit. Not only was it a chance to visit our favorite coaster park with friends, but it was also a great opportunity to take our first ride on what is currently the tallest and fastest roller coaster in the world, the Top Thrill Dragster.

It's 420 feet tall and reaches its top speed, 120 miles per hour, only 4 seconds after the train leaves the station. Obviously, it leaves the station rather suddenly. The weather on the Lake Erie coast was lovely, the freshly-painted rides were breathtaking, and we had fun catching up with our friends.

And to top it all off, the Dragster was having technical problems. That's not normally a positive thing, of course, but in this case it was kind of cool. Although we were strapped in for our first ride and gripping the handles with white knuckles, the sophisticated new launch system was unable to propel our train at 120mph. We shot off the launch pad, sure enough, but our train only reached a measly 100mph or so, which meant we didn't quite make it up all 420 vertical feet of track. We peeked over the top of the hill (we were seated near the front), but gravity took hold of the back of the train and tugged it like the elastic cord pulling a red rubber ball. We slowed down and started rolling backward off of the ride's highest point and did a reverse free-fall until we arrived back at our starting point at a very high speed.

That sounds scary, but it's happening more than Cedar Point would like. Everything from weather to wear-and-tear is giving the propulsion system fits, so every once in a while a train won't make it over, and ours was one of the lucky ones. The designers knew this was a possibility (thank you) and created a nice smooth braking system at both ends of the ride. So we sat for a minute, still strapped in, some of us woozy, as the maintenance people cleared the flashing lights from the console. Then the machine fired us again, and we cleared the hill and continued through the ride.

Gravity is a harsh mistress.

Here's a cool article from a trade journal, Machine Design, that describes some of the technical details of the ride in terms that we lay-people can understand. I especially liked this part:

Once blasted from the starting position the last thing anybody wants is to see the train rolling backward after not making the 420-ft climb. That scenario is unlikely, says [Cedar Point's Rob Decker, vice president of planning and design], but Cedar Point officials are prepared nonetheless.

Traditional coasters that gradually ascend the lift hill have antirollback devices that keep trains from reversing. Those systems aren't appropriate for a coaster of Top Thrill Dragster's immensity because a train that didn't make the hill would come back down going more than 100 mph. Traditional braking mechanisms would give passengers too much of a jolt. And once stopped, there's no other propulsion method in place to get the train moving again. [Ride manufacturer] Intamin's solution: a magnetic-braking system.

Permanent magnets mount to the bottom of each train, and copper-alloy fins are affixed to the track. Pneumatic cylinders pull the fins down so the train can launch over top, and then let them pop back up after the train blasts off. When the fins are up, they pass between the magnets, trimming the speed and eventually stopping the cars. "Because we are using rare-earth magnets, there's no need for a power source, and they work all the time. The ride can come to a halt safely, even in the event of a total loss of power," explains [Cedar Point's Monty Jasper, vice president of maintenance and new construction].

Unlikely, indeed. I'm glad the designers took the scenario into account.

I have to say, despite the thrill of the new ride, my favorite coaster in the park remains the classicly modern Millennium Force (three years ago it was the tallest/fastest ride in the world at a mere 310ft/93mph), followed closely by the gracefully twisted Raptor.

I'm also pleased to report that the Dramamine is still doing the trick. I carry the chewables.