The last element on our ride is the helix. The helix is simply a turn that keeps on going, generally over more than 360 degrees of rotation. A helix can be as simple as a constant radius, slowly descending curve. This element's been around pretty much forever, and has a lot of unique examples. Here's a pretty cool one as Busch Gardens Williamsburg.
Notice how the designer used the changing height of the helix and adjusted the radius and banking angles to create a really unique diving exit. For our ride I'd like to make an intense helix inside of the first turn off of the launch. This will save space and create a few near misses along the way. After the corkscrew the track is right at the ground, so I'll build an ascending helix up and over the first turn. I'll also make the radius decrease as the track ascends, to keep the g forces constantly high.
Cool, now we've got the last element of our design done and finished. What to do now but slow the train to a stop! For a long time coaster brakes were mechanical clamps which dissipated the train's final energy by grabbing metal fins on the bottom of cars. Here's a picture of these brakes on the track. The fin on the underside of each car passes through the gap in the middle of the gray blocks, which are computer controlled to precisely manipulate the coaster's speed (or stop it completely).
A revolution occurred in 1999 when Millennium Force (still my favorite ride in the world) opened at Cedar Point. This ride broke some 13 world records, but the important one was the first use of a magnetic breaking system. This technique uses permanent magnets mounted on the track to oppose the motion of the cars traveling past by simple magnetic repulsion. Because there is no longer physical contact the system is much easier to maintain and much quieter. Additionally, because the system imparts a force based on the velocity of the train (as opposed to a harsh static frictional force), the deceleration is much smoother. Here's a picture of some moveable magnetic breaks. With the help of pneumatics the assembly can rotate away from the track and completely remove themselves from affecting the ride's speed.
The discussion of brakes wouldn't be complete without a brief overview of blocks. Blocks on a rollercoaster refer to a section of track with a controllable entrance and exit. 2 trains should never be in the same block at the same time. This is because, as in any field, failures happen. If a wheel assembly were to fail and a train were to grind to a halt, there needs to be a way to make sure the next train won't plow full speed into the back of our unsuspecting riders. To achieve this, no train is allowed to enter a block until the one that preceded it has safely passed through the next block's control point. It's a complex topic, so here's an example on our ride. See here that a train is sitting at the launch, waiting to go (we'll call this train B). However, the train in front of it (train A) has not yet cleared the final brake of the ride.
This situation means that there is some slim possibility that train A will stall and get stuck on the circuit. To assure the safety of all the riders, train B must wait until the moment that train A has cleared the final brake. That way, even if train A were to fail immediately after clearing the brake, train B could be stopped by the final brake before a crash would occur.
At this moment train B is clear to launch. This type of blocking occurs for all coaster types across every block, which can include stations, holding brakes, lift hills and mid-course brakes. Mid-course brake runs (MCBRs) are used to allow greater capacity on longer rides. For example, here on Dragon Khan in Spain, there is a MCBR approximately half-way into the circuit time wise. You can see it here, it's the flat piece of track with catwalks. The catwalks allow riders to be evacuated if a major problem should occur.
In this example, 2 trains can be on the "live" part of the track at once. One can be between the lift and the MCBR, while another can be finishing up after the MCBR and towards the final brake. This allows for greater capacity, which means less lines, happier riders, and more revenue.
Well, our coaster is mostly complete. However, it seems to be floating in the air. Yep, we need some supports to hold it up. Unfortunately, this is one area where No Limits doesn't really excel. There is no simulation of the forces going into the supports, so creating them is largely an exercise in cosmetics. Honestly I just try and imitate real rides from photos. It'd be hard to analyze the dynamics of supports, especially with myself not having taken a materials class first. Anyway, let's move onto the final stuff, colors and themeing. I've never really been one to theme a ride, but it can significantly help pull people's attention to rides. Themes can make a mediocre ride interesting, but can't make up for a terrible ride path. Our ride doesn't really need a theme, as it's a pure thrill ride. However, I've decided that a Boilermaker Special badging is in order. Therefore, I'll prepare a special car texture and change the colors.
Colors are slightly important because they are a clear visual draw to a coaster and can create a small sense of distinction from ride to ride.
Alright, that's it for today's update. I'll have one more update, featuring a few pics of the final ride and a point of view video. As always, thanks for reading.As a side note I'll be updating the first entry to better cover launch systems and lift hills (it made more sense to put the discussion there).
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