Over the past few years launch coasters have been popping up everywhere. Universal’s Islands
of Adventure’s latest two roller coasters, Hagrid’s Magic Creature Motorbike Adventure,
and VelociCoaster, both have launches. The brand new ride at EPCOT, Guardians of the Galaxy:
Cosmic Rewind is also a launch coaster, as is the new Tron roller coaster at Magic Kingdom.
This trend extends outside of the big theme park names too. SeaWorld Orlando and Busch
Gardens Williamsburg both built quadruple launch coasters, Ice Breaker and Pantheon,
whilst Phantasialand built the world’s first launched flying coaster, FLY.
Launch coasters provide something that traditional rides, ones with chain lift hills, just can’t.
The initial punch of acceleration is simply more thrilling than a slow climb. As roller coasters
have developed over time, so too have roller coaster launches. Today, the theme parks have
seemingly settled on magnetic launch coasters, rides which use high-powered magnets to propel
guests to stupidly high speeds. All of the rides mentioned at the start of this video are magnetic
launch coasters - as are many others rides around the world. Magnetic launch systems come in two
types, Linear Induction Motors, LIMs, and Linear Synchronous Motors, LSMs. So - how do they work?
LIMs Linear induction motors,
known as LIMs, were first introduced back in 1992 - but they weren’t used to launch roller coasters.
Disneyland Paris and Vekoma used LIMs on their Big Thunder Mountain roller coaster to transport
trains from the end of the ride back into the station. These drives were entirely magnetic,
meaning they didn’t contact any part of the train, heavily reducing wear and tear. However,
it wasn’t long before another amusement company enhanced the technology. In 1996,
the world’s first LIM launch coasters opened to the public, Outer Limits: Flight of Fear at both
Kings Island and Kings Dominion. Developed by Premier Rides, the technology uses an
alternating magnetic field to push the trains along the track at an ever increasing speed.
Flight of Fear was able to accelerate guests from 0 to 54 mph (87 km/h) in just 4 seconds.
LIM launch coasters use pairs of electromagnetics, known as a stator, which are placed on top of each
other, or beside each other, nearby the rides track. They feature a small gap in the middle,
allowing for a metal fin on the train, often made from aluminium, to slide through. Due
to the arrangement of the electromagnets, once they’re powered, a travelling magnetic field is
created which constantly moves along the track. This constantly moving magnetic field causes the
aluminium fin on the train to create a magnetic field of its own, known as an eddy current. This
magnetic field opposes the one created by the electromagnets, causing a force to be applied to
the roller coaster train, as the two fields want to separate from each other. The force is exerted
in the opposite direction to its relative motion - in this case the relative direction of motion is
backwards, as the magnetic field waves travel forwards faster than the train. As a result,
the repulsion accelerates the trains forwards, to a speed desired by the designer. To maximise
power and efficiency, as the train speeds up, so does the electromagnetic wave generated by
the stators. However, LIM systems require an enormous amount of power to run and aren’t
extremely efficient. Some of the energy used is converted into heat, which is drawn away
from the electromagnets using large fans. Nevertheless, LIM launches have been used
on numerous roller coasters, from the many impulse roller coasters produced by Intamin,
to the Incredicoaster at Disney California Adventure Park.
LSM LIM’s initially ushered in a new era
for launch coasters. However, they were quickly followed by the debut of the Linear Synchronous
Motors, known as LSMs. In 1997, amusement ride manufacturer Intamin debuted Superman:
Escape from Krypton at Six Flags Magic Mountain, and Tower of Terror at Dreamworld - the world’s
first LSM launch coasters. Both rides were capable of accelerating guests from 0 to 100mph 160kmh
in 7 seconds. The idea of this technology was similar to LIMs, but differed in a few key ways.
LSM launch coasters use a series of electromagnetics, known as a stator, which line
the ride’s track. These may appear as a single row of electromagnets, like on VelociCoaster, or two
parallel lines, like on Ice Breaker. Each train is equipped with a set of large strong permanent
magnets, often located on the base of the ride vehicle. The permanent magnet on the train
allows for the electromagnets on the track to pass through the middle. To accelerate the train, the
electromagnets match the magnetic field generated by the permanent magnet on the train. However,
the magnetic field generated by the track is offset slightly. This causes the permanent magnet
on the train to be both attracted and repelled forwards at the same time. Effectively, the train
rides the electromagnetic field generated by the stator, being accelerated forwards in the process.
To successfully achieve this, LSMs require extremely precise control systems. The speed
of the travelling magnetic field must be exactly synchronised with the speed of the train at all
times for it to work properly. Therefore, as the train accelerates, so does the magnetic field
generated by the electromagnets. The precise nature of the technology makes LSMs much more
efficient than LIMs, requiring less power to run, therefore reducing operating costs. Furthermore,
the process used to launch the train can also be used in reverse to slow the trains down.
VelociCoaster at Universal's Islands of Adventure features two LSM launches, whilst Red Force at
Ferrari Land in Spain uses LSMs to accelerate guests from 0 to 180kmh (112mph) in 5 seconds.
Why magnetic launches? Magnetic launches aren’t
the only type of launch systems available to roller coaster designers however. Xcelerator
at Knott’s Berry Farm in the US features a hydraulic launch, whilst Do-dodonpa at
Fuji-Q Highland in Japan features a compressed air launch. Despite these alternative systems,
it was the magnetic launch that caught on, specifically Linear Synchronous Motors, LSMs.
By featuring no moving parts, magnetic launch systems are free from wear and
don’t need to be reset between launches. This makes it the ideal
launch system for larger theme parks, like the ones at Disney and Universal,
to accelerate train after train without hassle. Though, roller coasters with
launches often suffer from downtime more than their traditional lift hill counterparts.
Fortunately as time went on, manufacturers of roller coasters made their magnetic launches more
reliable. They also became more powerful, more efficient, and more flexible. Today,
roller coasters often feature more unique magnetic launches. Some use swing launches, where the train
cycles forwards and backwards through the launch, before gaining enough speed to complete the rest
of the layout. Others feature LSM launches placed on airtime hill elements, pushing guests out
of their seat as they’re accelerated to a high top speed. Some combine both, using fast-switch
tracks to allow riders to partially climb a hill, before rolling back through the launch,
climbing a spike, and completing the remainder of the track. It’s for all of these reasons that
Disney and Universal have been constructing magnetic launch coasters, and will likely
construct even more in the future.
Thank you for watching, and, we’ll see you all next time.