On every roller coaster you’ll find one of these - a restraint; the thing that keeps
you inside of the train, rather than out of it.
However, it might not look specifically like this.
Today, restraints, harnesses or whatever you know them as, come in a range of shapes and sizes.
Despite this, they all serve the same purpose; to keep someone secured to the seat throughout
the duration of their ride.
But this hasn’t always been the case.
You might be shocked to know that in the early days of amusement rides, restraints weren't even a thing.
Jump back in time over 100 years and you’ll find roller coasters that didn’t feature
any sort of restraint or harness, not even a seat belt!
Riders would simply sit on benches attached to a set of wheels, which they would then
ride down a shallow hill.
Early roller coasters operated with no form of restraint purely because the ride experience was so tame.
Plus at the time, safety regulations were far less restrictive than what we have today.
But as roller coasters got faster and more intense, new restraint methods were developed.
At first this came in the form of a bar, connected to the seat in front, which guests could hold
onto as they navigate the track.
However, by the 1920s, rides started to really pack a punch.
New roller coasters were built with steeper drops, causing the development of a fixed
bar, placed above the legs of riders, allowing them to hold on more securely.
Eventually, this evolved into a single position lap bar that had the ability to open and close,
a restraint type much more similar to the ones we have today.
These restricted guests and made it difficult to stand up during the ride, encouraging a
much safer riding position.
At the same time, other roller coasters had transitioned to using seatbelts as a form of restraint.
Scwarzkopf’s Jet Star models were an example of this, which due to the tighter design of
the train, only required a seatbelt to keep guests in their seats.
Shortly after, restraints evolved into securing individual riders, as opposed to an entire row of the train.
This way, the bars could be positioned closer to each guest, often improving comfort and safety.
At the time individual restraints were emerging within the industry, inverting roller coasters,
rides that go upside down, were being introduced to the world.
Here, different approaches were being taken by two competing companies.
Schwarzkopf continued to use the well developed lap bar design for their inverting rides,
first seen on Revolution at Six Flags Magic Mountain.
While Arrow Dynamics developed an all new over-the-shoulder-restraint, seen throughout
their corkscrew roller coaster models.
This over-the-shoulder-restraint sees the upper part of the riders body secured to the
seat; while the traditional lap bar would pin riders lower body to the seat.
While both systems were safe, most looping coasters were quick to adopt the over-the-shoulder variant.
This was mainly due to the fact that they were assumed to be safer, and more comfortable,
by both the general public and theme parks alike.
However, the lap-bar restraint continued to be used heavily on non-inverting roller coasters.
At the start of the new millennia, Vekoma developed the restraint even further.
Stealth, the first modern day flying coaster, introduced the vest restraint to the world.
This system was similar to the over-the-shoulder-restraint, but featured a flexible vest-like chest piece,
which supports the riders upper body.
This limits the movement of the guest within the seat drastically.
Several years later, Maurer Rides reintroduced the concept of using lapbars on inverting roller coasters.
Their latest idea saw guests secured by a bar that fits sideways across the riders lap.
This evolved further with the debut of the MACK Rides launch coaster; a ride which featured
extremely comfortable lap bars.
However, unlike previous designs, the lap-restraint came down from above the head of riders.
This allowed guests to have complete upper body freedom, while offering a familiar restraint
experience, similar to previous over-the-shoulder variations.
Since then, amusement manufacturers worldwide have rushed to introduce lap-bar designs onto
most of their inverting roller coasters.
However, it isn't possible to use lap-bars designs on all rides.
For these cases, companies have turned to vest restraints, in an attempt to improve
rider comfort compared to traditional over-the-shoulder variations.
As a result, in today’s world, most new inverting roller coasters will feature either
a lap-bar or vest restraint of some description.
Moving forwards, restraints will most likely continue to develop in the way of rider comfort,
improving the experience each guest has.
As the shape and design of restraints has changed over time, so too has the mechanism
employed to keep them in place.
Restraints can mostly be placed into two categories based on how they work,
ratchet designs and hydraulic designs.
Ratcheting restraints use mechanical mechanisms to ensure the harnesses are locked securely into place.
This type can quickly be recognised by the distinctive clicking sound made when the restraint is pulled closed.
These clicks are the result of a pin interacting with a mechanism to keep the restraint locked
in a specific position.
This often involves a cylinder, attached to the pivot point of the restraint, with multiple
grooves around its circumference.
As the restraint is pulled into position, the pin falls into the grooves of the cylinder,
locking it into place.
Each click signals the next groove the pin has locked into.
Due to the design of the grooves, the pin stops the cylinder from rotating in the opposite
direction, meaning the restraint cannot open once a pin is in position.
In the case of Bolliger and Mabillard inverted coasters, the system features 8 pins, 2 of
which fall into place at any one time.
This means that if one pin were to break, which is extremely unlikely, the other will
hold the restraint in place.
When riders re-enter the station, a mechanism located within the track pushes on the restraint
release located on the train.
This causes the pins move upwards, allowing the cylinder to rotate, and the restraint to raise.
Hydraulic restraints, on the other hand, work by using hydraulic fluid and a piston.
These can be easily recognised as unlike ratcheting restraints, they are infinitely adjustable,
meaning they can be moved to any position; and offer resistance to any movement, sometimes
making it hard for them to be pulled down by the rider.
The restraint itself is connected to a cylinder full of hydraulic fluid, which has a piston in its centre.
Tubes allow the fluid to flow from one end of the cylinder to the other, through what
is known as a check-valve.
This valve allows the hydraulic fluid to only travel from the closed end of the cylinder to the piston end.
As the restraint is pulled down, fluid is pushed through the valve and gathers behind
the piston, pulling down the cylinder.
As the valve restricts the flow of the fluid, the restraint cannot move up during the ride.
Naturally however, not all of the fluid will fit into the end of the cylinder housing the piston.
As a result, some has to be directed into a small bottle, known as the ‘bladder accumulator’.
To keep the system pressurized, the fluid that flows into the bottle squeezes a nitrogen gas filled balloon.
This allows the amount of fluid in the system to change without letting any air into it.
Connected in parallel to the check-valve is a spool-valve.
This is a simple on-off valve controlled by a small electromagnet and pushed closed by a spring.
When the restraint is locked into position the valve is turned off, meaning fluid must
flow through the check-valve.
When riders return to the station, the train connects with electrical contacts near the track.
This allows for the spool-valve to be powered, causing it to open.
As the system is pressurised this allows fluid to rush back into the open end of the cylinder,
forcing up the restraint.
As a form of redundancy, hydraulic lap-bars often feature two independent cylinder systems.
This means that if one was to fail, which alone is an extremely rare event, the other
would keep the restraint in place.
Due to the infinitely adjustable nature of the hydraulic restraint, most roller coaster
manufacturers use this system on their modern rides.
Though, no matter the type of system, once a restraints has been locked, that is its default position.
This means that the restraints cannot be opened during the ride,
but only when the train is in the station.
However, a roller coaster’s restraints can be opened in a special manor in the event
of a ride evacuation.
If the train is stopped in a safe location, a ride operator can use a specific method
or tool to open the restraints manually.
In the case of ratchet systems, each car often features a pedal, which when pressed, causes
the restraints to release.
For other mechanical systems a special tool would be used to achieve a similar outcome.
Meanwhile, hydraulic restraints require an electrical current to open.
As a result, ride operators would use a battery pack of some description to temporarily activate
the electromagnet, opening the spool-value, and releasing the restraints.
As yet another layer of safety, sensors can be found on every aspect of today’s modern
day roller coasters, including their restraints.
Each restraint often features a proximity sensor, showing the ride operators whether
it has been properly locked into place.
Sometimes this is indicated by a small green light near the seat on each car.
Further to this, the system will not allow the train to leave the station unless each
sensor confirms that all of the restraints are locked.
Some roller coasters nowadays feature more than just one restraint.
You’ll notice that depending on the ride in a question a seatbelt might accompany the train’s harnesses.
These can often serve one of two purposes.
Firstly, some seat belts are used to ensure that the main restraint can close correctly.
For example, if the seatbelt can comfortably connect to the restraint, or fit across the
riders lap, then the main restraint will be able to close securely.
This check is primarily used to ensure that larger guests are properly secured.
Other rides feature seatbelts purely for guest comfort.
Naturally, some riders find that they feel ‘safer’ with a seatbelt strapped around them.
This is why you’ll find some rides with seatbelts, and others without any.
Each manufacturer of roller coaster provides a different restraint system, each with multiple
layers of safety and redundancy.
So now you know both how restraints work, and how they’ve evolved over time to improve
both rider comfort and rider safety.
Next time you board a roller coaster, take notice of the restraints and the method they
use to keep you secure.
Can you hear the click of the ratchet, or feel the resistance of the hydraulic system?
Anyway, thank you for watching, and we’ll see you all next time.