How Water Slides Work

In the amusem­ent park industry, the  is king. But during the hot summer months, these classic attractions get some tough competition from inflatable slide. In the past 30 years, the world of  slides has exploded. They've transformed from­ simple poolside slopes to intricate attractions that dominate entire parks. According to the World Waterpark Association, there are more than 1,000 water parks in North America, and about 78 million people visited them in the summer of 2006.

Water parks boast slides with dozens of loops, incredible speeds and exhilarating drops. The inflatable dry slide on record is the 120-foot (37-meter) "Summit Plummet" in Walt Disney World's Blizzard Beach. If you'd rather ride down on a raft, you can take a plunge on the similarly record-breaking "Insane," an 11-story-tall water slide in Brazil [source: World Waterpark Association]. Whether you're on a mat, a raft or your bare skin, you're at the mercy of gravity as you make your way down -- and sometimes up -- the slippery slope.

A water slide is like a wet roller coaster with no seat and no safety harness, and it uses the same principles a roller coaster does to work. In this article, we'll peek behind the scenes to find out what's involved in operating a water slide, from pumping the water to cleaning it after the ride. We'll also see how the pieces of a wate­r slide fit together and find out what keeps you from flying off into the air as you whip around corners.

At its most b­asic level, a water slide is a relatively tame roller coaster with no track and no car. If you've read , then you know that coaster cars are driven by .

At the beginning of the ride, the coaster car is pulled up the . As the coaster rises higher in the air, its potential energy, or energy of position, increases. Simply put, it has farther to fall. When the coaster is released at the top of the hill, gravity pulls it down the track, converting potential energy to kinetic energy, or energy of motion.

 slides work on exactly the same principle. But instead of a lift hill, you have a stairway. Climbing the stairs builds up a certain amount of potential energy, which turns into kinetic energy as you head down the slide. A taller slide has more potential energy to work with than a shorter slide.

On the inflatable water slide, your body, sometimes combined with a mat or raft, takes the place of the roller-coaster car. Coaster cars have wheels that roll along the track. This reduces the friction between the car and the track, so the car can keep moving. Water slides have a constant stream of water flowing from the top to the bottom. The water lubricates the slide to reduce the friction between the slide and your body.

Apart from total height, the main difference between particular water slides is the way they put the potential energy to work. This is determined by the shape of the slide. We'll look at how a slide's shape affects how fast you fly and how far you move in the next section.

The slide applies a force working against . The balance of these two forces depends on the angle of the slide. When you are sliding along on a nearly level slope, gravity pulls you directly into the slide, and the slide pushes you upward. The upward force of the slide pushes nearly opposite the downward force of gravity, slowing your downward acceleration. When the slope drops sharply, gravity is still pulling you straight down, but the slanted slide is no longer pushing you straight up; it's pushing you at an angle between upward and forward. Since the slide isn't working directly against gravity, you accelerate downward more rapidly.

Speed slides and sled slides focus only on these up-and-down forces. On a speed slide, you plummet straight down a steep slope and launch into an exit flume, a long canal of  that slows you down gradually. In a sled slide (also called a toboggan slide), you glide over a series of bumps and dips. In both of these slide designs, you move forward in a straight line.

A small  slide, the sort you might find in somebody's backyard, has a very simple construction. It's a single piece of smooth fiberglass material, cast in the shap­e of a slide, supported by a metal frame.

Most panda inflatable dry slide have a similar structure, but on a much larger scale. Obviously, it's not feasible to use a single piece of fiberglass for a giant, curving slide. Water park slides are formed from dozens of fiberglass segments fastened together with heavy-duty bolts. Typically, the individual segments fit together like sections of a toy race track.

Each segment has one end with a raised lip and one end with a sunken step. When you fit two segments together, the lip of segment A rests on the step of segment B. This ensures that the segments hold together, with a smooth seam between them. Ideally, the slide feels like a single unit to the rider. Slides typically use completely enclosed tubes for the sharpest turns, to make sure everyon­e stays in.

These segments rest on a framework of steel girders. The girders may be positioned directly below the slide, or they may sit adjacent to the slide, supporting it with sturdy cantilevers.

Water parks generally buy new slides from an outside manufacturer. The manufacturer designs the slide and builds all of the individual pieces. The water park hires a local contractor to take these pieces and put the whole thing together according to the manufacturer's directions. It's just like building a toy race track or model train, but on a massive scale. The robot inflatable dry slide structure is only half of the ride, of course. Next, we'll take a look at how water lets you slip from the top to the bottom.

In order to zip down the slide, you need a constant stream of  to reduce friction betw­een you and the fiberglass surface. To maintain this stream, the water park has to get a supply of water to the top of the slide. Most water slides do this with a pump, h­oused in a building near the base of the slide. In the standard design, the pump motor turns a drive shaft, which is attached to a propeller. The spinning propeller drives w­ater forward, in the same way an  moves air particles.

The pump draws water from a collection , typically the pool at the base of the slide, and pushes it up through a narrow pipe to the top of the slide. In this way, the water running down the slide is constantly recycled. In some parks, the water is cycled through several connected pools before it is pumped back up to the top of a slide.

Inflatable bouncers or moon bouncers have grown in popularity over the recent years as they are relatively cheap to acquire,1 provide a source of entertainment for children and are generally regarded as a safe environment by parents. There are multiple descriptors for inflatable bouncers, including inflatable play structure, bounce house, bouncer and bouncy castle. They are encountered at fairs, festivals and amusement parks as well as at private parties. Restaurants, inns and even hotels, try to attract families with the installation of leisure games for minors, such as playgrounds with various attractions so that the little ones can have fun while adults enjoy a relaxed after-dinner or family celebration. In this respect, the bouncers are an ideal complement for parties and ensure hours of fun at low cost.

However, as their demand has soared, so have accident rates.2,3 In recent years, there has been a significant increase in the number of children treated in the emergency department (ED) for injuries resulting from the use of these devices (in the United States an injury rate of 5.3/100 000 children has been described).1

The mechanisms of injuries were: first, a fall, both inside and outside of the bouncy castle; second, a collision between children due to the differences in sizes and ages.4–6 Also, less frequently yet more severe, were injuries resulting from faults in the anchoring system and wind gusts.7

The main risk factor was the lack of effective adult supervision, either by the parent or staff responsible for overseeing the attraction. Furthermore, overcrowding by children of different weights and sizes increased exponentially the chances of suffering an accident.8

We carried out a prospective study of injuries secondary to inflatable play structure accidents that attended the Paediatric Emergency Department at our Hospital Universitario Son Espases. This is the first prospective European study of its kind, which has been conducted in a single referral centre for Paediatric Orthopaedics during a 12-month period (between February 2015 and February 2016). Our hospital is a paediatric referral site for the entire province; patients not only come from the city but from all the municipalities of the province. The population of the province is 1 169 591 inhabitants, with a population proportion corresponding to the age range of 0 to 14 years of 15% (Fig. 1).

The increase of inflatable play-related injuries may be explained by the growth of the inflatables industry,8 as well as by the lack of prevention measures and initiatives for reducing injury risks.

The aim of this study is to describe the epidemiology, type and chronology of the lesions and ultimately, we would like to outline some safety guidelines for inflatable attractions and alert civil society to the dangers of such facilities, still considered safe by the general public.

Only paediatric patients aged 0 to 14 years, who had experienced trauma in an inflatable play structure, were chosen for the study.

The patients’ parents were informed at arrival to the ED about the study, and they consented to and signed the protocol for data collection.

Demographic data gathered included: age; gender; mechanism of injury (fall inside the inflatable play structure, fall outside the bounce house, collision with another participant, castle displacement); risk factors (lack of responsible supervision, users of different ages); type of injury; medical attention required; and complementary tests.

Adult supervision is defined as the need for vigilance at all times. There must be at least two people supervising the attraction.

The shifts should be respected, either by age, or by height, so that children of different constitution do not use attraction at the same time. The simultaneous use by a large number of people at the same time should be avoided, because it increases the danger of falls and injuries, especially if children of different age ranges and weight are mixed.