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Turnstile

Adapted from Wikipedia · Adventurer experience

Turnstiles at Alewife train station, showing the entry points for passengers.

A turnstile is a special kind of gate that helps control how people move through an entrance. It is made so that only one person can pass through at a time. This keeps things organized and stops crowds from pushing through all at once.

Old turnstiles at Alewife station on the MBTA Red Line in Cambridge, MA, U.S.

Turnstiles can also be used to make sure only people who have the right permission can enter a place. For example, they might need a coin, ticket, transit pass, or some other way to show you are allowed in. Some modern turnstiles can use biometrics, like scanning a fingerprint, to check who can pass.

These gates are often found in places where you need to pay to enter, such as public transport or a pay toilet. They can also be used in offices or other buildings to make sure only certain people can enter certain areas.

History

Turnstiles were first made to let people pass while keeping animals out. They may have been used as early as the 16th century to control who could enter roads and special places.

In the 19th century, turnstiles became popular for controlling who could enter buildings and places like sports stadiums and swimming pools. In the 20th century, they were used more in places like train stations. They started with coins and tickets and later used special magnetic tickets and passes, beginning in Tokyo. In the United States, a man named Clarence Saunders helped make them more common in his first Piggly Wiggly store.

Applications

Turnstiles are used in many places such as stadiums, amusement parks, train stations, office buildings, airports, ski resorts, factories, power plants, casinos, construction sites, and zoos.

They help businesses count how many people are coming in. They also help security teams see everyone clearly as they enter one by one. This makes it easier to spot any problems or take away things that are not allowed. However, during emergencies, these barriers can be a problem because people need to leave quickly. That’s why places like the London Underground have special exits that don’t need turnstiles.

People with disabilities might find turnstiles hard to use. In these cases, places often have wider gates or manual gates to help. Some busy spots, like Heathrow Terminals 2 & 3 Underground station, might use only wide gates if people are carrying lots of bags.

Turnstiles can also count how many people go through a gate, even if no payment is needed. They are commonly used in amusement parks to track how many people enter and exit the park and ride each ride. The old Hampden Park stadium in Glasgow, Scotland, was one of the first football stadiums to install turnstiles.

Types

Waist-high turnstiles are often used at fairs, attractions, and arenas. People put a ticket or pass into a slot, and a sensor checks if they can go through. These turnstiles can move at different speeds. Some need coins or tokens, while others read a barcode.

Wall mount tripod turnstiles are fixed to a wall. This makes them useful in narrow spaces where floor installation isn’t possible.

Optical drop-arm turnstile

Optical turnstiles are different from traditional arm-style turnstiles. They use infrared beams to count people and check if they have the right entry pass. This can be better when a physical barrier isn’t needed.

The drop-arm optical turnstile mixes features of both tripod and optical turnstiles. When access is allowed, the arms drop down, letting people pass freely.

Full-height turnstiles are taller versions of waist-high turnstiles, usually about 7 feet high. They work like revolving doors and offer more security because they can’t be climbed over or ducked under. They can also be set to lock after each person enters, requiring the next person to pay or show their pass. These turnstiles are used in places like Chicago "L" stations and New York City Subway stations.

Images

An old turnstile and kiosk at the William Street entrance to The Recreation Ground in Bath, England.
Historic turnstiles displayed at the MTA Transit Museum in New York.

Related articles

This article is a child-friendly adaptation of the Wikipedia article on Turnstile, available under CC BY-SA 4.0.

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