Turnstiles Guide

Turnstiles are security devices that control pedestrian access to secured areas, designed as moving portions of fence or barricades that restrict unauthorized access. They typically have a physical barricade arm or gate that pivots freely when access is authorized. In this note, we examine full vs waist height turnstiles, sizing the number of turnstiles needed as well as prepping, installing and maintaining them.

Turnstiles are used to:

• restrict access to and from an area
• count people entering or leaving an area
• checkpoint monitoring
• prevent tailgating

As an extension of electronic access control, they permit traffic through secured areas with the use of a credential. For example turnstiles may be used to separate unsecured parking areas from a secured jobsite.

Turnstile Types 

A number of important types of turnstiles exist:

• Full Height - These turnstiles are revolving gates that extend to a height of 7 to 10 feet. Typically, they are designed to be adjoined on both sides by fence or wall. These are the most secure form, due to the difficulty in passing around or over these units when secured. The types of turnstile are best used when monitored entry through perimeter security is required. These turnstiles cost about $6,000 USD for a single sized unit and $10,000 USD for a double sized unit.
• Waist Height - This type of turnstile is used to restrict free access to specific areas. These units are valuable pieces of chokepoint design for controlling speed and position of pedestrian traffic. They are often mounted in groups of two or more. These units are easily jumped over, and are not appropriate for high-security applications. These units are best used to regulate traffic flow into public areas. These turnstiles cost about $4,000 USD each.
• Optical Turnstiles - This type is a variation on the waist height turnstile that lacks any physical barrier arm. Primary feature is to count traffic by use of infrared beams. Often used with access controls to determine authority to enter an area. These turnstiles use sirens and lights to indentify unauthorized access areas. These turnstiles are best used to monitor public access for large buildings like areas or convention centers. Pricing varies with options, but a typically equipped optical turnstile cost about $5,000 USD.

Sometimes regulations dictate the inclusion of ADA/Pedestrian Gates. These are gates that permit wheelchairs or carts through a secured, swinging opening. These gates are often located adjacent to turnstiles, since they do not easily permit wheelchair travel, but when used with access controls, specific individuals can be permitted to travel through gate rather than turnstile. These gates also permit an entry point for supply carts to travel through a fence line. Including at least one of these gates in a fenceline is common, and it is prudent to locate them adjacent to handicap parking areas or load/unload areas.

Proper sizing

Sizing is the most important factor when planning turnstile placement. These considerations significantly affect the total number of turnstiles required to do the job. If the number of required turnstiles seems unrealitically high, consider staggering shift changes to permit more time for traffic to flow. 

The number of turnstiles must be 'sized' according to the traffic volumes they must handle. This sizing is a rough calculation for how many people can travel through the turnstiles in a given period of time.

Consider the following design example:

You have been asked to furnish a quote for the number of turnstiles at the front employee entrance to a manufacturing plant. Full height turnstiles will be installed at the main fence line separating the parking lot from the plant building. There are 2,000 employees arriving or leaving work during this change, and 15 minutes have been set aside for this exchange of workers. How many turnstiles should be quoted for this job?

Answer: The resulting calculation determines that 15 turnstiles are required to handle 2000 people in 15 minutes. A typical full-height turnstile is designed to accomodate 450 - 500 per hour. This is an average pass through rate of 9 people per turnstile, per minute. If 2000 people must flow through turnstiles during a shift change, consider the time to handle that volume is limited to 15 minutes.

(Total Number of People) / ((Flow through turnstile per min) * (Number of mins available)) = (Number of Turnstiles)

(2000 people) / ((9 people per minute) * (15 minutes)) = (14.8 turnstiles)

Since turnstiles are furnished in 'single' and 'double' sized units, including either one or two turnstiles, the furnishing a quote for 16 turnstile (or 8 doubles) is prudent. Consider oversizing the number of turnstiles for the occasion that a unit is out of service. 

Site Prep

Installing turnstiles often require concrete pad preparation and fence cuts. This work should be carefully planned and communicated, as a gap in fencing may be present for an extended period of time. Security should be notified of these gaps, and extra supervision or policing of the area may be required until turnstiles are installed. Dirt work or setting concrete forms may be required

Turnstiles are not typically low-voltage machines and installation work must be coordianted with an electrician. This can be an especially tricky part of the job considering that turnstiles are often located in the elements and on distant fencelines. Consider the turnstile might also require extended data runs, especially if turnstile integrations will support access control functions.

Installation

Where possible, this equipment should be 'drop shipped' directly to the installation site. Depending on the type and number of turnstiles to be installed, the equipment weight may measure several thousand pounds. Due to bulk and weight, a material lift may be required to move and install this equipment. Installation of a turnstile should be considered a 'two-man' job, due to the unweildy bulk of these units.

Maintenance

Turnstiles typically see high use, and are often located outside in harsh weather. As a result, some periodic maintenance should be planned to service these machines. Weather proofing electronic equipment and keeping mechanical parts lubricated and adjusted should be considered an ongoing part of operating these units.