Choosing the Right Boom Gate: A Complete Guide to Length, Duty Cycle, and Safety

What a Boom Gate Must Do at the Entrance

Selecting a boom gate (also know as vehicle barrier) is not simply a choice between a short arm and a long arm. The correct system must suit the clear lane width, traffic demand, available headroom, operating speed, access-control equipment and required safety measures.

The FERN360 automatic vehicle barrier range gives installers and specifiers several practical configurations, including pole arms, fence arms and bend arms. The current range includes 3,000 to 4,500 mm arm versions, 6,000 mm arm versions and operating speeds of 1.4, 2 or 3 seconds.

This guide explains how to assess the main selection criteria before specifying a boom gate for a commercial car park, industrial site, body corporate, logistics facility or controlled vehicle entrance in New Zealand.

Start with the Required Boom Gate Length

The arm length should be selected from the clear opening that needs to be controlled, not from the total width of the driveway or the overall property entrance. Measure the usable vehicle lane from the barrier cabinet to the furthest point the arm must cover, allowing for kerbs, islands, posts, drainage channels and vehicle turning paths.

When a 3,000 to 4,500 mm arm may be suitable

FERN360 pole, fence and bend arm products are available with 3,000 to 4,500 mm barrier arm versions. This range can suit many standard vehicle lanes where the barrier cabinet is positioned close to the edge of the controlled opening.

For standard parking entrances, commercial driveways and smaller controlled access points, a shorter arm can help reduce the physical load on the mechanism and may simplify installation. The final selection still depends on the actual clear opening, the mounting position and the required safety clearance.

For example, the 1.4 second FERN360 pole arm is listed with 3,000 to 4,500 mm barrier arm versions. View our product.

When a 6,000 mm arm may be required

The FERN360 T30-60 models are listed with a 6,000 mm barrier arm. These longer versions may be considered for wider vehicle entrances where a shorter arm would leave an uncontrolled gap.

Longer arms require careful assessment of the mounting position, wind exposure, vehicle approach angle and available clearance. A 6,000 mm arm should not be selected simply because it provides more coverage. The longer arm must be supported by a suitable foundation, correctly balanced equipment and a safety design appropriate to the site.

The 3 second FERN360 pole arm is listed with a 6,000 mm barrier arm option. View our product.

Pole, Fence or Bend Arm: Which Format Fits the Site?

The arm style affects visibility, the appearance of the entrance and how the barrier interacts with the surrounding building or vehicle path.

Pole arms

A pole arm is the straightforward option for many vehicle entrances. It provides a clear visual barrier across the lane and can be specified in different lengths and operating speeds. Pole arm systems are commonly considered for parking areas, commercial driveways and controlled industrial access points.

Fence arms

A fence arm adds a more visually substantial barrier beneath the main arm. This can be useful where the visual presence of the barrier is important or where the entrance design calls for a stronger enclosed appearance.

FERN360 fence arm models are listed in both 3,000 to 4,500 mm and 6,000 mm versions. The 1.4 second fence arm is one option for sites where faster opening and closing are required, subject to the final traffic and safety assessment. View our product.

Bend arms

A bend arm can be considered where the entrance has restricted overhead clearance or where the barrier needs to work around a specific site layout. The required folded or raised clearance should be checked during the site survey, particularly where delivery vehicles, trucks or high-sided vehicles use the entrance.

Do not assume that a bend arm automatically solves a clearance problem. Confirm the raised-arm profile, vehicle height, nearby structures and maintenance access before final specification.

Operating Speed and Traffic Flow

The FERN360 range is listed with 1.4, 2 and 3 second operating speeds. A faster operating speed may help reduce waiting time at busy entrances, but speed alone does not determine whether a barrier is suitable for heavy traffic.

• 1.4 seconds: Consider where short wait times and faster vehicle processing are important, provided the site has suitable detection, visibility and safety controls.
• 2 seconds: A practical middle option where the entrance needs responsive operation without automatically selecting the fastest configuration.
• 3 seconds: Listed with FERN360 T30-60 models and 6,000 mm arm versions. The longer arm and wider opening require careful assessment of stopping distance, vehicle detection and safe closing behaviour.

Operating speed should be considered alongside the number of vehicles per hour, peak arrival patterns, queue length, opening frequency and the consequences of a failed or delayed barrier. A barrier that opens quickly but is paired with poor detection or an unsuitable traffic layout is not a better access-control solution.

How to Assess Duty Cycle

Duty cycle describes how frequently a boom gate can operate over a defined period. It is different from arm speed. Arm speed describes how quickly the barrier opens or closes, while duty cycle relates to how often the mechanism can repeat that movement without excessive heat, wear or performance loss.

Before specifying a model, estimate:

• Average vehicle movements per hour.
• Peak vehicle movements during shift changes or busy periods.
• Whether each vehicle requires one opening and one closing cycle.
• Whether the entrance operates continuously or only during business hours.
• Whether the site has separate entry and exit lanes.
• Whether delivery vehicles will cause the barrier to remain open for extended periods.

The current FERN360 product records confirm the available arm lengths, operating speeds, drive technology and anti-collision features, but do not publish a duty-cycle rating. For a high-traffic car park, logistics site or industrial entrance, request confirmation of the recommended duty cycle for the exact arm length and configuration before final approval.

This is especially important when comparing a 3,000 mm arm with a 6,000 mm arm. The longer arm can place different mechanical demands on the system, even where the catalogue lists the same general operating principle.

Safety Features to Include in the Access Design

A boom gate should be treated as part of a complete vehicle-control system. The barrier arm, motor, control board, vehicle detectors, warning devices, access readers and emergency release arrangements must work together.

FERN360 product records list an Adjustable Speed Drive, an Adaptive Angular Controller and multiple anti-collision features. The current product records do not detail the exact sensor package, safety-edge arrangement or control logic, so the final safety configuration should be confirmed for the selected model and site.

Key safety checks for installers and specifiers

• Use vehicle detection that prevents the arm from closing onto a detected vehicle.
• Assess whether additional presence detection is required for motorcycles, trailers or unusual vehicle profiles.
• Provide clear visibility of the barrier arm for approaching drivers.
• Consider reflective markings, warning lights and suitable entrance signage.
• Check the location of pedestrian paths and prevent pedestrians from being directed through the vehicle lane.
• Confirm emergency release and manual operation arrangements.
• Allow safe maintenance access around the barrier cabinet and moving components.
• Complete a site-specific risk assessment before commissioning.

For general guidance on managing vehicle and mobile-plant risks in the workplace, refer to the WorkSafe New Zealand vehicles and mobile plant guidance.

Product Specifications

For full model-specific information, including the available 3,000 to 4,500 mm and 6,000 mm configurations, View our product.

FERN360 Boom Gate Selection Checklist

Before requesting a quotation or approving an installation, confirm the following details:

1. Measure the required clear opening in millimetres.
2. Confirm whether the site requires a pole, fence or bend arm.
3. Identify the expected average and peak vehicle movements.
4. Confirm whether a 1.4, 2 or 3 second operating speed is appropriate.
5. Request the duty-cycle rating for the exact model and arm length.
6. Review vehicle, pedestrian and maintenance risks at the entrance.
7. Confirm the detection, anti-collision and emergency-release arrangements.
8. Check the power supply and interface requirements with the access-control system.
9. Confirm the product is suitable for the local environment and installation conditions.
10. Allow for made-to-order supply timing when planning the project.

The right boom gate is the one that matches the physical opening, traffic demand and safety design together. FERN360 provides a flexible range of arm styles, lengths and speeds, but the final selection should always be based on measured site conditions and confirmed model-specific specifications.