Why Locks Are Essential for Swing Gates — Understanding the Right Choice for Your Installation
A common question among new gate installers is: “Why do we need locks on automated gates when gate motors are normally irreversible and act as locks themselves?” The answer comes in two parts. First, it’s primarily swing gates that require locks. Second, it’s all about the leverage and pressure placed on the hinges, posts and foundations.
The Importance of Locking Swing Gates
Short, open-style swing gates can often lock securely in place using only the travel stops on the motor, especially if the gate rests against a positive stop on the ground or receiving post. However, as the gate’s length increases, the leverage on the motor mounting brackets rises dramatically.
For example, a 3-metre gate with just 20kg of pressure applied to the open end can produce over 400kg of force on the brackets, bolts and foundations. Add wind pressure on a closed-face gate, and these forces can multiply quickly. It’s worth noting that most brackets are only secured by 8mm bolts into aluminium posts, meaning the risk of damage or distortion is real.
Beyond the mechanical stress, there’s also the security concern. A determined intruder could apply enough pressure to create a gap wide enough to slip through a closed but unlocked gate.
Rules of Thumb for Gate Locks
- Any gate without a lock should come up against a positive stop, with light motor pressure holding it firm.
- Open-faced swing gates over 2.4m should include locks, even if they rest on a positive stop.
- Closed-faced gates over 2m wide and 1.5m high should also be locked.
Types of Gate Locks
The most commonly used gate lock is the electromagnetic lock. It’s popular because it’s simple, familiar to electricians and can compensate for poor gate alignments. However, it does have drawbacks. Electromagnetic locks require continuous power (12V or 24V DC) to hold closed and rely on relays or solenoids being turned off for a split second to release when opening. In the event of a power failure, security is compromised, the gate can no longer stay locked.
It’s worth asking: If electromagnetic locks are so reliable, why aren’t they integrated into most gate automation control boards?
The Superior Option: Power-to-Open Locks
The power-to-open lock is widely regarded as the best all-round solution. It provides a positive mechanical fix, operates without constant power and is supported by most automation manufacturers. These locks use internal springs to close the lock when the gate closes and require only a 0.5-second electrical pulse to unlock.
Even during a power outage, the gate remains locked and can be manually released with a key for manual operation.
The only potential issue is alignment, slight ground movement can cause misalignment and prevent locking. To prevent this, installing a gate rest underneath helps maintain consistent height and prevents sagging, especially if children climb or sit on the gate.
For gates without a positive stop or dual gates meeting in the middle, an electronic drop bolt may be used. Though more expensive, they serve well in specific configurations.
The Bottom Line
A well-designed gate with the right lock offers superior security, durability, and long-term reliability. When advising customers, always consider their unique setup — and recommend positive striker or power-to-open lock systems built into modern automation solutions.
See an Italian Lock Range for locks on automated gates.