Swing Gate Motor Types Explained: Ram vs Articulated Arm vs Underground

Swing gate motor types fall into three main categories: ram (linear), articulated arm (crank arm), and underground (self-supporting). 

Here's how each one differs on design, fit, and space.

Ram (Linear) Motors

• Design - A cylinder-shaped unit mounted between the gate leaf and the post. It extends in a straight line to push the gate open, then retracts to close it.
  

• Best For - Standard residential gates on narrow to moderate posts. It's the most common setup and the cheapest to buy and fit.
  

• Space Needed - Requires a narrow to moderate pillar, generally under 100 to 150mm from hinge to post face, since it has to sit in a straight line between gate and post.

Articulated Arm Motors

• Design - Mounts to the gate post, then extends a two-segment hinged arm out to the gate leaf at an offset point. The arm unfolds like an elbow straightening.
  

• Best For - Wide brick, stone, or masonry pillars where a ram can't find the correct angle, plus heavier timber or steel gates.
  

• Space Needed - The arm stays exposed when the gate is open, so you'll need clear space behind the gate for it to swing through.

Underground Motors

• Design - Lives inside a sealed foundation box installed below ground at the gate's hinge point. A pivot pin links the buried motor to the gate leaf above.
  

• Best For - Heritage properties, architecturally designed gates, or anywhere the entrance's visual line matters, since nothing shows above ground.
  

• Space Needed - Requires excavation at each hinge point, with drainage channels so water can't pool and corrode the mechanism.

Picking the wrong one is an expensive mistake. 

You order a sleek linear arm, it arrives, and your brick pillar turns out too wide for it to line up. Now you're paying for a return, a delay, and a second motor. 

Before comparing further, browse the full range of swing gate opener kits to see how these motor types translate into real products.

One quick note: this guide covers motor mechanism only, not single versus double gate leaves or swing versus sliding systems. 

Sort those choices out first, since they change which motors are even on the table.

How Ram (Linear) Gate Motors Work

A ram (linear) motor is a cylinder-shaped unit mounted between the gate leaf and the post. 

It extends in a straight line to push the gate open, then retracts to close it, and it's the most common setup on standard residential gates.

Hydraulic Piston vs Threaded Screw Drive

Ram motors run on one of two drive types. 

Hydraulic pistons use pressurised fluid for smooth, high-torque movement that copes well with frequent use, which is why they turn up mostly on commercial gates. 

Telescopic linear actuator motors work differently: an electric motor drives a stainless steel shaft along a copper worm gear. 

This is the mechanism behind our own swing gate arms, built with a cast alloy housing for a long motor life and quiet running. 

It's lighter and cheaper than hydraulics, standard on most 24V DC residential kits, and it self-locks the moment power cuts out.

Pillar Geometry and Trade-Offs

A ram needs a narrow to moderate pillar, generally under 100 to 150mm from hinge to post face, since it has to sit in a straight line between gate and post. 

A deep masonry or stone pillar puts the correct angle out of reach, and that's your cue to look at an articulated arm instead.

Rams earn their popularity honestly: they sit low and sleek against modern aluminium and steel gates.

They're the cheapest motor type to buy and fit, and they bolt onto narrow metal posts without structural work. The catch is travel-stop setup. 

Our own actuator runs from an 850mm retracted length out to 1,240mm fully extended, a maximum stroke of 400mm, and if that stroke isn't calibrated correctly, the ram over-extends and strains the motor and gate over time.

Good to know: Our double swing gate opener runs a 25% duty cycle at an average current of 1.7A on a 60W motor. 

Line that up against other brands' 80W or 100W arms, since a lower-wattage motor rated for the same gate weight does more work per watt, usually meaning lower running costs over the years.

How Articulated Arm Gate Motors Work

An articulated arm gate motor mounts its body to the gate post, then extends a two-segment hinged arm out to the gate leaf at an offset point. 

As the motor drives that joint, the arm unfolds in a pincer-like motion, the way an elbow straightens, which lets it compensate for a hinge set well back from the post face.

Where Articulated Arms Fit Best

Articulated arms exist for wide brick, stone, or masonry pillars, where a ram would fail to find the correct angle, making them the standard recommendation for heavier gates on substantial posts. 

Versatility is the biggest strength: an articulated arm gate motor handles wide pillars and heavy timber or steel gates that would overwhelm a ram, and tends to open faster too. 

Many models carry a higher duty cycle than a comparable ram, useful if your gate opens dozens of times a day on a busy driveway or small commercial site. 

Power consumption also tends to sit lower than hydraulic ram systems, particularly in 24V DC setups, which matters if you're planning a solar system, since every extra watt means a bigger panel and battery bank.

The trade-off is visibility. 

The arm stays exposed when the gate is open, so it won't disappear the way a ram or underground motor can, and you'll need clear space behind the gate for it to swing through. 

Articulated kits also usually cost a little more upfront than a basic ram.

How Underground Gate Motors Work

An underground gate motor lives inside a sealed foundation box, usually cataphoresis-coated or stainless steel, installed below ground at the gate's hinge point. 

A pivot pin links the buried motor to the gate leaf above, and the motor turns that pin to swing the gate. From street level, all you'll ever see is the hinge itself.

The Trade-Off: A Hidden Install vs Real Groundwork

That clean look comes with excavation attached. 

Fitting an underground motor means digging a concrete foundation box at each hinge, adding drainage channels so water can't pool inside, and making sure the box sits level and sealed. 

Poor drainage is the single biggest cause of failure here, since water sitting inside leads to corrosion and electrical faults over time.

In return, you get a fully hidden install, with no visible hardware, just the gate itself moving. 

That makes it the preferred choice for heritage properties, architecturally designed gates, or anywhere the entrance's visual line matters, and the sealed mechanism is also harder to tamper with. 

The trade-offs are practical: it carries the highest installed cost of the three once excavation and concrete work are added. 

The install needs an experienced professional, and retrofitting one onto an existing gate is difficult and expensive compared with swapping in a ram or arm.

Ram vs Articulated Arm vs Underground: Side-by-Side Comparison

The gap between these three motor types comes down to pillar width, gate weight, and how much hardware you're willing to see once the gate is open. Here's how they stack up side by side.

The gap in duty cycle and power draw between articulated arms and rams is the detail most buyers miss. 

If your gate opens dozens of times a day, that higher duty cycle and lower running cost can matter more than the small price gap at purchase.

Pro tip: Compare duty cycle and motor wattage side by side across brands, not just gate capacity on its own. 

A 60W motor rated to 350kg per leaf is doing more work per watt than a heavier 80–100W motor carrying the same load.

Which Swing Gate Motor Type Suits Your Property?

The right motor comes down to three things: how your property is built, how wide your pillars are, and whether you're retrofitting or starting fresh. 

Match those against the breakdown below before you buy, since swapping motor types after installation almost always costs more than getting it right the first time.

Retrofitting vs New Build

Automating an existing gate almost always means a ram or articulated arm: rams for narrow metal posts, articulated arms for wide brick pillars. 

Underground motors work best planned in from the start of a new build, since fitting one later means digging up a finished driveway. 

Several of our openers are sold as build-your-own kits for confident homeowners, though a hard-wired 230V AC connection still needs an electrician. 

Articulated arm and underground motors should always go to a professional, given the added mechanical and groundworks complexity.

Narrow Driveways and Wide Pillars

Clearance isn't only about pillar width. 

A gate swinging inward needs enough driveway depth to clear its arc without hitting a parked car, and one swinging outward needs clear footpath or road space, which council rules may restrict. 

If neither direction fits, a sliding gate is usually the better call, and we stock sliding gate opener kits for that scenario too. 

On the pillar side, when the hinge sits deep inside thick brick or stone, a straight ram can't reach the right angle, and the folding arm is what makes automation possible at all.

Heritage Properties and Double Leaf Gates

On heritage-listed homes, architecturally designed properties, or high-end estates, an underground motor is usually worth the extra cost, since there's no other way to automate a swing gate without visible hardware.

All three motor types work on single and double leaf gates. 

A double leaf setup simply needs two motors, one per leaf, plus a control board that sequences the opening so the leaves don't collide. 

Our double swing opener pairs two 60W motors to handle up to 700kg combined, 350kg per leaf, across gates up to 7m wide, while the single swing kit covers gates up to 5m wide. 

Match capacity to each leaf's own weight, not the combined total.

Access Control & Safety Features to Pair With Your Motor

Choosing the motor is only half the job. Most installations also need access and safety hardware, and our kits bundle several of these as standard.

• Remote controls - 5 included, system stores up to 120

• Keypads - wireless, secure PIN entry on several models

• WiFi/mobile app control - open the gate from anywhere with broadband and mobile data

• Vehicle loop sensors - trigger the gate open as a car approaches

• Obstacle detection - a photocell (PE) sensor detects obstacles between the posts and stops the gate

• Auto-reverse - if the photocell beam breaks during closing, the gate stops and reverses open

• Emergency stop/manual release - a quick release with a secure custom key for power failures

• Battery backup vs solar - backup keeps a mains gate running briefly during an outage; solar is a standalone power source for gates with no mains access at all

Important: Several of these aren't optional extras. Some are required for legal compliance, covered next.

Choosing a Swing Gate Motor for Australian Conditions

Australian weather puts real demands on gate hardware, from salt air on the coast to long stretches without mains power on rural properties. 

Get the housing material and power setup right from the start, since retrofitting for corrosion or off-grid access later costs far more than planning for it upfront.

Coastal Corrosion and Rural Solar Setups

Properties near the coast need motors that handle salt air. Look for cataphoresis-coated or stainless steel housings across all three types. 

Our arm actuator uses a stainless steel shaft with a cast alloy housing, and our kits carry an operating range of -20°C to +50°C with an IP55 rating against water and dust. Underground motors benefit most from stainless steel foundation boxes, since a buried housing sits in constant moisture. 

Wind matters too: solid timber or Colorbond gates act like sails in strong winds, so size your motor above the gate's static weight alone.

For rural and acreage properties without easy mains access, solar compatibility is often the deciding factor. We size our solar kits around how often the gate gets used.

Ram and articulated arm motors on 24V DC with low standby draw are easiest to pair with solar. 

Our solar farm gate kits use this approach, scaling the panel from 40W up to 120W depending on gate size and daily cycles. 

Underground motors can technically run on solar too, but the added groundworks make this a less common pairing.

AS/NZS 60335.2.103 Compliance

Swing gate automation in Australia needs to meet AS/NZS 60335.2.103, the safety standard for household gate and door operators, often referenced alongside AS 5007 for gate construction. 

At minimum, this means fitting one primary safety device, whether photoelectric beams, a reversing safety edge, or radar-based motion sensing, to stop the gate closing on a vehicle, pet, or person. 

This applies no matter which motor you pick, so budget for sensors from the start. We build compliant photocell sensors into our kits as standard.

Cost of Swing Gate Motors in Australia

Price depends on the motor type, your gate's weight, and how much groundwork the install needs. Here's what approximate budget for across all three options, from kit only to fully installed.

Prices shift with gate weight, site access, and how many safety accessories the install needs. Underground motors carry the widest range because excavation and drainage costs depend on soil conditions and your driveway's current state. 

DIY-friendly kits, like our build-your-own swing gate openers, sit toward the lower end of the price band since they cut out professional labour, though a hard-wired mains connection still needs an electrician.

Maintenance, Lifespan, and Warning Signs

A well-maintained swing gate motor typically lasts 10 to 15 years, and hydraulic or underground units can run even longer in low-corrosion environments. 

Test the gate and remote monthly, clean hinges and sensors quarterly, and book a professional service once a year for lubrication and travel-stop recalibration. Backup batteries generally need swapping every 3 to 5 years. 

Our kits carry a 12-month Australian back-to-base warranty, so keep proof of purchase on file.

A motor rarely fails without warning. Watch for a gate that's slowing down, stopping midway, or ignoring remote commands. 

A gate that drags or binds against its hinges, a motor housing that's hot after a normal cycle, or operation that works sometimes and fails at others are signs worth acting on early. 

Catching these fast usually means a repair instead of a full replacement.

The Bottom Line

Narrow posts and a tight budget point to a ram. 

Wide brick pillars or a gate that opens all day long point to an articulated arm. A heritage property where nothing should show above ground points to underground. 

Beyond the mechanism, size up for wind and coastal corrosion, plan for solar if you're off-grid, and budget for compliant safety sensors from day one.

We know gates. Pick the right motor once, and you won't be thinking about your gate again for the next decade.

Quick Answers to Gate Motor Questions

What is the difference between a ram and an articulated arm gate motor?

A ram pushes in a straight line and suits narrow posts, while an articulated arm bends at a joint to reach hinges set back on wide brick or masonry pillars.

Which gate motor is best for a swing gate?

It depends on your pillar width and gate weight, a ram for narrow posts, an articulated arm for wide pillars, or underground for a fully hidden install.

Can underground gate motors be used on any gate?

Not easily, they work best planned in from the start of a new build, since retrofitting one onto an existing gate means digging up a finished driveway.

How much does gate automation cost in Australia?

Installed prices range from $1,500 to $3,500 for a ram, $2,000 to $4,500 for an articulated arm, and $4,000 to $8,000 or more for underground with groundworks.

What is the cheapest gate automation system?

A ram (linear) motor is the cheapest option, starting from $600 to $1,500 for the kit alone.

How long do gate motors last?

A well-maintained gate motor typically lasts 10 to 15 years, with hydraulic or underground units running even longer in low-corrosion environments.

What AS/NZS standard applies to gate motors in Australia?

Gate automation in Australia must meet AS/NZS 60335.2.103, the safety standard for household gate and door operators, often referenced alongside AS 5007.

Can I install gate automation myself?

Yes for ram and some articulated arm kits sold as build-your-own, though a hard-wired mains connection still needs an electrician.

What is the difference between electromechanical and electro-hydraulic swing gate motors?

Electro-hydraulic motors use pressurised fluid for smooth, high-torque movement on commercial gates, while electromechanical motors drive a stainless steel shaft along a worm gear, and are lighter, cheaper, and standard on residential kits.