Cantilever Sliding Gate Calculations

Cantilever Sliding Gate Calculator

Calculation Results

Counterbalance Length: 0 m

Total Gate Length: 0 m

Estimated Total Weight: 0 kg

Min. Foundation Space: 0 m

Note: Ensure your roller carriages are rated for at least 0 kg to handle the dynamic pivot load.

function calculateGate() { var opening = parseFloat(document.getElementById('gateOpening').value); var pct = parseFloat(document.getElementById('counterPct').value); var wpm = parseFloat(document.getElementById('weightPerMeter').value); var unit = document.getElementById('unitSystem').value; if (isNaN(opening) || isNaN(pct) || isNaN(wpm) || opening <= 0) { alert("Please enter valid positive numbers for all fields."); return; } var counterLength = opening * (pct / 100); var totalLength = opening + counterLength; var totalWeight = totalLength * wpm; // Pivot Load Calculation (Simplified F = W * (L/C)) // Where W is weight, L is center of gravity relative to pivot, C is wheelbase var pivotLoad = totalWeight * 1.5; // Safety factor for cantilever stress document.getElementById('resCounterLength').innerText = counterLength.toFixed(2); document.getElementById('resTotalLength').innerText = totalLength.toFixed(2); document.getElementById('resTotalWeight').innerText = totalWeight.toFixed(2); document.getElementById('resFoundation').innerText = (counterLength * 1.1).toFixed(2); document.getElementById('resLoadRating').innerText = pivotLoad.toFixed(0); var units = document.getElementsByClassName('unit-text'); var weights = document.getElementsByClassName('weight-text'); for(var i=0; i<units.length; i++) { units[i].innerText = (unit === 'metric') ? 'm' : 'ft'; } for(var i=0; i<weights.length; i++) { weights[i].innerText = (unit === 'metric') ? 'kg' : 'lb'; } document.getElementById('gateResults').style.display = 'block'; }

Understanding Cantilever Sliding Gate Math

Designing a cantilever sliding gate requires precise calculations to ensure the structure remains stable without a ground track. Unlike traditional sliding gates, a cantilever system relies on a counterbalance (the "tail") and a set of roller carriages fixed to a concrete foundation.

The Counterbalance Ratio

The most critical factor is the counterbalance length. As a general engineering standard, the tail of the gate should be between 30% and 50% of the clear opening width. For example, a 4-meter opening typically requires a 1.6-meter to 2-meter counterbalance, making the total gate length 5.6 to 6 meters.

• 30% Ratio: Minimum requirement for light, aluminum gates.
• 40% Ratio: The industry standard for residential steel gates.
• 50% Ratio: Recommended for heavy industrial gates or high-wind areas.

Weight and Structural Load

Because the gate is suspended, the weight distribution places immense pressure on the roller carriages. The "Pivot Load" is often significantly higher than the static weight of the gate because of the leverage effect created when the gate is fully closed. Always select hardware (tracks and rollers) that exceed your calculated total weight by at least 50% to account for these dynamic forces.

Example Calculation

Suppose you are installing a driveway gate with these specs:

Parameter	Value
Opening Width	5 Meters
Counterbalance (40%)	2 Meters
Weight per Meter	30 kg
Total Result	7m Length / 210kg Weight

Safety Considerations

Never underestimate the foundation. The concrete pad for the rollers must be deep enough to resist the "tipping" force of the gate. In most climates, this means the foundation should extend below the frost line and be reinforced with rebar cage structures tied directly to the carriage mounting bolts.