Cantilever Gates

A cantilever gate uses counterbalance rather than continuous support. The gate is longer than the opening,typically 1.5 times the opening width. When closed, the visible gate section spans the opening while the counterbalance tail extends behind the support posts. Roller carriages mounted on the posts support the gate at two points, and the weight of the tail balances the weight of the gate spanning the opening.

As the gate opens, it rolls through the carriages. The tail section moves into the opening area while the gate section moves behind the posts. Throughout the travel, the gate remains supported by the same two roller points,it never touches the ground.

This floating operation is what makes cantilever gates valuable. No ground track means no track to clean, no debris interference, no ice buildup in the track, and no sensitivity to ground settling or heaving. The gate clears obstacles that would stop a track-mounted system.

The counterbalance tail is what makes cantilever gates work,and what makes them larger than track gates for the same opening. A 20-foot opening requires approximately a 30-foot gate (the opening plus a 10-foot tail). A 40-foot opening requires roughly a 60-foot gate.

This has two implications. First, cantilever gates need more lateral space than track gates,roughly 50% more for the tail when closed, though the open position is similar. Second, the gate is heavier and the support structure must be more substantial.

The tail section is typically the same frame construction as the gate section but may have different infill,sometimes open framework rather than matching the fence, to reduce weight while maintaining the necessary counterbalance.

Proper counterbalance is critical. An underweight tail causes the gate to sag and bind in the rollers. An overweight tail lifts the front of the gate and creates alignment problems. We calculate counterbalance based on gate dimensions, materials, and infill weight.

Support posts for cantilever gates carry substantially more load than slide gate guide posts. The posts must resist the vertical load of the gate weight plus the horizontal forces from wind, operation, and any impact loads. For large gates, posts may be 6x6-inch or 8x8-inch steel tube, or even structural columns.

Foundations must match the load. Cantilever support posts typically require larger footings than other gate types,deeper, wider, and with more concrete. Soil conditions matter significantly; poor soils may require engineered foundations, piers, or even pile-supported footings for heavy gates.

Post alignment is critical and must be maintained over time. Even slight post movement affects carriage alignment and gate operation. Quality foundations and proper concrete curing prevent the settling that causes alignment problems.

Cantilever gates automate well,often better than track gates because there is no track friction to overcome. The same operator types used for slide gates work for cantilever: chain drive for lighter gates, rack and pinion for heavy industrial applications.

Operator sizing accounts for gate weight (which is higher than a track gate for the same opening), length, wind load, and cycle requirements. The smooth rolling of quality carriages reduces the force needed to move the gate, partially offsetting the weight increase.

Because cantilever gates are common in industrial settings, high-cycle and high-speed operators are frequently specified. Gates may operate dozens or hundreds of cycles per day at facilities with heavy truck traffic. Operators must be sized for this duty cycle, not just the gate weight.

Safety device requirements match other slide gates: photo eyes, edge sensors, entrapment protection as dictated by the installation specifics. The guide post at the opening edge is a potential entrapment point that may require additional protection.

Cantilever gates cost more than track-mounted slide gates. The gate itself is larger (the counterbalance tail adds material), the frame must be heavier (to maintain rigidity without ground support), the carriages are specialized hardware, and the support posts and foundations are more substantial.

For a typical opening, expect cantilever gates to cost 20-40% more than equivalent track gates. The premium is justified when site conditions make track gates impractical or when reduced maintenance has value.

The total cost of ownership often favors cantilever gates for industrial applications. Track maintenance, debris-related service calls, and weather-related downtime add up over the gate's life. For facilities that operate continuously or where gate failure has operational consequences, the reliability of cantilever gates offsets the higher initial cost.