Dock Levelers

When loading or unloading cargo from trucks, a dock leveler forms a ramp to bridge the distance between the dock and truck. Dock levelers compensate for the up-and-down movement of the trailer during loading and unloading. They also support extremely heavy loads, service a wide range of truck heights, and compensate for tilted trucks.

The two most common types of dock levelers are recessed and edge-of-dock. A recessed dock leveler is installed in a pit formed in the loading platform. An edge-of-dock dock leveler is normally installed on the face curb of the loading platform.

Recessed or Pit-Style Dock Leveler

The recessed, or pit-style, dock leveler is the most common type of dock leveler because it has a greater operating range, load range, and life expectancy. Dock levelers are most often installed into pits that are formed into the concrete ahead of time. The pits are sized to meet the exact requirements of the dock levelers being used.

The standard range a recessed dock leveler can serve is 12 inches above and 12 inches below dock height. Special configurations of dock levelers can serve as much as 18 inches above and below, depending on ramp length and pit depth.

Recessed dock levelers are available with a spring-loaded mechanical activation system or powered with a push-button activation system. Powered, push-button models are easier to operate and are activated by either an air or hydraulic system.

Although the initial cost of a mechanical dock leveler is less than a powered dock leveler, the long-term operating cost for a powered dock leveler can be lower.

Edge-of-Dock (EOD) Levelers

 Edge-of-Dock (EOD) levelers are a low-cost alternative with a short ramp. An EOD is mounted to the face of the dock and secured to a curb channel embedded in the concrete. They are available in standard load capacities of up to 35,000 lb.

Due to its short ramp, the EOD is restricted to a narrow service range of 2 inches above or below the dock. It is suitable only for applications where there is little variation in bed height and where pallet truck under-clearance is sufficient.

Additional Information and Accessories

Dock levelers have long lives and contribute significantly to facility efficiency. When deciding between a hydraulic, air bag, or mechanical dock leveler, it’s helpful to consider the lifetime costs and safety features associated with each type. Estimates for the lifetime ownership costs are:

• Hydraulic - $1,000
• Air bag - $1,000
• Mechanical - $3,200

Safety features are important for numerous reasons. Air bag dock levelers are ergonomically correct, reducing the potential of employee injuries, and easier to use with their push button configuration. In addition, air bag dock levelers have a “stump-out” safety feature where fall-safe legs impede below-dock and dock-level situations. The safety legs come to rest on the floor while the dock leveler is being used.

Hydraulic and air bag dock levelers log fewer hours and therefore have longer working lives. Because mechanical dock levelers are upward biased and the springs and holdown are in the stressed condition, the moving parts wear over time. Conversely, hydraulic and air bag dock levelers are working only when they are being used and while the button is being pressed.

Hydraulic dock levelers can accommodate higher load capacities. Mechanical and air bag dock levelers can handle a maximum rating of 55,000 lb, while hydraulic dock levelers can be used for load capacities of up to 100,000 lb.

In order to increase the effectiveness of your dock leveler installation, consider optional features such as:

• Increasing the lip length to accommodate trucks with bumpers larger than 4 inches
• Applying a weatherseal to control the climate and protect against rodent entry
• Galvanizing dock leveler components with a zinc spray to protect against corrosive materials or harsh environments such as salt water

Since 1986, Nova has brought innovation and reliability to the loading dock equipment industry with a full line of effective, durable, and user friendly products.