News
Making Wise Choices
June 7, 2000
Following these six steps can help you select a dock leveler that meets your needs
Step 1. Consider your specific needs
Step 2. Put employee safety first
Step 3. Look for easy operation
Step 4. Consider maintenance costs
Step 5. Look for reliability and durability
Step 6. Check manufacturer and representative report
By Joe Monone
Product Manager Dock Products Group, Rite-Hite Corp. Milwaukee, Wisconsin.
Selecting the right dock leveler for your facility is now more complicated than ever. New models are being introduced, and truck designs are changing. Productivity is critical, and safety is becoming an ever-bigger issue at docks across the country.
Three basic types of levelers are available: hydraulic, mechanical, and power-assisted mechanical units. Each design has its place, depending on the applications, but there are distinct differences among them. Before you select a leveler for your facility, you should follow this six-step procedure for evaluating your needs. By analyzing these key areas, you'll be able to choose the best equipment for your operation.
Step 1. Consider your specific needs
Make sure that the leveler you choose matches your individual requirements. Consider the vehicle types that will use your dock, trailer dimensions, frequency of use, and load capacities. These factors will help determine the leveler that's best designed for your operation.
To select a leveler length, consider the type of traffic and activity at your dock. It's important to establish a safe, smooth path for forklifts to travel between the dock and the trailer. Remember, truck bed heights can vary dramatically. As a rule of thumb, the greater the distance between dock height and trailer bed height, the longer your levelers should be.
Today's trend toward wider, lower and higher capacity trailers has led to the need for longer levelers. Years ago, 6-ft. leveler lengths were standard. Now, 8-and 10-ft. lengths are common. These levelers can more safely and efficiently serve the newer trailers.
To select a leveler width, choose one that matches your specific needs. In the past, the most common leveler width was 6 ft. But with increased demand for maximum capacity, today's trailers average 8-ft. 6-in. wide, fully loaded to the end. That's why a wider leveler is usually a better choice. Wider levelers provide better accessibility to end loads and below-dock loads, while allowing more maneuvering room for lift trucks. Wider levelers also provide greater flexibility and meet future needs as your operation changes.
Choosing leveler capacity means making sure that the selected leveler has the structural strength to handle the gross weight, speed, and frequency-of-use of your material handling equipment (see Figure 2). Evaluate the following factors to help determine proper leveler capacity:
- Frequency of use. Determine how many trucks will be serviced at that dock opening per day and how many loads per truck. This can greatly affect your leveler's life expectancy.
- Gross load weight. Combine the weight of your heaviest capacity lift truck, including attachments, plus the weight of the heaviest load to determine gross weight.
- Angle of leveler ramp. Consider the typical ramp angle for most of your operations. The greater the angle, the more impact force the leveler must absorb.
- Forklift speed. How fast do your lift trucks usually travel? The faster they travel, the more punishment your levelers take.
- Required life expectancy. How long do you plan to keep this leveler in operation? Five years? Ten or 20 years? Higher capacity levelers have longer life expectancies.
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Step 2. Put employee safety first
Safety is one of the most critical considerations when selecting any loading dock equipment. The leveler covers the "danger zone" – the gap between the dock and trailer that is crossed by forklifts up to 100,000 times per year.
Make sure the levelers you choose are built for maximum safety in four key areas:
- Vacant dock drop-off protection.
- Free-fall protection.
- Protecting cross-traffic against voids in the floor.
- Protecting personnel during leveler maintenance.
When no trailer is in place at the dock face, forklifts can accidentally fall from the dock's edge to the driveway below. This can happen if conditions are slippery, brakes or other equipment malfunctions, operators are inattentive when backing up or drivers are impaired in any way. You can choose manual or automatic safety gate barriers or levelers with automatic barriers built into the lip. When choosing an automatic safety barrier leveler, look for these features:
- Solid construction – an integral steel barrier that can handle heavy forklift impacts.
- Adequate height – at least 7-in. tall to prevent overriding by the forklift tires.
- Ability to handle end loads – make sure the barrier can be moved out of the way, allowing you to handle end loads at dock level and below. Some levelers will not allow unobstructed end loading, making it impossible to safely reach end load pallets.
Automatic recycle provides cross-traffic protection against voids in the floor. If a leveler stays in a below-dock position after servicing trailers below dock height, a dangerous dip is created in the floor, which can be hazardous to forklift cross-traffic. To minimize this risk, choose a leveler with an automatic recycle feature.
If a trailer pulls away from the dock while the leveler is in use with a heavy load on the platform, the leveler may drop quickly, endangering personnel, cargo and equipment. To prevent this, you need a leveler with free-fall protection.
Personnel must be protected during leveler maintenance. Choose a leveler with a strong, reliable maintenance strut for supporting the platform in an upright position.
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Step 3. Look for easy operation
Convenience is a key consideration in choosing a leveler. For optimum productivity, you want a system that's easy to learn and operate, and easy on your personnel.
Hydraulic levelers provide fully automatic operation. Simple pushbutton controls raise the leveler and extend the lip. When the buttons are released, the platform floats down to the trailer floor. The leveler typically operates from 12-in. above to 12-in. below dock level. Normal below-dock operation to pull a chain. When the loading operation is complete, the pushbutton returns the levelers to its stored position.
Mechanical levelers require manual activation. These levelers are positioned onto trailers by pulling a chain at the rear of the leveler, which releases the "hold-down" system, allowing the platform to rise and the lip to extend. The operator then walks onto the platform, using body weight to lower the leveler onto the trailer bed. If the trailer is below dock height, the operator must pull a second chain near the front of the leveler to retract a set of support legs, so the platform can travel below the dock.
Power-assisted mechanical levelers offer limited convenience. If the trailer is at or above dock height, these models are positioned by pushing and holding a control button until the leveler reaches its highest position and the lip extends. The leveler then lowers by gravity to the trailer bed. On some models – if the trailer bed is below dock height – the operator must raise the leveler with the control button and then walk onto the leveler and pull a chain to retract the support legs.
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Step 4. Consider maintenance costs
Initial cost is only part of the picture when evaluating your leveler purchase. Anticipated maintenance and repair costs are also vital factors. Consider the accessibility of components for servicing. Look for simplicity of design. Check the overall quality of construction, and consider the frequency of required maintenance. Levelers can vary widely on these points, which all contribute to the unit's overall lifetime ownership cost.
Like any major piece of production equipment, a leveler requires periodic inspection and some degree of maintenance. Hydraulic levelers typically require less maintenance than other leveler types, due to overall design characteristics. Usually, periodic lubrication is all that's needed to keep hydraulic levelers operating properly. While these levelers can be more expensive at the outset, they often provide lower lifetime ownership costs.
Mechanical levelers require regular adjustments to the hold-down system. Components must be properly maintained to prevent failure.
Power-assisted levelers vary in the amount of maintenance required, depending on the model.
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Step 5. Look for reliability and durability
To get maximum reliability from your leveler, consider your application and make sure the equipment can meet the challenge. At first glance, structural differences between competitive models may not by obvious. When evaluating equipment, look closely for strength, stability, dependable design and quality construction. These factors should give you more dependable performance, longer life and lower ownership costs.
Also consider the track record of leveler type you're buying. Make sure you're choosing a design that has proved its performance over the long haul. Ask to see a manufacturer's list of satisfied repeat buyers who have had the equipment in operation for several years.
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Step 6. Check manufacturer and representative report
Make sure you select a manufacturer and local dealer who stand behind the equipment and provide complete service and support. Does the manufacturer offer a money-back or satisfaction guarantee? A no-risk trial installation? Guaranteed life expectancies of the equipment?
A quality manufacturer should offer you a structural and power system warranty ranging from 10 to 20 years, based on your specific application. Look for performance-based coverage, not "workmanship and materials."
Also keep in mind: Does the manufacturer back the equipment with solid local support? What about emergency service? Operator and maintenance training? Planned maintenance programs? These are all services you should expect, so get all the facts before you make your decision.
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