Selecting dock leveler :
Today selecting the right dock leveler for your facility can be more complicated than ever. New models are introduced very frequently. Truck designs are changing frequently. Productivity is critical to any industry. Safety is becoming an even bigger issue at docks. There are now three basic type of dock levelers. Mechanical, Hydraulic and Air powered levelers. Each leveler has its place depending upon the application. Thereare distinct differences between each type. Before you select a dock leveler for your facility.
- Your specific need and application
- Electric or gas powered forklift
- Easy of Operation
- Reliability/ Durability
Short levelers can limit your capabilities. If your leveler is too short , a steep incline or decline can created . In addition to being unsafe for the forklift driver, this can cause several materiel handling problems, including an inadequate amount of lip on the trailer bed , more wear and tear on forklift and the leveler, slower operations , and “ equipment that hang up on the crown “ . That point where the leveler deck and lip come together.
For the lift truck operator, ramps and inclines, overhead obstructions, dissimilar surfaces often wet and slippery, poor lighting in trailers, other vehicular traffic, pedestrian traffic, restricted views, sheer drops, trailer creep, congested staging areas, and accumulations of empty containers, pallets, and debris are hazards which can all be present at the same time within a very confined area. While OSHA does require training of lift truck operators on these types of hazards, many operations fail in providing detailed hazard assessment, operational procedures, and day-to-day enforcement of safety issues. In addition, those employees that do not operate lift trucks are rarely trained on dock safety issues even though they share many of the same risks as the lift truck operators.
The biggest reason to put a priority on dock safety is not so much related to the frequency of accidents in dock areas as it is to the potential severity of injuries that can occur in these types of accidents. Injuries sustained when lift trucks tip over or fall from docks, or those that occur when pedestrians are impacted by a lift truck, falling load, or tractor-trailer, tend to be very serious and sometimes fatal. Prevention of these types of accidents can be achieved through proper equipment, proper training, and enforcement of safe operating procedures.
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 the trailer that is crossed by forklift. Your loading docks are key areas where everyday your products and materiel pass for an uninterrupted process safety is important and critical as well your employs they are priceless.. The most valuable assets here is your employees and safety procedures they follow. The financial impact alone of a dock accident can be devastating to companies of any size. According to OSHA dangerous dock conditions are the cause of more than 25% of all reported forklift accidents.. the forklift, the factory environment, and actions of the operator can all contribute to fatal incidents involving forklifts. In addition, these fatalities indicate that many employees and employers are not using or may be unaware of safety procedures and the proper use of forklifts to reduce the risk of injury and death. Powered industrial trucks (referred to as PITs or forklifts) are used in numerous work settings, primarily to load and unload materials. Forklift overturns are the leading cause of fatalities involving forklifts.
Accidents can be costly and consequences is severe.
Forklift can fall off the dock for many reasons, and these accidents can occur regardless of weather or not the dock door is closed or open . studies show that a serious industrial accident can easily cost company over a million after insurances. This includes direct costs , such as medical expenses and compensation.
Many accidents are caused when the trailer makes unexpected departure from the dock.To prevent this from happening it is advisable to use vehicle restraints which should not be considered as replacement for built-in leveler free fall safety system.
Vacant dock Roll off / drop off protection
When no trailer in place at the dock , there is a danger that forklift could accidently fall from the edge of the dock to the drive way below. This can happen if floor conditions is slippery, if brakes or other malfunctions of the forklift. If the forklift attendant inattentive when backing up , or if drivers are distracted. That is why you consider choosing a leveler with barrier protection. you can choose manual or automatic safety gate barriers or levelers with automatic barriers built on to the lip . For convenience, reliability and safety.
It offer solid construction, it prevent fork lift roll off from the loading dock, whenever the dock leveler is in parked position. It have adequate height 9 “ . it have the ability handle end loads even during higher risk , bellow level end load operations.
Cross traffic safety
If a leveler stays in a below dock position after servicing trailer below dock height, a dangerous dip is created in the floor , which can be hazardous to forklift cross traffic. To minimize the risk . Choose a leveler with an automatic recycle [ auto return ] feature . This feature leveler will slowly travel to the bottom of the pit and then automatically re store it self . The roll off stop lip also serves to protect roll up doors on truck trailers positioned at the loading dock from impact and damage.
Free fall protection
If a trailer pulls away from your dock while the leveler is in use with heavy load on the platform, the leveler may drop quickly endangering personal , cargo and equipment. That is why you need a leveler with dependable free fall protection. This can be achieved by velocity fuse safety system in hydraulic leveler this achieved in mechanical leveler and some power assisted mechanical leveler by support legs . Mechanical safety legs will prevent the deck from falling to the lowest point of travel [ only if the leveler is operating above level ] The legs must be manually released to allow bellow level servicing . Although safety legs are a means of improving safety for a fall safe condition, this issue can be addressed by hydraulic dock leveler.
“ Stump out ” is a concern for levelers with mechanical safety legs . Dock leveler stump out occurs when a loaded lift truck enter a vehicle causing the trailer bed to lower to the point where the mechanical safety legs contact their supports.. The safety legs then stops any further downward movement of the levelers deck. As a result the lip of the leveler can present a steep angle of incline when the lift truck attempts to leave the trailer.
Protection during leveler maintenance
Make sure the personal are protected during leveler maintenance. Integral maintenance stand facilitates support during routine support and maintenance with lockable electrical disconnects.
Convenience is a key consideration in choosing your leveler. For optimum productivity you want a system that is easy to learn , easy to operate .
Activation and leveler positioning
Hydraulic levelers provide fully automatic operation. Simple push button control, raise the leveler and extend the lip. When the buttons are released, the platform floats down to the trailer floor. The leveler typically operates in a range from about 129 above to 129 below dock level. Normal below dock operation does not require the operator to pull a chain . When the loading operation is complete , the push button or [ [ automatic return to dock level function ] return to the leveler to its stored position. Includes a selector switch that enable the dock attendant to turn off the auto return feature during below dock end loading / unloading. The deck stop feature adds the ability for the operator to fully stop the travel of the leveler dock while in operation, all with one button. This enhances the operation and assist with protecting product loaded at the end of the trailer.
Types of Dock levelers :
Mechanical [ Spring Powered]
Levelers require manual activation. These levelers are positioned on to trailers by first 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 trailered. If the trailer is below dock height, the operator must also pull a second chain near the front of the leveler to retract a set of support legs, so the platform can travel below deck.
Power Assisted leveler [ PAL]
These levelers are positioned with push button , when leveler is used at or above dock height.For below dock use , operator walks on leveler and pulls chain to retract support legs.
Hydraulic dock leveler
Hydraulic dock levelers are high performance systems that operate at the touch of a button
Air powered Dock leveler
Air powered dock levelers are semi automatic: air bag lifting mechanism and mechanical lip.
Edge of Dock leveler [ E.O.D]
Edge of dock leveler correct height differences between loading dock platform and trailer . Hydraulic and mechanical versions of the edge of dock leveler available
Full range leveler float
During normal loading unloading, bed height changes as the fork lift enters and leaves the trailer, and the weight of the cargo in the trailer increases or decreases For maximum safety and efficiency, levelers should be able to freely float up and down, maintaining contact with the bed. Free float is even more important when loading or unloading truck with air ride suspensions, where bed heights can fluctuate even more if the air system has not been purged.Full range unobstructed float is critical when servicing trailer that are close to dock height. Mechanical and Power assisted levelers can float slightly above dock leveler below dock if the support legs have been retracted. When servicing trailers close to dock height the unreacted legs will stop the platforms downward movement.
Factors to consider ?
Lip extension/ retraction
Consider lip extension and retraction capabilities when choosing your leveler. Your best choice is a lip that will retract at any time during the leveler cycle, to avoid damage to cargo or equipment. Lip yield ability is also important. Most hydraulic and mechanical levelers have yieldable lips, lips that will retract when pressure is applied. However some levelers have a lip extension latch which is engaged as the leveler descends., with this latch in place the lip is not yieldable and the lip may extended at dock level .When no truck is present.
Initial cost is just part of the picture when evaluating your leveler purchase . Routine maintenance and repair is also a vital factor . Look for simplicity of design, check the overall quality of construction and consider the frequency of required maintenance, which all contribute to the overall lifetime ownership cost of the unit.
Electric or Gas Powered Forklift ?
Electric forklift have lower grade capacity or gradeability as they are lower compared to gas powered forklifts. Electric forklifts have maximum grade capability of 10% and gas powered can go up to 15% (please check this with the manufacturer specifications). If you have pneumatic tires then it can loose additional height while loading when compared to solid rubber tires.
Hydraulic leveler offer maintenance advantage
Like any production equipment a dock leveler requires periodic inspection and some degree of maintenance. needed Hydraulic leveler typically requires less maintenance than other types due to overall design characteristics. Usually periodic lubrication is all that is needed to keep hydraulic levelers operating properly for years. While hydraulic leveler can be more expensive initially but often provide lowest lifetime ownership cost. Mechanical levelers requires regular adjustments to the hold down system and are more prone to failure if components are not properly maintained. power assisted levelers vary in the amount of maintenance required depending upon the model. Increased safety, user preference and reduced maintenance are also important A broader range of options like deck stop, independent lip control, automatic return to dock and the ability to interlock the dock leveler to other safety products or energy saving products can be linked like overhead door, inflatable dock seal / shelter, vehicle restraint and or safety barrier. With hydraulic dock leveler installing hydraulic velocity fuse provide protection in a “ fall safe “ condition. The velocity fuse locks the leveler and stops its downward movement within a few inches when a fall safe condition happens.
Air powered levelers offer improved simplicity compared to hydraulic levelers. A high volume, low-pressure pump inflates the air bladder. Using air as the working fluid eliminates messy hydraulic fluids and avoids issues with leaky seals and connections.. An airbag leveler uses a bag that, when inflated, lifts the trailer up to the dock, it is been introduced 21 years ago, three out of five docks use them.”Airbags are simple and basic,” he notes. “They have really driven down the price of hydraulic systems, because up until the time airbag levelers came out, hydraulic levelers had no competition.” Air suspension trailers are changing the industry ” he says. The deck height of air suspension trailers can be raised or lowered. The hydraulic leveler floats with the trailer, something that mechanical and airbag levelers can’t do.