Determining Dock Lift Capacity
There are several important factors to consider when configuring a dock lift to accommodate a lift truck application. One of the first items to identify is the lifting capacity rating of the dock lift. Determine the overall weight of the lift truck, fully loaded, and then add 20% as a safety factor to determine the lifting capacity rating of the dock lift required.
Most dock lift applications are used with manual or powered pallet trucks, with capacities generally ranging from 4,000 to 8,000 lbs. When a lift truck operates on a platform, however, the dock lift must have a substantially higher capacity to safely support the added weight.
Understanding Lift Truck Weight and Edge Loading
As a rule of thumb a lift truck weighs 2X as much as its rated lifting capacity; for example, a 5,000 lb. capacity rated lift truck could weigh up to 10,000 lbs. unloaded, resulting in a total rolling load of approximately 15,000 lbs. when fully loaded. Most of this weight is carried by the front axle, which in some cases can bear up to 80% of the total load. It is essential to ensure that the dock lifts edge load rating is sufficient to support these concentrated loads at the platform ends as the lift truck moves across the dock lift.
Platform Size Considerations
It is recommended that the dock lift platform width allow room on both sides of the lift truck for the lift truck operator to easily be able to get on or get off the lift truck. The dock lift platform length should be long enough to accommodate the overall length of a fully loaded lift truck and room for the lift truck operator to be able to walk around the fully loaded lift truck.
Adding Safety: Automatic Roll Off Stops
To accommodate additional safety dock lifts can be equipped with an optional automatic roll off stop barrier system. The automatic roll off stop is designed to prevent a lift truck from accidentally driving off the end of the raised dock lift platform and falling to floor level. The automatic roll off stop is installed on the dock lift platform end that is opposite to the truck end.
When the dock lift is in the lowered position, the roll off stop remains level with the platform, providing the lift truck with easy, unobstructed access to drive onto the platform. When the dock lift “Up” button is activated, the automatic roll off stop is powered up into the raised position creating a barrier behind the lift truck that remains in the raised position until the platform is fully lowered.
Hinged Bridge Plates
Hinged bridge plates are installed on the truck end of the dock lift platform and when lowered provide a transition plate to allow product transfer from the dock lift platform to the bed of the truck. As the capacity of the dock lift increases so does the thickness of the hinged bridge plate. As standard hinged bridge plates are manually raised and lowered however to further promote safety and reduce the physical effort required the hinged bridge plates can be hydraulically powered to raise and lower using push button controls.
Operator Controls and Accessibility
It is common for the lift truck operator to be able to raise and lower the dock lift while remaining seated on the lift truck. This operating feature can be achieved by either installing the push button controls on a post that is located on the platform within reach of the seated lift truck operator or installing the push button controls on a 20’ coil cord. The coil cord is attached to the external power unit and is 4’ in length when retracted and extends up to 20’ in length. When not in use the push button on the coil cord can be wrapped around the dock lift guard rail for storage.
For information on any Pentalift product please contact the Pentalift Sales Department.