Dock height and truck bed height will determine the operating grade of the dock leveler. The general selection criteria is the maximum grade percentage from dock to vehicle: when using electric powered handling equipment it is 10%, and for gas or diesel powered equipment 15%. Exceeding these grade percentages may result in equipment "hang up", damage to handling equipment and load spillage.
Discussed earlier in the guide, vehicle beds range from 30" to 62" in height. The question is: what vehicles will be serviced at the facility with the greatest frequency? Once this is determined, all or a majority of the docks should be made to accommodate this bed height.
Dock & Vehicle Height Differential
A dock area should be flexible enough to accommodate any vehicle. The most common dock height is 48” – 52”.
Substantial height differences between dock and trailer can create severe dock leveler
grades, decreasing the overall effectiveness of the operation.
Improper applications and use of dock levelers when there is a severe grade difference
can lead to damage and premature failure of the dock levelers. Customized dock levelers
can be made to suit unique applications and offset the height difference.