Most industrial buildings are designed with a level truck approach to the loading dock area. With a level approach, the truck backs into position at the loading dock and the back of the trailer is somewhat square to the building’s foundation wall.
However, due to space restrictions, it is not uncommon for trucks to have to back down a sloped ramp to the loading dock; this is referred to as a declining truck well.
Declining Approaches and Dock Levelers
At a declined approach, as the truck backs down the ramp, the top of the trailer will impact the building wall above the overhead door before the back of the trailer makes contact with the dock bumpers.
To prevent the top of the trailer from impacting the building wall, it is recommended during construction that the dock leveler pit area be projected forward of the foundation wall. A projected dock leveler pit is often referred to as a cantilevered pit.
Follow the link below to see an example of a declined approach:
Projected Pit Dock Leveler Benefits (PDF)
As a rule of thumb, the dock leveler pit should be projected 1” beyond the foundation wall per degree of decline.
For example, a loading dock area with a 6% decline should have the pit area projected 6” beyond the face of the foundation wall.
Installing dock bumpers on the face of the projected pit will stop the incoming vehicle in position before the top of the trailer contacts the building wall.
Declining Approaches and Vehicle Restraints
Declined approaches can also have an impact on the selection and installation of vehicle restraints at the loading dock. With a truck backed into position at a declined approach, the trailer sits at an angle, making it more difficult for the vehicle restraint to engage properly with the trailer’s rear impact guard (RIG).
Vehicle restraints are designed with both a horizontal and a vertical operating range to capture the truck’s rear impact guard.
In some extreme declined approaches, the angle of the trailer’s rear impact guard requires a horizontal extension plate to be provided for the vehicle restraint at the time of installation. This moves the vehicle restraint forward, ensuring that the forward-to-back hooking range of the restraint is maintained.
Additional Information
For additional information on any Pentalift product, please contact the Pentalift Sales Department.