Most businesses that entail shipping or receiving goods will have one or more loading docks to help facilitate the loading and unloading of trucks. These exterior entrances are designed to accommodate the height of a standard trailer truck, allowing the truck to nestle up to the building itself rather than forcing workers to use flimsy, unreliable ramps.
Loading docks have a wide array of features that often go unnoticed by the untrained eye. Surrounding the dock itself is typically a cushioned bumper that protects the building from being damaged by contact with the trailer and to seal off the entrance from the elements while the truck is docked with the building. Most loading docks also have bright yellow bumpers outside the dock that act as a barricade.
Many busier facilities will use a mechanical dock leveler that works as an adjustable bridge to fill the gap between the trailer and the dock itself, allowing motorized lifts direct access to palletized goods within the trailer itself. Some of these loading docks also have hydraulic restraint systems, which ensure that the trailer stays secured to the building during unloading procedures.
Business.com has lots of information available about loading docks. Take a look here and you will find some helpful links.