From: Roger Turk <73527.1356(--nospam--at)compuserve.com>
Date: Wed, 2 Feb 2000 18:00:22 -0500
Your loading dock situation appears quite unusual, with forklifts going up
and down ramps, and appears dangerous at best, particularly with a fully
loaded forklift going down a ramp.
Loading docks that I am familiar with either have the floor of the warehouse
elevated above adjacent level ground or have the ground depressed at the
loading dock so that the truck bed would be at or near the dock level. The
depressed loading dock presents a couple of problems that must be considered,
but, first, Architectural Standards, Sixth Edition (nothing in more recent
editions) states that the slope of the *truck* ramp should not exceed 1:8 and
have a minimum length of 30 feet (40 feet recommended). Depending on the
size of the truck, dock height should be between 3'-8"+/- (for 35' long
trucks) to 4'-8"+/- (for 55' long trucks).
Now, the parts that need particular attention for a depressed loading dock:
1. The dock height is measured from where the sloping ramp (or extension
thereof) intersects the vertical plane at the outside edge of the warehouse
slab, otherwise there can be 1-foot or more difference in elevation between
the bed of the truck and the warehouse floor, even if the bed height of the
truck matches the dock height exactly. Since most depressed loading docks
have a reverse slope at the bottom of the pit to drain water away from the
building, you can't set the dock height at the outside edge of the warehouse
2. The top of the truck extends a considerable distance beyond the edge of
the truck bed in a depressed loading dock. If the top of the truck is 8-feet
above the bed of the truck, the top will project out 1-foot beyond the bed,
and, if provision is not made for it, the top will strike the wall of the
building before the bed of the truck hits the bumper. The warehouse slab
should extend out beyond the face of the building a sufficient distance to
prevent the truck top from hitting the building. I like to use 15-inches
minimum as bumpers are typically only 4-inches thick and quickly become
thinner. If the trucks intended to use the loading ramps have cargo areas
with the inside higher than 8-feet, I will extend the warehouse floor out
further than 15-inches.
Hope this helps.
A. Roger Turk, P.E.(Structural)
David Finley wrote:
>>What is the usual grade for loading dock ramps? The loading docks will be
used by forklifts loading/unloading palletized materials from trucks.
Therefore the forklifts will go up and down the ramps while loaded.<<