Lesson 1/Learning Event 5
a large supply of aggregate and have adequate space on the front side for loading vehicles without causing
congested traffic areas.
Aggregates stored in stockpiles will be loaded by scooploaders or clamshells. These machines are most efficient
for loading vehicles with clean aggregate off the top of the stockpiles. Near the bottom of the stockpile, the
product becomes embedded in the ground and tends to be contaminated. This layer is then lost for use.
When you use conveyors to build stockpiles of aggregate, remember that the conveyor can be elevated between
12 and 20. Adjust the elevation of the conveyor so that the rock product does not drop over 3 to 5 feet. Also,
the wheels on the conveyors can be rotated 90, thereby enabling you to build radial stockpiles with little
equipment repositioning effort.
If yours is a long term operation, you will need to plan for permanent facilities and structures at the crusher site.
The buildings and facilities you will need include office space for the production records, a building for spare
parts and maintenance tools, storage, and an area for POL storage, parking, and latrine facilities. If aggregate
must be washed, you will need to provide water from a stream or well. Another special consideration is for a
lighting system if the plant is to be in operation after dark.
All through the plant erection stages you should make plans for the road networks within the plant. These well
planned roads are needed to prevent congestion, decrease the time haul units are in the plant, and for safety. The
following three road networks are needed for:
haul units bringing rock from the quarry,
trucks hauling the product aggregate to construction sites, and
service vehicles such as jeeps, 3/4-ton trucks, maintenance trucks, etc.
The plant roads should be one way where possible. You should construct them wide enough for the largest haul
unit expected and design them to support heavy loads. These roads should be maintained constantly. In dry areas
where there is little rainfall, a water truck should be used to wet down the roads to eliminate dust. In wet areas
crushed rock should be placed on the roads to keep haul units from sliding off into ditches. A maximum speed
limit should be posted for vehicular traffic within the plant and on the haul roads.