(AI +
Al =
AZ =
1.85 =
D =
Az) x 1.85 x Distance= Cubic yards
Area of one end cross section
Area of other end of cross section
Constant factor
Distance between two end areas that
must be changed to a decimal form; for example,
250 feet = 2.50, 125 feet = 1,25, 75 feet = .75, and so
forth
To compute the equation take the area of one end
section (cross section) plus the area of the other end and
multiply the sum of the two areas by a constant factor
of 1.85. This value should now be multiplied by the
distance between the two end areas to determine the
number of cubic yards. (See fig. 4-12.)
Earthwork equations to compute the volume of
concrete are outlined in chapter 7. Other areas, such as
equations to compute for prime and tack costs, single-
and double-surface treatments, and asphalt volumes, are
outlined in chapter 8.
EQUIPMENT ESTIMATES
Equipment estimates are used with production
schedules to determine the construction equipment
requirements and constraints for a construction project.
One fact that must be remembered is that the speed of
the equipment usually averages between 40 to
56 percent of the posted speed limit. The primary factors
responsible for the variation in the percentage of the
posted speed limit are as follows: road conditions, the
number of intersections, the amount of traffic, and
hauling distances. Other factors considered are the types
of material hauled (for example, damp sand or loam is
much easier to handle than clay), safety (equipment
limitations), operator experience, conditions of the
equipment, work hours, and the local climate.
Equipment production must be determined so the
amount and type of equipment may be selected.
Equipment production rates are available in the Seabee
Planners and Estimators Handbook, NAVFAC P-405.
The handbook provides information on estimating
construction work elements and material quantities,
including equipment and manpower requirements. The
production rate per day should be estimated for each
piece of equipment. Consider the factors discussed
above, information obtained from NAVFAC P-405, and
your experience. The quantity of work divided by the
production rate per day produces the number of days
required to perform the project. Equipment required to
support each construction activity is documented on the
Construction Activity Summary Sheet (CAS sheet) (fig.
4-13), which is part of the project package. One of the
purposes of the project package is to allow the project
supervisor and the assigned P&E crew to perform a
documented thorough analysis of their assigned project
and to lay out an organized sequence plan of operation
in order to complete the assigned tasking. Detailed
information on project packages, project planning,
project execution, and construction project supervision
are outlined in the Naval Mobile Construction Battalion
Crew Leaders Handbook.
4-11