1 September 1997
(2) "Nonpay volume" based on fill
obtained from audits and contract modifications.
measurement is the volume of material that results in
Adjustments should be made to this data reflecting
overfill and/or washes away.
current pricing levels.
o. Operating time. "Operating time" is the
c. Similar projects. Information may be
"Effective working time" (See "Effective working
obtained from similar projects with similar
characteristics to prepare a dredging estimate.
p. Percentage of effective working time. (See
d. Regional dredge teams. The use of regional
dredge teams is recommended. Members of regional
dredge teams can be contacted for guidance on
q. Required volume.
production rates, effective times, cost data, or other
(1) "Required volume" based on excavation
measurement is the volume of material to be removed
e. Combining Methods. A combination of the
from within the required pay prism.
methods, as previously described, may be used at the
discretion and judgment of the cost engineer.
(2) "Required volume" based on fill
measurement is the volume of material to be placed
f. Computer programs. When historical data is
within the pay prism.
not available, CEDEP may be used to compute a
production rate, or the production rate may be
r. Time efficiency. "Time efficiency" is the ratio
computed using recognized commercially generated
of the "Operating time" to the "Dredging time," and is
programs or industry generated programs. The cost
expressed as a percentage. Also known as "Percentage
engineer should include in the estimate a complete
of effective working time" (% of EWT).
statement of the source of computer program used in
15-3. Development of Dredging Estimate
15-4. Project Overview
a. It is the general policy of the Corps of
Engineers that dredging estimates be performed by
a. The cost engineer should review the known
cost engineers. The method of development of
project conditions and scope of work for the following
dredging estimates, in descending order, are as
items and determine which items are judgmental and
which are factual at the time the estimate is prepared.
b. Historical information. The simplest and
b. Location of work. This information is
most reliable approach for estimating production for
necessary to make a determination of availability of
all types of dredges is to rely upon dredging records
for the same or similar type work performed by the
distances, disposal areas, and restraints placed on the
same or at least a similar dredge. The dredging
various types of dredge operations.
records include the daily dredging reports. If project
conditions have changed, for example, a different
c. Type of material to be dredged. Information
horsepower or haul distance, historical production
may be obtained from geotechnical investigations,
information must be adjusted and documented for use
expert opinion, historical data of specific site or
in the estimate. Using such adjustments is a valid
adjoining areas, site visits, or similar projects with
method for obtaining production rates when historical
data is not available. Some valuable sources of
historical dredging data include daily reports of
d. Placement area. Information should be
operations, operations personnel, other districts, and
obtained on location, size, type, regulatory and permit
regional dredge teams. Cost and pricing data may be