AFM 91-19 / TM 5-629 / NAVFAC MO-314
24 May 1989
operator cost computed on line 3g is $12,290.98
round-trip distance of 6 miles, yielding a total of
(1,066 hours x $11.53 per hour) for the tractor
408 miles on line 4c. A cost of $0.35 per mile
mower and $5,099.70 for the riding mower.
for the truck, multiplied by the 408 miles, gives
Operator costs for the 21-inch power mower and
us a cost of $142.80, which is entered on line 4e.
the weedeater are computed similarly.
(c) The truck drivers will spend about an
hour driving over to pick up the riding mowers,
(c) The cost of providing a supervisor is
waiting as they are loaded, driving them to the
calculated on lines 3h, 3i, and 3j. In this case, it
site, and returning. This 1 hour figure is shown
is assumed that one supervisor will handle all
on line 4f. This figure is multiplied by the
four operations on a full-time basis and that the
number of round-trips (line 4a), and the result,
job will take 2 weeks to complete. The supervi-
68, is entered on line 4g. The truck drivers are
sor is a WS-6, and document A (figure 6-1)
WG-4s, with a composite pay rate of $11.53 per
indicates this wage to be $16.87 per hour. The
hour, as shown by document A (figure 6-1).
80-hour work period costs $1,349.60 for the
This figure is entered on line 4h. The total driver
supervisor, as shown on line 3j. The supervisor
cost of $784.04 (68 hours x $11.53 per hour) is
cost and operator costs are combined in the total
entered on line 4i. The transportation costs for
column to produce a total labor cost of
the 21-inch power mowers and the weedeaters
$28.943.00 on line 3k.
are computed similarly. There is no driver cost
(3) Transportation Costs:
for the tractor mowers since their time spent
(a) The tractor mower is driven to the
driving to and from the site was accounted for
site by its operator. Line 3d indicates that it
earlier in their nonproductive time. Transporta-
must be driven to the work site 133 times, and
tion costs are totaled on line 4j.
this is entered on line 4a. In 133 trips, it is
(4) Total Cost. The total mowing cost of
driven 798 miles, and at 10 miles an hour this
$53,928.91 is shown on line 5f.
takes 79.8 hours. Document B (figure 6-2)
d. The completed document C for applying a
shows that the tractor operating cost is $18.46
PGR in our example is shown in figure 6-4. The
per hour, so the 79.8 hours spent traveling to
calculations are made in the same way as for the
and from the site incurs a cost of $1,473.11,
other operations. The cost of the PGR (and
which is entered on line 4e.
herbicides, if needed) is calculated under line 2.
It is the dominant cost factor in the spraying
(b) The calculations for those operations
requiring trucks to transport workers and equip-
(1) The gallons per acre are, in our exam-
ment to the site are somewhat different. The
trucks are assumed to take them to the work site
ple, a combined PGR and herbicide. (The two
could be calculated separately, if they were
in the morning and to pick them up in the
applied that way.) In this case, a gallon covers 5
afternoon. Therefore, the trucks make two
round trips each day. The riding mowers need
acres, so only 0.2 gallons are required per acre
67 mower-days to do the job (line 3d) and thus
(line 2a). The cost of the combined agents is
require 34 truck-days since each truck transports
estimated at $78.00 per gallon (line 2b), and the
operation is to cover the total area of 2300 acres
2 riding mowers. At 2 round-trips per truck per
(line 2c). The total chemical cost on line 2d is
day, 68 total round-trips are required. This is
entered on line 4a. Line 4b shows an average
the product of lines 2a, 2b, and 2c.
Cost of Grounds Maintenance Operations
Place: Air Base Somewhere
Location: Runways and Taxiways
Type of area:
Figure 6-4. Cost of PGR Application for "Air Base Somewhere."