PURCHASED
BY
THE FOREST SERVICE FOR OFFICIAL USE Using the Sta99ered Setting System
What Are Logging Costs? By JOHN CAROW and ROY R. SILEN .
Pacific Northwest Forest and Range Experiment Station, Forest Service,
U.
S. Department of Agriculture Reprinted from
THE
Timberman
WOOOS MANAGEMENT LOGGING FORESTRY TRANSPORTATION
519 S. W. Park Avenue
•
Portland 5, Oregon
April 5, 1957 issue
Using the Staggered Setting System 7
What are
LOGGING By JOHN CAROW and ROY R. SILEN
Pacific Northwest Forest and Range Experiment Station, Forest Service,
U.
S. Department of Agriculture What does it cost to log old
growth Douglas fir by the
staggered setting system?
How does the size of the cutting
unit affect cost of yarding?
What yarding method is least
expensive?
How closely does a predicted
item of logging cost for a single
clear cutting check with actual
cost?
and related questions have
THESE
been asked frequently since the
staggered setting system was first incro­
duced. They are still not fully answered
buc experience from five years of con1­
mercial operation with inedium-sized
settings on the H . J. Andrews Experi­
mental Foresc provides some helpful
guidelines.
.
Direct logging coses were found to
be well in line with regional averages.
Initial road costs were higher, how­
cvc:r beca:use the ex:tensive area of old
,l!t·o,vth H1nhe·r on t'fre experimental for­
est \v:ts IYrencd uf1 more rapidly and
more co1npletely. Expecience records
further showed that average costs for
a large number of cutting units could
be predicred reliably. For an individ­
ual unit, however, unexpected factors
_
led to cost variacions as large as · Oo/o.
1
Cutting Area Layout
logging Methods
Methods used for laying our cutting
areas and designing road systems have
been described by Silen, Rurh and Auf­
d-erheide in an Experiment Station re­
search note (No. 72, December 1950)
and previous The Timberman articles
(March 1949 and April 1955). Boun­
daries were carefully selected to pro­
mote efficient logging, minimize ero­
sion and scream clogging, provide for
safe and ea.sy slash burning, minimize
wind ch row, and leave adequate sources
of seed. On about half of the units, a
logging plan was prepared in advance
and specified in the sale contract. On
the others, the operator was permitted
to choose the 1nethod or combination of
methods he thought best fitted the log­
ging show. Cutting areas havi? ranged
from 15 to 70 acres in size.
Large crawler tractors and arches
were used on gentle topography. On
steep ground, high-lead yarding was
standard practice, using 150 horse­
power diesel-powered yarders. While a
few smaller areas were logged to one
spar tree, most cutcing units required
two or more settings. External yarding
distances up to 1200 feet were ­used but
normally they were less than 700 feet.
In a few instances, skylines were rigged
for yarding steep, difficult settings, or
used in combination with tractors on
gentle ground. On rhe cable settings,
and prior to 1953 on the tractor sides,
loading was by tree booms. Loading for
tractor shows was with a mobile loader
since 1953. All hauling was with truck
and trailer equipment. No short-log op­
erations are covered in the study.
_
The Forest Area-Timber and Topographic Conditions
The Andrews Experimental Forest occupies a 15,000 acre watershed within
the Willamette National Forest, 50 miles east -of Eugene, Ore. In line with
its purpose of testing and demonstrating methods of old growth management,
a total of 34 separate areas, averaging 27 acres in size, had been cut
by 1954 . .Production of 64 million board feet from 1950 to 1954-an aver­
age of 12.8 million feet per year-shows that the operation is a commercial
venture and not just an isolated experiment.
COSTS The timber was offered for competitive bidding in five separate sales,
thus insuring that logging methods and costs would be reasonably compar­
able to those of other operations in the region.
Timber on the forest is predominantly 400- to 470-year-old Douglas fir
,
•
with smaller quantities of hemlock, red cedar and other species. Volumes
range from 30,000 to 119,000 board feet per acre. Tree diameters average
42 inches, but ofte·n reach 80 inches. logs harvested in the study averaged
about 800 board feet. About 20 "/. of the forest is on gentle slopes and
flats. The balance is steep with many areas having slopes of 70 °lo to 80 %
.
Occasionally the terrain is interrupted with rock outcrops and bluffs. The
Cost Reports Reflect
All Logging Factors
All sales agreements provided for ac­
curate cost records and log scale from
each cutting unit and in son1e instances
from parts of units when more than
one cutting method was used. These
records, with average figures on volume
per acre, average volume per log, slope,
and external yarding distance, provided
the basic data for the current analysis.
Such cost data reflect the influence of
all factorS;rhat were involved on a job.
Many of these such as W'eather, fire
restrictions, breakdowns, and labor
changes often obscure the effects of
the few variables that are available for
making estimates in advance of cutting.
On the other hand, bookkeeping rec­
ords have the advantage of including
the costs of lost time, imperfect coor­
dination, and other nonproductive
items that are often missed in short
time-cost studies.
Cost experience records from log­
ging on the experimental forest are
summarized in rable 2 by logging meth­
od (see next page). Average figures
are given for logging by tracror, by
high-lead, and by various combinations
(including skyline). Six to ten cutting
units are the basis of each average. All
comparisons arc on nee cruck scale.
Comparisons of these average coses
are easy to understand and generally
satisfactoty. However, the changing
value of the tlolfar 6'\fe'r the Jive-year
period m;k6 compatisoM based on
man-hours pet thousa·n.d board-feet
somewhat more exact. Thus, a.ctual
coses are used in che more general com­
parisons, but wherever exact relation­
ships are described che coinparisons
generally are on a man-hour basis.
main features of the areas logged by different methods in terms of timber
volume, size of clear cutting and topographic conditions are given in
TABLE 1­
The last rwo columns of table 2 give
average logging costs, all methods, for
both the Experimental Forest and the
Douglas fir region. Regional costs were
collected by the forest service from a
sample of 50 to 60 operators cuccing
on che national forests during the same
1950-54 period. Except for high road
costs, which resulted from rapid initial
development of rhe Experimental For­
est and a longer road haul, logging on
the Andrews has had a cost experience
well in line wich ocher national foresc
areas. This is particularly true in the
important direct cost items. The higher
supervision, administration, and fire
prevention and protection charges were
usually the resulc of_· special research
requirements chat were not included
in standard timber sales.
TABLE I-Essential characteristics of areas logged by different
.
methods, H. J_ Andrews Experimental Forest, 1950-54.
Logging Method
Item
Number of cutting units .
• • . . . . . . .
Areas logged, acres . . .
.
M
Highle d
o
Tractor
•••
high-
mt ,
leod
Mlxedl
e hods
including
.skyline
9
9
10
6
82.5
223.3
334.0
268.5
Tractor
.
.
,. . , .
.
.
7,740
15,8 02
21,778
18,569
Range in .slope, percent,. ,.......
0-20
30-70
10-70
20-8 0
ll:ange in cutting-unit size, acres.,.
2.3-41.0
8.3-48.0
12.0-54.0
18.0-70.5
65-108
42-98
34-8 4
42-119
698 -1,024
590-960
504-1,043
596-880
Volume removed,
bd. ft., net. , •
Range in \IOlumo per acre
of cutting units,
M
,
bd.-ft• .
. . . . .
Ra ng e in average volume
per log, bd.-ft•
. .
, . . . . . • . . ,
,,
(1) V11rious combinations of high·lead, tractor, and skyline yarding, usually under adverse condWons.
TABLE 2-Costs and man-hours, by logging method, H. J, Andrews Experimental Forest compared with
Douglas fir regional averages, 1950-54.
Andrews Experimental Forest
Douglas fir Tractor
Cost· and man-hour items1
Tractor
High-lead
and
logging
logging
high-lead
logging
DIRECT
Mixed2
logging
methods,
Including
skyline
Average
all
region, average all logging logging
methods
methods ------- Dollars per M board-feet, net truck scale -------
Felling and bucking. . . . . . . . . . . . . . . .
3.44
3.76
4.10
3.91
Yarding
3.61
5.24
4.64
5.45
Loading
1.35
1.51
1.70
8.40
10.51
11.30
11.30
Total
Trucking . . . . . . . . . . . . . . . . . ... . . . .
(Cost per MBM /mile)
.
.. . . ... . . . . . . . (0.227)
10.227)
3.88 4.52
1.56
6.48
7.05
10.44
10.92
10.36
11.57
11.30
11.30
11.30
7.91
10.227)
10.227)
10.227)
I
;I
(0.244)
Road maintenance . .. . . . . . . . . . . . . . 0.80
0.80
0.80
0.80
0.80
0.63
Fire protection 0.62
0.62
0.62
0.62
0.62
0.32
Slash disposal 0.41
0.41
0.41
0.41
0.41
0.33
13.13
13.13
13.13
13.13
13.13
9.19
Scaling . . . . . . .. . . . . . . . . . . . . . . . . . 0.19
0.19
0.19
0.19
0.19
0.20
Office expenses . . . .. . . . . . . . . . .. .
.
2.41
2.41
2.41
2.41
2.41
1.87
Supervision . . . . . . .. . . . . . . . . . . . . .
.
1.08
1.24
1.52
1.22
1.31
0.69
Payroll taxes, insurance, vocation pay . .
0.71
0.99
1.03
0.92
0.95
0.91
Equipment depreciation . . . . . . . . . . . .
1.22
0.75
0.70
0.80
0.80
1.23 Road construction
8.78
8.78
8.78
8.78
8.78
5.11 Total . . . . . . . . . . . . . . . . . . . . . .
14.39
14.36
14.63
14.32
14.44
10.01
Total logging cost. . . . . . . . . . . . .
35.92
38.00
38.20
38.37
37.93
30.77
Total
I
INDIRECT ------- Man-hours per M board-feet
Felling and bucking . . . . . . . . . . . . . . .
0.89
0.95
1.06
0.95
Yarding
0.72
1.25
1.12
1.27
Loading
0.29
0.38
0.40
0.43
Total man-hours . . . . ... . , ... .
(1) Cost
items generally follow
.
1.90
Forest Service stumpage appraisal
deflnltlo1u, With the- followhig exceptions: Felling, bucking, yarding,
and
foadlng' C&sfs
itrdude
s·oJJptfes and repairs. Tractor yarding includes
(jl Yle1f'ir bdrs· a·ncf diVt!Jrsions in
chantable trees is induded in felling and
cash
minor costs {during
1950
tractor trails. Felling unmer­
bucking cost. Scaling includes
only) for dumping and rafting. All general
and admini lrative costs, plus crew hauling, are listed under office
expense. Road construction includes rood
erosion control costs,
engineering
and special
2.58
(2)
2.58
-------
2.65 Various combinations of high-lead, tractor, and skyline yarding,
usually under adverse conditions.
(1:1) Average costs reported to
forest Sorvice by 49 to
ing companies during
U. S.
1950-54,
Comparison of experimental-forest
64
cooperat­
average figures with regional averages cannot be exact since many
different criteria were used over the period lo distribute cost items.
For instance, the regional average figures for trucking road devf;lcp·
men! contain undetermined parts of overhead costs, while with the
Andrews' cost records, overhead items hove been reported separately.
·
Felling and Bucking Costs Average $3.80 per MBF
Steep Slopes and Long Distance$ Jlv;;r@ C9$tly
figure. This variation arose mostly
from difference between gross woods
HIGJi-LJlh;D Jog
_ ging "'"' carried
scale and net scale due to defect and
on exclusively, or n. a.rly so, on tO cut­
breakage and also differences in piece
ting units. Some were yarded uphill,
rate, which was sometimes adjusted for
some downhill, and some on a com­
difficult terrain or low timber volumes.
bination of slopes. In terms of costs
Dollar costs do not reflect differences
for a whole cutting unit, there was no
in required effort as directly as man­
discernible pattern with regard to the
hours. As has been common in cutting
direction of yarding on slopes. How­
operations, worker efficiency advanced
with the continual improvement in
ever, the steeper slopes were definitely
. saws and the changeover from rwo­
more costly to yard. As one would ex­
man to one-man saw operations. In
pect, costs also increased with longer
1954, only 0.87 manhours were re­ external yarding distances, with smaller
quired per M board feet, net log scale, . volumes per acre, and with smaller av­
as compared with about 1.05 man hours
erage log volumes. Cutting-unit size
in 1950. Average over the five years
had little effect. Spreading of rig-up
was 0.96 man hours per M.
costs over large settings was offset by
LABOR. REQUIREMENT range increased direct yarding time because
of longer yarding disrances.
among the units was considerable, vary­
. Felling .and bucking was generally
on a piece-rate basis that paid cutters
$0.70 per M for falling and $0. 70 per
M for bucking on a gross woods scale.
Fallers were also credited with a 40w
foot log of stump diameter for every
snag or cull tree they cut, and with a
32-foor log of the diameter bucked to
compensate for a rigging cut.
In dollars the average cost of felling
and bucking over 5 years averaged
$3.80 per M board feet, net scale. This
compares with a $4.52 average cost re­
ported to the forest service by a sam­
ple of operators in the Columbia-Wil­
lamette area for 1954. By cutting units,
the cost ranged from $2.27 to $7.08 per
M, indicating that local circumstances,
in many cases difficult to predict, may
cause wide variation from an average
ing from 0.58 to 1.80 man hours per M.
The reason for the variation often is
not shown in the data, but requires
consideration of many situations that
could be observed on the job. For ex­
ample, statistical tests failed to show
any correlation of cutcing efficiency
with ground slope, board-feet per acre,
board-feer per log, logs per acre, or cur­
ring unit size. However, the operator
had ready explanacions for extreme var­
iation in costs. The lowest-cost unit, re­
quiring only 0.58 man-hours per M,
was cut in September of 1954 by three
of his best sawyers. Net volume per
acre averaged 71 M board-feet, and
there was very little cull. On the oth r
hand, the highest cost occurred on a
unit Cut in mid-winter on a very steep
and rocky slope. The timber was fairly
defective and averaged only 42M board­
feet per acre, nee volume. Differences
in cull and breakage have an important
part in cutting-cost variations, since
men are aid on gross scale but costs
compute on net scale.
J
Lowest Yarding Cost with Tractor and Arch Production data from all or parts of
9 cutting units showed an average la­
bor requirement of 0. 72 man-hours per
M and only small variation among units
irrespective of area or timber character­
istics. However, an undetermined part
of the cost advantage that tractors had
over high-lead was due to the topo­
graphy of less than 30% slope. This is
generally where the heaviest timber
volumes and the largest logs occurred.
Ofren tractors picked up the cheapest
logs on settings that were predomi­
nantly high-lead.
YARDING DISTANCES were less
than 800 feet for tractors and within
this short haul little variation could be
expected among cutting units. In ad­
dition, tractor yarding was halted dur­
ing wet weather to avoid soil compac­
tion and sedimentation. In one instance
a comparison was set up between high­
lead yarding and tractor yarding on
gentle topography with a 700-foot ex­
ternal yarding distance. This showed
similar yarding labor costs per M for
the two methods: $2.20 for tractor and
$2.41 for high-lead. Labor costs of trac­
tor yarding averaged $1.83 per M over
the four-year period. Supplies, main­
tenance and repairs added another
$1.78 to bring the total tractor yarding
cost to $3.61.
The· following equation combining
the effects of these variables was de­
veloped to predict yarding labor re­
quirements on high-lead units:
Man-hours per M
+
=
0.7 5
0.7 X slope in percent X
external yarding dist. in ft.
M bd.-ft. per acre X bd-fr. per log
The formula predicted actual labor
needs within 0.22 man-hours for two­
thirds of ·rhe units included in chis
study and may be useful as a rule of
thumb to predict man-hours for shows
with comparable timber and equip­
ment.
For example, in timber that averaged
71 M board-feet per acre and 590
board-feet per long log, one curring
unit on a 60% slope had a long 1200­
foot -external yarding distance. The
1nan-hours per M labor requirement for
high-lead yarding predicted by the
equation is:
Man-hours per M
+
=
0.75
0.7 x 60 x 1200
71 x 590
0. 75
+
1.20
=
1.95
Records from this setting indicate the
actual requirement was 1.86 man-hours
per M. The man-hour estimate multi­
plied by the going labor rate gives an
estimate of direct labor cost in dollars
pet M.
lj
DIRECT LABOR CHARGES for the
9 units logged by high-lead averaged
$3.64 per M for yarding. Supplies,
maintenance, and repairs added 44%
more so that the total high-lead cost
was $5.24. Among units the cost varied
from $3.52 to $8.44. Causes of extreme
variations could not have been pre­
dicted from information available be­
fore logging.
The ren cutting units logged parrly
by tractor and partly by high-lead had
labor requirements and costs interme­
d.iate between those of tractor and high­
lead ­in direct proportion to the areas
involved. Thus, an area yarded half by
ttactor had a labor cost halfway be­
tween the costs of tractor yarding and
high-lead yarding. On ten clearcuts the
average direct labor charge for yard­
ing was $3.24 per M. Cost of supplies,
maintenance, and repairs was $1.40,
for a total of $4.64 per M.
Combination Logging
Methods Most Costly
I
I
I
Six cutting units were logged using
various combinations of high-lead, trac­
tor, and skyline yarding. Yarding costs
on these units averaged highest of all.
Direct labor charge was $3.41; sup­
plies, maintenance, and repairs aver­
aged $2.04, for a total of $5.45 per M.
Generally the units were on very rough
topography or logged under adverse
conditions. Costs from individual units
were consistent in that they reflected
the proportions yarded by the several
methods.
WEATHER CONDITIONS un­
doubtedly influenced costs by all meth­
ods. However, no straightforward com­
parisons of logging under different
weather conditions are possible from
the data even though some logging was
done in all seasons. Tractor yarding, for
instance, offers no opportunity for such
comparisons because it was halted
whenever the soil was wet enough to
cause serious compaction and sedimen­
tation. A comparison of three high-lead
units, operated predominantly during
the winter months (November through
April), gives an average yarding labor
cost of $4.38 per M. For five high-lead
shows, operated predominantly from
May through October, the costs were
$3.08 per M or a difference of $1.30
per M. However, weather was respon­
sible for only part of the difference
here since the three winter-logged
units were also very steep and had low
volumes per acre.
A similar comparison for units
logged by combination of tractor and
high-lead gives $3.19 per M for wet­
season logging and $2.79 for dry-sea­
son logging-a difference of 40 cents
per M. For mixed methods, including
skyline logging, the comparison is
$4.83 per M for yarding labor costs in
winter and $3.06 per M during the May
through October season-a difference
of $1.77 per M. Although its effect can­
not be separated from those of other
factors in this study, weather is obvious­
ly one of the more important elements
in logging costs.
Loading Costs Have Little
Relation to Logging Methods
This was true except in shows that
were difficult to yard, even by cable
methods. Tractor yarding costs least
(table 2), but this is due mosrly to the
extremely high cost of a few units
logged by high-lead and skyline meth­
ods. On these units, low log production
caused by difficult yarding often con­
trolled the rare of loading and resulted
in high costs. For instance, the ex­
clusion of only 4 such units out of 2 5
logged b y high-lead o r mixed methods
would result in practically the same av­
erage loading costs for all logging
methods.
Loading cost variation from unit to
unit was due partly to difference in
average log vcilumes and partly to a
number of local circumstances. The
formula:
Man-hours per M
559
av. bd.-ft. per log
-
=
0.378
gives a reasonable but by no means pre­
cise estimate of the labor requirement.
Total cost of loading-including sup­
plies, maintenance, and repairs - was
1.31 times the direct labor cost and
averaged $1.53 per M board-feet for all
the cutting. Costs for individual units
ranged from $0.63 to $3.83 per M.
Transportation, Road, and
Other Logging Costs
TRUCK HAUL from cutting units
on the Andrews Experimental Forest to
the Springfield-Eugene market is 50
miles; 8 on gravel road and 42 on
paved. The going rate for trucking has
been $9 to $9.25 per M gross, truck
scale. Cost on a net scale basis has
averageJ $11.30 per M, with only small
fluctuation becaµse ,of cull differences.
Transporta!ion ucl .co.;J.J coius are un­
related ro fogging merho<l.
More than 27 miles of gravel road
and 3 permanent bridges were con­
structed to reach the initial cutting
units on the 9000-acre area. This rep­
resents 38% of the final road system.
An additional 45 miles, mostly short
spurs, will be ne
- eded to log the reserve
units. The system of staggered settings
has thus opened a large part of the
forest to management within a rela­
tively short period.
ROAD COSTS per M board feet cut
have been high for the initial cuttings.
However, subsequent cuts near the ex­
isting road network will have little or
no development charges, and much of
the area is now accessible for prompt
salvage, quick protection, and other
needs of management. Roads have cost
$20,000 to $32,000 per mile or $7.15
to $11.22 per M board-feet net log
scale. The average cost has been $8.78
per M for the toral volume logged.
MAINTENANCE COSTS on these
operator-built roads plus the five miles
of government-built access road have
ranged from $0.61 to $0.96 per M. Ex­
cept for supervision, payroll taxes, and
depreciation, indirect costs are not. re­
lated to logging method ·and only over­
all averages are shown. Costs o( pro­
tecting the cutting areas from - fire- and
disposing of slash on clear cuttings and
rights-of-way are also unrelated to log­
ging method.
40% Variation in
Estimated Costs Shown
Five years of cutting show-experience
costs consistent with regional averages.
Differences are not significant unless
relatively large.
For1nulae that have been developed
from these carefuliy kept records might
be used to predict some cost items. Of
more importance is the considerable
variation in recorded logging costs re­
sulting from local conditions that can
neither be anticipated in planning nor
accurately measured after the job is
done. The study reported here has
shown repeatedly that predications for
a single clearcutting, based on either
local records or regional averages,
should allow for variations ranging to
40% above ·or below the ·estimated cost.