LOGGING IN THE DOUGLAS FIR REGION. 
133 
Table 22. — Estimated cost of lines, per thousand feet of timber, toith the over- 
head skidder. 
I 
s 
"8 
i 
i 
3 
o 
ft 
a> 
o 
& 
"S 
5 
Case 1 (900-foot 
span). 
Case 2 (1,200-foot 
span). 
Case 3 (1,500-foot 
span). 
Type of line. 
1 
o 
o 
En 
o 
O 
"5 
a 
1-1 
o 
o 
&H 
g«~ 
be 
Hi 
o 
o 
o 
&H 
©+j 
o 
Q 
Ins. 
If 
1 
i 
1 
£ 
1 
it 
I 
1 
if 
15 
10 
20 
10 
20 
10 
30 
3 
$0.50 
.25 
.20 
.11 
.09 
.20 
.50 
.20 
.20 
.50 
Feet. 
1,300 
1,100 
2,100 
1,100 
2,100 
800 
800 
250 
2,200 
1,300 
§650 
275 
420 
121 
189 
160 
400 
50 
440 
650 
$0. 043 
.027 
.021 
.012 
.01 
.016 
.014 
.016 
Feet. 
1,600 
1,400 
2,600 
1,400 
2,600 
800 
800 
250 
2,200 
1,600 
$800 
350 
520 
154 
234 
160 
400 
50 
440 
800 
$0. 053 
.035 
.026 
.015 
.012 
.016 
.014 
.016 
Feet. 
1,900 
1,700 
3,200 
1,700 
3,200 
800 
800 
250 
2,200 
1,900 
$950 
425 
640 
187 
288 
160 
400 
50 
440 
950 
$0. 063 
1 skidding line 
.045 
.032 
1 slack pulling line. . . 
.019 
.014 
1 tightening line 
Loading guys 
.016 
.034 
.016 
1 main cable (extra).. 
Total 
3,355 
.159 
3,908 
.187 
. .. '4.490 
.2.9 
Both chokers and tongs are used to attach the logs to the skidding 
line. In some cases tongs furnish the sole attachment; in others, 
chokers. Both forms of attachment are sometimes used. Where 
only one tong is used it is attached to a ring on the end of the skid- 
ding line. Where more than one tong is used they are attached to 
the butt lines or chains, and the butt lines are attached to a ring on 
the end of the skidding line. Where chokers are used they are 
attached directly to the end of the skidding line, no butt chains 
being used. Sometimes one tong and one or more chokers are used, 
the tong being attached directly to the end of the skidding line. 
The cost of chokers and butt lines per thousand feet does not 
amount to as much as in ground yarding (see discussion of rigging, 
cost under " Ground yarding"), probably ranging from 1 to 3 cents. 
The cost of the replacement and maintenance of blocks, carriage, 
etc., no one is in a position to discuss confidently. The amount per 
thousand feet is small, ranging from 1" to 3 cents. 
It is conservative to say that the cost of the fuel used in yarding 
and loading with this system, when the steam for the skidding and 
loading engine is supplied by a common boiler, is just about equal to 
the cost of the fuel used in yarding with a ground system. 
The cost per thousand feet for lubricants, waste, and packing used 
in skidding and loading with this system ranges from 1 to 2 cents. 
(See "Ground yarding.") 
The cost of the upkeep of the skidder ranges from $30 to $40 per 
month. (See discussion of the maintenance cost of ground yarding 
engines under " Ground yarding.") _ - 
The manufacturers of this machine estimate its efficient life at 
20 years. It may be that with proper maintenance this figure is not 
too high. However, it is no doubt too high to be used by 
concern or timber appraisers, at least in most cases. 
The factor of 
