Matt Fonseca, October 18, 2006
Timber Measurement Society, Central Meeting, Medford Oregon
THE DRIVERS OF PRODUCT RECOVERY
Scribner Decimal C, Diagram Rule
1" x 12"
1" x 12"
1" x 12"
1" x 12"
1" x 12"
1" x 12"
1" x 12"
1" x 12"
1" x 12"
1" x 10"
1" x 10"
1
x
8
1
x
10
1" x 4"
1" x 6"
1x 4
Maximum scaling cylinder is:
• 20’ east of the Cascades and in California
• 40’ west of the Cascades and in Alaska
Two segment log
d = 15”
D = 18”
S2d is interpolated as 17”
Segment 1: 16’ long, 15” s.e.d. = 14 decimal C or 140 bf Segment 2: 16’ long, 17” s.e.d. = 18 decimal C or 180 bf
Total log volume = 320 bf
Small end Large end diameter "d" S2d diameter "D"
Segment 1 (S1) Segment 2 (S2)
Recorded length 32'
(14.8”)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 2034567891011121314151617181920
Length of log segm ent in fee t
Scribner short log volume chart (Revised)
Scribner long-log volume chart
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1011121314151617181920
Length of log segment in feet
Sm
all-
end
dia
. lo
g s
egm
ent
in in
ches
US Cubic Log scaleSegment 1 calculation: (152 + 172) x 16 x .002727 = 22.4 ft3 (0.634 m3)Segment 2 calculation: (172 + 182) x 16 x .002727 = 26.7 ft3 (0.756 m3)
Total log volume = 49.1 ft3 (1.390 m3)
Small end Large end diameter "d" S2d diameter "D"
Segment 1 (S1) Segment 2 (S2)
Recorded length 32'
BC Cubic Log scaleLog volume: (192 + 232) x 10.1 x .00015708 = 1.412 m3 (49.9 ft3)
Log #1, 164 lbs20 b.f. lumber = 18.1 b.f.
5" 16' 6" 2.7 c.f b.f. rec. = 0.911.35 ccf/mbf LRF = 6.7
Log #2, 418 lbs20 b.f. lumber = 44.8 bf
6" 20' 9" 6.4 c.f b.f. rec. = 2.243.20 ccf/mbf LRF = 7
Log #3, 235 lbs20 b.f. lumber = 27.4 b.f.
7" 12' 8" 3.7 c.f b.f. rec. = 1.371.85 ccf/mbf LRF = 7.4
Log #4, 446 lbs20 b.f. lumber = 54.77.1 c.f. b.f. rec. = 2.73
8" 14' 11" 3.55 ccf/mbf LRF = 7.7
Log #5, 241 lbs20 b.f. lumber = 30.8
9" 8' 10" 3.9 c.f b.f. rec. = 1.541.95 ccf/mbf LRF = 7.9
Typical distribution of fiber in the lumber manufacturing process
Lumber Chips Sawdust Shavings ShrinkageBoards 41% 31% 12% 13% 3%Stud 48% 34% 7% 8% 3%Dimension 48% 33% 7% 9% 3%Hardwood 44% 25% 14% 10% 7%
Note: Based on recoveries on the following average small-end diameter logs 10” - boards, 7” – studs, 10” – dimension, 13” – hardwood.
Factors affecting lumber recovery; milling efficiency (cont.)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Sm all-end diam eter
Per
cen
t o
f lo
g v
olu
me
Dry chips
Shavings
Shrinkage
GreenChips
Sawdust
Lum ber
Material balance by diameter (dimension mill)
Lumber recovery by small-end diameter of log and mill type, actual log volume (B.C. Firmwood) (LRF)
170
195
220
245
270
295
320
345
370
395
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
SED inches
BF
lum
ber
/m3
log
13 15 18 20 23 25 28 30 33 36 38 41 43 46 48 51 53 56 58 61 64 66 69 71 74 76
SED cm
BF
lum
ber
/ft3 lo
g
Boards StudDimension Hardwood
4.8
5.4
6.0
6.6
7.2
7.8
8.4
9.0
9.6
10.2
10.8
Scribner Short Log Rule recovery by lumber product and log diameter
0.90
1.10
1.30
1.50
1.70
1.90
2.10
2.30
SED inches
BF
lum
ber
/BF
log
SED cm
Boards Studs
Dimension Hardw ood
Scribner Long Log Rule recovery by lumber product and log diameter
0.90
1.10
1.30
1.50
1.70
1.90
2.10
2.30
2.50
2.70
2.90
3.10
SED inches
BF
lum
ber
/BF
log
SED cm
Boards Studs
Dimension Hardw ood
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Small-end diameter
Per
cen
t o
f lo
g v
olu
me
log
e
Dry Chips
Shrinkage
Greenchips
Corevolume
Plywood
Plywood recovery by small-end diameter, product output scaled logs
2.00
2.50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
6.50
SED inches
Ft2 3/
8"/B
F lo
g
SED cm
Scribner SL Scribner LL
Doyle International 1/4"
Green chip sample = 922 gBone-dry sample = 497 g
497 ÷ 922 = 53.9% fiber.539 x 71,000 = 38,269 lbs
Lumber chip recoveryExample:#5 larch, 1”x 4”x 8’ = 13.44 bf per ft3 rough green
Target size is: 0.94” x 3.80” x 8’
•1000 ÷ 13.44 = 74.4 ft3 of lumber per MBF
• 74.4 ÷ 80.1 ft3 per BDU = 0.93 BDU/MBF
• 0.93 x $80/BDU = $74.40/MBF as chips