United States
Department of
Agriculture
Forest
Service
Ochoco
National Forest
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3160 NE Third Street
P.O. Box 490
Prineville, OR 97754
(541) 416-6500
Date: 4/23/04
2550
CRNG
John Deere Timberjack Demo- Preliminary Soils Discussion
Kristin Bail – Crooked River National Grasslands District Ranger
The purpose of this memo is to discuss preliminary observations of the John Deere Timberjack
Bundler. This machine was demonstrated on the Crooked River National Grasslands on 9/24/03
on dried western juniper trees which had been hand felled.
Equipment Specifications: this machine has a 30 foot boom, 8 large rubber tires with a width of
2.5 feet (30 inches). This machine has a 10 pounds per square inch ground pressure which is
average for rubber tired type logging equipment.
Size of bundles: approximately 8 to 10 feet with an approximate dry weight of 500 pounds.
Retrieval of Bundles: would have to be picked up by a truck or forwarder. The John Deere
forwarder can stack 15 on a load.
Condition of Juniper Slash: this slash was dry. The bundler can draw the material in better
when wet because the material is more flexible. On other commercial type timber slash the
Timberjack worked better on delimber pile slash than on tractor piled slash.
Ground Limitations: can negotiate 45 percent slopes straight up and down slope. The JD
bundler does not weigh as much as comparable forwarder.
Production Rate: can produce a bundle every one to two minutes. In light juniper concentrations
can do an acre in less than two hours. At a minimum of 15 tons/acre the JD Timberjack can be
competitive with grapple piling.
Cost: $120 dollars per acre minimum to run. In comparison, this is the average cost of fire
suppression per acre. Grapple piling is similar to this minimum cost.
Soil Disturbance Discussion: the John Deere Timberjack bundler is similar to standard
forwarder/processor type machinery in terms of overall projected soil disturbance levels. The
Timberjack bundler would be traveling on roughly a 60 foot skid trail pattern for a single pass
with a forwarder or tractor and truck picking up the bundles for another pass.
Disturbance Calculations: For a given acre with trails at 60 feet apart the number of trails
comes out to 3.5. Each trail has two tire tracks at 2.5 feet wide which gives 5 feet of
disturbed ground per trail. 3.5 trails/acre X 5 feet total width of tires/trail X 209 feet/ac
length = 3657.5 square feet/acre. This equals ( 3657.5 sq/ft/ac divided by 43,681 sq/ft/ac
total) = 8.4 percent disturbance per acre due to this treatment.
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Assumptions: If traffic is kept to two passes or less (one for the Timberjack bundler and
one for a forwarder) then compaction is assumed to be non-detrimental since it is less
than 3 to 5 passes. If a tractor and truck are used to load the bundles then the number of
passes are assumed to be greater (3 to 5). The compaction is assumed to be detrimental
in the case of multiple passes (detrimental compaction is defined as a 15 percent increase
in bulk density for residual soils and a 20 percent increase in bulk density for ash soils.
R6 Supplement 2500-98-1; 1998).
Detrimental disturbance (defined as the removal of more than 50 percent of the A horizon
from an area greater than 100 square feet, which is a least 5 feet in width. Et al, R6
Supplement; 1998) was not observed in this trial on flat ground.
A soil pit was excavated on this CRNG site to help evaluate site conditions:
Location: T13S,R14E, Section 23 to the east of Hwy 26. This was mapped as the Lamonta
series (map unit LaC, Lamonta loam from Soil Survey of Trout-Creek Shaniko Area, 1970)
which is classified as a fine, smectitic, mesic Abruptic Argiduric Durixeroll. This pedon fits this
general series concept.
Horizon
A1
A2
2Bt1
Depth
(inches)
0 to 1.5
1.5 to 4
4 to 10
texture
Ashy sandy loam
Ashy sandy loam
Gravelly clay loam
Clay
%
12
14
27
structure
Roots
3 vfine-fine
3 vfine-fine
2 vfine-fine
50
m. fine platy
2 f-m sbk
2f-m sbk//abk
3m-co prism.
2Bt2
10 to 16
clay
2Bt3
16 to 18
Gravelly clay
40
3f-m abk
Btqm
18 to 21
Mod cemented
duripan
R
21+
few vfinefine
Few vfinefine
Field
pH
6.6
6.6
6.4
6.2
6.2
3m-k platy
Interpretations: These type of soils are most susceptible to detrimental compaction and
displacement in the ashy A horizons and 2Bt1 horizons. The smectitic clay subsoils will shrink
and swell with annual wetting and drying and are not very susceptible to compaction. The key
here is to maintain the ash capping in place to avoid reducing site productivity. Annual freeze
and thaw cycles help to decompact the A horizons.
Regional Standards and Guidelines Compliance:
Assuming less than 3 passes: meets Regional Standards and Guidelines ( Et al, R6 Supplement;
1998) of designing activities to minimize detrimental soils disturbance and stay below the 20
percent level.
Trails: 2 percent (assuming some main trails are going to be over 15% increase)
Roads: 1.5 to 2 percent
Strorage/Loading of bundles: 1 percent
Total 4.5 to 5 percent
Assuming 3 or more passes: meets Regional Standards and Guidelines of staying below the 20
percent detrimental soil conditions level.
Trails: 8 to 9 percent
Roads: 1.5 to 2 percent
Storage/Loading for bundles: 1 percent
Total 10.5 to 12 percent
Looking at these preliminary figures and assumptions it appears that both scenarios will meet
Regional Standards and Guidelines for detrimental soil conditions.
If you have any further questions please e-mail or call me.
Jim David
Forest Soil Scientist