MECHANIZED PROCESSING OF BIG BROADLEAVED CROWNS
AN OPERATIONAL REALITY
P. Ruch, X. Montagny, A. Bouvet (FCBA) E. Ulrich, P. George (ONF)
FORMEC 2016, Warsaw, Poland 7th September 2016
Crown mechanization: a challenge!
2
Motor-manual workforce Demand of biomass Invasion of irritating caterpillars (Thaumetopoea
processionnea) in Moselle human health problems
3
Crowns: a source of additional biomass Important resource in public forests: 17 500 ha/year in 3 regions => 247 000 – 411 000 m3/year (oak and beech)
Last thinnings
Regeneration cuttings (3 progressive regeneration cuttings and
final clear cutting)
Specifications of the logging system
4
Capable of processing the crowns from the permanent corridors while preserving the remaining trees and the regeneration
Efficient whatever crown’s morphology, reliable and cost-effective
Operated from an enclosed cab
5
The logging systems tested
Single machine system
Two machines system
Case studies : 2 forwarders, 5 logging sites, 2013/2014
Case studies : 1 excavator + 1 forwarder, 2 logging sites, 2015
Grapple saw
weight scale on the boom
Single machine system
6
HSM 208F 12 T + Compactor
Valmet 801 Combi 13 T
• Crane 10 m + grapple saw+ weight scale • Enclosed cab with air filtration • 8 wheeled machine with flat tiles tracks
Two machines system
7
Excavator TEREX TCX 125 Ponsse Gazelle 10 T
• Crane 5,9 m • Grapple saw
• Crane 10 m • Boom scale
Single machine system
8
Content of the case studies Time studies on a sample of cycles (from 5 to
18 forwarding cycles by site, total 73 cycles) Work step recorded every 15 seconds (Instant
Observations method) Moving empty Processing : moving out the boom, preparation of
the crown, crosscutting… Loading and moving from one crown to another Moving back with load to the landing area Unloading
9
Characteristics of the 7 logging sites
10
FEN-P054FEN-P076
FEN-P191
FEN-P083
SAN-P194
CHA-P185
RAN-P5
0
20
40
60
80
100
120
0 20 40 60 80 100
Ha
rve
st t
on
s/h
a
Density of remaining trees (DBH ≥40 cm), N/ha
Regeneration cuttings Last thinnings
Triangles = HSM, Scares = Valmet, Circles = 2 machines system. Fresh tons
Characteristics of the crowns
73 forwarding cycles for 276 crowns (522 tons)
11 Mean and confidence interval of 95%
Results
Lesson 1 Machines equipped with grapple saw were able to process all crowns
Lesson 2 The distance between the corridors and the crane’s capacity are key factors
Lesson 3 Using a crane preserves the remaining trees and/or the regeneration
12
Results: machines suited for the processing of the crowns!
Productivity: main determinants (1/5) Lesson 4 The forwarding distance influences forwarder’s
productivity
13 But distance is not the only criteria…
4
6
8
10
12
14
16
18
20
0 250 500 750 1000
Pro
du
ctiv
ity
t/p
mh
Forwarding distance (m)FEN-P076 FEN-P054 CHA-P185
Lesson 5 The high expansion rate of crowns hinders the overall transported tonnage…
14 … whereas the compactor increases loading rate
0%
20%
40%
60%
80%
100%
120%
140%
160%
Load
ing
rate
SAN-P194 RAN-P5
Gazelle 10_S
FEN-P076 FEN-P054 FEN-P083FEN-P191
COMBI_13_S HSM F12_S HSM F12_CCHA-P185
Loading rate = mean load/theoretical load capacity
Productivity: main determinants (2/5)
15
Lesson 6 Time consumption for processing crowns is the lowest for the single machine system
Productivity: main determinants (3/5)
0
100
200
300
400
500
600
700
800
SAN-P194 FEN-P076 FEN-P054 FEN-P083 FEN-P191 CHA-P185 RAN-P5
s/t
Unloading
On load moving
Processing + loading
Loading
Slash processing
Processing
Moving empty
2 machines systemSingle machine system about 600 to 700
s/t for the 2 machines system, (global productivity of the whole system of 5.1 à 6.2 t/pmh)
200 to almost 400 s/t for the single machine system (9.7 up to 17.8 t/pmh)
Time consumption for a fresh ton
16
Lesson 7 Productive working time is proportional to number of saw cuts
Processing time (for the single machine system loading is included) and number of saw cuts Correlation coefficient (Pearson, r) = 0.92; p < 0.0001.
Productivity: main determinants (4/5)
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 5 10 15 20 25 30 35 40 45
Pro
cess
ing
tim
e (
s)
Number of saw cuts
SAN-P194
FEN-P076
FEN-P054
FEN-P083
FEN-P191
CHA-P185
RAN-P005
17
Lesson 8 Additional processing of the slash hinders productivity
Productivity: main determinants (5/5)
Lesson 9 The higher the crop per ha, the better the productivity of the operation
7% of the working time for RAN-P5
and up to 21% for CHA-P185
Extracting costs
18
FEN-P054
FEN-P191
FEN-P083
SAN-P194FEN-P076
0
2
4
6
8
10
12
14
16
18
6 7 8 9 10 11 12 13
Tech
nic
al c
ost
€/t
Mean productivity t/h
60% 70% 80%
Single machine system, the technical costs vary between 7.6 and 14 €/ton Two machines system, the technical cost of the excavator varies from 12.8 to 16 €/ton + forwarder’s technical costs are about 7.3 €/ton => 20.1 €/ton to 23.3 €/ton
Conclusion
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The full mechanization of large broadleaved crowns is an operational reality and has been facilitated by the development of wood energy
The grapple saw has proven to be an efficient and easy to use tool, in addition to being a small investment for the entrepreneur
The single machine system, a forwarder equipped with a grapple saw, is the best performing system
An asset of the 2 machines system (excavator with grapple saw and forwarder) is the capacity to separate the operations in time
This study contributed to highlighting the various factors which influence the productivity of the systems
Thank you for your attention!
Contact: [email protected]