Productivity and physical workload of cutting crews in sao hill softwood plantations
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Date
1996
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine University of Agriculture
Abstract
Physical
workload
and
cutting
of
productivity
two-man
raker and peg toothed saws were compared when clearfelling
a
Pinus
elliottii
compartment
in
Sao
Hill
forest
plantation. Three logging crews working with the two types
of saw were studied between July and October 1990. Heart
rate data was collected after every 30 seconds using a
SPORT TESTER while maximum aerobic power was estimated
using sub-maximal tests on a cycle ergometer respectively.
A total of 1271 trees with an average Dbh of 25 cm were
felled and bucked into logs. Analysis of the data revealed
that:
(a)
Effective
cutting
time
when
using
raker
and
peg
toothed saws were 8.8 and 9.6 min/tree respectively.
For a 7 hour workday only about 4.7 hours were spent
for productive work.
(b)
Raker-toothed
saws
had
higher
rates than peg-toothed saws.
cutting
production
Production rates
raker and peg- toothed saws ranged from 3.25
for
3.6
and 2.98 - 3.16 m3/crew - h respectively.
(c)
The heart rates of the workers during effective
cutting time were 112 - 117 and 115 - 118 beats/minIll
when using raker and peg-toothed saws respectively.
Maximum aerobic power of the workers averaged 2.54
1/min ranging from 2.37 to 2.74 1/min.
(d)
Oxygen consumption rate was on the average 1.23 1/min
ranging from 1.11
1.30 1/min when using raker-
toothed saws. The demand averaged 1.28 1/min with
peg-toothed saws ranging from 1.14 - 1.38 1/min. Thus
energy demand when using peg-toothed saws was about
28% higher than for raker-toothed saw cutting. This
indicated that raker- toothed saws could be a better
choice for cutting operation.
(e)
Physical workload on the workers when cutting using
the
two
types
differences.
of
saws
showed
no
significant
The workload indices during effective
cutting time using raker and peg-toothed saws were
43.7
52.6 % and 44.8
53.6% respectively. This
showed that the cutting operation was a moderate
energy demanding job.
Description
Keywords
Softwood plantations, Cutting crews, Sao hill