AGRICULTURAL ENGINEERING
HARMFUL FACTORS IN THE WORKPLACES OF TRACTOR DRIVERS
Ričardas Butkus, Gediminas Vasiliauskas
Aleksandras Stulginskis University, Lithuania
[email protected]; [email protected]
Abstract
Results of various studies show that the most prevailing risk factors on workers of agricultural sector are noise and
vibration. These hazards are especially important in transportation and most field works. Results from previous studies
show that vibro-acoustic environment in tractors operated in Lithuania usually cannot be attributed as acceptable, but
technical solutions implemented by manufacturers had definitely positive influence on working conditions. Noise
level reduced from 90 dB(A) (tractors of 1980 – 1990 years of manufacture) to 73 dB(A) (tractors manufactured from
year 2000). As renewal of tractors is not sufficient, there is still a large number of old machinery i.e. noise levels might
be as high as 92 dB(A) which allows to work safely only one hour per day without personal protection. It was found
that values of whole body vibration (WBV) during ploughing operation might be as high as 1.5 m∙s-2 which excess
the vibration limit value of 1.15 m·s-2, while hand-arm vibration (HAV) did not exceed the vibration action value
of 2.5 m·s-2. Significant effect of tyre pressure was noticed on vibration values measured on driver’s seat. Vibration
acceleration values may be reduced to safe 0.5 m·s-2 by selecting appropriate tyre pressure.
Key words: Tractor, noise, vibration, noise exposure, vibration exposure.
Introduction
Agriculture is attributed to one of the most
risky economic activity sectors. Large number of
occupational injuries and diseases are diagnosed to
operators of tractors and combine harvesters in various
countries. The most common risk factors in tractor
cabs are noise, vibration and dust. According to the
results obtained by Spirgys and Vilkevičius, 70% of
work accidents occur because of incorrect operators’
actions or inappropriate work organization. More than
70% of all occupational diseases are diagnosed to the
operators of various mobile machinery, which are
usually caused by high levels of noise and vibration
(Spirgys et al., 2008). Research findings provided by
Melemez & Tunay (2010) show that noise and vibration
levels at tractor cabs are mostly influenced by a tractor
type, exploitation duration and operating conditions.
Technical solutions used for cab noise insulation
and vibro-isolation as well as tyre pressure and soil
conditions are also influencing factors. Construction
of tractor cab depends mostly on technology, which
means that modern machinery offers better working
conditions (Melemez & Tunay, 2010). Futasuka
provides the results of 10 tea plucking machines and
their WBV effects on workers in Japan. 68.6% of
these workers have complaints manifesting as stiff
shoulders syndrome, while 31.4% are complaining
about backache (Futasuka et al., 1998).
Research results provided by Strelkauskis,
Merkevičius & Butkus (2012), reveal the fact that
WBV might be 1.38 times higher for used machinery
in comparison to modern tractors when driving on
gravel road at speed of 7.5 km∙h-1. Similar results
were also presented in the study of Starkus & Butkus
(2010) and Butkus & Vasiliauskas (2013), where they
found that noise levels in cabs of old tractors might
exceed the exposure action values. Their results
242
also revealed that noise levels might be as high as
95 dB(A) in tractors, manufactured around 1980.
Such machinery constitutes approx. 50% of tractors
operated in Lithuania.
The EU Directive 2003/10/EC regulates the
minimum health and safety requirements to workers
arising from noise. Limit values and exposure action
values in respect of the daily noise exposure levels
(LEX, 8h) and peak sound pressures (ppeak) are fixed at:
a) peak sound pressure (ppeak): maximum value of
the C-weighted instantaneous noise pressure;
b) daily noise exposure level (LEX,8h) for a nominal
eight-hour working day as defined by ISO 1999:2004;
c) weekly noise exposure level as a time-weighted
average of the daily exposure levels for 5 working
days.
The exposure limit values and exposure action
values in respect of the daily noise exposure levels
and peak sound pressure (LC,peak ) are fixed at:
• Exposure limit values: LEX,8h = 87 dB(A), ppeak
= 200 Pa, LC,peak = 140 dB(C);
• Upper exposure action values: LEX,8h =
85 dB(A), ppeak = 140 Pa, LC,peak = 137 dB(C);
• Lower exposure action values: LEX,8h =
80 dB(A), ppeak = 120 Pa, LC,peak =135 dB(C).
Vibration exposure values according to EU Directive
2002/44/EC (Directive 2002/44/EC, 2002) are as
follows:
Hand arm vibration:
• Exposure limit value (ELV) calculated for 8
hours: A(8)≤5 m∙s-2;
• Exposure action value (EAV) A(8)≤2.5 m∙s-2.
Whole body vibration:
• ELV: 1.15 m s-2 or vibration dose of 21 m∙s -1.75;
• EAV: 0.5 m s-2 or vibration dose of 9.1 m∙s -1.75.
Aim of the work was to investigate noise and
vibration levels in agricultural tractors and to
Research for Rural Development 2016, volume 1
pressure level (LA,eq), equivalent C-weighted sound pressure (LC,eq) and peak C-weighted sound pressure le
(LC,peak) were measured. Measurements were carried out in the tractors’ cabs when all doors and windows w
closed. Position of the measurement microphone was at the driver’s ear level approx. 100 mm from the
Tractor crankshaft rotation frequency was 1500 – 1800 min-1 and the driving speed was 7.5 km∙h-1. Noise
HARMFUL FACTORS IN THE
vibration
measurements were carried out on asphalt
paving,
while
detailed
analysis and noise expos
WORKPLACES OF TRACTOR DRIVERS
Ričardas
Butkus,
Gediminas
Vasiliauskas
calculations were done from the measurement results which were carried out on gravel paving and plough
operations. Duration of noise level measurements was at least 60 s and the measurements were repeated th
times. Results of noise levels are presented as arithmetic average and standard deviation. Noise exposure
determine exposurecalculated
levels and
provide safe work Bruel & Kjaer (B&K) type 4447 was used to perform
as follows:
recommendations.
the measurements.
LEX.8h=Hand-arm
LAeq.Te + 10vibration
lg(Te/T0),
dB(A)
was
measured on the steering
where:
L
–
equivalent
A-weighted
sound
pressure
level
exposure
duration
Te;
Aeq.Te
Materials and Methods
wheel. Accelerometer B&Kover
type
4524 was
placed
T
–
reference
duration
of
8
hrs.
0
Results obtained in this study were gathered by between the wheel and hand and fixed as required by
several stages. Tendencies
of noise to
level
derived
Weighted
values
of x, was calculated du
According
thewere
lower
exposureISO 5349.
value of 80
dB(A),average
durationacceleration
of particular
operation
from 30 agriculturalthe
tractors,
while vibration values y and z axis and total vibration acceleration value ah
work shift.
were collected from 10Vibration
tractors.measurements
All tractors were
werecabs
measured.
in tractor
were carried out according to the requirements of ISO 5349
manufactured over ISO
the 2631-1.
time period
1980
– 2013.
WBV
measurements
at driver‘s
were the measurements.
Human
vibration
meter Bruel
& Kjaer
(B&K) type 4447
was usedseat
to perform
Detailed measurements Hand-arm
of noise and
vibration
performed
by using
the seat-pad
with built
in type
triaxial
vibration
was were
measured
on the steering
wheel.
Accelerometer
B&K
4524 was placed betw
the wheel
and (three
hand and
fixed
as required
by ISO 5349.
acceleration
values of x, y and z
carried out in five wheeled
tractors
of them
were
accelerometer
B&K Weighted
type 4524.average
Vibration
acceleration
werevibration
measured.
andperiod
total vibration
valueawahand
made over 2006 – 2012
and two –acceleration
1988 – 1999)
dose value for eight working hours
WBV measurements
at driver‘s seat
performed
by using
the seat-pad
with built
which were: Massey Ferguson
6480 (manufactured
werewere
calculated
VDV(8).
Vibration
exposure
valuein triaxial accelerom
and
vibration
dose
value
for
eight
working
hours were calcula
B&K
type
4524.
Vibration
acceleration
a
w calculated as follows:
in 2008, 1900 moto hrs.), Claas Atles 926 RZ (2006, A(8) was
VDV(8).
Vibration
exposure
value
A(8)
was
calculated
as
follows:
2100 hrs.), Belarus 920.4 (2012, 860 hrs.), T–150K
V8 (1988, 6860 hrs.) and New Holland 8870 (1999,
1 n 2
9200 hrs.).
A(8) =
a wiTi ,
(2)
T0 i =1
Noise level measurements and exposure
calculations were where:
carried outawiaccording
the
– frequencytoweighted
acceleration average (RMS) during i–th operation;
requirements of international Tstandard
ISOof 9612.
i–th operation
in seconds;
i – duration
where:
a – frequency weighted acceleration
Noise level measurements inT0tractor
cabs duration
were in seconds wi(28 800s).
– work-shift
average (RMS) during i–th
done by using first class sound pressure level meter
operation;
Calculations
were
also
performed
according
to
equation
(2) in order to find the duration which should no
f the work was toDELTA OHM HD-2010.
investigate noise and vibration
levels in agricultural
to determine
Parameters,
such as tractors and
–
duration
of
i–th operation
seconds;
T
exceeded
in
order
to
have
the
A(8)
value
lower
than
vibration
action
value ofin0.5
m∙s-2.
evels and provide safe work recommendations.
i
continuous equivalent A-weighted sound pressure
– work-shift
seconds
(28 conditions but diffe
Whole body vibration measurements wereTalso
carried out duration
under theinsame
working
0
level (LA,eq), equivalent C-weighted sound pressure
800s).
tyre pressures. Tractors New Holland 8870 and
Belarus 920.4 were used for these measurements. Tyre pressu
and Methods
(LC,eq) and peak C-weighted
sound
pressure
level
were
reduced
from
2.6 bar to
bar level
in steps
ofderived
0.3 bar from
(7 cases in total). Measurements were carried ou
s obtained in this study
were gathered by
several
stages.
Tendencies
of0.8
noise
were
(L
)
were
measured.
Measurements
were
carried
Calculations
were
also performed
C,peak
uneven
gravelfrom
road10
and
repeated
times.
Parameter
VDV(8)
was used toaccording
assess thetoWBV and calculated
tural tractors, while vibration
values were
collected
tractors.
Allthree
tractors
were
manufactured
out
in
the
tractors’
cabs
when
all
doors
and
windows
equation
(2)
in
order
to
find
the
duration
which
should
follows: of noise and vibration were carried out in five wheeled
me period 1980 – 2013. Detailed measurements
were
closed.
Position
of
the
measurement
microphone
not
be
exceeded
in
order
to
have
the
A(8)
value
lower
hree of them were made over 2006 – 2012 period and two – 1988 – 1999) which were: Massey
4
-2
was
at
the
driver’s
ear
level
approx.
100
mm
from
than
vibration
action
value
of
0.5
m∙s
.
6480 (manufactured in 2008, 1900 moto hrs.), Claas Atles 926 RZ (2006, 2100 hrs.),
Belarus
∑ awi,
eq,8h T920.4
i
4
VDV(8)
, mmeasurements
⋅ s-1.75
ear.6860
Tractor
rotation8870
frequency
was
Whole body vibration
were also
0 hrs.), T–150K V8 the
(1988,
hrs.) crankshaft
and New Holland
(1999, 9200
hrs.). =
8
-1
1800 min
and the driving
speed out
wasaccording
7.5 carried
level measurements1500
and –exposure
calculations
were carried
to the
of working conditions but
outrequirements
under the same
acceleration average (RMS) during i–th operation;
-1
wi – frequency weighted
km∙hNoise
. Noise
and where:
vibration inameasurements
were
nal standard ISO 9612.
level measurements
tractor cabs were
donedifferent
by usingtyre
firstpressures.
class sound
Tractors New Holland 8870
T
–
duration
of
i–th
operation
in seconds;
i
on asphalt
paving, while
analysisequivalent
evel meter DELTAcarried
OHM out
HD-2010.
Parameters,
such detailed
as continuous
A-weighted
sound
and
Belarus
920.4
were
used
for these measurements.
T0 –were
work-shift
duration in seconds (28 800s).
and C-weighted
noise exposure
done
soundcalculations
pressure (L
peakfrom
C-weighted
sound pressure
level from 2.6 bar to 0.8 bar
evel (LA,eq), equivalent
C,eq) and
Tyre pressures
were reduced
the measurement
resultsVibration
carried
out
ere measured. Measurements
were carried
outwhich
in thewere
tractors’
when
allindoors
and
windows
dose
was cabs
used
as on
estimate
of vibration
as it(7iswere
more sensitive
the peaks in the acceleration lev
steps
of 0.3
bar
cases
in total). toMeasurements
sition of the measurement
microphone
was at the
driver’s Duration
ear level of
approx.
mm from
ear. gravel road and repeated
gravel paving
and ploughing
operations.
were100
carried
out onthe
uneven
-1
and
the60driving
km∙h
. Noise VDV(8)
and
ankshaft rotation frequency
wasmeasurements
1500 –Results
1800 was
min
noise level
least
s and speed
the was
and-1atDiscussion
three7.5
times.
Parameter
was used to assess the
measurements were
carried out were
on asphalt
paving,
while Results
detailedofanalysis
noise exposure
measurements
repeated
three times.
WBV and
and calculated
as follows:
ns were done from noise
the measurement
results which
were carried
out and
on gravel paving and ploughing
levels are presented
as arithmetic
average
. Duration of noisestandard
level measurements
was
at
least
60
s
and
the
measurements
were repeated three
deviation. Noise exposure was calculated as
ults of noise levelsfollows:
are presented as arithmetic average and standard deviation. Noise exposure was
(3)
as follows:
Σ
(1)
LEX.8h= LAeq.Te + 10 lg(Te/T0), dB(A)
(1)
awi – frequency weighted acceleration
LAeq.Te – equivalent A-weighted sound pressure level over exposure durationwhere:
Te;
average (RMS) during i–th
T0 – reference duration of 8 hrs.
where: LAeq.Te – equivalent A-weighted sound pressure
operation;
ding to the lower exposure value level
of 80over
dB(A),
duration
of particular
operation was calculated
during
exposure
duration
Te;
Ti – duration
of i–th operation in seconds;
hift.
T0 – reference duration of 8 hrs.
T0 – work-shift duration in seconds (28
on measurements in tractor cabs were carried out according to the requirements of800s).
ISO 5349 and
1. Human vibration meter
Bruel & to
Kjaer
4447 was
used
According
the (B&K)
lower type
exposure
value
of to80perform the measurements.
arm vibration was measured
on the steering
wheel.
Accelerometer
B&K type 4524
was placed
dB(A), duration
of particular
operation
was calculated
Vibration
dosebetween
was used as estimate of vibration
and hand and fixedduring
as required
by ISO
values of x, y and z axis
the work
shift.5349. Weighted average acceleration
as it is more sensitive to the peaks in the acceleration
measured.
ibration acceleration value
ah weremeasurements
Vibration
in tractor cabs were levels.
measurements at driver‘s
performed
the seat-pad
carriedseat
outwere
according
to by
theusing
requirements
of with
ISO built in triaxial accelerometer
dose value
for eight
working hours were calculated
e 4524. Vibration acceleration
w and vibration
5349 and aISO 2631-1.
Human
vibration
meter
Vibration exposure value A(8) was calculated as follows:
A(8) =
1
T0
n
Σa
i =1
2
wi i ,
T
Research
for Rural
Development
awi – frequency weighted
acceleration
average
(RMS) during2016,
i–th volume
operation;1
Ti – duration of i–th operation in seconds;
T0 – work-shift duration in seconds (28 800s).
(2)
243
HARMFUL FACTORS IN THE
WORKPLACES OF TRACTOR DRIVERS
Ričardas Butkus, Gediminas Vasiliauskas
Equivalent A-weighted sound pressure (LA,eq) and C-weighted peak (LC,peak) levels of 30 tractors were divided
into three categories by manufacturing year. Tendencies in noise levels are shown in Figure 1.
120
LA, eq
Sound presure level dB
110
Lc, peak
y = -10.3x + 123.77
R² = 0.90
100
90
80
70
y = -9.7x + 99.3
R² = 0.89
60
50
40
1 (1980–1990)
2 (1991–2000)
3 (2001–2013)
Period
Equivalent
A-weighted
pressure
and C-weighted
(LC,peak
) levels
of 30
tractors
were
divided
Equivalent
A-weighted
soundsound
pressure
(LA,eq(L
) and
peakpeak
(LC,peak
) levels
of 30
tractors
were
divided
A,eq) C-weighted
into categories
three categories
by manufacturing
year.
Tendencies
in noise
levels
are
shown
in Figure
1.
into three
by
manufacturing
year.
Tendencies
in
noise
levels
are
shown
in
Figure
1.
Figure 1.
1. Tendencies
Tendenciesof
ofLLA,eqand
andLLC,peaksound
soundpressure
pressurelevels
levelsaccording
accordingtotomanufacturing
manufacturingyear.
year.
Figure
A,eq
C,peak
120 120
Acceleration, m·s-2
Sound presure level, dB
Sound presure level, dB
Acceleration, m·s-2
Sound presure level, dB
Sound presure level dB
Sound presure level dB
As shown in Figure 1, technical modernization and manufacturingLA,
quality
had
LA,
Lc,
peak influence on noise
eq eq
Lc,significant
peak
110 92 dB(A) (manufacturing period of 1980 – 1990)
110from
levels
which
reduced
to
73
dB(A)
period
Results
and
Discussion
or to use hearing protection. (manufacturing
Exposure durations
y
=
-10.3x
+
123.77
of 1991
– 2000). A-weighted
These
results
were
obtained
by
using
the
methodology,which
complies
with
the
requirements
of
100
Equivalent
sound
pressure
(L
)
and
y = -10.3xA,eq
+ 123.77 to reach the exposure of 80 dB(A) for five different
100
R²
=were
0.90 tractors are presented in Table 1.
EUC-weighted
Directive 2009/76/EC.
R²
=
0.90
peak (LC,peak
)
levels
of
30
tractors
90 90LA,eq and LC,peak are presented in Figure 2 for ploughing and transportation (on gravel
Measured
divided
intonoise
threelevels
categories by manufacturing year.
Average WBV and HAV acceleration values are
80
paving).
Maximum
A-weighted
registered
as high
as 92.3
80
Tendencies
in noise
levels are SPL
shown
in Figurein1.tractors was
shown
in Figure
3. dB(A) in transport and 89.7 dB(A)
when As
ploughing.
This
means
8 hour modernization
exposure would exceed
the
exposure
value of 87values
dB(A).changed
Lowest
70 1,that
shown in
Figure
technical
Hand-arm
acceleration
y = -9.7xvibration
+ 99.3 limit
70
y = -9.7x
+ 99.3
noise
were found
74.2 dB(A)
in transport
operations
and
71.5
dB(A)
in
ploughing.
Considering
the
-2
-2
R²
=
0.89
and levels
manufacturing
quality
had
significant
influence
from 0.81 m·s
to 2.28 m·s and did not exceed fact,
the
60
R² = 0.89
not60which
exceed reduced
80 dB(A)from
it is recommended
to shorten
work
duration
or to use hearing
protection.
that
onLEX,8h
noiseshould
levels
92 dB(A) action
value of 2.5
m·s-2. Maximum
WBV acceleration
50 the exposure of 80 dB(A) for five different tractors
Exposure
durationsperiod
to reach
presented
Table 1.lower in
50
(manufacturing
of 1980 – 1990) to 73 dB(A) value was 1.4 m·s-2,are
while
it wasinslightly
40 1991 – 2000). These results other cabs. Special attention must be given to if the
(manufacturing period
40 of110
were obtained by using the1 (1980–1990)
methodology,which 2 work
duration is full3 work
shift, i.e. 8 hours. This
(1991–2000)
(2001–2013)
1 (1980–1990)
2 (1991–2000)
(2001–2013)
100
Period
complies with the requirements
of EU Directive
would exceed the3vibration
action value of 0.5 m·s-2
Period
2009/76/EC.Figure 1.Tendencies
and in 2levels
tractors
wouldtoexceed
vibrationyear.
limit value
90
according
manufacturing
of LA,eqand LC,peaksound pressure
-2
Measured
noise levels LA,eq
of 1.15
m·s
and in one
tractor exposure
level close to
and
L are presented
sound pressure
levels
according
to manufacturing
year.
Figure 1.Tendencies
of Land
A,eqL
C,peak C,peak
As shown
in Figure
1,80
technical
modernization (on
and manufacturing
quality
significant
influence
on noise
in Figure
2 for
ploughing
and transportation
1.15 m·s-2. Values
ofhad
vibration
exposure
are presented
Aslevels
shown
in Figure
1, technical
modernization
and manufacturing
quality had
significant
influence on noise
which
reduced
fromA-weighted
92 dB(A)
(manufacturing
of
1980–1990)
to
73
dB(A)
(manufacturing
period
gravel paving).
Maximum
SPL registeredperiod
in Table 1 and these results show that noise exposure
levels of
which
reduced These
from 92
dB(A)
(manufacturing
period
1980–1990) to 73complies
dB(A) (manufacturing
period of
1991–2000).
results
wereobtained
by using
the of
methodology,which
with
the
requirements
70
in
tractors
was
as
high
as
92.3
dB(A)
in
transport
and
action value of 80
dB(A) or
vibration
action value
of 1991–2000).
These
results wereobtained by using the methodology,which
complies
with
the requirements
of of
EU Directive
2009/76/EC.
-2
89.7 dB(A)
when
ploughing.
This
means
that
8
hour
0.5
m∙s
is
reached
over
1
or
2
hours
of
operation
when
EU Directive
2009/76/EC.
LA,areeqpresented
Lc, peak
LA, 2for
eq ploughing
Lc, peak and transportation (on gravel
in Figure
Measured
noise levels60LA,eqand LC,peak
exposure noise
wouldlevels
exceed
value in
of Figure
used old
tractors are exploited.
andexposure
LC,peak
arelimit
presented
2for
transportation
(on graveland
Measured
LA,eqthe
paving). Maximum
A-weighted
SPL
registered
in tractors
was ploughing
as high asand
92.3
dB(A) in transport
87
dB(A).
Lowest
noise
levels
were
found
74.2
dB(A)
Noise
exposure
might
be
reduced
to
acceptable
50
paving).
Maximum
A-weighted
SPL
registered
in
tractors
was
as
high
as
92.3
dB(A)
in
transport
and
89.7 dB(A)when ploughing. This means that 8 hour exposure would exceed the exposure limit value
of 87
Ploughing
Transport
indB(A).
transport
operations
71.5
dB(A)
levelwould
by transport
using the
personal
protection,
89.7 dB(A)when
ploughing.
This
means
8ploughing.
hour74.2
exposure
exceed
exposure
limit
of 87
Lowest
noiseand
levels
werethatin
found
dB(A)
in
operations
and value
71.5meanwhile
dB(A)in
Considering
the
that
Lwere
should
exceed
reduction
of vibration
and its and
effects71.5
operators
is
dB(A).
Lowest Figure
noisefact,
found
74.2
in transport
dB(A)in
should
not
exceed
80
itoperations
isand
recommended
toonshorten
work
ploughing.Considering
theand
fact,
that
LEX,8hnot
EX,8h
LC,peak
noise
levels
indB(A)
tractor
cabs
for dB(A)
ploughing
transportation.
2. levels
LA,eq
80
dB(A)
it
is
recommended
to
shorten
work
duration
complicated.
the of
most
and
practicable
duration or to use the
hearing
durations
to80
reach
theOne
exposure
80 effective
dB(A)
five
different
should not
exceed
dB(A)
it
isofrecommended
to for
shorten
work
ploughing.Considering
fact,protection.
that LEX,8hExposure
Average
WBV
and HAV
acceleration
values
are shown
in Figure
tractors
presented
in
Table
1. Exposure
duration
or toare
use
hearing
protection.
durations
to reach
the 3.
exposure of 80 dB(A) for five different
tractors are presented in Table 1.110
5
2.0
WBV
HAV
110
WBV
HAV
100
4
1.5
100
90
3
90
1.0
80
2
80 70
0.5
1
70 60
0
0.0
60 50 a)
b)
Ploughing
Transport
Figure 3. Average values
50of WBV and HAV in tractor cabs when driving on gravel road (a) and ploughing (b).
Ploughing
Transport
LA,
eq levels
Lc, in
peak
LA,
eqfor-2ploughing
Lc, peak and
noise
tractor0.81
cabsm·s
Figure
2.
LA,eqand LC,peak
-2 transportation.
Hand-arm vibration acceleration
values
changed
from
to 2.28 m·s
and did not exceed the action
4
4
3 WBV
3
2
2
1
HAV
HAV
cceleration, m·s-2
WBV
5
ration, m·s-2
cceleration, m·s-2
244
ration, m·s-2
-2
-2
.2.Maximum
acceleration
value
was
whileand
it was
slightly
lower in other cabs.
value of
2.5Figure
m·s
AverageWBV
and
values
in1.4
Figure
and and
LWBV
noise
levels
inare
tractor
cabs
form·s
ploughing
transportation.
L2.
A,eq
C,peak
Figure
LHAVacceleration
LC,peak
noise
levels
inshown
tractor
cabs
for3.,ploughing
and
transportation.
A,eq
AverageWBV and HAVacceleration
values are shown in Figure
3.
5
2,0
2,0 1,5
WBV
HAV
Research for
Rural
Development 2016, volume 1
WBV
HAV
1,5 1,0
1,0 0,5
So
60
LA, eq
Lc, peak
LA, eq
Lc, peak
50
Ploughing
Transport
HARMFUL FACTORS IN THE
WORKPLACES
OF2.TRACTOR
Ričardas Butkus, Gediminas Vasiliauskas
Figure
LA,eq and LDRIVERS
C,peak noise levels in tractor cabs for ploughing and transportation.
Average WBV and HAV acceleration values are shown in Figure 3.
4
WBV
2.0
HAV
Acceleration, m·s-2
Acceleration, m·s-2
5
WBV
HAV
1.5
3
1.0
2
0.5
1
0
0.0
a)
b)
Figure 3. Average values of WBV and HAV in tractor cabs when driving on gravel road (a) and ploughing (b).
Figure 3. Average values of WBV and HAV in tractor cabs when driving on
Hand-arm vibration acceleration values
changed
m·s-2 to
2.28 m·s-2 and did not exceed the action
gravel
road (a)from
and0.81
ploughing
(b).
-2
-2
value of 2.5 m·s . Maximum WBV acceleration value was 1.4 m·s , while it was slightly lower in other cabs.
Table 1
Durations to reach exposure lower value of noise and action value of vibration (LA, eq / aw) in ploughing
Tractor
1
2
3
4
5
LA, eq / aw
74 / 1.12
72 / 0.96
72 / 1.25
90 / 0.99
83 / 1.48
t, H:MM
>8:00 / 1:30
>8:00 / 2:10
>8:00 / 1:18
0:48 / 2:00
4:00 / 0:55
solutions might be tyre pressure reduction. Vibration
acceleration values and time history (passing the same
distance and time of 40 s) of acceleration values at
different tyre pressures (2.6 and 0.8 bar) are presented
in Figure 5.
As seen in Figures 4 and 5, tyre pressure decrease
has a significant effect on vibration values, which
might decrease by 0.5 m∙s-2 when comparing the case
1 (2.6 bar) and 7 (0.8 bar). Vibration dose VDV(8)
analysis show similar results, as vibration dose
reduced from 43.8 m∙s-1.75 to 25.1 m∙s-1.75 and from
28.5 m∙s-1.75 to 19.0 m∙s-1.75 respectively for different
test objects.
Results presented in this study clearly show the
necessity to perform risk assessment arising from
noise and vibration in the workplaces of machine
operators. Farmers should also consider either the use
of personal protection or any organizational changes
in order to reduce the negative effects of noise and
vibration in agriculture.
Conclusions
1. Results of noise measurement in tractor cabs
of different manufacturing year revealed that
technical development of tractor cabs had a
significant effect on noise level, which decreased
Figure 4. Time history of whole body vibration acceleration values at different tyre pressures
(peak Max is the above curve in all cases).
Research for Rural Development 2016, volume 1
245
Figure 4. Time history of whole body vibration acceleration values at different tyre pressures
(peak Max is the above curve in all cases).
2.0
50
y = -0.0857x + 1.9266
R² = 0.95
1.8
1.6
WBV, VDV(8), m·s -1,75
WBV acceleration, m·s-2
As seen in Figures 4 and 5, tyre pressure decrease has a significant effect on vibration
values,FACTORS
which might
HARMFUL
IN THE
decrease by 0.5 m∙s-2 when comparing the case 1 (2.6 bar) and 7 (0.8 bar). Vibration dose VDV(8) analysis show
Ričardas Butkus, Gediminas Vasiliauskas
TRACTOR DRIVERS
-1.75
-1.75WORKPLACES OF
-1.75
-1.75
to 25.1 m∙s
and from 28.5 m∙s
to 19.0 m∙s
similar results, as vibration dose reduced from 43.8 m∙s
respectively for different test objects.
1.4
1.2
1.0
0.8
Tractor 1
Tractor 2
0.6
0.4
y = -0.0579x + 1.3843
R² = 0.89
1
2
3
4
5
6
7
Tyre pressure variant
45
y = -2.5062x + 41.888
R² = 0.79
40
35
30
25
20
10
y = -1.3478x + 28.572
R² = 0.89
Tractor 1
Tractor 2
15
1
2
3
4
5
6
7
Tyre pressure variant
b)
a)
Figure 5. Dependence of WBV acceleration (a) and dose (b) to tyre pressure.
Figure 5. Dependence of WBV acceleration (a) and dose (b) to tyre pressure.
from 90 dB(A) (manufacturing year 1980 – 1990)
to 73 dB(A) for newer machinery (the year 2000
and later).
2. Noise measurement results carried out in the
cabs of tractors Massey Ferguson 6480, Claas
Atles 926 RZ, T–150K, Belarus 920.4 and New
Holland 8870 during ploughing and transportation
operations show that noise levels were in the range
from 71.5 dB(A) to 92.3 dB(A). Safe working
conditions with exposure value of less than 80
dB(A) are satisfying when working duration is
30 min (when LA,eq=92 dB(A)) and 4 hrs. (when
LA,eq=83 dB(A)).
3. Results of whole body vibration measurements
during ploughing operations show that vibration
acceleration values varied from 0.96 m·s-2 to
1.48 m·s-2, which means that action value of
0.5 m·s-2 was exceeded in all tractors when work
shift duration is 8 hours. Exposure limit value of
1.15 m·s-2 was exceeded in two tractors. Hand-arm
vibration action value was not exceeded in any
case.
4. Tyre pressure decrease from 2.6 to 0.8 bar
significantly influence whole body vibration,
which was reduced on average by 0.5 m·s-2 while
vibration dose value was reduced by one third.
References
1. Butkus, R., & Vasiliauskas, G. (2013). Research of vibro-acoustic environment in cabs of agricultural
tractors: International conference Engineering for Rural Development, 23-24 May 2013 (pp. 20-26),
Jelgava, Latvia.
2. Directive 2003/10/EC of the European Parliament and of the Council of 6 February 2003 ‘On the minimum
health and safety requirements regarding the exposure of workers to the risks arising from physical agents
(noise)’ (Seventeenth individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC)
// OJ, 2003, L 42/38.
3. Directive 2002/44/EC of the European Parliament and of the Council of 25 June 2002 ‘On the minimum
health and safety requirements regarding the exposure of workers to the risks arising from physical agents
(vibration)’ (sixteenth individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC)
// OJ, 2002, L 177/13.
4. Futatsuka, M., Maeda, S., Inaoka, T., Nagano, M., Shono, M., & Miyakita, T. (1998). Whole – body
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5. International Organization for Standardization. (2001). International standard: Mechanical vibration Measurement and evaluation of human exposure to hand-transmitted vibration - Part 1: General
requirements. ISO 5349-1:2001.
6. International Organization for Standardization. (2001). International standard: Mechanical vibration Measurement and evaluation of human exposure to hand-transmitted vibration - Part 2: Practical guidance
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7. International Organization for Standardization. (2001). International standard: Mechanical vibration and
shock - Evaluation of human exposure to whole-body vibration - Part 1: General requirements. ISO 26311:1997/Amd.1:2010.
8. International Organization for Standardization. (2009). International standard: Acoustics - Determination
of occupational noise exposure - Engineering method. ISO 9612:2009.
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HARMFUL FACTORS IN THE
WORKPLACES OF TRACTOR DRIVERS
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9. Memelez, K., & Tunay, M. (2010). The investigation of the ergonomic aspects of the noise caused by
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10. Spirgys, A., & Vilkevičius, G. (2014). Mobilios žemės ūkio technikos naudojimo saugos problemų analizė
ir jų sprendimo būdai (Safety problems and their analysis and solutions in mobile agricultural machinery).
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