OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
Table 1. Anthropometric Data of workers
Classifications Age Weight Height
Range 22-26 56-65 160-165
Mean 24 60.5 162.5
2.2 Experimental apparatus:
COSMED pulmonary function equipment Fitmate Pro was used to measure the heart rate. This equipment
consists of a POLAR heart rate belt for measuring the Heart rate (beats per minute). When belt was put around
the chest of the subject and one end of a probe for transferring the signal from human heart to machine was
attached to body of worker and other end was connected to the main unit and it produces a variation in heart rate
with respect to time. The test was conducted of three different heights 1= floor to knee height. 2= floor to waist
height, 3=floor to shoulder height. Three different size boxes were made (description of the boxes are shown in
the table below) with two handle positions on them. First position is on the top (5cm away from) the top edge
and second at the mid of the box. The boxes were made of 1cm thick wood board. While making the boxes
Drury’s guidelines were kept in mind. The sharp edges and corners were removed for the safety from the boxes
as shown in figure 1.
Table 2. Box’s specifications
Box sixes
Handle positions
25*25*25 Upper
35*35*35 Lower
45*45*45 ----
Figure1. Isometric view of boxes used in experiments
3. Experimental procedure:
As in previous studies it has been found that most difficult position in manual lifting is lifting from the floor
height. And lifting from floor could be up to knee, waist or shoulder height mainly. So keeping these information
in mind these three handling position were decided to check the optimal position of the handle. Two handle
positions were used for the experiment one at top and other at mid of the box. Optimality of the handle was
checked at three different horizontal heights and three different weights of three different size boxes. The detail
of the box size, handle position, vertical distance, weights and horizontal distance are given in the table below.
Taguchi’s L18 technique was used to perform the experiments. 18 experiments were conducted with different
combinations of above given parameters and variables. And the frequency of lifting was fixed in all experiments
as 6/min and each experiment was conducted for the time of 10mins. As Grandjean (1985) and Green et al.
(1986) stated that HR reflects an increase in both mental and physical workloads. And Dutta & Taboun (1989)
shown that HR consumption varies when weight handled varies. So HR of workers was measured to check the
effect of above parameters and variables on the workers. Then the workers were asked to lift the box and place it
up given height defined by Taguchi L18 techniques. The experiments were conducted at room temperature. Each
experiment was repeated for three times to check the accurate value. The rest of 45 min was given to worker
after performing the experiment. The worker was asked to lift the boxes free style and without any rush. No
moral support was given to the worker during the experiments.
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