Annexure XVI, 2.2f
Introduction:
The women in areas like Rajasthan and other parts where there is scarcity of
water have to carry water for long distances of more than 5 kms. They carry the
water in earthen pots on their heads, carrying load on their heads means that a
continuous pressure is applied on the head and it leads to neck pain. The neck
consists of mainly cervical vertebrae. The top two bones of the cervical region of
the spine called C1 and C2 are under maximum pressure. The structures of
these bones are highly specialized to facilitate the movement of the head. Most
of the neck injuries or defects are due to compression loading of the cervical
spine.
This is a novel way of carrying water load on the shoulders as well as head. In this
arrangement maximum of the load is carried on the shoulders. A neck support is also
provided so that the load carried on head does not lead to neck pain. The cervical bone is
given proper support. Hence the cervical bone is given proper support to minimize the
stress due to continuous loading. This arrangement might help the women in rural areas
in carrying more water to longer distances without having any injuries or problems.
When the load on the shoulders is kept constant thru out the journey then the
shoulders may have some pain, in that case a rope is provided with pulleys attached to the
frame. When you pull the rope with your hands then the load is momentarily balanced by
your hands and you can relax your shoulders. A neck collar is provided so that while
carrying water the user can carry some on his head (about 5kgs) and rest on the back
frame.
Material used in the structure:
The materials used are spiral web nylon custom webbing and epoxy
cycloaliphatic molded and for cushioning purpose ETHAFOAM polyethylene
foam.
Properties of the main frame material:
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•
•
•
•
•
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Density
Water absorption
Tensile strength yield
Tensile Modulus
Flexural Modulus
Flexural yield strength
Compressive yield strength
1.2 g/cc
0.4 %
70Mpa
3 Gpa
3 Gpa
90 Mpa
270 Mpa
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The cushioning material used is ASTM D 1596.
The belt and the bag material used is nylon6, 40% glass fiber filled. Its properties
are:
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Density
1.36 g/cc
•
Water absorption
4.6 %
•
Tensile strength yield
200 Mpa
•
Tensile modulus
13.5 Gpa
•
Flexural modulus
12.4 Gpa
•
flexural yield strength
350 Mpa
•
Compressive yield strength
270 Mpa
Cost:
The total cost = cost of the material + cost of furnishing
=> (63 + 40 + 300) + 100
So the final cost is ~~> Rs. 500
** The maintenance cost of this product is very low as the base of rigid and
molded and then net is strong enough to support the load.
Assembly of the apparatus:
• The frame is epoxy molded, which is first prepared.
• The belts on the shoulders have a epoxy frame in them at both the ends. These
plates are stitched to the belts using nylon strings.
• Stitching should be done with a single rope.
• The plates on the shoulder belts have a slider such that belts can be fixed to the
epoxy frame by sliding them upwards, it’s a press fit.
• The neck support is optional. It can be attached to the frame’s horizontal strip by a
screw.
• The ropes for the hand will be attached to the bag of water and will be passed
over the pulleys and are convenient to hold them with hands.
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Weight calculation:
Total volume of the epoxy frame = 180 cc
Density of the epoxy used is 1.2 g/cc
Hence the total weight of the epoxy frame = 216 gms.
Weight of the nylon6 net is 400 gms.
And weight of the cushioning is 100 gms.
So the total weight of the arrangement is 750gms (including pulley and other
ropes etc.)
Calculations:
The free body diagram of the body shows that the force applied by the water at the back
is directly balanced by the shoulders but is transferred by the belt which is attached to the
frame.
Due to symmetry most of the forces are balanced and equally distributed.
Forces at shoulders are around 103 N.
The forces at the belt and frame joint are the crucial points. The moments in one direction
cancel out each other while the moment in the downward direction acts on the joints.
The stress calculated in this frame is less than 180Mpa so it is possible to work in it.
Further that the flexural stress is also very less that the maximum in the epoxy frame.
All the calculation can be shown but it needs some assumptions which have to be made in
accordance to the literature such that the force on the upper belt will be almost twice that
of the down joint etc.
Safety of the user:
The instrument is designed while keeping in mind the safety of the user. All the
edges of the frame are made rounded so that it wont hurt when the user has to
lift his/her hand up. Cushioning is provided on the inner side of the casing so it
won’t touch the body part directly. The materials used in this structure don’t affect
the human body even when in contact.
In case of women the social safety is also kept in consideration as in rural parts
the traditions are still very orthodox.
Market:
There is a need for different arrangement to carry water as using same heavy mud pots to
carry water. It’s a problem in many parts of the country. Since the product is not very
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expensive so even the people living in rural parts will be able to afford such a thing. Both
the manufacturer and the user will be equally benefited by this arrangement.
Impact:
The arrangement is light and makes carrying water really easy for all. Further more the
problems in the neck and shoulders will be reduced. But this product has a disadvantage
as the water in the nylon bag will not remain cool as in the case of mud pots. This novel
way of carrying water may be used to carry any other thing as the frame is strong enough
to bear a load of 25 kilograms and the bag can be replaced by any other arrangement.
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