GRAVITY GOODS ROPEWAY
longer and costlier. Unlike those, as the
rope of gravity ropeway is suspended in the
air, the alignment is straight which results
in a short route.
Energy efficient: Gravity ropeway operates
solely from the gravitational force. It does
not require any external power or fuel. This is
very important for a country like Nepal where
we can save costs by reducing the import of
fossil fuels for air and surface transports.
Environment friendly: Gravity ropeway is
environment friendly technology. It neither
causes noise nor air pollution. It does not
disturb ambient environment and the existing
ecology. It has no or negligible impact on
the surrounding environment as it does not
require heavy cuts and fills as in case of
building motorable roads. The alignments are
worked out very carefully in order to avoid the
clearance of trees and vegetation. Being a low
cost technology, as per existing regulation,
the Initial Environmental Examination (IEE)/
Environmental Impact Assessment (EIA) for
gravity ropeway installation is not required.
Simple technology: Gravity ropeway employs
very simple and robust technology which
can be operated and maintained by local
communities. It does not require external
experts apart from the inputs and technical
facilitation in surveying and designing, which
can also be done by local engineers and
technicians.
Nominal operation and maintenance cost: As
the gravity ropeway does not require any fuel or
highly skilled manpower for its operation and
maintenance, its running and maintenance
costs are nominal.
1.5 Limitations
Like all other technologies, gravity ropeway also
has some limitations which are discussed below:
Span: Through the learning experience of
Practical Action, the span of gravity ropeway
is currently limited to 1500 metres for
operational efficiency and safety. When the
span exceeds over 1500 metres, the tension
due to the self load of the wire rope increases
as it is suspended between two points only. In
addition, the energy loss due to the friction will
be more in longer span ropeways. Therefore,
for safety and efficiency, the span of gravity
ropeway is recommended to the limit of 1500
metres only.
Slope: One of the limitations of gravity ropeway
is that it cannot be operated in a gentle slope.
Experience shows that it requires at least 15
degrees of slope to operate smoothly. The
upper limit can go as high as 40 degrees if
proper loading ratio is maintained and an
arrangement to prevent derailing of the trolleys
from the track ropes is placed. However,
according to current practice, preferable slope
for gravity ropeway is from 20 to 30 degrees.
Up hauling capacity: Gravity ropeway is mainly
for transporting produces from hilly villages to
the road/trail head markets. It has very limited
capacity to haul up goods from the market to
the villages up in the hills. As a rule of thumb,
the downward moving load should be three
times heavier than the upward moving load.
Loading ratio: The speed of the trolley in gravity
ropeway is mainly dependent on the slope
and loading ratio along with several other
factors including application of lubrication in
the pulleys and wire ropes, and application
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