GRAVITY GOODS ROPEWAY
14. Lubrication: Lubrication prolongs the life of
the rope by keeping it free from corrosion. It
makes the rope water repellent and friction
resistant. During the rope manufacturing,
suitable lubricants are used in the core, on
strands and on the finished rope to protect it
while in transit, storage and haulage. Factory
lubrication only is not sufficient to last for the
useful life of the ropeway. For lubrication of the
gravity ropeway ropes non drying type and non
bituminous lubricant should be periodically
used to minimise friction between pulleys
and rope. Ultimately it prevents the wire from
corrosion due to weathering.
15. Kinks : As shown in
the diagram at right
kink damages the
strands and wires
reducing the life of
the rope. The most
common form of kink is the formation of a
loop of wire/wires pulled out from the rope.
Kink can be minimised by careful handling of
ropes mainly during uncoiling, hauling, and
transferring
16. Pre-stretching of Wire Ropes and Elasticity:
Pre-stre tching is a process of cyclic loading
of the rope between 10 and 50 per cent
of the minimum breaking load until the
virtual elimination of “initial or construction
stretch.” A pre-stretched wire rope has a
definite and known Modulus of Elasticity.
During the construction a new wire rope is
stretched which increase the length of the
rope by a certain amount. This stretch is
also called “construction stretch” which is
caused by the compression of the core due
to gradual bedding-in of wires and strands
under load. For ropes with steel cores, the
stretching increases up to 0.5 to 1.0 per cent
of the rope length. The pre-stretched ropes
are preferred in the gravity ropeway to prevent
frequent slackening of the wire ropes when it
is in operation. In a ropeway system, where
the clearance between the wire rope and
the ground below is just enough, an undue
slackening of the wire rope would cause the
trolley to touch the ground obstructing the
smooth movement of the trolley.
17. Pre-forming : Pre-forming is a technique used
during the production of a rope where the
individual strand is set in a helical form to
ensure that it lies in the rope without tending
to unwind. This is important to make sure
that undue winding does not take place after
the wire rope is placed in service. This is more
essential in the Lang’s lay rope as the winding
tendency is more in it than in the ordinary
rope.
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