The smallest component of a rope.
The element of a rope that is composed of a
construction of wires which are helically stranded in the
same direction in one or more layers around a core.
The element in the middle of a round rope, around
which the strands of a stranded rope or the ropes of a
cable laid rope are helically stranded.
Fibre core FC
- Natural fibre core NFC
- Synthetic fibre core SFC
Steel core WC
- Wire strand core WSC
- Independent wire rope core IWRC
Combination of core and strands
CLASSIFICATION OF ROPES
ACCORDING TO THEIR INTENDED USE
Ropes that run over rollers, sheaves or reels and thus
assume their bend.
Examples: hoisting ropes, crane ropes, lift ropes, scraper
ropes and haulage ropes for cable cars.
Ropes which are for the most part firmly clamped and
not moved over rollers.
Examples: anchoring ropes for masts and booms and
guide cables for lifts.
Ropes on which rolls of conveying devices run.
Examples: carrying ropes for cable cars, cable cranes and
gravity return scrapers.
Ropes which are used to suspend loads
Cross-laid strands consist of at least two layers of wire that
are stranded in the same direction, and the wires of two
superimposed layers cross and touch at specific points.
Parallel-laid strands consists of at least two wire layers
that are all laid in one operation in the same direction.
The lengths of lay of all wire layers are the same, and
the wires from two superimposed layers are parallel,
resulting in linear contact. Parallel lay ropes thus consist
of at least two strand layers that are all laid helically
around a rope core in a single operation.
LENGTH OF LAY
The length of lay of a strand is the lead of an external wire
measured parallel to the strand's longitudinal axis as it makes
a complete spiral around the axis of the strand.
The wires in the strands have the same direction of lay as
the strands in the rope.
Lang lay Lang lay
Right-hand zZ Left-hand sS
The wires in the strands have the opposite direction of
lay as the strands in the rope.
WINDING FROM BELOW
Right-hand lay rope
Left-hand lay rope
WINDING FROM ABOVE
Right-hand lay rope
Left-hand lay rope
FILLING FACTOR (f)
The relationship between the sum of the metallic nominal cross
sections of all wires in the rope (A) and the area (Au) of the circle
circumscribed by the rope with nominal diameter (d).
METALLIC CROSS SECTION (A)
The product of the factor for the metallic nominal cross
section (C) and the square of the rope's nominal diameter.
A = C · d2
MINIMUM BREAKING FORCE (Fmin)
A defined value in kN which must not be undershot by the
measured breaking force (Fm) in a prescribed breaking force
test. It is usually calculated as the product of the square of the
nominal diameter (d), the rope grade (Rr) and the break force
CALCULATED BREAKING FORCE (Fe.min)
A defined value in kN which must not be undershot
by the breaking force determined in a test. It is usually
calculated as the product of the square of the rope
diameter (d), the factor for the metallic cross section (C)
and the rope grade (Rr).
ACTUAL BREAKING FORCE (Fm)
The breaking force determined in a test according to a
CALCULATED LENGTH MASS (M)
A value which is calculated as the product of the factor for the
calculated length mass (W) and the square of the rope's nominal
M = W · d2
The lifting capacity of a rope is calculated from the minimum
breaking force. This is divided by the prescribed safety factor for the
Rotation-resistant ropes are ropes that are
designed such that they create a reduced
torque and a reduced rotation under load. In
general, they are composed of a construction
of at least two strand layers that are helically
stranded around a core. The outer strand layers
in this construction are stranded opposite to
the strand layer below.
The rotational property is less than or equal to 1 rotation/1,000 d,
when a load corresponding to 20% of the minimum breaking force
is lifted; a swivel may be used.
The rotational property is greater than 1 rotation but less than
4 rotations/1,000 d, when a load corresponding to 20% of
the minimum breaking force is lifted; a swivel may be used in
accordance with the recommendations of the rope manufacturer
and/or with the approval of a competent person.
The rotational property is greater than 4 rotations/1,000 d under
a load corresponding to 20% of the minimum breaking force; a
swivel should not be used.
1 rotation = 360°
d = rope diameter
Fmin = minimum breaking force of the ropet