Wire ropes are extensively used in hoisting, haulage and material handling equipment.

1. CLASSIFICATI
ON AND
CODING OF
WIRE ROPES
• PREPARED BY: BHADRESH
CHAUDHARI
• MACHINE DESIGN (2171909)

2. WIRE ROPES
• Wire ropes are extensively used in hoisting, haulage and
material handling equipment. They are also used in stationary
application such as guy wires and stays. The advantages of wire
ropes are as follows:
• High strength to weight ratio
• Silent operation even at high velocities; and
• Great reliability.
• The wire rope consist of strands, each strand comprising
several steel wires. The number of wires in each strand is
generally 7, 19 or 37, while the number of strands is usually
six.

3. CLASSIFICATION OF WIRE ROPES (STRAND
CONSTRUCTION)
• SINGLE LAYER : The Single Layer Principle is the basis of this
strand construction. The most common example is a single
wire center with six wires laid around it. It is called a 7-wire(1-
6) strand.
• FILLER WIRE : This construction has two layers of the same-
sized wires around a center wire, with the inner layer having
half the nuber of wires as the outer layer. Small filler wires,
equal in number to the inner layer, are laid in the valleys of the
inner layer.

4. • SEALE : The Seale construction has two layers of wires around a
center wire with the same number of wires in each layer. All wires in
each layer are the same diameter and the strand is designed so that
the larger outer wires rest in the valleys between the smaller inner
wires.
• WARRINGTON : The Warrington construction has 2 layers of wires.
The inner layer is a single size of wire and the outer layer has two
diameters of wire, alternating large and small. The larger outer- layer
wires in the valleys and the smaller ones on the crowns of inner layer.
• COMBINED PATTERNS : When a strand is formed in a single operation
using two or more of the foregoing constructions, it is referred to as
a combined pattern. Beginning from the center wire, the first two
layers constitute a Seale pattern. The third layer, with two different
wire sizes in Warrington pattern. The fourth layer of the same
diameter wires form a Seale pattern.

5. Single Layer
Warrington
Seale
Combined pattern
Filler Wire

6. LAY OF WIRE ROPES
• The lay of the rope refers to the manner in
which the wire are helically laid into strands
into the rope.
• If the wires in the strands are twisted in the
same direction as the strands, then the rope
is called a Lang’s lay rope.
• When the wires in the strand are twisted in a
direction opposite to that of the strands, the
rope is said to be regular-lay or ordinary-
lay.
Lang’s-Lay
Regular-Lay

7. • Regular-lay ropes are more popular than the Lang’s-lay ropes.
The balance resulting from the opposite direction of twisting
the strands to that of the wires is advantageous. Regular-lay
ropes offer the following advantages:
• They have more structural stability.
• They have more resistance to crushing and distortion.
• They have less tendency to rotate under load.
• There is less possibility of kinking.
• They are easy in handling during installation.
• In Lang’s-lay ropes, the same direction of twisting results in
outer wires being bent on a larger arc of a circle. Lang’s-lay
ropes are difficult to handle and install. They are less resistant
to crushing and distortion. Lang’s-lay ropes are likely to
untwist unless both ends are permanently fastened.

8. CODING OR DESIGNATION OF WIRE ROPES
• The wire rope is designated by three numbers:
• The first number indicates the diameter of the
rope in millimetres;
• The second number indicates the number of
strands; and
• The third number indicates the number of wires
in each strand.
• 35mm 6x19 : Indicates 35 mm diameter of rope with
6 strands and each strand has 19 wires.
Diameterofrope
7x19 ()

9. CLASS OF WIRE ROPES
• The class of wire rope is represented by only second and third
number. For example 6x19 indicates the class of the wire rope.
The class of wire ropes can also be designated as follows:
• 6x37 (18/12/6/1) : It indicates the class of wire rope with 6 strands and
each strand is having 37 wires. Out of 37 wires 18 are in the outermost
layer, 12 are in second layer, 6 are in third layer & 1 is in the innermost
layer.
• 6x19 (12/6/1) : It indicates the class of wire rope with 6 strands and
each strand is having 19 wires. Out of 19 wires 12 are in the outermost
layer, 6 are in second layer & 1 is in the innermost layer.
• 6x7 (6/1) : It indicates the class of wire rope with 6 strands and each
strand is having 7 wires. Out of 7 wires, 6 are in the outermost layer and
1 is in the inner layer.

10. REFERENCE
• Design of Machine Elements by V B Bhandari
• Sample Copy from IADC Drilling Manual
• Machine Design by R. B. Patil