2) Peak Performance Practices - Wire Rope

7/27/2019 2) Peak Performance Practices - Wire Rope

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Section Page1 - Introduction. . . . . . . . . . . . . . . 1

2 - The Basics: Wire Rope

Components, Construction

and Classifications . . . . . . . . . . 3

3 - Characteristics of

Mining Rope . . . . . . . . . . . . . . 11

4 - Inspecting Wire Rope,

Sheaves and Drums . . . . . . . . 15

5 - Receiving and Handling

Wire Rope . . . . . . . . . . . . . . . . 21

6 - Structural StrandBoom Pendants . . . . . . . . . . . . 25

7 - Recommended Practices for

Extending Wire Rope Life . . . 27

Glossary . . . . . . . . . . . . . . . . . . . . 31

Index . . . . . . . . . . . . . . . . . . . . . . 33

CONTENTSWIRE ROPE


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Wire rope is used in a variety of ways to pull, lift or

support one or more objects, or to transmit forces or

energy from one place to another. It is an essential

component in a wide range of applications, from

elevators and ski lifts to cable cars, broadcast trans-

mission towers, cranes and conveyor systems, as

well as in mining shovels and draglines.Understanding the principles that govern wire rope

performance in surface mining equipment is indis-

pensable to achieving peak performance practices

and avoiding the cost of premature wire rope

replacements.

This document is designed to provide basic infor-

mation about the design and construction of wire

rope, and its proper care and use on shovels and

draglines.

It is intended to help mine management, mainte-

nance personnel and equipment operators maximize

the life and performance of wire rope.

For further information on training, wire rope selec-

tion and after-sale support, please contact your

P&H MinePro Services representative.

Page 1

1 - Introduction


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ComponentsStandard wire rope is a flexible line made of wires

twisted or braided together to provide tensile

strength. Wire rope consists of three basic compo-

nents: a central core that serves as the ropes foun-

dation and support system; individual wires; and

multi-wire strands wrapped around the central

core (Figure 1). These components can be com-

bined in literally hundreds of arrangements, yield-

ing different characteristics for different applica-

tions.

Cores As the foundation of a wire rope, the core

must be able to support the normal bending andcompressive loads imposed on the ropes strands.

Wire rope cores may consist of a fiber core (FC),

an independent wire rope core (IWRC), or a wire

strand core (WSC).

A fiber core may be made of natural fibers such as

manila or sisal, or of synthetic filaments, such as

polypropylene or glass fibers. An independent

wire rope core or a wire strand core is most often

made of steel. Fiber core ropes offer considerably

more bendability than steel but they are seldom

used in todays surface mining equipment.

Wires The individual wires in a wire rope maybe of uniform diameters but are more often a com-

bination of different diameter sizes arranged in

specific geometric patterns. By a wide margin,

most of the wire used in wire rope today is manu-

factured from high carbon steel, although other

materials are also used, including iron, stainless

steel and bronze.

Strands Wire rope strands may be laid in any ofa wide variety of geometric patterns. Strands form

the basis of wire rope construction and classifica-tion covered later in this section.

Page 3

CORE

WIRE

CENTER

WIRE

STRAND

WIRE ROPE

2 - The Basics:Wire Rope Components,Construction andClassifications

Figure 1 Wire rope is made from three basic com-

ponents: the core, individual wires and strands.


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PEAK PERFORMANCE PRACTICES WIRE ROPE

Page 4

Grades and FinishesAs the most common material used in wire rope

manufacture, high carbon steel is available in sev-

eral grades, as designated by the plow steel

strength curve. This curve originated in England

long ago to differentiate the quality of steel used

in the manufacture of plows, and it has been used

ever since.

In increasing levels of performance, the most

common grades are: mild plow steel (MP);

improved plow (IP); extra improved plow (EIP or

XIP); and extra extra improved plow (EEIP or

XXIP).

For comparison purposes, extra extra improved

plow (EEIP) provides approximately 10% greater

nominal strength than extra improved plow (EIP),

and about 25% more than improved plow (IP). It

should be noted that in applications involving high

cycle bending, higher wire strength does not nec-

essarily mean longer fatigue life.

The most common finish for steel wire is bright

or uncoated. Steel wire may also be galvanized, or

zinc coated, to protect against corro-

sion. Drawn galvanized wire offersthe same strength as bright wire, but

wire which is galvanized at finished

size provides approximately 10%

less strength. Although most wire

rope is uncoated, both internal and

external lubrication are essential to

allow wire rope to bend and flex.

Construction:Types of LayIn addition to its component parts,

wire rope is identified by its con-

struction. The differences can be

seen in the ways in which the wires

are laid to form strands, and in the

way the strands are laid about the

ropes core.

All types of lay are similar in that all wires are

wound to form a helix, or spiral, around the

strands central wire, as are the strands around theropes core. However, the types of lay differ in

that they can be laid in regular or lang config-

urations.

Note that the wires in regular lay ropes appear to

line up parallel to the axis of the rope, as shown in

Figure 2 A and B. In lang lay ropes, the wires

appear to form an angle with the ropes axis,

Figure 2 C and D. Distinct manufacturing

techniques are used to produce these differences.

In addition, regular lay and lang lay ropes can be

wound to the right, similar to the threading in a

right hand bolt (Figure 2 A and C) or to the

left (Figure 2 B and D). Thus, the various

types of lay are: Right Regular Lay (RRL), Left

Regular Lay (LRL), Right Lang Lay (RLL) and

Left Lang Lay (LLL).

Right regular lay is used in the widest range of

applications. Right lang lay and, to a lesser extent,

left lang lay ropes are used in many equipment

applications. Left lang lay ropes are typically used

Figure 2 A comparison of typical wire rope lays: A. Right Regular

Lay; B. Left Regular Lay; C. Right Lang Lay; D. Left Lang Lay.

A

B

C

D


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2 - The Basics: Wire Rope Components, Construction and Classification

in special applications such as plain-faced or

smooth drums. Users often alternate between left

lay and right lay to minimize wear to the drum.

Advantages of lang lay Regular lay is morestable and more resistant to crushing than lang lay.

Regular lay is also more common, especially in

smaller diameter ropes, but lang lay offers certain

advantages, including superior fatigue resistance

and abrasion resistance. There are a few provi-

sions worth noting, however.

For example, in Figure 3 note how the axis of the

wire relates to the axis of the rope in regular layand lang lay strands. When regular lay rope is

bent, as when passing over a drum or sheave, the

same amount of bend is imposed on the crowns of

the outer wires. This increases the pressure and

wear on the rope.

The worn crown combined with the shorter

exposed length allows the wire to spring away

from the rope axis, resulting in reduced fatigue

resistance.

Another reason for lang lays superior fatigueresistance is that its outer wires provide about

30% more exposed area than regular lay.

Comparing the valley-to-valley distances of the

individual wires in the two examples in Figure 4,

the regular ropes distance is 7/8 in. (22.2 mm)

versus 1-1/8 in. (28.6 mm) for the lang lay.

Because the individual strand wires are less in line

with the axis of the rope, there is less axial bend-

ing of the outer wires, and greater torsional flex-

ure. Overall, lang lay exhibits 15 to 20% superior-

ity over regular lay when bending. Lang lay is

used in applications where it is subject to repeated

bending and the ends are fixed.

Page 5

Figure 3 Lang lay construction provides a greater wear area than regular lay, increasing its fatigue resistance.

WEAR AREAWEAR

AREA

SUPPORTING

INNER WIRE

LANGREGULAR

a

b

a

b

Figure 4 The wear patterns in regular lay (above

left) and lang lay (above right) are distinct.


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Page 6

Critical disadvantages of lang lay Langlay rope has two critical limitations. First, if

either end of the rope is not fixed, it will rotateseverely when subjected to a load. Second, it does

not withstand the crushing forces against a drum

or sheave as well as regular lay. Therefore, lang

lay rope must always be properly secured at both

ends, and it should never be used over small diam-

eter drums or sheaves under extreme loads. It also

follows that lang lay does not respond well to

inferior drum winding conditions.

Lay as a unit of measureIn addition to helping define a ropes construction,

rope lay is also used as a unit of measure. One

rope lay is the length of one complete spiral of a

strand about the ropes core.

Measuring a ropes lay length is an important part

of rope inspection and is covered in Section 4.

Preformed vs. non-preformed wire

Preforming wire, i.e., forming individual wiresand strands to the helix shape during manufactur-

ing, makes the wires and strands lay at rest in

the rope. Preforming wire also improves fatigue

resistance. Wire rope used in mining shovels and

draglines is preformed. Non-preformed wire will

broom when cut, unless the end is first secured

with wire seizing (Figure 5).

Figure 5 To prevent strands and individual wires from unraveling or brooming, seizing is applied to

wire rope before cutting.

Single Layer Filler Wire

Figure 6 Some of the common classifications of wire rope are


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Wire Rope ClassificationsWire ropes are classified according to three basiccriteria: the number of strands in the rope; the

number and arrangement or pattern of wires in

each strand; and a word or letters to describe the

geometric arrangement of the strands. Some

arrangements are filler wire (FW), Seale (S) and

Warrington (W).

Single Layer: the most basic rope pattern, con-sisting of uniform-diameter wires wrapped around

a single center wire of the same diameter. The

example shown (Figure 6) is a 7-wire strand.

Filler Wire (FW): two layers of same-sizedwires wrapped around a center wire in which the

inner layer has half as many wires as the outer

layer. Small filler wires equal in number to the

inner layer wires help position and support the

two layers.

Seale (S): two layers of wires, equal in number,around a center wire. The large outer wires rest in

the valleys of the inner layer of wires.

Warrington (W): two layers of same-sizedwires in the inner layer, and two alternating diam-

eter sizes in the outer layer. The larger outer wires

rest in the valleys of the inner wires, and the

smaller outer wires rest on the crowns of the inner

layer of wires.

Combined Patterns, e.g., Warrington

Seale (WS): two or more of the above patternscombined in a single operation. In the example

above, an inner layer of Warrington is combined

with an outer layer of Seale. Another type of com-

bined pattern is Seale Warrington Seale (SWS).

Multiple Operation, or 2-Op: strandsrequiring two separate manufacturing operations

in which one of the above patterns is covered with

an outer layer of uniform-diameter wires. The sec-

ond operation is required to provide the outer

layer a different direction or length of lay to meet

particular performance requirements.

Construction vs. ClassificationIn addition to its class, a wire rope is also identi-

fied by its construction. For example, a 6x7 rope

designates a rope with six strands with each strand

having seven wires. Other designations include

6x19, 6x37, 6x61, 7x19, 7x37, 8x7, 8x19, 19x7,

etc.

However, these are nominal designations which

may or may not reflect the ropes actual construc-

tion. Each designation includes multiple types of

construction. The 6x19 class, for example,

includes 6-strand ropes with 16 through 26 wires

per strand; the 6x37 class includes 6-strand con-

structions with 27 through 49 wires per strand.

Page 7

Seale Warrington Warrington Seale Multiple Operation

ve. Each classification is based on the geometric arrangement of wires and strands.


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Page 8

To avoid confusion, it is best to order wire rope by

its actual construction, not just its classification. A

full description of a wire ropes construction typi-

cally includes the following:

length

diameter

preformed or non-preformed

direction and type of lay

finish

grade

type of core.

Certain assumptions may be made if one or more

of these specifications is omitted. If the direction

and type of lay are omitted, it is assumed to be

right regular lay (RRL). If the finish is not shown,

it is assumed to be uncoated or bright. For

example:

500 ft 3/4" 6x21 FW pref RLL IP IWRC

The above description defines a 500 foot length of

rope, 3/4 inch (19 mm) in diameter, with six

strands, 21 wires per strand, filler wire, pre-

formed, right lang lay, improved plow steel, and

an independent wire rope core.

Most wire ropes used for drum applications on

shovel and dragline applications are constructed of

six, seven or eight strands.

6x25FW

6x26WS

6x41WS

6x49SWS

6x55/6x61SWS

Compacted6Strand

Compacted8Strand

Compacted6Strand

PlasticImpregnated

Compacted8Strand

PlasticImpregnated

8x19

8x37

GalvanizedBoom

SupportStrand

Draglines

Boom Hoist Line

Drag Line

Hoist Line

Boom Pendants

Shovels

Boom Hoist

Crowd & Retract

Hoist Rope

Trip Rope

Boom Pendants

Wire Rope Selection Guide


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Why Wire Rope Must Be Freeto MoveWire rope is often referred to as a complex

machine made of many moving parts, and for

good reason. A rope of 6x37 construction has

approximately 222 wires: six strands, each with

37 wires, plus the core. Note that the actual count

may vary by specification and manufacturer. All

these components must be able to slide and move,

both individually and in concert with adjacent

strands and wires. To understand why and how a

ropes wires and strands move, consider what hap-

pens as a 1 in. (25.4 mm) rope passes over a 30 in.

(762 mm) sheave.

As shown in Figure 7, the rope is subjected simul-

taneously to the opposing forces of tension and

compression. As a result, the inside length of the

rope retracts while the outside length expands.

Using the mathematical formula for a circles cir-

cumference (where C is the circumference and D

is diameter) the outside of the bend is about 3-1/8

in. (79.4 mm) longer than the inside bend (Figure

8). Note that we divide the circumference by 2

because the rope is in contact with only half the

circumference of the sheave.

Page 9

30"

1"

32"

TENSION

COMPRESSION

p = 3.14 C = p x D2

Outside circumference =

3.14 x 32 = 100.48 = 50.24 (1276.1 mm)2

Inside Circumference =

3.14 x 30 = 94.20 = 47.10 (1196.3 mm)2

Difference =

50.24 - 47.10 = 3.14 or about 3-1/8 (79.4 mm)

Figure 8 The difference between the inside and outside bends of the wire rope is about 3-1/8 in.(79.4 mm).

Figure 7A wire rope passing over a sheave or

drum is subjected simultaneously to the opposing

forces of tension and compression.


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Page 10

To allow the rope to adjust to this kind of bend-

ing and flexing, the clearances between its compo-

nents are precision engineered to tolerances mea-sured in 10,000ths of an inch (0.0025 mm). This

kind of metal-on-metal sliding contact also helps

explain why proper lubrication is essential to wire

rope performance.

The D/d RatioThe relative sizes of a sheaves diameter, D, and

a ropes diameter, d, is one of the factors that

determines the ropes fatigue resistance and ser-

vice life.

In the previous example, the sheaves diameter is

30 in. (762 mm) and the rope's diameter is 1 in.

(25.4 mm), producing a D/d ratio of 30 to 1. As

the D/d ratio decreases, the bend is drawn tighter

and tighter, increasing the tension on the rope,

reducing its fatigue resistance, and causing the

rope to wear prematurely.

Fatigue life of drum ropes is a function of both

bending stress over the drum and pulsating axial

stress from the loading. Using larger ropes than

specified will hurt bending stress but help axial

stress. Slightly larger ropes have been applied suc-

cessfully when within the limitations of the

groove size and spacing.

It is important to remember that, for any given

rope diameter, changing to a smaller sheave diam-

eter reduces its service life when bending is the

determining factor. Conversely, using the same

rope on a larger sheave increases its service life

(Figure 9). Larger diameter sheaves also have

higher rotational inertias and thus could accelerate

external wire wear and breakage such as a fairlead

application where sheave overspinning is a factor.

100

90

80

70

60

50

40

30

20

10

0

RELATIVE

ROPES

ERVICEL

IFE

0 10 20 30 40 50 60

D/d RATIO

Figure 9 A rope working with

a D/d ratio of 26 has a relative

service life of 17. If the samerope is used on a sheave that

increases the D/d ratio to 35,

the ropes relative service life

increases from 17 to 32, a gain

of 88 percent.


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With so many varieties of wire rope available,

sorting out the specifics required for a particular

application can be a challenge. Of the characteris-

tics listed in this section, two of the most impor-

tant for shovel and dragline operations are abra-

sion resistance and fatigue resistance (Figure 10).

Abrasion ResistanceA ropes abrasion resistance is its ability to with-

stand wear and metal loss due to sliding contact

with other materials, including metal sheaves and

rollers, drums, and rock. The chief causes of metal

loss are rope running through sheaves that are too

small, an improper fleet angle, and pulling a

drag rope through the roll at the edge of a pit.

Generally speaking, larger diameter wires

offer greater abrasion resistance because

they have more surface to wear away than

smaller wires.

In addition to its metal being worn away,

wire rope can be distorted or peened.

Peening occurs when the ropes exterior

surface is flattened by striking against a

hard object.

Metal loss and peening often occur simulta-neously. Metal loss reduces a ropes strength

and can cause individual wires to break. The

distortion caused by peening limits the normal

sliding action and adjustment of wires during

normal operation, resulting in reduced fatigue

life. Peening also causes the metal in the wire

to harden, making the wires more brittle and

less flexible.

Fatigue ResistanceA ropes fatigue resistance is its ability to endure

repeated bending over a period of time. The ropes

key points of vulnerability are where it passes

over sheaves and drums, points of restriction suchas the ropes end attachments, and areas subject to

load changes.

The greatest load changes occur at the ropes pick-

up points, the parts in contact with the sheaves

Page 11

3 - Characteristicsof Mining Rope

Figure 10 Wire rope is a complex machine made of many

moving parts which are subject to abrasion and fatigue.


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Page 12

6

9

10

10

12

12

14

16

18

6x7

6x19 S

6x21 FW

6x26 WS

6x25 FW

6x31 WS

6x36 WS

6x41 SFW

6x46 SFWNUMBEROFOUTSIDEWIRESPERST

RAND

LEAST

RESISTANCETO

ABR

ASION

GREAT

EST

LEAS

TRESISTANCETOBENDING

FATIGUE

GREATEST

Figure 11 The X Chart demonstrates the inverse relationship between abrasion resistance

and bending fatigue resistance. As abrasion resistance increases, fatigue resistance decreases,

and vice versa.

and drums when the initial shock load of each lift

is applied.

Vibration on ropes is often of a bending nature,

and the stress is maximized where the vibration is

dampened, i.e. at the pick-up and termination

points. This bending causes rubbing between the

inner and outer strands. When vibratory bending

failures occur, it is very common for the wire

breaks to be in the inner wires.

Vibration sends energy in the form of shock waves

through the rope and that energy must be absorbed

at some point. Wherever the waves are dampened

is where the energys impact will be concentrated,

including the end attachments and the tangent

where the rope contacts the sheave or drum, i.e.

the pick-up points.

As a rule, the greater the number of outside wires

in a strand, the greater its fatigue resistance will

be. This is due to the fact that smaller wires have

a greater ability to bend, and more wires usually

means smaller wires.

From the above, it should be clear that as a ropes

abrasion resistance increases its fatigue resistance

decreases, and vice versa. Since most applications

require a balance of these characteristics, the

industry has developed a rope selection aid called

the X Chart (Figure 11).

High Performance Wire RopeTo help offset the inverse relationship between

abrasion resistance and fatigue resistance, andprovide the best of both attributes, most manufac-

turers offer high performance ropes.

Compacted Strand One type of high perfor-mance rope is compacted strand. Each strand is

drawn through a die to compact and create a


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3 - Characteristics of Mining Rope

smooth flat surface all around the strands (Figure

12) prior to laying them around the core. This

process increases the metallic surface of the ropeand provides a flattened outer wire surface,

enhancing breaking strength, fatigue resistance,

abrasion resistance and crushing resistance.

Virtually all ropes used on shovels are compacted,

as are some dragline ropes.

Figure 12 Compacting the outer strands of a wire

rope increases its surface area, improving resis-

tance to bending fatigue, abrasion and crushing.

Swaging is another compacting technique in

which hammers are used to compact the strands,

resulting in a very dense cross section. Die form-

ing is a more controlled process than swaging and

results in greater product uniformity.

Plastic-Filled IWRC Rope and Plastic-

Coated Rope Plastic-filled wire rope is ropewhose internal spaces are filled with a matrix of

plastic. Plastic filling improves bending, abrasion

and fatigue life by reducing internal contact

between wires and strands, thus reducing internal

and external wear. The plastic filling helps support

and separate the ropes outer strands. It keeps the

lubrication from escaping, helps keep foreign

material out, can help prevent corrosion, and

makes the rope cleaner to handle.

Various constructions of wire rope are available

with a plastic coating which may be applied to the

ropes exterior or just the gap between the IWRC

and outer strands.

Plastic filled or coated wire rope helps keep the

grooving in sheaves and drums polished and in

good condition. It prevents corrugation because

there is full contact with the groove.

Strength

A third consideration in selecting wire rope for

shovels and draglines is its strength. In addition to

the plow steel strength curve, several other mea-

sures of strength are applied to wire rope.

Nominal strength refers to the manufacturerspublished catalog strength. This figure is calculat-

ed according to standard industry procedures.

Since a ropes strength decreases with use over

time, nominal strength applies only to new,unused rope.

Minimum acceptance strength is rated 2-1/2% below the nominal strength to allow for vari-

ables that might affect a ropes breaking strength

during testing. A minimum acceptance strength

for a nominal breaking strength of 100,000

pounds would require an actual breaking load by

test to destruction of at least 97,500 pounds.

Breaking strength measures the amount oftensile load required to pull apart a piece of rope.

It is important to distinguish between dynamic

and static breaking strength, however. Most mini-

mum breaking strengths listed in catalogs are

obtained under quasi-static or slow loading speed

test conditions, but most rope failures happen as a

result of dynamic loads, i.e. when the rope is

moving rapidly.

Page 13

FLATTENEDSTRAND

SWAGED


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Page 14

Reserve strength is the combined strength ofall the wires in a rope except those in the outside

layer of the strands.

Crushing ResistanceA fourth consideration for shovels and draglines is

a wire ropes crushing resistance, i.e., its ability to

maintain its round shape when one layer of rope is

spooled on top of another. In shovel and dragline

applications, only the boom hoist ropes may be

spooled in this way; all others are spooled in a

single layer.


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Regular inspection is an essential part of any wire

rope peak performance program. Catching a prob-

lem in its early stages of development allows you

to adjust operating practices and prevent potential-

ly dangerous breaks while the rope is under load.

Inspecting a rope, especially for the first time,

begins with good preparation, as outlined in the

steps below.

1. Gather your inspection tools and sup-

plies. For a complete inspection of the rope,sheaves, drums and end attachments, youll need

(Figure 13):

an inspection log

a caliper

a tape measure

sheave and drum groove gauges

chalk

cleaning cloths

carbon paper and clean white paper

a pen and pencil

leather gloves

2. Identify the rope. Before you can know

what to look for in your inspection, you have to

know something about the rope. Begin by identi-

fying its diameter and construction. Note that all

measurements of a ropes diameter must be per-

formed at the widest point, as shown in Figure 14.

2a. Measure the rope diameter. To get anaccurate dimension, measure three times at the

same location. On a six-strand rope, for example,

youll measure all three diameters, i.e. the dis-

tance between the outsides of strands 1 and 4, 2

and 5, and 3 and 6, as shown in Figure 14. On an

eight-strand rope you may want to measure allfour diameters.

Page 15

4 - InspectingWire Rope, Sheavesand Drums

Figure 13 The essential tools for inspection

of ropes, sheaves, drums and attachments.


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Repeat these measurements at several locations on

the rope, especially at the pick-up points, in areas

of heavy wear, and in areas close to the end

attachments. Record them in the inspection log.

2b. Compare your measurements with

the ropes catalog or nominal diameter.Keep in mind that all manufacturers make their

ropes with diameters larger than their nominal list-

ings. This is to allow for the initial pull down of

the diameter when new, unused rope is placed

under load for the first time and the wires seat

in.

Note that there is no industry standard for the dif-ference between nominal and manufactured diam-

eter sizes. For specifics, check with the individual

manufacturer.

A change in diameter can be a warning sign of

potential or actual failure, so it must be measured

during every inspection. A new ropes initial mea-

surement should be taken after it has had a chance

to seat in. The initial measurement is then used as

a reference for future comparisons.

A gradual decrease in diameter is to be expected

over time, but a sudden decrease, especially a

large one, may be a sign of a broken core.

2c. Identify the ropes construction. Thisis done by making a physical count of the ropes

strands and wires per strand. The rope manufac-

turers test certificate should simplify the task.

Just be sure the rope matches what is on the cer-

tificate.

Note that manufacturers do not always supply test

certificates, and those who do usually do so only

by special request.

3. Verify the ropes breaking strength.Again, this can be done by checking the manufac-

turers test certification. Remember, there is a dif-

ference between static breaking strength and

dynamic breaking strength and, in most cases, the

test certification will be based on a quasi-static

test. If youre not sure, check with your supplier.

4. Review the retirement criteria and

verify the design factor. The design factor is

a ratio of a ropes nominal or catalog strength tothe rated load of the application intended.

Multiplying this rated load by the design factor

provides the minimum catalog strength of the rope

required for the application.

Rated Load x Design Factor = Minimum Catalog

Strength

Most ropes designed for surface mining applica-

tions employ a design factor of 5.0. Using this

design factor, a rated load for the application of 80

tons (81.3 tonnes), requires a rope with a mini-mum catalog strength of 400 tons (406 tonnes),

calculated as 80 x 5 (81.3 x 5). Always consult the

manufacturer when a rope of a different catalog

strength is intended to be used.

5. Review the ropes inspection history.

This can be a big time and money saver, but only

if the records are accurate and up to date. The

inspection history can provide valuable clues as to

Page 16


Figure 14 The correct way to measure a ropes diameter is across the widest point, from crown to crown

of opposite strands, not from valley to valley.

ACTUAL

DIAMETER

INCORRECTCORRECT

16

5

4 3

2


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4 - Inspecting Wire Rope, Sheaves and Drums

Page 17

the cause and remedy of rope problems. If the

inspection log indicates rope removal due to local-

ized damage in a particular area, inspect that areafirst.

Inspection MethodsThere are many different methods and procedures

used to inspect wire rope used on mining equip-

ment. These can and do vary from mine to mine,

the type of equipment at the mine, the functional

application of the wire rope and the specific safety

standards and requirements enacted at the particu-

lar mine site. Thus the responsibility for definingand implementing inspection procedures rests

with the management of each individual mine, the

specifics of which cannot be addressed here.

Rope Retirement CriteriaUsing a rope beyond its useful life is a dangerous

practice that can put peoples lives in jeopardy.

Any cost savings gained by delaying rope replace-

ment can be lost quickly if the rope breaks during

operation and causes bodily injury or damage tothe machine.

Always replace wire rope according to the equip-

ment manufacturers or wire rope manufacturers

specifications for the application. Follow the spec-

ifications for length, diameter, class of construc-

tion, breaking force, and type of rope attachments

or terminations. Maintaining 2-1/2 to 3 wraps of

rope on the drum for all authorized working con-

ditions determines the shortest length.

Note: Physical dimensions of the outer geome-try of rope attachments can vary from one man-ufacturer to another. Do not order ropes withattachments from suppliers other than the origi-nal equipment manufacturer without first verify-ing it will fit into the physical opening and permit

the normal range of movement after installation.

No precise rules can be given for determination of

the exact time for replacement of wire rope and

strand since many variable factors are involved.

Some variables include:

number of hours in service

type of application (how the rope is used)

the loads applied to it, and their frequency

frequency of lubrication, or no lubrication

effect of corrosive environment

A shorter working life of rope and strand will

result from lack of maintenance. The remaining

strength and safety of a wire rope or strand in con-

tinued use is determined by both careful inspec-

tion for signs of deterioration, and the judgement

of an authorized, qualified person.

Note: Discard criteria will vary based on theapplication; for example, hoist ropes versus

drag ropes.

Use the following basic criteria when evaluating

the condition (strength and safety) of wire rope

and strand. If any doubt exists about the remaining

useful life of a wire rope or strand it should be

removed from service!

Running Rope Retirement Criteria

Six randomly distributed broken wires in onelay length, or three broken wires in one

strand in one lay. Six wires broken at the

drag rope socket (in this case, the rope could

be shortened and re-socketed).

ONE ROPE LAY

Figure 15 The length of one rope lay is the distance

required for a single wire to make one complete helical

convolution about the ropes core.


22/40

Page 18


Probable Cause

Overload or localized wear. If overload is sudden, it

will cause a square-off break.

Overloading, kinking, damage or localized wear weak-

ening one or more strands.

Lack of proper lubrication. Exposure to salt or alka-

line water. Idle periods.

Shock loading.

Rolling the reel over an obstruction or dropping from

the truck onto any hard surface results in rope

distortion or damage. Use of chains for lashing or use

of a lever against the rope.

Result of improper handling, installation or operating

abuse.

Kinks or bends in rope due to improper handling dur-

ing installation or service. Repetitive contact point

causing severe localized wear.

Excessive fleet angle or lack of attention when rope is

installed. Worn grooves, worn flanges, lack of a level

wind system.

Damage due to scraping of rope over sharp surface

or because of improperly fitted clamps or clips.

Ropes operated over damaged sheaves or drums or

improperly aligned equipment. Drum groove too deep

for fleet angle of rope.

Severe bending. Possibly due to excessive vibration,

or due to poor operating conditions.

Allowing rope to drag or rub over any small radius

bend.

Overloading or poor spooling.

Problem

Rope broken square-off

One or more strands broken

Undue corrosion

Protruding rope core

Ropes damaged in transit to

location

Ropes show kinks, dog legs,

or other types of distortion

Ropes show excessive wear

in spots

Ropes damaged by irregular

or improper winding on drums

Unequal pressure and

distortion of wires and rope

Side wear on rope

Fatigue breaks in wire

Spiraling or curling

Ropes show excessive

flattening or crushing

Wire Rope Inspection Checklist


23/40

4 - Inspecting Wire Rope, Sheaves and Drums

Note: The number of wire breaks that cannotbe accepted varies with rope usage and con-

struction. For general applications, this six-and-three criteria is satisfactory. Common practiceby mine operators for draglines is to use this

criteria for hoist ropes only.

One outer wire broken at the contact point

with the core of the rope which has worked

its way out of the rope structure and pro-

trudes or loops out from the rope structure.

Wear of one-third the original diameter of

outside individual wires from abrasion.

Kinking, crushing, cutting, birdcaging,

unstranding or any other damage resulting in

distortion of the rope structure.

Evidence of any heat damage from any cause

including an electric arc.

Protruding core (from an opening between

strands).

Valley breaks - when two or more wire frac-

tures are found.

Severe corrosion particularly in the vicinity

of end attachments. Reductions from nominal rope diameter of

more than 10% of a new rope after installa-

tion, or an observable increase in rope lay

length.

Rope Pendant Retirement Criteria

More than two broken wires in one lay in

sections beyond end connections or more

than one broken wire at an end connection.

Loose or damaged strands.

Standing Rope Retirement Criteria

More than two broken wires in one lay in

sections beyond end connections or more

than one broken wire at an end connection.

Loose or damaged strands

Note: Where possible, ropes should be rotat-

ed out of sheave contact areas for inspection.

Strand Pendant Retirement Criteria

Visible or sounding breaks in 25% of the

outer wires or 10% of the total, whichever isless; or 10% loss of strength based on size

and load capacity of each broken wire.

Significant rust staining at the socket termi-

nation, indicating internal corrosion and pos-

sible wire breaks.

Significant reduction in diameter at the sock-

et, indicating internal core breakage.

Excess catenary, indicating internal wire

breaks and loss of load carrying ability.

Inspecting Sheaves andDrumsUse the appropriately sized groove gauges to

check sheaves for wear, keeping in mind that

gauges designed for field use are based on differ-

Page 19

A

CB

Figure 16A sheave groove gauge should make 150

contact with the groove, as in Example A. Example B

is too tight, and example C is too loose.


24/40


ent groove dimensions than those used by manu-

facturers for new components.

Field gauges are made to the ropes nominal or

catalog diameter plus a minimum acceptable frac-

tional oversize value based on the ropes diameter

and construction.

This allows the gauges to be used to establish the

minimum condition for worn grooves (Figure 16).

When the gauge perfectly fits the groove, the

groove is at the minimum allowable contour. Any

narrower fit means the groove is not recommend-

ed for further use.

In addition to the groove contour, a full inspectionincludes the grooves depth, width and smooth-

ness. Corrugations or imprinting caused by the

ropes texture (Figure 17) can seriously damage

the rope and is cause for replacing the sheave.

Corrugation is more likely with bright rope than

with plastic coated rope; plastic-coated rope may

even help smooth the groove.

Also examine sheaves for damaged or chipped

flanges, cracks in the hubs or spokes, out-of-

roundness, waviness, alignment with other

sheaves, and for wear or damage to bearings andshafts.

The main functional drums on shovels and

draglines use grooved barrels with a single layer

of rope. For drum inspections, check the drums

general operating characteristics. Adequate tension

must be maintained on the rope so that it winds

properly. Be sure the rope follows the groove and

that the wraps are tight and consistent. If any

looseness or irregular winding is observed, check

the rope for kinks. Pay particular attention for any

scuffing as it leaves the drum groove.

Measure the grooves for proper contour, as in the

sheave inspection procedure above. Also check

that adjacent grooves have enough clearance

between them that one wrap of rope does not

scrub the next wrap. Drums that become corrugat-

ed need to be corrected or replaced.

Page 20

Figure 17A corrugated sheave can cause seri-

ous damage to a wire rope.


25/40

Receiving and handling of wire rope calls for spe-

cial caution. Improper unloading, unreeling, wind-

ing, and storage can cause permanent damage,

making a rope useless even before its been put

into service.

Upon receipt of a shipment, the rope should be

carefully inspected to see that it matches the ship-

ments paper work, including description tags,

purchase orders, invoices, etc.

Unreeling and WindingBefore a rope is unreeled, the reel must be mount-

ed on a shaft supported by jacks or a roller payoff

so the reel can turn. As the rope is unreeled, ten-

sion must be maintained on the rope with a brak-

ing device or similar mechanism to avoid slack in

the rope which can lead to kinking.

If rope is to be transferred from one reel to anoth-

er, or from a reel to a drum, care must be taken to

avoid causing a reverse bend in the rope. Areverse bend is induced when unreeling from the

top of the pay-off reel to the bottom of the take-up

reel, or vice versa. This will cause the rope to

rotate more under load and, more importantly, it

will cause uneven loading of the strands and

wires, thus greatly reducing its life.

The correct way to transfer the rope is from the

top of one reel to the top of the other, or from bot-

tom to bottom (Figure 18).

Page 21

5 - Receiving andHandling Wire Rope

Figure 18 Transferring a wire rope from the top of one reel to the bottom of another reel or drum can create a

reverse bend. The correct method is to make such transfers from top to top or bottom to bottom.

CORRECT

REEL

REEL

REEL

REEL

DRUM

DRUM

DRUM

DRUM

INCORRECT


26/40

When working with shorter cut length

coils of rope, the coil should be wound

and unwound by standing it androlling it like a tire. It should never be

laid flat and the free end pulled out.

Laying the coil flat makes it extremely

susceptible to kinking and reverse

bends (Figure 19).

Storing Wire Rope

Wire rope should be stored under a

roof and/or covered by a tarp. If this is

not possible, liberally coat the outerlayers with lubricant. Keep rope away

from heated air and moisture.

Reels should be stored and moved in an upright

(on edge) position and not on the painted side.

Used rope should be lubricated, if possible, and

stored on reels the same as new.

End Preparations and

TerminationsRopes are normally shipped with their ends seized

to prevent the strands and wires from unraveling.

In some applications, seized ropes can be installed

with no further preparation required.

Where tight openings or tight bend radii are

involved with drums or sockets, however, special

end preparations, or beckets, may be required. For

example, beckets are used when another rope or

tugger line is used to pull the new rope into

place. Four basic types of preparations are shownin Figure 20.

Wire rope should never be shortened, lengthened

or terminated with the use of a knot. A single knot

in a wire rope can reduce its strength by 50 percent.

Ferrule Becket Hoist RopesMost of the wire rope consumed on excavators is

used as drum ropes (hoist, drag, etc.) and most

drum ropes on shovels (95%) use ferrule becketfittings for end preparations. Adhere to the follow-

ing principles when working with ferrule beckets.

1. Pull-off strength The ferrule should beswaged onto the rope so as to develop at least 30-

35% of the rope's breaking strength. Any less and

the ferrule can pull off. Pull-off strength is a func-

tion of swaging force and ferrule length.

Page 22


Figure 19 A coil of rope should never be laid flat

and uncoiled. Uncoiling in this way can easily

create kinks or reverse bends.

INCORRECT

CORRECT


27/40

2. Ferrule size,

length Although fer-

rule diameters arefairly universal for a

given rope size,

length is not. It's best

to know and specify

the ferrule size and

length. Shovels typi-

cally use shorter fer-

rules due to space

limitations. Longer

ferrules may not fit in

the sockets properly.

3. Dead wraps Toprevent overloading

the ferrules, the system depends on the friction

provided by the dead wraps on the drum. As such,

ropes should be purchased that provide 1.5-2.0

dead wraps for shovels and 2.5-3.0 dead wraps for

walking draglines on the drum when the most pos-

sible rope is reeled out. This is easy to check by

visual observation.

4. Rope length In most applications where fer-rule beckets are used, it is difficult to equalize therope lengths. Unequal lengths, however, will pro-

duce significantly unequal loading and shorter

rope life. It is critical that hoist ropes that use fer-

rule becket fittings be replaced in sets. It is also

critical that the lengths of the two hoist ropes in a

replacement set be kept within the tight tolerance

specified (Figure 21).

Wedge Sockets

Wedge sockets should be used only with standard6 to 8 strand wire rope. For rope larger than 9/16

in. (14.3 mm) in diameter, use the next larger size

socket. For example, a 9/16 in. rope requires a 5/8

in. (15.9 mm) wedge socket.

Page 23

5 - Receiving and Handling Wire Rope

MATCHED SET TOLERANCE 0.50"

WIRE PULLING LOOP FERRULE BECKET

Figure 21 For matched sets of hoist ropes with ferrule becket end fittings, the rope lengths must be kept

within the tolerance specified (typically, 0.50").

Figure 20 End preparations, or beckets, are used when another rope is needed

to pull the operating rope into place. Four basic types of beckets are shown.

PAD EYE LINK BECKET TAPERED &WELDED END

TAPERED ENDWITH LOOP


28/40

The tail length (Figure 22) should be at least 6

rope diameters but never less than 6 in. (152 mm).

For example, for a 2 in. (51 mm) rope: Tail Length

= 2x6 = 12 in. (304.8 mm).

Note: Always remove the end preparationbefore seating the wedge in the socket. Thisallows the strand and wires to slide relative toeach other as they conform to the tight radius of

the wedge.

Align the live end of the rope with the center line

of the socket pin. Secure the dead end with proper-

ly sized U-bolt or fist grip clips (Figure 23). Never

attach the dead end of the rope to the live rope.

Poured Spelter SocketsSpelter sockets make highly efficient end termina-

tions, particularly for large diameter ropes and

boom pendants.

The socket is attached to the rope by inserting the

broomed out end of the rope or structural strand

into the cone-shaped socket and pouring molten

zinc into the socket and letting it cool (Figure 24).

However, due to the rigidity of the attachment, the

ability of the rope or strand to bend or adjust at the

fitting is extremely limited. Thus, high stress

caused by vibration is created at the point where

the wires enter the socket. This calls for frequent

inspection for broken wires or strands at this point.

Be sure to check the socket manufacturers policy

regarding resocketing.

Page 24


Figure 22 A wedge socket is easy to use but it is critical

that the rope is attached correctly. Never attach the dead end

of the rope to the live rope. If a rope clamp is used it should

not be tightened until after the wedge is seated in the socket.

TAIL

LENGTH

CORRECT INCORRECT

Figure 23 Wire rope clips are available in two

basic styles: U-bolt and fist grip. Both provide the

same efficiency.

Figure 24 Molten zinc is commonly used to

secure wire rope to a spelter socket. Some manu-

facturers use specially formulated resin instead.

U-BOLT CLIP FIST GRIP CLIP


29/40

Boom and mast support pendants are normally

made of galvanized structural strand with non-pre-

formed wires. The outer layers of these wires arelaid in alternating directions, i.e. left lay and right

lay, for torque-balanced construction. This is

called cross-laid strand (Figure 25). In some

strand constructions the innermost wires may be

laid in a parallel arrangement called parallel con-

tact core. It offers more contact area between

adjacent wires to handle the higher internal strand

pressures toward the strand center (Figure 26).

End terminations are usually poured spelter sock-

ets.

Structural strand is prestretched to minimize addi-tional stretching during operation. To ensure that

each assembly is measured to the same length, it

is measured before prestretching and again after

prestretching, under load.

However, because used strand may sustain some

additional stretch, it will tend to be slightly longer

than new, unused strand. Pairing a new pendant

with a used one may cause the new pendant to

carry a larger load, making it likely to fail before

the used pendant. As a result, boom and mast pen-

dants should always be replaced in full sets,unless a true equalizing link arrangement is used.

Because of the high stresses placed on the strand

where it enters the socket, fatigue breaks are most

likely to occur at that point. Be sure to inspect this

area carefully on a regular basis and lubricate

every three months through the lube fittings pro-

vided.

Page 25

6 - StructuralStrand BoomPendants

Figure 26 Parallel contact core construction

increases the contact between the core and adja-

cent wires to handle the higher internal strand

pressures toward the strand center.

Figure 25 Cross-laid strand construction helpsbalance torque forces in structural strand.

CORE

CORE


30/40


31/40

Assuming there is no damage to the rope in ship-

ping, handling and storage, a wire ropes service

life is affected from the time it is installed.Improper installation or securing of its end termi-

nations can reduce its life. Be sure to follow the

proper procedures and use properly sized sheaves.

Break in new wire rope Any time a newwire rope is installed, it needs to be broken in

properly. Start the equipment and allow the rope

to run through an operating cycle at slow speed

with no load.

Carefully observe all the working parts of the sys-

tem, including sheaves, drums and rollers, to seethat the rope runs smooth-

ly and without obstruc-

tion. If any problem is

encountered, correct it

before proceeding any

further.

Repeat this process sev-

eral times, gradually

increasing the load

and speed. This

allows the

rope to

stretch and the wires and strands to seat in and

adjust to normal operating conditions.

Inspect twin sheaves for uneven wear Onshovels and some draglines, both grooves of twin

sheaves should be the same depth. If one groove is

deeper than the other, rope performance and ser-

vice life will decrease and sheave wear will

increase. Check the equipment manufacturers tol-

erances for groove wear and repair or replace the

sheave as needed.

Keep martensite in check Martensite is ahard-to-see wire surface condition that leads to

broken wires. It is formed by the very localizedhigh heat of friction on the crowns of

wire rope followed by rapid cool-

ing of the wires beneath them.

The formation of martensite

can be prevented by using

properly sized sheaves,

limiting sheave over-

spinning and avoid-

ing digging tech-

niques that

Page 27

7 - RecommendedPractices for ExtendingWire Rope Life

Figure 27 Wire rope suppliers carefully wrap rope on reels to insure damage-free rope

shipments.


32/40

produce high friction contact situations or exces-

sive rope oscillations. Also avoid rope contact

with hard objects such as rock, especially whenoperating at high line speeds.

Keep wire ropes properly lubricatedThis allows the wires and strands to adjust to

changing loads and prevents corrosion. Lubricate

the ropes as needed with each inspection. Where

sheave overspinning occurs it is a good practice to

lubricate the sheave groove with an open gear type

of lubricant to dampen the relative motion and

prevent Martensite formation in the rope wires.

Also lubricate pendant sockets every threemonths. Some larger diameter pendant sockets

have a lube fitting in the zinc/resin. These fittings

should also be lubricated at no more than three-

month intervals. For shovels equipped with rope-

operated crowd and retract functions, refer to the

manufacturers instructions for maintenance and

replacement procedures and safety precautions.

Shovels

The leading cause of rope failures on shovels is

drum dampening, i.e. the shock created in slack

rope when sudden loading occurs. Depending on

the style of bail and equalizer, letting the bail

go slack and then taking it up too rapidly

can cause excessive

vibration in the rope.

This is especially

true on bailless dip-

pers. Vibration can

be minimized bystarting the digging

cycle slowly and

loading the rope

gradually while

increasing the ten-

sion on the rope.

Adjusting the digging angle can also reduce the

load on wire rope. Loading increases with the dig-

ging angle and crowd distance (Figure 28).

At a digging angle of 15 it takes 1.035 times as

much power, or 3.5% more, to lift a given load as

it does directly below the boom point. At an angle

of 45 it takes 41.4% more power. And at an angle

of 60 it takes twice as much power.

Digging as low under the boom point as possible

helps to reduce rope stress and extend the useful

life of wire rope.

Page 28


4100A

LC ROTATIONLC ROTATION

Figure 28 The load on the hoist rope increases with the digging angle. At a dig angle of

15, it takes 3.5% more power to lift a load as it does directly beneath the boom point. At

60, twice as much power is required.

60

45

15 30

0

Dig Angle Affects Power RequirementsDig Angle Power Required

to Lift Load*0 100%15 103.5%30 115.4%45 141.4%60 200%

*As a percentage of load


33/40

DraglinesAs with shovels, the most efficient digging range

is directly beneath the boom point (Figure 29).

Casting the bucket beyond this point increases the

stress and load on the rope. As the bucket is pulled

closer to the dragline, digging efficiency decreases

and the load on the ropes increases, including the

dump rope(s).

Most of the wear on dragline ropes occurs in the

areas that run through the fairleads, about one-

third to one-half the full length of the rope.

Reversing the drum and bucket ends of the rope

places worn areas of the rope in areas less vulner-

able to further wear, and vice versa.

Some additional wear on drag ropes occurs at the

base of the wedge socket. Resocketing the rope

when there are six broken wires at the drag sock-

et, or at approximately every 1/5 of its service life,

until the rope becomes too short to use will maxi-

mize its useful life.

A heavy application of "sticky" lubricant such as

open gear lubricant in the grooves of the vertical

fairleads can help the rope start and stop the

sheaves and limit the formation of martensite in

the wires.

Used hoist ropes can be salvaged for reuse as drag

ropes by cutting to length sections of used rope

that pass inspection, if the ropes are the same

diameter. Likewise, suitable sections of old hoist

and drag ropes can be used as dump ropes if they

are the right size.

Similarly, dragline rope life can be extended by

reversing them end for end when the ropes reach

approximately 40 to 50 percent of their expected

service life.

Page 29

7 - Recommended Practices for Extending Wire Rope Life

Figure 29 As the bucket is drawn closer to the dragline, the power required to lift the same load increases.


34/40


35/40

BENDABILITY The ability of a rope to bend

in an arc.

BOOM PENDANT A non-operating wire rope

or structural strand secured with end terminations

to provide structural support for the boom.

BRIGHT ROPE Rope that is made fromuncoated wires.

BROOM The spreading out of a rope's strands

and individual wires at the rope's end.

CATENARY A curve formed by a strand or

wire rope when supported horizontally between

two fixed points, e.g., the main spans on a suspen-

sion bridge.

COMPACTED STRAND A type of high per-

formance wire rope whose exterior strands are

purposely flattened to increase the ropes exposedsurface; compacting enhances both fatigue resis-

tance and crushing resistance.

CORE The central part of a rope that serves as

the ropes foundation.

CORRUGATION A wrinkling or shaping into

a series of ridges or furrows.

CRUSHING RESISTANCE A ropes ability

to retain its round shape when outside forces act

on it, especially when multiple wraps or layers of

rope are wound on a reel or drum.DESIGN FACTOR The ratio of a ropes nom-

inal or catalog strength to its anticipated maxi-

mum load in operation.

DOG-LEG A permanent bend or kink in a

wire rope caused by mishandling or improper

operation.

DRUM A cylindrical grooved or smooth barrel

on which wire rope is spooled for storage or oper-

ation.

END PREPARATION A treatment of the end

of a wire rope to prepare it for being pulled by

another rope into a tight opening as in a drum.

END TERMINATION The treatment at the

end of a rope designed to be the permanent end

termination that connects the rope to the load.

FATIGUE RESISTANCE A ropes ability to

withstand repeated bending under stress, as when

passing over a sheave; a relatively large number of

wires in a ropes design improves its bendability.

FILLER WIRE Small wires used in a strand

as spacers between an inner and outer layer of

larger wires.

FLEET ANGLE That angle between the

rope's position at the extreme end wrap on a drum,

and a line drawn perpendicular to the axis of the

drum through the center of the nearest fixed

sheave. See DRUM and SHEAVE.

INDEPENDENT WIRE ROPE CORE (IWRC)

A complete wire rope in its own right used as

the core of a larger wire rope.

INTERNALLY LUBRICATED Wire rope or

strand that has all its components coated with

lubricant.

LANG LAY A method of wire rope construc-

tion in which the crowns of the wires in a strand

appear to be at an angle to the ropes axis.

LAY The pattern in which a strands wires are

helically wrapped around the central wire and the

strands are wrapped around the ropes central

core.

Page 31

Glossary ofCommon Terms


36/40


Page 32

LAY LENGTH The distance measured paral-

lel to the ropes axis in which a single wire makes

one complete helical convolution about the core;also called pitch.

PEENING A flattening on the outer surface of

a wire rope due to the rope contacting a solid

object.

PITCH An alternate term for lay length.

REGULAR LAY A method of wire rope con-

struction in which the crowns of the wires in a

strand appear parallel to the ropes axis.

RESERVE STRENGTH The percentage of a

ropes nominal strength remaining with the ropes

outer layer of wires removed.

SEALE A strand construction in which two

layers of wires, equal in number, are wrapped

around the center wire; the large outer wires rest

in the valleys of the inner layer of wires.

SEIZING A method of preparing the ends of a

rope for installation; soft wire or strand is bound

around the ends the rope to prevent it from flatten-

ing, distorting or unraveling; also called whipping.

SHEAVE A grooved pulley for use with wire

rope.

STRAND A grouping of wires laid in a helical

pattern about a central wire; groups of strands are

laid about the ropes core.

STRETCH The lengthening of a rope under

load.

SWAGE A method that employs hammers to

compact wire rope strands and fittings.

WARRINGTON A strand construction inwhich one of the layers, usually the outer layer, is

made up of alternating large and small wires.

WIRE STRAND CORE (WSC) A wire

strand used as the foundation of a wire rope.


37/40

Page 33

Abrasion resistance . . . . . . . . . . . . . . . . . . . . . . . . .11

Boom Pendants . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Breaking strength . . . . . . . . . . . . . . . . . . . . . . . .13,16

Broken wires . . . . . . . . . . . . . . . . . . . . . . . . . . .17-19

Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . .11-14

Classifications . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-8

Compacted strand . . . . . . . . . . . . . . . . . . . . . . . .12-13

Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-8

Cores . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Corrugation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20Cross-laid strand . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Crushing resistance . . . . . . . . . . . . . . . . . . . . . . . . .14

D/d ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Dead wraps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Design factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Draglines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

End preparations . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Extending wire rope life . . . . . . . . . . . . . . . . . . .27-29

Extra extra improved plow (EEIP or XXIP) . . . . . . . .4

Extra improved plow (EIP) . . . . . . . . . . . . . . . . . . . .4

Fatigue resistance . . . . . . . . . . . . . . . . . . . . . . . .11-12

Ferrule becket . . . . . . . . . . . . . . . . . . . . . . . . . .22-23

Fiber core (FC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Filler wire (FW) . . . . . . . . . . . . . . . . . . . . . . . . . . .6-7

Finishes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Fist grip clips . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Flattened strand . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Grades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Improved plow (IP) . . . . . . . . . . . . . . . . . . . . . . . . . .4

Independent wire rope core (IWRC) . . . . . . . . . . .3,13

Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-20

sheaves and drums . . . . . . . . . . . . . . . . . .19-20

Inspection checklist . . . . . . . . . . . . . . . . . . . . . . . . .18Lay

lang . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6

left lang lay (LLL) . . . . . . . . . . . . . . . . . . . . .4

left regular lay (LRL) . . . . . . . . . . . . . . . . . . .4

regular . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5

right lang lay (RLL) . . . . . . . . . . . . . . . . . . . .4

right regular lay (RRL) . . . . . . . . . . . . . . . . . .4

Lay length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Link Becket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Martensite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Measurements . . . . . . . . . . . . . . . . . . . . . . . . . .15-16

Metal loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Mild plow steel (MP) . . . . . . . . . . . . . . . . . . . . . . . .4

Minimum acceptance strength . . . . . . . . . . . . . . . . .13

Minimum catalog strength . . . . . . . . . . . . . . . . . . . .16

Multiple operation (2-Op) . . . . . . . . . . . . . . . . . . . .7

Nominal strength . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Non-preformed wire . . . . . . . . . . . . . . . . . . . . . . . . .6Pad Eye . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Parallel contact core . . . . . . . . . . . . . . . . . . . . . . . .25

Peening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Preformed wire . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Plastic coated rope . . . . . . . . . . . . . . . . . . . . . . . . . .13

Pull-off strength . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Reserve strength . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Retirement . . . . . . . . . . . . . . . . . . . . . . . . . . .16-17,19

Seale (S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Selection guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Service life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Sheave groove gauge . . . . . . . . . . . . . . . . . . . . .19-20

Shovels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Single layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-7

Spelter Sockets . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Storing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Strands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Structural strand . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Swaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Tapered and Welded End . . . . . . . . . . . . . . . . . . . . .23

Terminations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

U-Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Unreeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Warrington (W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Warrington Seale (WS) . . . . . . . . . . . . . . . . . . . . . . .7

Wedge Sockets . . . . . . . . . . . . . . . . . . . . . . . . . .23-24

Winding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Wire strand core . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

X chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Index


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P&H gratefully acknowledges the Wire Rope Technical Board and its Wire Rope Users Manual,

Third Edition for permission to reproduce source material for this publication. We also thank

Bridon American Corp. and Wire Rope Industries, Ltd. for their kind assistance.

Suggestions, Ideas?It is our hope you have found this handbook informative and helpful, but we recognize that every mine has its own

methods of operation and unique set of equipment requirements, and that no single handbook can answer everyones

needs.

If you have any suggestions regarding how we can improve this book, we would be pleased to consider them for

inclusion in a future edition.

Please e-mail your comments and suggestions to P&H MinePro Services at [email protected], or call us at

(414) 671-4400 and ask for Marketing Communications.


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In addition to a full complement of wire rope from the industrys leadingmanufacturers, P&H offers comprehensive wire rope services, including:

Wire rope recommendations based on applications analysis

Wire rope installation

Wire rope handling and maintenance training

Sheave and drum re-grooving/replacement

Wire rope inspection and failure analysis

P&H TripRite dipper trip control system

For further information, contact your local P&H MinePro Services representative or call 1-888-MINEPRO. Outside

the U.S. and Canada, phone (414) 671-4400 or fax (414) 671-7785. Visit us on the internet at www.minepro.com.

Serving All Your Wire Rope Needs

2) Peak Performance Practices - Wire Rope

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Transcript of 2) Peak Performance Practices - Wire Rope