crane wire rope inspection
TRANSCRIPT
Crane User’sGuide
Contents Page(s)
Choosing the right wire rope for your application . . . . . . . . . . 4
Wire rope recommendations for crane applications . . . . . . . . 6
XLT4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Ropes for rotational stability . . . . . . . . . . . . . . . . . . . . . 9
Flex-X 7CC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Wire rope weights and minimum breaking force for cranes . . . 11
Guidelines for installation and maintenance . . . . . . . . . . . 12
How to inspect and when to replace your wire rope . . . . . . . 14
How to identify and correct problems with your wire rope . . . . 16
Drum spooling . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Rope unbalance . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Block rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2
It takes more than the right wire ropes to operate your cranes. It also takes the right knowledge
and experience. When you know the ropes – that is, how to choose, use and maintain each of the many types of ropes – you’ll know how to assure maximum service life and performance for each crane application.
When it comes to showing you the ropes, no one does it like Union, a WireCo WorldGroup brand. As the largest producer of wire rope, we offer everything you need for your crane’s wire rope needs. Eight WireCo WorldGroup manufacturing operations and seven distribution centers in North America, plus manufacturing facilities in Germany and China, give our customers unparalleled support and global reach. Union can deliver the right wire ropes for your machine and application no matter where your worksite may be. All the more reason to call us.
This crane user’s guide is only one example. On the following pages, you’ll gain valuable information to help you:
Choose the right wire roPes. Knowing the ropes starts by understanding the wide variety of wire ropes available for your many needs. This guide contains practical information to help you.
Care and maintain wire roPes.You can help assure maximum service life and performance by following the proper care and maintenance procedures – including regular inspections – outlined in this guide.
identify and Prevent Common Problems in the field.This guide also tells you how to recognize and prevent some of the more common causes of wire rope damage during handling, installation and usage.
let us show you the ropes
broad range. best manufacturer. Unmatched support.
At Union, we understand the crane market . Our years of climbing on the rigs with you,
combined with the latest metallurgical practices and unique design capabilities, have
enabled us to continue to innovate and provide the most cost effective line of crane ropes in
the world . Union is part of the global leader in manufacturing, engineering and distributing
wire rope, wire rope assemblies, high carbon wire, and electromechanical cable: WireCo
WorldGroup . We apply thorough design and manufacturing controls – including complete
material traceability. And we are the only manufacturer in the world that is QPL qualified, API
certified, and registered to both ISO 9001:2000 and AS-9100 Quality Systems. So buy from
the best…WireCo WorldGroup – The world is our worksite .
3
W ith each application, your choices of wire ropes can be many. How do you know
which one works best for you? Ropes include a combination of characteristics that give them specific performance abilities. Before you choose, it pays to look closely at each rope’s special characteristics.
no single wire roPe Can do it allAll wire ropes feature design characteristic tradeoffs. In most cases, a wire rope cannot increase both fatigue resistance and abrasion resistance. For example, when you increase fatigue resistance by selecting a rope with more wires, the rope will have less abrasion resistance because of its greater number of smaller outer wires.
When you need wire rope with greater abrasion resistance, one choice is a rope with fewer (and larger) outer wires to reduce the effects of surface wear. But that means the rope’s fatigue resistance will decrease. That’s why you need to choose your wire rope like you would any other machine. Very carefully. You must consider all operating conditions and rope characteristics.
the basiC CharaCteristiCsof wire roPeHow do you choose the wire rope that’s best suited for your job? Following are the most common characteristics to be considered when selecting a rope for an application.
Strength Wire rope strength is usually measured in tons of 2,000 lbs. In published material, wire rope strength is shown as minimum breaking force or nominal (catalog) strength.
These refer to calculated strength figures that have been accepted by the wire rope industry.
When placed under tension on a test device, a new rope should break at a figure equal to – or higher than – the minimum breaking force shown for that rope.
The published values apply to new, unused rope. A rope should never operate at – or near – the minimum breaking force. The minimum breaking force of the rope must be divided by the design factor required for the application to determine the maximum load allowed on the rope. During its useful life, a rope loses strength gradually due to natural causes such as surface wear and metal fatigue.
FAtIgue reSIStAnce Fatigue resistance involves fatigue of the wires that make up a rope. To have high fatigue resistance, wires must be capable of bending repeatedly under stress – for example, as a loaded rope passes over a sheave during operation.
Increased fatigue resistance is achieved in a rope design by using a large number of wires. It involves both the wire properties and rope construction.
In general, a rope made of many wires will have greater fatigue resistance than a same-size rope made of fewer, larger wires because smaller wires have greater ability to bend as the rope passes over sheaves or around drums. To overcome the effects of fatigue, ropes must never bend over sheaves or drums with a diameter so small as to bend wires excessively. There are precise recommendations for sheave and drum sizes to properly accommodate all sizes and types of ropes.
Choosing the right wire rope for your application
benefit offewer oUtsidewires Per strand
abrasion resistanCe
> Increases with larger wires .> Decreases with
smaller wires .
benefit ofmore oUtsidewires Per strand
fatigUe resistanCe
> Decreases with larger wires .> Increases with
smaller wires .
4
Every rope is subject to metal fatigue from bending stress while in operation, and therefore the rope’s strength gradually diminishes as the rope is used.
cruShIng reSIStAnce Crushing is the effect of external pressure on a rope, which damages it by distorting the cross-section shape of the rope, its strands or core – or all three.
Crushing resistance therefore is a rope’s ability to withstand or resist external forces, and is a term generally used to express comparison between ropes.
When a rope is damaged by crushing, the wires, strands and core are prevented from moving and adjusting normally during operation.
In general, IWRC ropes are more crush resistant than fiber core ropes. Regular lay ropes are more crush resistant than lang lay ropes. 6-strand ropes have greater crush resistance than 8-strand ropes or 19-strand ropes. Flex-X® ropes are more resistant than standard round-strand ropes.
reSIStAnce to metAl loSS And deFormAtIon Metal loss refers to the actual wearing away of metal from the outer wires of a rope, and metal deformation is the changing of the shape of outer wires of a rope.
In general, resistance to metal loss by abrasion (usually called “abrasion resistance”) refers to a rope’s ability to withstand metal being worn away along its exterior. This reduces strength of a rope.
The most common form of metal deformation is generally called “peening” – since outside wires of a peened rope appear to have been “hammered” along their exposed surface.
Peening usually occurs on drums, caused by rope-to-rope contact during spooling of the rope on the drum. It may also occur on sheaves.
Peening causes metal fatigue, which in turn may cause wire failure. The hammering – which causes the metal of the wire to flow into a new shape – realigns the grain structure of the metal, thereby affecting its fatigue resistance. The out-of-round shape also impairs wire movement when the rope bends.
reSIStAnce to rotAtIon When a load is placed on a rope, torque is created within the rope as wires and strands try to straighten out. This is normal and the rope is designed to operate with this load-induced torque. However, this torque can cause both single part and multiple part hoisting systems to rotate. Load-induced torque can be reduced by specially designed ropes.
In standard 6- and 8-strand ropes, the torques produced by the outer strands and the IWRC are in the same direction and add together. XLT4 ropes use the torque created by the strand lay and the rope lay to minimize the total rope torque. In rotation-resistant ropes, the lay of the outer strands is in the opposite direction to the lay of the inner strands, thus the torques produced are in opposite directions and the torques subtract from each other.
“sqUared ends”> Typical example of
breaks due to fatigue .
“CrUshing”> Typical example of
external pressure on a wire rope .
Cross-seCtion of a worn wire
> Original cross-section
> Worn surface
Cross-seCtion of a Peened wire
> Original cross-section
> Peened surface
5
let us show you the ropes you’ll need to keep your cranes working. On the following charts, you’ll see the wire ropes we recommend for your many different applications. Your specific application may vary, of course, and that’s why you can
depend on a world leader such as Union to help you choose the right rope.
wire rope recommendations for crane applications
important note when changing ropes:
mobile Cranes: When changing wire ropes, ensure the minimum breaking force is equal to or higher than the rope it replaces. If you change from a standard rope to a rotation-resistant rope, the required design factor will change. ASME B30.5 requires a design factor of 3.5 for standard ropes and a design factor of 5.0 for rotation-resistant ropes. If changing from a standard rope to a low-torque rope, the required design factor will not change . The XLT4 low-torque rope may be used with a design factor of 3.5.
tower Cranes: When changing wire ropes, ensure the minimum breaking force is equal to or higher than the rope it replaces. ASME B30.3 requires a design factor of no less than 5 for all load hoist ropes .
Anytime you change the construction or grade of the rope on a crane, ensure the crane’s load charts are verified or updated as needed.
aPPliCation reCommended roPe Comments
main hoist rope flex-X® 6 regular lay iwrC Xlt4™ flex-X 35 flex-X 19 Ps regular lay 6 x 26 regular lay iwrC 6 x 25 regular lay iwrC
auxiliary Xlt4
hoist rope flex-X 35 flex-X 19 Ps 19 x 7 8 x 25
boom hoist rope flex-X 9 flex-X 6 regular lay iwrC flattened strand 6 x 26 regular lay iwrC
tag line 6 x 19 regular lay iwrC 6 x 36 regular lay iwrC
Characteristics needed are resistance to bending fatigue, resistance to crushing and resistance to wear . Flex-X 6 provides the best combination of necessary characteristics, plus higher strength. If block rotation is a problem and the drum is grooved, XLT4 is recommended . For smooth drums, Flex-X 35 or Flex-X 19 PS should be considered.
Rotation resistance is a primary concern in an auxiliary hoist and for applications utilizing grooved drums, XLT4 is recommended. For smooth drum applications, Flex-X 35 should be considered . Both of these ropes may be used with a swivel. For less demanding applications, Flex-X 19 PS provides a good combination of rotation resistant properties and resistance to crushing .
The primary characteristic needed in a boom hoist rope is resistance to drum crushing . Flex-X 9 is best suited to handle this situation . Flex-X 6 also works well in many boom hoist applications. Though alternate lay ropes may be specified on your equipment, it generally will not perform as well as those listed here .
Most standard construction ropes will perform in this application .
Crawler and trUCk Cranes
6
aPPliCation reCommended roPe Comments
holding line and flex-X® 6 iwrCclosing line 6 x 26 regular lay iwrC
boom hoist and refer to Crawler Crane sectiontag line
These applications need a solid combination of resistance to fatigue and abrasion. Flex-X 6 fills this need better than conventional ropes .
Clamshells and graPPles
aPPliCation reCommended roPe Comments
hoist rope flex-X 35 Xlt4
trolley rope flex-X 7CC 7-flex 6 x 36
boom hoist rope flex-X 9 flex-X 6 regular lay iwrC flattened strand 6 x 26 regular lay iwrC
tower Cranes
7
Rotation resistance is necessary for block stability in long block fall distances incurred with tower cranes . Flex-X 35 is recommended for this application. XLT4 is also recommended . Both of these ropes may be used with a swivel .
Fatigue resistance and resistance to wear are important for trolley ropes . Flex-x 7CC offers the best combination of these characteristics making it the best choice for trolley ropes .
The primary characteristic needed in a boom hoist rope is resistance to drum crushing . Flex-X 9 is best suited to handle this situation . Flex-X 6 also works well in many boom hoist applications . Alternate lay ropes may be specified on your equipment but it generally won’t perform as well as those listed here .
From Union comes a revolutionary crane rope design called XLT4*. “XLT” because it has extremely
low torque; “4” because it has the minimum breaking force of a 6-strand XXXXIP (4X) IWRC rope.
more lift. less torqUe.lower Cost.What sets XLT4 apart from other ropes is its unique design, which packs more high-tensile steel wire into the rope’s diameter, giving XLT4 one of the highest strength-to-diameter ratios ever achieved – with a minimum breaking force 33% higher than standard 6-strand XIP ropes.
Under load, XLT4 generates near-zero torque, matching or surpassing the stability of Category 1 35 x 7 class rotation-resistant ropes. Yet, thanks to its unique design, XLT4 is not classified as a “rotation-resistant” rope. It can be used with or without a swivel as a mobile crane hoist rope at design factors as low as 3.5 to 1.
And, for value, nothing performs like XLT4. Not only does it cost less than a 35 x 7 classification rope, its compact construction keeps moore steel in contact with sheaves and drums for unmatched resistance to crushing and wear – for lower maintenance, less downtime and longer service life.
faster, more effiCient Crane oPeration.XLT4’s powerful advantages go beyond high strength, low torque and economical cost. With the rope’s high capacity, lifts may be feasible using fewer parts of line – boosting the speed, efficiency and productivity of crane work.
easy to install. easy to Use.While XLT4’s unique construction is different in appearance and feel compared to other wire ropes, you’ll be pleasantly surprised by the way it spools and operates. As with any wire rope, proper installation is key – particularly for the base layers and all layers that do not come off the drum during normal operation. To maximize performance and to avoid “pull-in”, the rope must be spooled on the drum under load, ensuring that the rope is both tight against adjacent wraps and tight around the drum. As with any wire rope, XLT4 will perform better on a grooved drum.
Although differing in appearance and feel, field experience has shown that XLT4 presents no problems in terminations using wedge sockets or wire rope clips. XLT4 requires no special end preparation.
*Patent Pending
Xlt4: extremely low torque – extremely high strength
Xlt4 sPeCifiCations
nominal nominal minimUm aPProXdiameter diameter breaking forCe weightInchES InchES TOnS OF 2000 LBS. LBS./FT.
12 15.8 .045 1/2 17.7 .051 14 21.4 .061
9/16 22.3 .065 5/8 27.4 .079 16 27.8 .079
19 39.0 1.1 3/4 39.2 1.1 22 52.0 1.5
7/8 53.0 1.5 23 56.8 1.6 24 61.7 1.8
1 68.9 2.1 26 72.1 2.1 28 83.3 2.4
1-1/8 86.7 2.6
8
3/16 0.064 1.57 3/16 1/4 0.113 2.77 1/4 5/16 0.177 4.30 5/16 0.18 4.63
3/8 0.25 6.15 3/8 0.26 6.63 7/16 0.43 11.8 0.35 8.33 7/16 0.36 8.97 13 0.60 20.4 1/2 0.49 15.4 0.45 10.8 1/2 0.47 11.6
16 0.90 30.6 9/16 0.65 19.4 0.58 13.6 9/16 0.60 14.7 18 1.2 38.5 5/8 0.78 23.8 0.71 16.8 5/8 0.73 18.1 19 1.3 42.9 3/4 1.16 34.0 1.02 24.0 3/4 1.06 25.9
22 1.7 57.2 7/8 1.58 46.0 1.39 32.5 7/8 1.44 35.0 25.4 2.2 75.8 1 2.05 59.8 1.82 42.2 1 1.88 45.5 26 2.3 79.3 1 1/8 2.57 75.2 2.30 53.1 1 1/8 2.39 57.3
28 2.7 91.6 1 1/4 2.83 65.1 1 1/4 2.94 70.5 30 3.1 105 1 3/8 3.43 78.4 1 3/8 3.56 84.9 32 3.5 119 1 1/2 4.08 92.8 1 1/2 4.24 100
rotation-resistant Crane roPes sPeCifiCationsMInIMuM BrEAkIng FOrcES In TOnS OF 2,000 POundS.
ropes that provide load stability can often provide the best and most economical service in specific applications when you
choose, handle and use them properly.
XLT4 ropes are specially designed to provide very low torque, a high minimum breaking force and high resistance to wear in multi-layer spooling. This rope is not “rotation-resistant” and can be used on mobile crane hoist applications at a minimum design factor of 3.5 and can be used with a swivel at the dead end.
Contra-helically laid, rotation-resistant ropes are different from standard ropes because they’re designed to reduce rope torque. Modes of failure and wear for rotation-resistant ropes can differ from those for standard rope constructions. The very nature of these ropes requires special handling, selection and usage not encountered with standard constructions.
These ropes are susceptible to kinking, crushing and unbalancing in the form of “core pops” and “birdcages.” Use extreme care to avoid operational practices that can possibly lead to these conditions.
There are different types of rotation-resistant ropes, categorized by their resistance to rotation. Category 1 rotation-resistant rope (Flex-X 35) has at least 15 outer strands, has three layers of strands (over a center) and has little or no tendency to rotate, or, if guided, transmits little or no torque. Category 2 rotation-resistant rope (Flex-X 19 PS and 19 x 7) has 10 or more outer strands, has two or more layers of strands (over a center) and has a significant resistance to rotation. Category 3 rotation-resistant rope (8 x 19 RTW) has no more than 9 outer strands, has two layers of strands (over a center) and has limited resistance to rotation. For best performance, Category 2 and 3 rotation-resistant ropes should not be used with a swivel. Category 1 rotation-resistant rope handling, installation and usage.
wire ropes for rotational stability
9
Category 1 Category 2 Category 3 fleX-X® 35 fleX-X® 19 Ps 19 X 7 XiP® 8 X 19 XiP®
diameter approx. minimum diameter approx. minimum approx. minimum diameter approx. minimum Millimeter weight breaking Inches weight breaking weight breaking Inches weight breaking lbs. / ft. force lbs. / ft. force lbs. / ft. force lbs. / ft. Force
note: These strengths apply only when a test is conducted with both ends fixed. When in use, the strengths of these ropes may be significantly reduced if one end is free to rotate.
container crane hoist and trolley ropes are subjected to the stressful combination of bending
fatigue and abrasion from operating over a series of intricate sheaves and drums. Union has developed Flex-X 7cc, a wire rope for container cranes that’s so revolutionary it’s guaranteed to provide you with a significant lift in service life when compared with standard ropes.
Flex-X 7cc will operate longer – no matter what load conditions you put it under. A combination of superior design and manufacturing technique helps reduce metal fatigue, internally and externally, while helping to extend the life of sheaves and drums.
fleX-X 7CC lasts longer.Flex-X 7CC’s longer service life will result in lower maintenance costs due to fewer rope changes.
All ropes gradually lose strength due to wear and fatigue but test data has proven that Flex-X 7cc has superior fatigue life over standard rope. With the ropes subjected to the same operating conditions (load and sheave diameter), the chart at right illustrates how Flex-X 7cc’s service exceeded standard rope by 46% when both ropes reached 80% of the standard rope’s strength.
flex-X 7CC, a container crane rope thatguarantees a lift in productivity.
fleX-X 7CC sPeCifiCations
nominal aPProX minimUm diameter weight breaking forCe InchES LBS./FT. TOnS OF 2000 LBS.
1/2 0.50 15.3 9/16 0.63 19.3 5/8 0.80 22.7
3/4 1.13 32.4 7/8 1.55 43.8 1 2.01 56.9
1-1/8 2.54 71.5 1-1/4 3.14 87.9 1-3/8 3.80 106
10
fleX-X 7CC
FLex-x 7CC Standard
6 X 19 and 6 X 36 Class iwrC ComPaCted strand flattened strand
diameter XiP® XXiP® fleX-X® 6 fleX-X® 9Inches approx. weight minimum lbs. / ft. breaking force
6 X 19 & 6 X 36 Class SPEcIFIcATIOnSiwrC / fleX-X 6 and fleX-X 9 / flattened strand roPesMInIMuM BrEAkIng FOrcES In TOnS OF 2,000 POundS.
the 6 x 19 classification of wire ropes includes standard 6-strand round strand ropes with 16 through 26 wires per
strand. The 6 x 36 classification of wire ropes includes standard 6-strand round strand ropes with 27 through 49 wires per strand. Although their operating characteristics vary, all have the same weight per foot and the same minimum breaking force, size for size.
The Flex-X® process compacts each strand, which improves the rope’s strength, stability, abrasion resistance, fatigue resistance and crushing resistance.
These characteristics make Flex-X 6 an excellent choice for the main hoist rope for mobile cranes and the hoist rope on most overhead cranes. Flex-X 9, specifically designed for boom hoist applications, features compacted strands and swaging for extra drum crushing resistance
wire rope weights and minimumbreaking force for cranes.
approx.weightlbs. / ft.
minimumbreakingforce
approx.weightlbs. / ft.
minimumbreakingforce
approx.weightlbs. / ft.
minimumbreakingforce
3/16 1/4 0.116 3.40 5/16 0.18 5.27
3/8 0.26 7.55 8.30 0.32 8.8 7/16 0.35 10.2 11.2 0.41 11.9 1/2 0.46 13.3 14.6 0.55 15.3
9/16 0.59 16.8 18.5 0.70 19.3 5/8 0.72 20.6 22.7 0.86 22.7 0.95 26.2 0.74 21.7 3/4 1.04 29.4 32.4 1.25 32.4 1.35 37.4 1.06 31.0
7/8 1.42 39.8 43.8 1.67 43.8 1.85 50.6 1.46 41.9 1 1.85 51.7 56.9 2.18 56.9 2.40 65.7 1.89 54.4 1 1/8 2.34 65.0 71.5 2.71 71.5 3.05 82.7 2.39 68.5
1 1/4 2.89 79.9 87.9 3.43 87.9 2.95 84.0 1 3/8 3.50 96.0 106 4.25 106 3.57 101 1 1/2 4.16 114 125 5.01 125 4.25 119
1 5/8 4.88 132 146 4.99 140 1 3/4 5.67 153 169 5.79 161 1 7/8 6.50 174 192
2 7.39 198 217 2 1/8 8.35 221 244 2 1/4 9.36 247 272
note: Many wire ropes are also available in PFV, a plastic impregnated rope design from Union .
standard 6 X 19 Class and6 X 36 Class Crane roPes.
11
the Preferred teChniqUe forinstalling roPe onto a Crane.
1. Unload roPe ProPerly and relieve any twists.
Pull the rope off the shipping reel or unroll it from a shipping coil as shown. (If done improperly, you may kink the rope, which will result in permanent damage to the rope.) Then lay the rope on the ground in a direct line with the boom. This helps release any twist in the rope.
2. attaCh roPe’s end to drUm. Pull the rope over the point sheave and attach the end to the drum. Before making any end attachment, be sure the rope strands are free to adjust. (In other words, make sure the end of the rope is not welded together.)
3. wind roPe onto drUm slowly and CarefUlly. At this point, it isn’t necessary to provide additional load other than the weight of the rope being pulled across the ground.
4. sPool first layer tightly. It’s essential on smooth-faced drums
that the first layer is spooled with wraps tight and close together since the first layer forms the foundation for succeeding layers. If need be, use a rubber, lead or brass mallet (but never a steel hammer) to tap the rope in place.
5. sPool mUltiPle layers with sUffiCient tension. It’s very important to apply a tensioning load to the ropes during the rope breaking-in process. (If not, the lower layers may be loose enough that the upper layers become wedged into the lower layers under load, which can seriously damage the rope.) The tensioning load should range from 2 to 3% of the rope’s minimum breaking force.
6. for roPes in mUlti-Part systems: Reeve the traveling block and boomtip sheaves so the rope spacing is maximized and the traveling (hook) block hangs straight and level to help assure block stability. Avoid dead-ending the rope at the traveling block if possible.
7. CheCk roPe for twist. With the rope slack, pull enough rope out to allow it to hang in a loop (right). If the rope hangs without twisting together, there is no twist in the rope. If the rope twists together (left), the rope has twist in it. Follow steps shown on next page to relieve twist from the rope.
guidelines for installation and maintenance.
when yoU’re installing wire roPe, there’s a Primary ConCern:
Getting the rope on the equipment without trap-ping any twist that may have been induced during handling or installation .
Unreel rope from a shaft supported by two jacks. Uncoil rope by rolling it along ground like a hoop.
make sure the foundation layer is spooled tightly.
the result of improper tensioning is a “pulling in” of the rope.
incorrect Correct
twist in rope no twist
12
breaking in yoUr new wire roPe.After installation, you should properly break in your rope, which allows the rope’s component parts to adjust themselves to your operating conditions.
With the boom fully raised – and fully extended if you’re using a hydraulic boom – attach a light load at the hook and raise it a few inches off the ground. Allow to stand for several minutes. Then cycle the load between the full “up” and “down” positions several times. Stand back and watch the drum winding and rope travel for any potential problems.
After making the lifts with a light load, increase the load and cycle it up and down a few times. This procedure will train the rope and help assure smooth operation during its useful life.
Ideally, you should run these loads with reeving that lets you place the loads on the block with all rope off the drum except the last three wraps. If this isn’t possible, alternate methods must be used to assure proper tensioning of the rope on the drum.
always leave three wraPs on drUm.Although ASME B30.5 states that two wraps must remain on the drum when the hook is in the extreme low position, we recommend at least three wraps always remain on the drum.
rigging in tight qUarters.If you can’t lay the new rope out on the ground before rigging – and you need to pull it directly from the reel – further steps are necessary. First, you should mount the reel on a shaft through flange holes and on jack stands, making sure you spool as illustrated below. While unspooling, do not allow the reel to “free-wheel.” Brake the reel by applying pressure to a flange. Never apply braking pressure to the rope on the reel – or pass the rope between blocks of wood or other material.
relieving twist.To relieve twist that may be trapped in a rope spooled directly off a reel to the drum, raise the boom to its highest position while letting out the rope until the rope almost touches the ground. Let the rope hang free without added load while standing clear. When twist is fully relieved, proceed with rigging the crane.
lUbriCate roPes often for long life.To properly maintain your rope, the first place to check is for obvious signs of abuse from other parts of the rope system. But the biggest part of maintenance involves regular lubrication to reduce friction between the rope’s components as well as the friction between rope and sheaves or drums.
Your rope receives internal lubricant at the factory, but it’s not enough to last the rope’s entire life due to constant bending over sheaves and drums. The need to keep ropes properly lubricated can’t be overemphasized.
Clean roPes first.Remove excess dirt, rock dust or other materials that can prevent field-applied lubricants from properly penetrating into the ropes.
lUbriCate Using one of two methods.One is called manual lubrication such as spray or drip systems that apply lubricant when you want. You can also swab or paint lube into your moving rope by hand, or pour lube onto your rope as it passes a certain point.
The other is called automatic lubrication that drips or sprays lube onto your rope as it passes over a sheave at preselected intervals.
install from reel top over the point sheave.
what lUbriCant shoUld yoU Use?
There are two lubricants you should not use. never apply heavy grease to the rope because it can trap excessive grit and dust, which can externally damage the rope or be forced inside, causing hidden damage. nor should you apply used “engine oil” because it contains materials that can damage your rope .
The kind and amount of lubricant will vary according to the type and use of your wire rope . But the lubricant should have these traits:
> Penetrate to the rope core . The best way is to apply at a place where the rope bends, such as over a sheave, exposing the wires and strands to provide a better opening to the core .
> Contain enough adhesive and film strength to stick to wires in the rope and the spaces around the wires .
> Be free of acids and alkalis .
> Resist corrosion .
> Stay put without being easily washed away .
13
despite their durability and strength, wire ropes used on cranes will wear out and
need to be retired from service. That’s why regular inspection is so crucial to your long-term success. It’s important to appoint a qualified trained person to conduct the inspection and understand the mechanics of inspection. This section offers you general guidelines, but for more detailed information, please consult our Techreport 107.
how often to insPeCt.Obviously, the more you use a wire rope, the more often you need to inspect it. According to the ASME standards, owners or users are required to visually inspect all wire ropes at least once every day when in use. A qualified, trained person should be appointed to conduct the inspection. That person is also required to periodically inspect all wire ropes and keep a written record, noting any damage and recording when ropes are replaced. This will give you a basis for judging the proper time to replace your ropes.
We recommend you set up a long-range inspection program, including examination of ropes removed from service.
foCUs on yoUr roPe’s CritiCal Points.While you’re required to inspect the entire rope length, we recommend you pay particular attention to the critical points of a wire rope. These are the points subject to greater internal stresses, greater external forces or are more susceptible to damage. Rope deterioration normally occurs more quickly at these points, so it pays to expand your inspection in these important areas:
PiCk-UP Points. These are sections of ropes repeatedly placed under stress when you apply the initial load of each lift such as those sections contacting the sheaves or on the drums.
end attaChments. Attachments at the dead end and drum restrict the free movement of wires, normally leading to broken wires that are more difficult to detect. Inspect with an awl to expose them, and if you find more than one broken wire, replace the rope or cut off the affected area and reattach the fitting. Corrosion can be more prevalent in this area. Be sure to also inspect the fitting itself.
drUms. Check for signs of wear that could damage wire rope. For grooved drums, inspect the grooves for smoothness and absence of corrugation. For smooth drums, check for wire rope corrugation. It’s also important to verify that the required minimum number of dead wraps remain on the drum and to check the condition of the drum flanges.
sheaves. The grooves on sheaves usually
how to inspect your wire ropes.
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> It’s important to remember there are minor – sometimes major – differences among applications, even on machines with similar designs .
That’s why it takes the best judgment of a trained, knowledgeable inspector to choose the critical points on each rope application for closer inspection .
how to find broken wires.
One of the most common signs of rope deterioration is broken wires, normally the outside wires at the crowns of the strands . During your inspection, it’s very important to search for broken wires, especially the areas of the rope in contact with sheaves and drums when loads are picked up .
1. The first step is to relax your rope to a stationary position, move the pick-up points off the sheaves . Clean the grease from the rope with a cloth – a wire brush, if necessary – so you can see any breaks .
2 . Flex the rope to expose any broken wires hidden in the valleys between the strands .
3. Visually check for any broken wires. One way is to run a cloth along the rope to check for possible snags .
4 . With an awl, probe between wires and strands and lift any wires that appear loose . Evidence of internal broken wires may require a more extensive rope examination.
wear smaller over time. With a groove gauge, check each sheave for proper groove size and contour, as well as smoothness. Grooves that are too small or tight can cause pinching and increased wear while grooves that are too wide can cause flattening of the rope – both of which can reduce your rope’s life.
heat eXPosUre. Watch for evidence of heat exposure which can damage the rope and its lubricant. Any contact
with an electrical arc such as welding is reason for removal of the entire rope. Never use the rope as the ground for an arc welder.
abUse Points. Check for “bright” spots where ropes are subjected to abnormal scuffing and scraping. Look for any condition that causes the rope to be asymmetrical.
typical valley wire breaks.
typical crown wire breaks.
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According to the ASME B30.5 standard for mobile cranes, there are no precise rules to
determine the exact time to replace rope because so many variables are involved. Once a rope reaches a specified removal criteria, it may be allowed to operate to the end of the work shift, based on the judgement of a qualified person. The rope should be replaced after that work shift at the end of the day – or at the latest prior to the equipment being used by the next work shift.
The following required standards established by ASME B30.5 that provide specific reasons to replace wire ropes.
broken wires. For running ropes including XLT4 ropes, replace when you see six randomly distributed broken wires in one lay – or three broken wires in one strand in one lay.
For rotation resistant ropes categories 1, 2 and 3, replace when you see two randomly distributed broken wires in six rope diameters – or four randomly distributed broken wires in 30 rope diameters.
Broken wire removal criteria apply to wire ropes operating on steel sheaves and drums. The user should contact the sheave, drum or crane manufacturer for broken wire removal criteria for wire ropes operating on sheaves and drums made of material other than steel.
one broken wire eXtending from roPe’s Core. When you see one outer wire broken at the point of contact with the rope’s core which has worked its way out or looped out from the rope structure, you’ll need to conduct additional inspection of that section of rope.
eXtensive roPe wear. When wear reaches one-third the original diameter of the outside individual wires, it’s time to replace the rope.
roPe distortion. Replace any rope with evidence of kinking, crushing, birdcaging or any other damage resulting in distortion of the rope structure.
heat damage. Because heat exposure can damage the rope and its lubricant, always remove ropes damaged by heat from any cause.
when to replace your ropes.
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redUCtions in nominal diameter.Replace any rope when its measured diameter has decreased more than 5% below its nominal diameter.
what rePlaCement roPe to Use.Your replacement rope should have a minimum breaking force at least as great as the original rope furnished or recommended by the crane manufacturer. Any deviation from the original size, grade or construction must be specified by the wire rope manufacturer, crane manufacturer or a qualified person. See pages 6-7.
what aboUt idle roPes? All wire ropes that have been idle for one month or longer due to shutdown or storage of the crane on which they’re installed should be inspected according to ASME standards before you place them in service. Make sure an authorized person inspects for all types of rope deterioration.
always measure the largest dimension when measuring your rope.
Proper method of measuring ropes with odd number of outer strands, using caliper with plates.
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how to determine the ProPer direCtion of drUm winding.
Overwind left to right, use right lay rope .
right lay overwind
Underwind right to left, use right lay rope .
right lay Underwind
Overwind right to left, use left lay rope .
left lay overwind
Underwind left to right, use left lay rope .
left lay Underwind
drUm sPooling: a tight sitUation for Crane oPerators.
When you’re installing a new rope onto a crane, there’s a primary objective: spool
the rope onto the equipment tightly without trapping any twist in the rope on the drum. (See installation guidelines for details.)
For multiple-layer spooling, it’s essential to get the first layers of rope spooled with sufficient tension. Particularly with smooth-faced drums, the first layers must be tight with each wrap snug against the preceding wrap. Since the first layer provides the “grooving” for upper layers, wraps must be placed tightly together. If not, wraps in upper layers will pull down between wraps already on the drum, which can cause crushing damage and reduced rope strength and service life.
When you encounter spooling problems, check the following list to identify the possible cause. If any of these are incorrect, the result can include open (or loose) spooling, random spooling or stacking of rope against drum flanges.
drUm alignment.Before spooling, make sure the drum is level and at right angles to the boom. Many drums are mounted on the frame so that adjustment can be made in alignment.
drUm winding.Wire rope should wind onto the smooth-faced drum as shown. Make sure you wrap the rope left or right and over or under as recommended.
Use of a swivel.Except for Category 1 rotation-resistant ropes and XLT4, a swivel end termination will let the rope lay lengthen when loaded. As the rope spools onto a drum, the unlaid rope travels over the point sheave and accumulates between the drum and point sheave. This leads to block rotation, erratic spooling, unbalancing and decreased rope service. Category 1 rotation resistant ropes and XLT4 may be used with a swivel without these concerns.
fleet angle.One of the most important factors in proper winding of rope on drums. For smooth-faced drums, this angle should be between 1/2° and 1-1/2”. For grooved drums, it should be between 1/2” and 2”. Fleet angles larger than these can cause spooling problems and the rope to rub against the flanges of the sheave – plus may lead to rope crushing and abrasion on the drum. Fleet angles smaller than these may cause the rope to pile up at the flanges.
Point sheave.When more than one sheave is in use at the boomtip, make sure the lead line presents the optimum fleet angle to the drum.
how to identify and correct three common problems in the field.
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grooved drUms.Groove spacing must be adequate to prevent the rope from crowding out adjacent wraps as the rope spools across the drum. In addition, groove spacing must not be excessive, which can allow wraps of the next layer to pull down between wraps of the previous layer, causing abrasion and crushing.
drUm flanges.Flanges should be perpendicular to the drum face and not worn, deformed or spread outward. These conditions can cause spooling problems at the change-of-layer point as additional layers are spooled.
imProPer installation.When a rope has been installed in such a way that twist has been introduced into the rope, spooling problems can result. (See installation guidelines for details.)
riser striPs and kiCk Plates.If spooling problems persist after you’ve considered the above conditions, try using riser strips and kick plates. For details on these accessories, check with your crane manufacturer or call Union for technical service.
Also called “wavy rope,” unbalance is an indication or result of abnormal movement of
strands in an operating rope. It usually involves two or more outer strands of rope rising out of position, standing higher than remaining strands with no apparent cause or evidence of external physical force .
Anytime you see an unbalanced rope, you should increase your rope inspection frequency . Find out the cause and correct the problem before you install your next rope .
the causes.Unbalance often shows up in the middle of a rope system where you don’t expect it. It’s usually caused by “milking” of the rope – in other words, a lay change in the rope . The causes are many: swivels, small diameter sheaves, improper-sized or worn sheave grooves or sheave misalignment, to name a few .
Standard 6-strand regular lay ropes are generally more resistant to unbalance than other ropes .
how to correct unbalance problems.There are several practices you can implement to minimize rope unbalance problems . These include:
ELIMInATE SWIVELS AT dEAd EndS. A swivel end termination will lengthen the lay in the rope when
loaded, which can cause an unbalance in the rope .
rEMOVE WELdEd EndS OF rOPES. Where a rope has been torch cut, make sure the strands are free to adjust before the rope is clamped or seated in an end termination . However, this does not apply to Flex-X 35. Leave the welded ends on Flex-X 35
LOOk FOr Any ShEAVE MISALIgnMEnT. Misalignment of sheaves in multi-part reevings and improperly aligned idler sheaves can also contribute to unbalance problems .
ASSurE PrOPEr grOOVE cOnTOurS. Use a groove gauge to inspect sheave and drum grooves for proper contour. If sheave grooves are too small or are worn deeper and narrower by an old rope, they’re too tight for new ropes. If grooves are too wide, the ropes tend to flatten out and become oval-shaped . Any of these conditions can restrict strand movement and cause twist to build up in the rope .
cOnSIdEr A 6-STrAnd rOPE cOnSTrucTIOn.Standard 6-strand regular lay ropes are less susceptible to unbalance than other ropes .
rEMOVE Any TWIST In rOPE. See rope installation guidelines for details .
Cross-seCtion views of three sheave
groove Conditions.
A B CUsing a gauge, a is correct, b is too tight and C is too loose.
Rope unbalance: a problem of unequal proportions .
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150˚
A lso called cabling, block rotation occurs when multi-part reeving twists together
at a certain height, entangling the parts of rope between the traveling block and boomtip. It can happen with little warning, making it virtually impossible to lift or lower a suspended load. Twisted hoist lines can bring a construction project to a sudden halt, resulting in downtime.
But the good news is this. You can minimize block rotation through proper installation and handling, as well as take corrective measures
the key is Understanding torqUe.Every wire rope – regardless of type, classification, grade or manufacturer – will develop torque when loaded.
Torque is normal and natural, caused by the way wire ropes are made. Wires are first laid together in a spiral to form strands, then several strands are laid together in a spiral to form the rope. When loaded, wires and strands try to straighten out, thus creating torque.
Another source of torque is any change in the rope lay length. This is normally caused by “milking” or rotation at the end of the rope.
Torque in a rope affects the tendency of the traveling block to rotate. Thus, it’s important to minimize any torque.
how to helP redUCe bloCk rotation.There are at least seven different operating practices you can use to minimize block rotation on your crane.
Change the rigging geometry. This includes the following operating practices:
– Use larger diameter traveling block sheaves to increase the rope spacing. As the diameter of the traveling block sheave increases, the chances for block rotation are reduced.
– Use the outer (farthest apart) sheaves – traveling block and boom.
– Dead-end the rope at the boomtip to increase the spread between the wire rope parts.
Use the shortest fall length Possible. The length of fall, or the distance from the pick point to the point sheaves, is critical. Longer fall lengths are less stable and more likely to lead to block rotation.
avoid odd-Part reeving. An even number of parts is more stable.
Use taglines on lifts. Attach a tagline to restrain the load block and keep the load from rotating.
block rotation: a very entangling problem.
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Use a different roPe ConstrUCtion. Standard 6-strand ropes do not provide any rotation resistance. There are different levels of rotation resistance that can be obtained from specialty ropes. For maximum block stability use XLT4. The unique design of XLT4 results in extremely low torque under load. This characteristic makes XLT4 one of the most stable ropes in multiple part reeving comparable to Category 1 rotation-resistant ropes. Both XLT4 and Category 1 ropes are also used in single part hoisting.
There are other specialty ropes that provide lower levels of rotation resistance. These ropes have been divided into categories based on their rotation resistance. The lowest level of rotation-resistant ropes is Category 3 which include our 8 x 25. Our Flex-X 19 PS and 19 x 7 ropes are Category 2 rotation-resistant ropes. They provide greater rotation resistance than Category 3 ropes. Flex-X 19 PS is very resistant to crushing in multiple layer spooling and is frequently used in multi-part hoisting applications.
Use a swivel only with Xlt4 and Category 1 roPes. XLT4 and Category 1 ropes, due to their special design, may be used with a swivel. Other wire ropes should not be used with a swivel.
With standard ropes, Category 2 (Flex-X 19 PS and 19 x 7) rotation-resistant rope and Category 3 (8 x 25) rotation-resistant rope, a swivel in an end termination will allow rotation in a direction that unlays the outer strands when the rope is loaded. This can cause a reduction in rope strength, unbalance in the rope and spooling problems.
While the rope rotation only occurs between the swivel and the first sheave, the unlaid rope travels over the sheave as the load is lifted and introduces unlaying to the section of the rope beyond the sheave. This unlaying becomes trapped and will not come out of the rope when the load is removed.
The trapped unlaying causes twist in the rope, which leads to block rotation, erratic spooling, unbalancing and decreased rope service. Remove the swivel from the rope termination and follow steps to remove twist from the rope to optimize rope service.
CheCk sheave alignment and groove size. Improper sheave alignment or groove size can “milk” the lay in a rope and cause torque.
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L
D
S
Industry testing has been conducted to help you assess the block stability of your rigging configuration and
rope selection. The bands on this graph approximate the block stability for four types of wire ropes in multi-part systems:
– 6-strand, right regular lay, IWRC– Category 3 (8-strand, rotation-resistant)– Category 2 (19-strand, rotation-resistant)– XLT4 & Category 1 (35 x 7 rotation-resistant.
four independent variables are used in pairs to locate a reference point on the graph that indicates the stability of the lift being made. the ratios used include:
L/S = Length of fall (ft.) ÷ Spacing of the rope (ft.).
L = Length of fall measured from the centerline of the point sheave to the centerline of the traveling block sheave as shown in the diagram .
S = Average diagonal spacing of the rope at the boom point and the traveling block sheaves as shown in the diagram .
d/d = (d) Average pitch diameter of point and block sheaves (in.) ÷ (d) nominal rope diameter (in.).
For 2-part reeving, S = average pitch diameter of point and block sheave
For 3-part reeving, S = 2/3 of 2-part
For 4-part reeving, S = diagonal distance of rope parts
For 5-part reeving, S = 4/5 of 4-part
For 6-part reeving, S = diagonal distance of rope parts
For 7-part reeving, S = 6/7 of six-part system
Some graphs were developed in field research jointly conducted by Wire Rope Technical Board and the Power crane and Shovel Association.
when the reference point on the graph lies above the appropriate band, block rotation will probably occur. if the reference point lies below
how to evaluate block stabilitydue to rigging geometry.
The band for XLT4 and Category 1 rotation-resistant ropes is based on torque values . The bands for 6-strand, Category 2 and Category 3 rotation-resistant ropes were developed in field research jointly conducted by Wire Rope Technical Board and the Power crane and Shovel Association .
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warning
In the real world, accidents do happen,and that’s why you need to take specialprecautions. Before installing wire rope
in your applications, always read andfollow the warning label attached toeach product.
Any warranty, expressed or implied as to quality, performance or fitness for use of wire rope products is always premised on the condition that the published strengths apply only to new, unused rope, that the mechanical equipment on which such products are used is properly designed and maintained, that such products are properly stored, handled, used and maintained, and properly inspected on a regular basis during the period of use .
Seller shall not be liable under any circumstances for consequential or incidental damages or secondary charges including but not limited to personal injury, labor costs, a loss of profits resulting from the use of said products or from said products being incorporated in or becoming a component of any other product .
warranty
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Our manufacturing standards typically exceed the minimum design standards for a wire rope. We take an active role in industry associations that develop wire rope specifications and standards, such as ASTM A1023.
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