major developments in rope technology and its …€¦ · major developments in rope technology and...
TRANSCRIPT
Major developments in rope technology and its implications for transforming hoisting performance
November 2015, Dr. Oliver Fries
Agenda
Who are we?
Trends in the crane rope industry
Steel wire ropes
Hybrid ropes
Synthetic ropes
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• Steel wires• Steel wire ropes• Electro mechanical cables
• High performance wire ropes for crane and mining markets
• Leading manufacturerof synthetic ropes
• High performance wire rope forcrane and fishing market
• Synthetic rope manufacturer
• Steel wires• Wire ropes• Low cost manufacturing
• Synthetic rope manufacturer• Engineered products• Manufacturer of nets
• Global oil & gas wire ropes• Specialty crane ropes• Mining ropes• Engineered assemblies for OEMs
Who are we? Significant dates in our history
• Structural projects
In addition to these acquisitions, we have grown in the past few years by providing the best quality, innovation and service.
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Trends in the crane rope industry (1/2)
Basic requirements - sufficient for most of the smaller cranes types
– Rotation resistance for low lifting heights
– Spooling behavior on drums
– Corrosion resistance
– Meet breaking force
– Diameter tolerance
Performance requirements - demands are increasing with new cranes
– Higher rotation resistance needed for higher lifting heights
– Diameter tolerance over complete length
– Wire quality (spec. above standard; limit of wire grade)
– Excellent crushing resistance on drums
– Higher MBL (benefit from smaller rope diameter)
– Special features (high compaction, swaging, plastic)
– Higher Lifetime
No special
trend
Permanent
improvement of
existing designs
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Technical trends in the rope industry (2/2) Special requirements for solving problems
– Early discard on drums of bigger mobile cranes
– Limit of rotation resistance with high lifting height and low reeving (high MBL)
– Rope diving on drums (low pretension)
New innovative designs and material
– Hybrid ropes
– Synthetic ropes
– Smart Rope (Future)
EN 13001-3-2 new version (CEN/TC147 in 2014)
– New: Proof of static strength and fatigue strength
– Life time calculation is not accurate in the new standard
– ISO 16625 in combination with M-class definition in ISO 4301 are based on long term experience
Cost saving initiatives by the OEM
– What is the most cost effective rope for the application
– Where are compromises concerning performance and quality possible?
Addressed by
EWRIS/DSV/
Universities and
FEM working
group
High focus area
New design ideas
necessary
High attention in
the market.
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Steel wire rope – Flattening of wires (1/4)
Some hoist ropes on bigger mobile cranes (crawler and all terrain) are facing issues with flattening of wires mainly in cross over zones of the drum
Mainly with newer models
This known effect was not a problem in the past in the mobile crane industry and is independent on the rope manufacturer or existing rope designs
Lifetime of ropes dropped down in some cases to 25%
Two stages: Flattening effect (1) and wire breakes (2) as a possible direct consequence
(1) Wire flattening (2) Wire breakes
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Steel wire rope – flattening of wires (2/4)
What is influencing this effect?
Crane
– Drum diameter
– Pretension on the lower layers
– Maximum line pull force
– Length and angle of the drum cross over zone
Rope
– Amount and size of the outer wires
– Smoothness of the outer surface
– Lateral E-Modulus (stiffness)
– Wire material and properties
– Rope design
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Steel wire rope – flattening of wires (3/4)
Possible solutions
Change of the Crane Drum geometry
– Existing drums cannot be changed on mobile cranes easily. Biggest impact by the drum diameter
– Increasing length of the crossover zones and decreasing angle
Reducing maximum line pull
Increase the pretension on lower layers
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Steel wire rope – flattening of wires (4/4)
Possible solutions
Increase of the outer contactsurface of the rope
– Amount of outer strands
– Swaged rotation resistant ropes.Swaging factor like Parafite.g.that is used on boom hoisting
Change of the outer wire
– Impact on wire grade (1770,1960,2160,2260,2350,2400,2xxx)
– Number of wires in the outer strands
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Parafit
16 outer strands 18 outer strands
Doublefit
1+5 1+6
Hybrid ropes – 4 Strand Hybrid (1/3)
• 4 Strand Hybrid
• Torque balanced rope
• Approx. 35% better strength to weight ratio
• LCP fiber (Liquid crystal polymer);
Vectran ultra modulus fiber
• Braided core
• Wedge socket and resin poured button
• Approx +50% in cost
Advantages
Approx. 35% better strength to weight ratio
Better outer protection of the fiber compared to full synthetic ropes
Easy handling during installation and rigging
High bending fatigue values
Removal criteria can be detected visually and with NDT
Outer surface properties like friction is similar to steel wire ropes
Reeving system does not need to be changed
Challenges
Lateral stiffness is lower than steel wire ropes. Rope gets a little oval form when spooling
Proper spooling needs to be done with higher pretension
Hybrid design is currently not covered in the standards
Hybrid ropes – 4 Strand Hybrid (3/3)
Hybrid ropes - Turbolite V1
• 8 Strand Hybrid• High bending fatigue performance
• Use of Aramid fibers (Technora)
• 15% weight reduction
• Developed a new manufacturing method and applied for
another patent in 2013 concerning production improvement
• Multiple versions currently in production in Kirkel for
comparison tests
Drawn galvanized
steel wires used for
compacted outer
strands Plastic Jacket
over the core
Polyester over-braid
on the Technora fiber
core
• Approx. 8% weight reduction
• Core strand made out of fiber
• Focus on mining applications
• 1-5/8” (41mm) Field trial started in
Central Plains Cement - Sugar Creek, MO
• Single drum, two skip winder 750ft
suspended length
• Rope is in use more than 30.000 cycles without issues
• Potential crane applications
• Further field trials mid of 2016
Hybrid ropes - Turbolite V2
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Synthetic crane ropes
Since Conexpo 2014, this topic is discussed in the mobile cranes
Thanks to Samson, Manitowoc and DSM to show a product on a crane
Some market facts:
– 22mm rope replaced 19mm steel wire rope (70t RT crane)
– 12 strand construction with stiff core
– No major changes in the hoisting system
– Price is 2-3 times higher than steel wire rotation resistant ropes
– Positive feedback from crane driver during our investigation
– Several years of testing before release
– Other rope manufacturers are also working on this topic
– Activities started more than 5 years ago
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Synthetic crane ropes – WireCo example
Special drum design needed (patented by Deep Tek)
Used on a knuckle boom crane
Lankhorst created a new rope design with optimized fatigue and load bearing characteristics with special DSM Dyneema fiber and special coating technology
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Synthetic crane ropes – advantages (1/2)
Approx. 80% weight reduction
Actual hook load can be increased especially with high reeving
Easy to handle during installation and rigging
Can save reeving time and amount of operators
Higher safety for the worker that handles the rope
No risk of injury due to broken wires
Very good rotation resistance
Reduced wire damage on drums
No kinking or bird caging
Clean operation without grease
No re-lubrication necessary
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Synthetic crane ropes – advantages (2/2)
High bending flexibility
Corrosion resistance
Better wear resistance on sheave material
Industry experience with similar ropes and fiber material on all kind of applications existing
Good bending and tension fatigue performance
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Synthetic crane rope – challenges (1/4) Temperature range:
– Strength of the rope depends on temperature
– Below 0°C – up to approx +10% higher strength
– Strength is dropping above 0°C; limit at 60°C/70°C
– Influence of the temperature on max. bending cycles
Bending over sheaves is creating temperature dueto friction of the millions of fiber filaments
Missing standard for synthetic crane ropes
– Design, care, maintenance, inspection and discardcriteria are currently not covered
– ASME B30.30 chapter 30-2 and FEM activities
– Visual criteria. No magnetic NDT possible.
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Synthetic crane rope – challenges (2/4)
Drum spooling
– Synthetic ropes have very low lateral stiffness (80-90% lower)
– Change shape (oval) during spooling on the drum is approx. 25 x timeshigher
– Larger diameter reduction under tension
– Need to accept the complete different „look“ of the deformed synthetic ropeon the layers
– Higher sensitivity on the effect on flattening and diving of the rope to lowerlayers when spooled with low prestretching
– End connection on the drum can be a spliced eye with rope breaking force
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Synthetic crane rope – challenges (3/4)
Elongation
– Elastic: at max.load (20%MBL): approx 1.3% vs 0.3% with Steel wire rope
– Viscoelastic: Contraction of the rope recovers after some time
– Permanent: occurs within the first loads; steel wire rope also effected but lower elongation
Cut and abrasion resistance
– Risk of easy sabotage
– Sharp edges can destroy the rope immediately
– Higher abrasion on he drum flanges
– Long complex crane configurations may have abrasion points in certain combinationsand system deformations
– All kind of outside damage on the construction site
– Sharp edges on the groove of existing steel or cast drums can wear out the synthetic rope
– Jacket for outside protection vs possiblitity for visual inspection
UV influence on the exposed fibers over time. Rope is fading after some time
Creep – all synthetic ropes face a certain creep depending on material properties, time, temperature and load – in most cases for mobile cranes not an issue
Effect of ice: abrasion or cutting effects?
Crane overall balance: drum, rope, hook block
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Synthetic crane rope – challenges (4/4)
Due to temperature limit, steel sheaves for heat transfer are recommended
More dead wraps on the drum needed due to lower static friction (approx8x instead of approx 2.5x for steel wire ropes)
Not all end connections can be used so far
– Spliced with a soft eye for drum connection and thimble on the hook
Limited lifetime of the rope and possible loss of breaking strength over years
Drum design: Increased load on the drum barrel and decreased load on theflanges
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Lankodeep® AHC rope
Synthetic crane rope – conclusions
The usage or replacement of steel wire ropes with synthetic ropes for some crane segments will take time and will rather be a evolution over years but not a revolution
Technical challenges and standards need to be solved first before gaining bigger acceptance in the crane market
Need to optimize geometry of rope guiding and storing elements
Limit in substituting synthetic ropes on existing crane models
Further benefit in developing smaller diameter synthetic ropes to reduce dimensions and weight of crane components
Rope cost need to be reduced to an acceptable level
Synthetic Rope design need to be adapted to solve the challenges
WireCo Worldgroup has rope designs in place for field test
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WireCo WorldGroup is the global leader in manufacturing, engineering and distributing
of wire rope, wire rope assemblies, wire, electromechanical cable and high tenacity
fiber ropes and strength members.
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