What are the effects of bending on synthetic fiber ropes and slings, and how do they differ from steel wire and round slings? Dennis and Brooks will address reduction factors and bending fatigue properties of fiber ropes in various lifting applications. Moderator: Tony Fastuca, VP, Sales & Marketing, ASC Python America Speakers: Brooks Nunley, Technical Sales & Key Account Manager, Cortland Company & Dennis Sherman, Technical Sales Manager-Crane, Samson Rope Technologies

1. CBOS
Speaker: Dennis Sherman,
Samson Rope
Technologies

2. What is CBOS?
• Cyclic Bend Over Sheave
• Why is it important?
• Constant bending over sheaves creates:
• Energy which dissipates itself in the form of heat
• Abrasion or “scissoring”
• Heat can create issues with:
• Creep failure in certain fibers
• Accelerated abrasion
• Coating breakdown

3. CBOS Life Predictive Model
Samson has developed a model for predicting cycles to failure (CTF).
Cycles to failure = f(Cycle Speed, Safety Factor, Temperature)
Label Cycle/min as input SF as input CTF as output
Red 6 8.3 20,000
Blue 6 4.8 5,000
Orange 5 4.5 10,000

4. Predicted Life &Temperature
Temperature: Heat generation is a function of SF / Frequency – well understood through existing
empirical data and DSM theoretical model.
*Collaboration with DSM thermal modeling initiative to streamline further tension modeling work.

5. CBOS Life Predictive Model
Samson has developed a model for predicting strength retention following CBOS.
Residual Strength = f (Cycle Speed, Safety Factor, Time, Temperature)
Label CBOS Cycles as input SF as input Residual Strength, %*
Red 11,000 12 80
Blue 5,000 8 95
Orange 25,000 12.5 20

6. Heat-set vs. non heat-set
• Compact structure allows for more
consistent diameter (vs time/loading
history), but…
• Heat-setting reduces overall fatigue life
• Installation tensions and bedding-in to be
considered based on crane/winch
configuration (during development cycle)
Samson does not typically recommend heat-setting rope due to reduction in overall fatigue life.
However, pre-tensioning options can be considered through development process.
Samson Technical Bulletin:
http://samsonrope.com/Documents/Technical%20Bulletins/TB_HMPE%20Post%20Production%20Process_AUG2013_WEB.pdf

7. Coefficient of Friction (CoF)

8. CoF isVariable
• Depends on many factors:
• Drum surface roughness
• Drum material/coating
• Tension
• Contaminants
• Dirt
• Oil
• Paint chips
• Rust
• Wet/dry usage
• Rope wear
• Temperature?

9. Test Methods
Test Method ASTM D3108 Samson
Acceptance
Established and
Recognized
Proprietary
Used For Yarn Rope
Wraps Constant Decreased
Tension Increased Constant

10. 0
2000
4000
6000
8000
10000
0246810
MeasuredLoad(lbs)
Wrap Count
Line Tension
Termination Tension
Test Methods
Spooling Direction
As the rope pays off the winch, loads transfers to the termination

11. CoF Calculations
The peaks indicate static CoF, the moment before the
rope slips on the drum (indicated by the red arrows)
For each θ
position, a CoF
value is calculated
using the
measured loads
on the line and at
the termination.

12. Effect of Oil Contamination
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
CoF
Line Tension
No Oil With Oil
Oil presence can have significant impact on load transfer to termination.
Tests performed using hydraulic oil applied directly to drum.
CoF Termination Tension
Line
Tension Reg
With
Hydraulic
Oil
Reg
(lbs)
With
Hydraulic
Oil (lbs)
% Term
Tension
Increase
w/Oil
5 kips 0.079 0.059 106 363 342%
10 kips 0.051 0.032 622 1946 313%
15 kips 0.032 0.024 1971 3238 164%

13. DPXTechnology
DPX technology is a unique way to tailor COF and specific gravity to application requirements can also provide improved
CBOS performance
Factors influencing CoF:
• Structure and material of rope (fiber, coating,
construction)
• Type of surfaces rope contacts in application
• Contact pressure
• Presence of other species (i.e. water, oil, etc.)

14. Spooling

15. Spooling
“FoXFiRE” spooling tester facilitates knowledge built
around rope spooling characteristics and other
important performance attributes.

16. Spooling
Drum/
Winch
Design
Coefficient of
Friction
Spooling
Effectiveness
Rope Wear &
Fatigue
“Custom”
tests
Flange
Pressure
Termination
Tension
Rope-on-
drum
“Packed
Rope”
Min. Wrap
Count
Self-packing
Installation
Tension
Guidance
Layer Count
Guidance
Application-
specific
Rope-on-
Flange
abrasion
comparisons
Rope Diving
damage
Abrasion
module
(Future)
Customer
Support
Future
Application
Development

17. InvestigatingWinch behavior
 Diving
 Gap creation
 Cinching down
 Unplanned step-up or reversal of direction

18. Spooling Considerations: Non-Jacketed Rope
• Prefer grooved drums (on mobile cranes)
• Allows grooves to “lock” first layer into place
• Smooth drum increased diving frequency/severity
• Rope must be installed under tension
• Apply maximum possible tension to full rope length (dead-wraps to outboard termination)
• “Bedding-in” rope cross section to design / operating diameter through a series of loading cycles (3
– 5 cycles)
• Rope will form to fit layer gaps during spooling
• Rope core - limits allowable shape change
• Up to 5 layers w/out spooling assistance (i.e. level-wind) with successful results
• Diving events
• Typically occurs when bottom layers spooled at low load followed by high tension load on higher
layers
• Unlike wire, synthetic rope is not destroyed in a diving event due to material malleability
• Frequent diving events may increase generation rate of external abrasion due to rope-on-rope
contact at high contact pressures
• Respooling rope under tension can mitigate re-occurrence

19. Spooling Considerations: Jacketed Rope
• Drum surface dependent on loading scenario
• Grooved surface “locks” first layer into place
• Eliminates shifting of bottom layer wraps
• Reduces gaps that could propagate to higher
layers and result in diving to bottom layer
• Higher layers compress into groove-like
configuration following extended use
• Success in towing environment with smooth
drum winch design
• Rope must be installed under tension
• Bedded-in rope cross section to match operating diameter
• Jacket forms groove-like configuration
• Control core andTurbo jacket limit allowable shape change
• Spooling up to 15 layers with appropriately geared level winder
• Diving events
• Minimal diving observed during trials
• Level wind ensured negligible generation of gaps

20. Overview of a Run
Speed Ratio (SR)
is the relative
speed of the
winch vs. line
Each step in the
SR represents a
new layer in the
winding/unwind
ing process

21. Diving and Step-up
Dives are
indicated by
sudden spikes
Unexpected
shifts indicated
early layer
change (step up
or down)

22. Gapping and Cinching
Noise on signal
indicates
gapping or
repeated mini
dives
Overall slope in SR we
believe to be tied to
the line cinching or
relaxing on the drum
(Elasticity + COF)

23. Sheave Profile
• Tight grooves will lower bend fatigue life
• Wider grooves (even flat) will not significantly effect
bend fatigue life
• Fleet angles should be avoided to reduce abrasion
• “V” grooves should be avoided

24. 12-Strand Rope Elongation Properties

25. Fiber vs. SteelWire

26. Value Saving
 Jobsite efficiency and total cost of ownership
 Cranes that utilize a variety of reeving patterns
 Jobsite uptime or reduced labor
 Conditions that require cold weather package
 Rope does not lose strength in sub-zero temperatures (-190°F)
 Operating in chemical and saltwater environments
 High resistance to chemical degradation = longer life
 Transportation weight restrictions, DOT or road limits
 Reduced over-the-road weight (1,900 lbs. for RT9130E-2 Main/Aux)

27. Life Compared toWire
• Life is dependent on crane use conditions
• Wire fatigues vs. fiber abrades
Retirement Advantage Comments about K-100
Crushing on drum Fiber Rope Can deform without damage
Kink, pig tail, bird cage Fiber Rope Little to no memory
Heat damage Steel Wire rope Recommended operating temp limit of 60°C
Wear from heavy use Fiber Rope Longer life at higher load cycles
Corrosion Fiber Rope High chemical resistance
Cut strands Steel Wire rope Sharp edge may damage rope under load
Bird nest on drum Fiber Rope Less likely to occur
Extended hoist rope life

28. Value to the Crane Owner/Operator
 Weight improvements:
 Total system weight
 Overhaul weight, diving drives sizing for headache balls and hook block
 Long-term lift capacity improvements
 Reduced axle weight / operating cost over the road
 Handling:
 No load spin or cabling
 Easier to handle/reeve
 Eliminate becket from system
 Eliminate fishhooks that can cut hands
 Operating in chemical and saltwater environments
 High resistance to chemical degradation = longer life
Job site efficiency and total cost of ownership
 Longer winch and drum life
 Reduce change outs from damage (kinking, bird-caging, diving)
 No grease = reduced maintenance $$
 Faster and safer to handle

29. Industry Guidance

30. Industry Standards / Guidelines
• ASME B30.30 Ropes
• Document in process of being developed (since 2011)
• Safety standard for rope (wire & synthetic) on B30 equipment
• FEM - European Materials Handling Federation
• Equipment, rope, and fiber manufacturers working together to create a European guideline for use of
synthetic rope on mobile cranes
• Guideline Published Q3 2017
• InternationalOrganization for Standardization (ISO)
• Start working group September 2018 ISO/TC 96/SC 3
• Potential for synthetic version of ISO4309
• Typically working groups last 5 years for new standards

31. Ultraviolet (UV)Testing

32. UVTesting Protocol
• Prolonged UV exposure
• Simulated 5-year exposure near retirement target without wear
• Retirement criteria dependent on combined use/exposure
• Test method created to simulate South Florida UV conditions
• Accelerated UV exposure
• ASTM test method stipulates procedure for exposure cycles
• UVB more damaging / shorter test time
• UVA similar to ambient spectrum / longer test time
• 5-year simulated exposure testing on K-100TM

33. Strength Retention after UV Exposure

34. Retirement Criteria

35. Inspection & Retirement

36. Mitigating Abrasion
• Grind, remove scoring and
repaint
• Remove rust and repaint
prior to installation

37. Terminations

38. Terminations
 Outboard termination
 Full-strength termination
 Field spliceable
 Eliminate wedge socket
 Inboard termination
 Designed to meet the same holding strength requirement as wire.
 Terminations at drum connection should be capable of holding 2.5x
the designed line pull. This includes tension reductions from
remaining wraps on the drum.
 Designed to manage spooling performance
 Uses existing wedge pocket

39. DrumTerminations

41. Exhibit Center
90 companies
11:30 am – 2:30 pm
Marriott Ballroom

44. #SCRAcrw