NAARSO 2017
WIRE ROPE
Presented by
C W Craven
Wire Rope Order
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NAARSO 2017 MCO
5000’ 1‐1/4” 6X19 Seale RRL XIPS PPC Bright
Lube with Castor oil 1A or equiv.
Must meet requirements of ANSI B77.1‐2014
Minimum Breaking Strength of ……………
• Wire Rope is a working machine.
• A wire rope has been selected / designed for a particular application.
– Diameter
– Breaking Strength
– Material
– Flexibility
– Abrasion Resistance
Ab i R i t
– Other factors: Lay, Lay Length, Core, lube, Strand Construction, Corrosion Resistance, Economics. • Wire Rope is made up of 3 Basic Parts
– Wire
– Strand – Core
NAARSO 2017 MCO
Core Types
• Fiber Core – Hemp/Sisal (FC) (outdated)
– Poly Propylene (PPC)
– Thermoplastic • Wire Strand Core (WSC)
• Independent Wire Rope Core (IWRC)
Independent Wire Rope Core (IWRC)
• Custom / Combinations
Carbon Steels Used in Wire Rope
• The following terms have been around since the early days • of wire rope, when ropes were made to drag a plowshare thru the fi ld
field.
• IRON rope – Actually low carbon steel (obsolete)
• TS – Traction Steel
• EH – Extra High Strength Traction Steel
• PS / MPS – Plow Steel / Mild Plow steel (obsolete)
• IPS – IMPROVED PLOW STEEL (mostly larger diameters)
• EIPS (XIPS or XIP) – EXTRA IMPROVED PLOW STEEL (standard)
• EEIPS (XXIPS or XXIP) EXTRA EXTRA IMPROVED PLOW STEEL
• Grades of plow steel wire rope strength increase by approximately 15% increments.
• Stainless steel and other non ferrous metals are also used.
NAARSO 2017 MCO
Strand Construction
Larger wires = less flexibility / fatigue resistance but greater abrasion resistance.
resistance but greater abrasion resistance
Smaller wires = more flexibility / fatigue resistance but has less resistance to abrasion. Many more strand types, including compacted strands, rotation resistant, and lock coil. These are most common for FC rope.
Rope Classification
6 x 19 Classification ropes contain 6 strands with 15 through 26 wires per strand, no more than 12 of which are outside wires.
i.e. a 6 Strand wire rope having 19 wires per strand.
NAARSO 2017 MCO
Rope Lay
RRL ‐ Right Regular Lay – Most Common
RLL ‐ Right Lang Lay
LRL – Left Regular Lay
LLL – Left Lang Lay
Lay Length
The distance 1 strand takes to make a complete revolution around the rope.
(Usually measured and divided over several lay lengths)
A significant localized increase in the lay length after the rope has broken in needs to be investigated.
Overall length
O
ll l th
Significant changes in overall length (rate of stretch) after construction stretch has been removed are of concern.
NAARSO 2017 MCO
Corrosion Resistance and lube type • “Bright” plain steel
• Galvanized, can be pre draw or post draw
• Stainless Steel or other metals
• Lubricants:
– Depends upon the application
– What is the rope going to interact with?
Application Standards
• Crane and Rigging Applications – ASME B30
• Elevators
– ASME A17
• Passenger Ropeways
– ANSI B77
ANSI B77
• Amusement Rides
– ASTM F‐24
NAARSO 2017 MCO
Wire rope maintenance
• Protect from damage
• Lubrication
– Don’t over lube
– Use the proper lube, must be compatible with construction lubricant and items that rope comes in contact with. ie sheaves, liners, environmental concerns. • Periodic Inspection
– Rope
Rope (diameter and lay length checks, visual inspection, (diameter and lay length checks visual inspection
MRT)
– Installation/Application
• Don’t make the rope work harder than it’s needs to (shorter life)
Inspection
• External examination, MRT (ferrous ropes), and internal inspections.
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• What are we looking for?
– Fatigue / Damage / Abuse indications
– Application issues
– Broken wires
Broken wires
– Changes in length, lay length, or diameter
– Internal issues
NAARSO 2017 MCO
Inspection – Application Issues
• End connections:
– U bolt clips
• Installed correctly
– Quantity, torque, spacing, orientation
– Fist grips (double saddle clip)
– Wedge sockets
– Crimped or swaged end connections
– Thimbles
U‐Bolt Clip Installation
NAARSO 2017 MCO
Wedge Socket Installation
Incorrect
Correct
Inspection – Damage and Abuse
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NAARSO 2017 MCO
Crushing
Kinking
Abrasion
High Stranding
Heat and chemical
Improper application or use
Inspection ‐ Broken Wires
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Outer wire breaks / Valley breaks
Localized damage / evenly distributed
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Cause?
Allowable number of allowable broken wires depends of the following:
– Application • Crane & Rigging, Elevator, Passenger Ropeway, Amusement Ride, Etc.
– Location
• In the splice area?
In the splice area?
• Adjacent to end connections?
– Quantity
• How many?
• How close to each other?
Allowable broken wires in a ropeway ANSI B77
• Broken wires in one lay length in excess of 7 ½% of the cross sectional metallic area of the rope or 25% of the metallic cross sectional area of one strand (localized damage), or
• Broken wires in five lay lengths in excess of 10% of the metallic cross sectional area of the rope (uniformly distributed damage). Broken filler wires are not counted.
• NOTE –
NOTE When calculating the number of broken wires When calculating the number of broken wires
from the metallic cross sectional area, the results will be rounded down to the next whole wire.
• Ropeway mfg. may have more stringent requirements.
NAARSO 2017 MCO
Allowable broke wires
• Amusement Ride: As specified by the ride manufacture.
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• Elevators: See Elevator inspection code (ASME A17)
• Crane and rigging applications (ASME B30)
Length and diameter measurements
• Diameter measurement
6 strand rope = measure in 3 planes and at various locations then average the results. 8 strand = 4 planes
NAARSO 2017 MCO
Inspection – Internal issues
• Broken Wire ‐ Valley Break
• Rouging
• Core issues
Visual Inspections
OUTER WIRE BREAKS – CROWN BREAKS
(FATIGUE)
NAARSO 2017 MCO
Visual Inspections
INNER WIRE BREAKS ‐ VALLEY BREAKS
(FATIGUE)
Valley Break – 1 Wire
NAARSO 2017 MCO
Core from same rope
NICKING AND MULTIPLE BROKEN WIRES
NICKING AND MULTIPLE BROKEN WIRES
NAARSO 2017 MCO