Wire rope selection criteria

Replacement wire rope must be selected and installed according to the equipment manufacturer's, the wire rope manufacturer's, or a qualified person's recommendations and the requirements of 1926.1414. Employers must follow the selection and installation rules in 1926.1414(a).

• Follow the rope and equipment manufacturer's instructions or a qualified person's written recommendation before installing replacement rope.
• Ensure the replacement rope meets any applicable design-option requirements in 1926.1414(b).
• Coordinate selection with inspection procedures in 1926.1413 so inspections remain an effective safeguard against sudden rope failure.

Wire rope (other than rotation-resistant rope) must either meet the ASME B30.5-2004 criteria in Option (1) or be designed with a sufficient minimum breaking force and design factor under Option (2). See 1926.1414(b).

• Option (1): Comply with section 5-1.7.1 of ASME B30.5-2004 as adopted by OSHA in 1926.1414(b)(1).
• Option (2): Design the rope so the minimum breaking force and design factor, relative to rated capacity, make the inspection requirements in 1926.1413 effective to prevent sudden rope failure, per 1926.1414(b)(2).

Option (1) requires the wire rope (other than rotation-resistant rope) to comply with section 5-1.7.1 of ASME B30.5-2004, except paragraph (c) of that ASME provision does not apply. See 1926.1414(b)(1).

• This means using the construction, minimum strength, and other requirements specified in ASME B30.5-2004 section 5-1.7.1, as incorporated by reference in 1926.6.
• Verify rope meets the ASME requirements with manufacturer documentation when selecting replacement rope.

Option (2) requires wire rope to be designed so its minimum breaking force and design factor, relative to the equipment's rated capacity, are sufficient that the inspection rules in 1926.1413 will effectively prevent sudden rope failure. See 1926.1414(b)(2).

• In practice, this means sizing the rope and choosing construction so regular inspections (monthly/annual and pre-use where applicable) detect deterioration before the rope becomes a sudden-failure hazard.
• Document the design rationale and consult a qualified person or the rope/equipment manufacturer to demonstrate the chosen design factor is adequate.

"Compatible with the safe functioning of the equipment" means the rope's size, construction, core type, fittings, and strength must match the equipment's design and manufacturer's specifications so the equipment operates safely. See 1926.1414(c).

• Verify rope nominal diameter and construction fit drums, sheaves, sockets, and clips.
• Confirm the rope's minimum breaking force and design factor are appropriate for the equipment's rated loads and reeving configuration.
• Follow equipment and rope manufacturers' installation instructions and consult a qualified person when in doubt.

Fiber core ropes must not be used for boom hoist reeving except when used on derricks. See 1926.1414(d)(1).

• If the equipment is a derrick, fiber core is permitted for boom hoist reeving; otherwise select a suitable non-fiber-core rope.
• Always confirm compatibility with the equipment manufacturer's guidance under 1926.1414(a).

Rotation-resistant ropes may be used for boom hoist reeving only when the specific requirements in 1926.1414(e)(4)(ii) are met. See 1926.1414(d)(2).

• Those requirements include minimum drum and sheave pitch diameters, meeting certain ASME provisions, and a minimum operating design factor for the boom hoist reeving system.
• Don’t use rotation-resistant ropes on boom hoist reeving unless you can satisfy every condition in 1926.1414(e)(4)(ii).

Type I, Type II, and Type III rotation-resistant ropes are defined by strand count, layer construction, and resistance to rotation: Type I has the most rotation resistance, Type II has significant resistance, and Type III has limited resistance. See 1926.1414(e)(1)(i), 1926.1414(e)(1)(ii), and 1926.1414(e)(1)(iii).

• Type I: At least 15 outer strands, at least three layers of strands laid helically over a center in two operations, outer strand lay opposite underlying layer; designed to have little or no tendency to rotate or transmit torque.

• Type II: At least 10 outer strands, two or more layers laid in two or three operations, outer strand lay opposite underlying layer; provides significant resistance to rotation.

• Type III: Limited resistance to rotation, constructed with no more than nine outer strands and two layers in two operations (see the text following the definitions for details).

• Choose the type based on the required rotation resistance and the operating design factor rules in 1926.1414(e)(2).

Rotation-resistant ropes (Types I, II, and III) must have an operating design factor of no less than 3.5. See 1926.1414(e)(2)(ii).

• Note that higher minimums apply in some cases (for example, Type I generally requires a design factor of at least 5 under 1926.1414(e)(2)(iii)).
• Confirm operating design factor calculations with the rope and equipment manufacturers or a qualified person.

Types II and III with an operating design factor of less than 5 must not be used for duty cycle or repetitive lifts; Type I must have an operating design factor of at least 5 unless both the wire rope manufacturer and the equipment manufacturer approve a different factor in writing. See 1926.1414(e)(2)(i), 1926.1414(e)(2)(iii), and 1926.1414(e)(2)(iv).

• Type I: Operating design factor ≥ 5, unless both manufacturer and equipment manufacturer approve another factor in writing.
• Types II and III: Must have operating design factor ≥ 5 for duty-cycle or repetitive-lift service; they may be used with lower design factors only under the limited conditions in 1926.1414(e)(3).
• If you plan to use a lower design factor, get written approvals and meet the additional inspection and operational requirements.

When Types II or III with operating design factor less than 5 are used, a qualified person must inspect the rope in accordance with 1926.1413(a), and the rope may be used only if the qualified person determines there are no deficiencies constituting a hazard; more than one broken wire in a single rope lay is considered a hazard. See 1926.1414(e)(3)(i).

• Inspections must follow the procedures in 1926.1413(a).
• Consider any instance of more than one broken wire in the same rope lay to be a hazard and take appropriate action (remove from service or repair) per the qualified person’s judgment.

Operations using Types II or III with operating design factors less than 5 must be conducted in such a manner and at such speeds as to minimize dynamic effects. See 1926.1414(e)(3)(ii).

• Keep lifting speeds and handling procedures controlled to reduce shock loading, snatch, and other dynamic forces that can overstress the rope.
• A qualified person should set operational limits and confirm procedures are followed during each lift.

Each lift made under the limited-use provisions for Types II or III with operating design factor less than 5 must be recorded in the monthly and annual inspection documents, and past use must be considered by the qualified person before reusing the rope. See 1926.1414(e)(3)(iii) and inspect per 1926.1413.

• Maintain clear records of each lift in the inspection logs so the qualified person can consider prior use and wear when authorizing reuse.
• Include relevant details such as date, load, speed, operating conditions, and inspection findings.

Rotation-resistant ropes may be used in boom hoist reeving only when all specified requirements are met, including minimum drum and sheave diameters, ASME provisions, and an operating design factor of at least 5 for the boom hoist reeving system. See 1926.1414(e)(4)(ii) and the subparagraphs for details.

Key requirements include:

• Drum first-layer rope pitch diameter must be at least 18 times the rope nominal diameter (1926.1414(e)(4)(ii)(A)).

• All sheaves in the boom hoist reeving system must have rope pitch diameters of not less than 18 times the nominal diameter of the rope (1926.1414(e)(4)(ii)(D)).

• Meet the requirements of 1926.1426(a) and 1926.1426(b) as applicable.

• Conform to specified ASME B30.5-2004 sections (see 1926.1414(e)(4)(ii)(C)).

• The operating design factor for the boom hoist reeving system must be not less than five (1926.1414(e)(4)(ii)(E)).

• The operating design factor is defined as the total minimum breaking force of all parts of rope in the system divided by the load imposed on the rope system when supporting the static weights of the structure and the load within the equipment's rated capacity (1926.1414(e)(4)(ii)(F)).

• If provided, a power-controlled lowering system must be capable of handling rated capacities and speeds as the manufacturer specifies (1926.1414(e)(4)(ii)(G)).

• Verify all these items in writing and confirm with the equipment and rope manufacturers prior to using rotation-resistant rope for boom hoist reeving.

For multiple rope reeving using rotation-resistant ropes in boom hoist reeving, the minimum pitch diameter for sheaves must be 18 times the rope's nominal diameter (instead of the 16× value in the referenced ASME provision). See 1926.1414(e)(4)(ii)(C).

• This increases the ASME B30.5-2004 dimensional requirement to reduce bending stress and prolong rope life in boom hoist reeving applications.
• Ensure sheave and drum dimensions are documented and verified against the 18× requirement before using rotation-resistant ropes in boom hoist reeving.

Wire rope clips used with wedge sockets must be attached to the unloaded (dead) end of the rope only, except where a device is specifically designed for dead-ending rope in a wedge socket. See 1926.1414(f).

• Do not place clips on the loaded end of the rope when the connection uses a wedge socket unless the device is explicitly designed for that use.
• Follow rope and fitting manufacturers' instructions for clip spacing, number, and torque.

Socketing must be done in the manner specified by the manufacturer of the wire rope or fitting. See 1926.1414(g).

• Use the manufacturer’s recommended materials, procedures, and cure times for poured sockets, swaged sockets, or other termination methods.
• Keep documentation of the socketing procedure and verify the work was performed by trained personnel or a qualified person.

Type I rotation-resistant rope must have an operating design factor of at least 5 except where both the wire rope manufacturer and the equipment manufacturer approve a different design factor in writing. See 1926.1414(e)(2)(iii).

• If you want to use a lower design factor for Type I, obtain written approval from both manufacturers documenting the basis for the lower factor.
• Maintain that written approval as part of the equipment and rope selection records.

For boom hoist reeving, the operating design factor is calculated as the total minimum breaking force of all parts of rope in the system divided by the load imposed on the rope system when supporting the static weights of the structure plus the load within the equipment's rated capacity. See 1926.1414(e)(4)(ii)(F).

• Include every rope part in the reeving that shares load when computing total minimum breaking force.
• Use static weights (e.g., boom, attachments) plus the maximum rated load when determining the denominator for the factor.

You must choose rope strength and design factors so that regular inspections under 1926.1413 reliably detect deterioration before a sudden failure can occur, and document that rationale per 1926.1414(b)(2).

Practical steps:

• Select a rope with sufficient minimum breaking force and design factor based on duty, loads, and reeving.
• Implement inspection intervals and acceptance criteria in 1926.1413 (monthly/annual and pre-use where required).
• Keep inspection records and use them to reassess rope service life; consult a qualified person when wear approaches acceptance limits.

For the rule in 1926.1414(e)(2)(i), "duty cycle or repetitive lifts" refers to frequent, repeated lifting operations that place continuous or recurring stress on the rope; Types II and III with operating design factors less than 5 are prohibited in such service. See 1926.1414(e)(2)(i) and the limited-use provisions in 1926.1414(e)(3).

• If lifts are infrequent, non-repetitive, and not part of a continuous duty cycle, Types II/III may be used with design factor <5 only if you satisfy the inspection, operational speed, and recordkeeping requirements in 1926.1414(e)(3).
• When in doubt about whether a task is duty-cycle service, treat it as repetitive and select rope with an appropriate design factor.

A qualified person must treat more than one broken wire in any one rope lay as a hazard; the rope must not be used if such a condition exists. See 1926.1414(e)(3)(i) and inspection rules in 1926.1413(a).

• The qualified person must document the finding and remove the rope from service or take corrective action per the manufacturer's instructions and inspection criteria.
• Include this finding in the monthly/annual inspection records required by 1926.1413 and 1926.1414(e)(3)(iii).

When provided, a power-controlled lowering system used with rotation-resistant ropes in boom hoist reeving must be capable of handling rated capacities and speeds as specified by the manufacturer. See 1926.1414(e)(4)(ii)(G).

• Verify the lowering system meets the manufacturer’s ratings for both load capacity and lowering speed before using the system with rotation-resistant ropes.
• Keep manufacturer documentation and any related testing records with the equipment files.

A "qualified person" for selecting and inspecting wire rope is someone with the knowledge, training, and experience necessary to make proper selection, installation, and inspection judgments for the rope and equipment; such inspections must meet the criteria in 1926.1413(a) and selection/installation must follow 1926.1414(a).

• The qualified person could be an appropriately trained employee, a manufacturer's representative, or a third-party engineer with demonstrated experience in wire rope and reeving systems.
• Employers should document the qualifications (training, certifications, or experience) of the person performing selection and inspections to show compliance with 1926.1413(a).