Crane Sheaves and Drums: The Wear Limits Inspectors Measure

By Patrick SalazarSep 23, 202627 min read

When the same crane keeps eating rope, the rope is rarely the problem, and a crane sheave inspection usually proves it. Every foot of a running line passes over the sheaves and onto the drum under load, and a groove that has worn to the wrong shape will take a new rope to its removal criteria in a fraction of the life the last one got. The rope is the consumable.

The condition of the sheaves and the drum decides how fast it gets consumed, and it is the part of the reeving system that almost nobody measures between rope changes.

The short version is that OSHA names sheaves and drums on the inspection lists but sets almost no dimensional limits for them. The numeric limits in the regulations are written on the rope and on the drum wraps. The limits on the groove, the flange, the bearing and the drum barrel come from the manufacturer.

Where the standards name sheaves and drums

In 1926.1412, the general inspection section of Subpart CC, sheaves and drums appear by name once, and it is in the 12-month inspection. 29 CFR 1926.1412(f)(2) requires that at least every 12 months a qualified person inspect the equipment, with disassembly as necessary to complete the inspection, and item (f)(2)(ii) is “sheaves and drums for cracks or major wear.” The next item, (f)(2)(iii), covers pins, bearings, shafts, gears, rollers and locking devices for distortion, cracks or major wear, which is where a sheave pin and its bushing land.

The shift inspection under (d)(1) does not mention sheaves at all. What it requires each shift is (d)(1)(vi), wire rope reeving for compliance with the manufacturer’s specifications, and (d)(1)(vii), the wire rope itself in accordance with 1926.1413(a). That reeving check is part of the operator walkaround whether or not anyone calls it that. The monthly inspection under (e) repeats the shift items with a record retained for a minimum of three months.

General industry reads the same way with older words. For overhead and gantry cranes, 1910.179(j)(3)(iii) lists “cracked or worn sheaves and drums” as a periodic inspection item, at the 1-to-12-month intervals defined in (j)(1)(ii)(b), and (j)(3)(iv) covers worn, cracked or distorted pins, bearings, shafts, gears, rollers, locking and clamping devices. The frequent inspection at daily-to-monthly intervals includes (j)(2)(vii), rope reeving for noncompliance with manufacturer’s recommendations.

For crawler, locomotive and truck cranes in general industry, 1910.180(d)(4)(iii) uses the identical phrase, “cracked or worn sheaves and drums,” on its periodic list. Which of the two rule sets governs your machine is its own question, covered in 1910.179 versus 1926.1412.

1910.179 goes one step further than Subpart CC and sets design conditions the inspector checks against. Paragraph (h)(1)(i): sheave grooves shall be smooth and free from surface defects which could cause rope damage. Paragraph (h)(1)(ii): sheaves carrying ropes which can be momentarily unloaded shall have close-fitting guards or other suitable devices to guide the rope back into the groove when the load comes back on.

Paragraph (h)(1)(iii): the sheaves in the bottom block shall have close-fitting guards that keep the ropes from fouling when the block is lying on the ground with the ropes loose. Paragraph (h)(1)(v): all running sheaves shall have means for lubrication, with permanently lubricated, sealed or shielded bearings counting. None of those carries a dimension. “Smooth and free from surface defects” is a pass-or-fail judgment, and “worn” and “major wear” are left to the person holding the gauge.

The ASME volumes are where the design detail lives. ASME lists B30.5-2025 as the current mobile crane volume. The 2021 edition’s table of contents lists Section 5-1.7, “Ropes and Reeving Accessories,” in the construction chapter and Section 5-2.4, “Rope Inspection, Replacement, and Maintenance,” in Chapter 5-2 on inspection, testing and maintenance.

OSHA leans on B30.5 directly: 1926.1433(b) requires mobile and locomotive cranes manufactured on or after November 8, 2010 to meet listed portions of B30.5-2004, and items (b)(10) and (b)(11) on that list are section 5-1.7.4, “Sheaves,” and section 5-1.7.5, “Sheave sizes.” B30.2-2022 does the same job for top-running overhead and gantry cranes, and ASME B30.30-2023, Ropes, applies across the B30 equipment volumes to the construction, selection, installation, attachment, testing, inspection, maintenance, repair, use and replacement of wire rope, hybrid rope and synthetic fiber rope.

The B30 comparison chart lays out which volume covers which machine.

The practical consequence is that the numeric limits an inspector can quote from a regulation here are rope limits, the drum-wrap count and, in one narrow boom-hoist case, a diameter ratio. Every wear limit on a groove, a flange, a bearing or a drum barrel comes from the B30 volume or, far more often, from the crane manufacturer’s service literature and the rope manufacturer’s groove tolerances.

When a report condemns a sheave, it should name the criterion and where it came from, because “major wear” on its own is an opinion, and a compliance officer, an insurer or an owner’s engineer will ask what it was measured against.

Crane sheave inspection: how a groove gauge is used and what it tells you

A sheave gauge is a set of steel profiles, one per nominal rope diameter, each cut to a groove radius. Sets are commonly sold with two profiles per rope size: one for a new or remachined groove and one at the manufacturer’s minimum for a worn groove. You seat the profile in the bottom of the groove, square to the sheave, and look at it against light. A groove in tolerance shows the profile bedded along the bottom with the arc of the groove following the gauge.

A groove worn under-size shows the gauge riding on the flanks with daylight at the bottom, or refusing to seat at all. A groove worn over-size shows daylight at the flanks with the gauge touching only at the bottom. Rotate the sheave and repeat at several points around the circumference, because wear is rarely uniform.

The two directions of wear do different damage to the rope. A groove that has worn narrow, or one that was cut for a smaller rope, pinches the rope. The strands are squeezed together, the outer wires are loaded on their edges, and the rope cannot flex freely as it bends over the sheave.

That pinch is why a fresh full-diameter rope over an old groove fails early: the previous rope wore the groove down to its own reduced diameter, and the new rope is being forced into a shape sized for a rope that was near its removal point. A groove that has worn wide gives the opposite problem. The rope is supported over a smaller arc, so the bearing pressure between rope and sheave concentrates on fewer outer wires, the rope flattens, and crown wear shows up faster.

Both conditions accelerate the outer-wire breaks that 1926.1413 counts.

Corrugation is the third condition and the one a gauge alone can miss. As a rope runs over the same groove for long enough, it prints its own strand pattern into the groove bottom. That imprint then files every strand that passes over it, and once the rope’s lay no longer matches the imprint, which happens as soon as the rope stretches or is replaced, the groove is cutting rather than supporting.

Run a finger across the groove bottom, look at it under a light held low, and treat a visible strand pattern as wear even when the gauge sits close to profile.

Whose number applies is a question the inspector has to settle before the gauge comes out. The crane manufacturer’s service manual is first, because the sheave is their part. The sheave manufacturer’s data is second. The rope manufacturer’s published groove tolerances for the rope actually installed are the fallback, and a qualified person decides which criterion governs when they disagree.

Flanges, bearings, pins and alignment

The groove is one of five things checked on a sheave, and the other four get the same visit.

Flanges chip, crack and wear thin. A chipped flange edge is the kind of surface defect 1910.179(h)(1)(i) is written against, and it scuffs the rope every time the rope enters the groove off-center. A flange worn thin at the rim is losing the depth that keeps the rope in the groove when a load swings. On a boom tip the flange is usually paired with a rope guard or retaining pin, and the guard clearance is inspected at the same time.

On overhead cranes, the close-fitting guards required by 1910.179(h)(1)(ii) and (iii) are checked for presence, security and clearance to the sheave, because a missing bottom-block guard is exactly how a rope jumps a sheave when the block sits on the floor.

Bearings are checked by hand before anything else. A running sheave should turn freely with the rope slack. One that drags, grinds or has to be pushed makes the rope slide across the groove instead of rolling, and sliding is abrasion. Radial and axial play in the sheave on its pin is checked by rocking it: play means a worn bushing, a worn pin, or both, and a wobbling sheave presents the groove to the rope at a changing angle.

1926.1412(f)(2)(iii) is where pins and bearings live on the annual list, and 1910.179(h)(1)(v) is why an inspector asks when the running sheaves were last greased. Sealed bearings meet the lubrication requirement, but they can fail without the warning a dry grease fitting gives, and they are checked the same way.

Alignment shows in the wear pattern. A sheave whose pin is bent, or whose mounting has been sprung, wears one flank of the groove more than the other, and the rope shows a matching one-sided scrub. Fleet angle, the angle between the rope running from the drum to the first sheave and a line perpendicular to the drum axis through the center of that sheave, is set by the geometry of the machine, and the manufacturer gives the limit.

When it is exceeded the rope rubs the sheave flange on the way in and piles or crosses at the drum flanges, and both the flange and the rope show it. Two-blocking bends boom-tip sheave assemblies, and a history of it is worth asking the operator about directly.

Cracks are the finding that changes the conversation. Both 1926.1412(f)(2)(ii) and 1910.179(j)(3)(iii) put cracks ahead of wear, and a cracked sheave or drum flange is not a monitor-it item. Cast sheaves tend to crack at the hub and at the rim. Fabricated drums tend to crack at the flange-to-barrel weld.

Where a crack is suspected under paint or grease, the answer is to clean it and look, and where it is suspected in a drum weld, the answer is nondestructive testing rather than an argument about whether the line is a scratch.

Drums: crush, crossover points, and the two wraps the rules require

The drum is inspected as a sheave with a longer groove and more ways to go wrong. On a grooved drum, the grooves are gauged like sheave grooves, with attention to the pitch between grooves, because a rope that has worn smaller will start to pile and cross on a drum pitched for its nominal size. On a smooth drum the first layer has to be wound tight and even, since every layer above it takes its shape from the first.

The rope anchor is checked for security and for the manufacturer’s method: 1910.179(h)(2)(iii)(b) requires the rope end to be anchored by a clamp securely attached to the drum, or by a socket arrangement approved by the crane or rope manufacturer.

The number that is written down is wraps. 1910.179(h)(2)(iii)(a) requires that no less than two wraps of rope remain on the drum when the hook is in its extreme low position. 1926.1417(t) says the same thing for construction cranes: neither the load nor the boom may be lowered below the point where less than two full wraps of rope remain on their respective drums, and 1910.180(h)(3)(x) repeats it for mobile cranes in general industry. The rule has a companion in the rope inspection section.

When a damaged section of rope is cut out under 1926.1413(a)(4) or (c)(3) and the undamaged portion kept in service, the employer must ensure the drum still has two wraps when the load or boom is in its lowest position, and joining lengths by splicing is prohibited. OSHA added that language in the 2010 final rule after commenters pointed out that shortening a rope could leave too little on the drum.

An inspector verifies it the direct way: lower the block to its working low point, or the boom to its lowest angle, and count.

Crushing is a drum problem that gets blamed on the rope. Multi-layer spooling loads each wrap against the layer below it, and where the rope climbs from one layer to the next it crosses the wraps underneath at an angle. Subpart CC defines those locations. Under 1926.1401, crossover points are where one layer of rope climbs up on and crosses over the previous layer, at each flange as the rope reaches it and begins to wrap back.

Flange points are the points of contact between rope and drum flange where the rope changes layers. Repetitive pickup points are the short portion of drum the rope works on a single layer during short-cycle operation. All three are named as critical review items in 1926.1413(a)(3)(iii), which requires the competent person to give particular attention to wire rope at flange points, crossover points and repetitive pickup points on drums.

Crushing that amounts to major distortion of the rope structure is a Category I deficiency under 1926.1413(a)(2)(i)(A), which lists it alongside kinking, unstranding, birdcaging and core protrusion, and 1910.179(m)(1)(vi) lists severe kinking, crushing, cutting or unstranding as a condition that could mean an appreciable loss of strength.

Spooling faults are what an inspector sees most on drums, and the rule that addresses them is short. 1926.1417(m) requires that when a competent person finds a slack rope condition that requires re-spooling, it be verified before the lift starts that the rope is seated on the drum and in the sheaves as the slack is removed.

OSHA’s explanation in the preamble is the field description: the requirement prevents a loose coil from becoming cross-coiled on the drum, a portion of the rope coming off the drum altogether, or the rope being pulled alongside a sheave instead of seating in it.

A rope that has been cross-coiled under load carries the crush marks afterward, often at a repeating interval that matches one wrap around the drum, and a rope that has been pulled alongside a sheave shows a flattened, scrubbed band on one side with no wear opposite.

Drum diameter matters to fatigue life and is one of the few dimensional limits OSHA does state, in a narrow case.

Where rotation resistant rope is used for boom hoist reeving, which 1926.1414(e)(4)(ii) allows only when a load hoist is used as a boom hoist for an attachment such as a luffing attachment or a boom and mast attachment system, item (A) requires the drum to provide a first-layer rope pitch diameter of not less than 18 times the nominal rope diameter, and item (D) requires all sheaves in that boom hoist reeving to have a pitch diameter of not less than 18 times nominal.

Item (C) notes that B30.5-2004 section 5-1.3.2(d) specifies a value of 16 for sheaves used in multiple rope reeving and raises it to 18 for this application. Outside that case, the ratios of sheave and drum pitch diameter to rope diameter sit in the B30.5 load hoist mechanism section, 5-1.3.2, which 1926.1433(b)(5) applies in part to cranes built on or after November 8, 2010, and in the crane manufacturer’s literature; OSHA’s own text discloses only the one figure.

Selection is left to the people who hold the rest: 1926.1414(a) requires replacement rope to be selected on the recommendations of the wire rope manufacturer, the equipment manufacturer or a qualified person, and, as OSHA noted when it added 1926.1414(c), a rope too large for the machine can jump a sheave.

Reading the rope for the sheave’s faults

Rope wear patterns are the sheave inspection you can do without pulling a pin, and the annual rope inspection is written to force it. 1926.1413(c)(2)(ii) requires the 12-month rope inspection to cover the surface of the entire length of the rope, with particular attention to the critical review items, the sections normally hidden during shift and monthly inspections, wire rope subject to reverse bends, and wire rope passing over sheaves.

1910.180(g)(2)(i) says heavy wear or broken wires may occur in sections in contact with equalizer sheaves or other sheaves where rope travel is limited, or with saddles, and requires particular care there; 1926.1413(a)(3)(v) has the same item. An equalizer sheave sees the same short section of rope flex through the same small arc for the rope’s entire life, which is why both rules single it out.

The patterns map to causes with reasonable reliability. Even crown wear around the full circumference is normal service, and the question is only how far along it is. Wear concentrated on one side of the rope is a misaligned or wobbling sheave, or rope being pulled against a flange. A rope that is shiny and polished on the crowns but shows nicked or broken wires down in the valleys between strands has been running over a corrugated groove or being pinched in an under-size one.

The groove is loading the strand edges rather than the crowns. Broken wires clustered in one zone of the rope, repeating at an interval, correspond to one bad sheave or one drum crossover, and the interval tells you which. A rope losing diameter fast with no visible outer breaks is abrasion from the groove, corrosion inside the rope, or core deterioration, and 1910.179(m)(1)(i) names those three causes: loss of core support, internal or external corrosion, or wear of outside wires.

The counts that turn a pattern into a removal decision are in 1926.1413(a)(2)(ii), the Category II list. In running wire ropes: six randomly distributed broken wires in one rope lay, or three broken wires in one strand in one rope lay, where a rope lay is the length along the rope in which one strand makes a complete revolution around the rope. In rotation resistant ropes: two randomly distributed broken wires in six rope diameters, or four in 30 rope diameters.

In pendants or standing ropes: more than two broken wires in one lay beyond the end connections, or more than one broken wire in a lay at an end connection. And, separately, a diameter reduction of more than 5% from nominal. Category III, in (a)(2)(iii), is core protrusion or other distortion indicating core failure in rotation resistant rope, prior electrical contact with a power line, and a broken strand. The difference between the categories is what happens next, covered below.

The running-rope and sling distinction, and why the sling numbers differ, is in wire rope sling versus running rope, and the general rope procedure is in the crane wire rope inspection guide.

Plastic sheaves deserve a specific note because the question comes up on every machine that has them. In the 2010 preamble to Subpart CC, OSHA recorded that the question of whether the broken-wire criteria apply equally with plastic sheaves was left open in committee, that no public comment was received, and that the criteria apply regardless of the material of which the sheave is made. The counts in 1926.1413 are the counts, whatever the groove is made of.

What gets measured, what the standard says, who sets the limit

Tools that belong in the bag

The bag for this work is short, and most of it exists to put a number where the rules leave a word. A sheave groove gauge set covering every rope diameter in the fleet, with worn and new profiles, is the item that separates a sheave inspection from a glance. Calipers wide enough to measure rope diameter across the crowns of the strands, not across the valleys, because the 5% limit in 1926.1413 is a reduction from nominal and an undersized reading condemns rope that is fine.

A tape and a crayon to mark out one rope lay and count within it. A straightedge and feeler gauges for flange wear and drum flatness, a light held low across the groove, a small mirror for the back of a boom-tip sheave, and a pry bar for rocking sheaves on their pins. Solvent and a brush for the section of rope or drum under suspicion, because 1926.1413(d) prohibits rope lubricants of a type that hinders inspection, and nobody can count wires through a coat of tar.

When the finding is the sheave and not the rope

Decision rules that survive contact with a real machine:

1. Rope at Category II with a sheave in tolerance. The rope is replaced, or the rope manufacturer’s established removal criterion (or one it has approved in writing for that rope) is applied under 1926.1413(a)(4)(ii)(A), and the finding stays on the rope. Record the groove readings anyway so the next inspection has a baseline.
2. Rope at Category II with a groove out of tolerance. The rope finding and the sheave finding are written separately, and the report says the sheave is the cause. Replacing the rope without the sheave schedules the next replacement. Under 1926.1412(f)(4) the qualified person decides whether the sheave is a safety hazard now or a monitor item. Either way the new rope does not go back on that groove.
3. Cracked sheave, drum or flange, with any rope condition. Out of service until corrected. A crack in a load-path part is the easy call under 1926.1412(f)(4) and (f)(5), or under 1910.179(l)(3)(i), and it is not a wear-limit question.
4. Sheave that will not turn freely. A finding under (f)(2)(iii) even when the groove gauges clean, because the rope is sliding. Lubricate or replace the bearing and re-check rotation before the rope goes back to work.
5. Fewer than two wraps at the lowest position. The machine is outside the configuration the rules require, and the fix is rope length or a lowest-position limit, not a note. See 1910.179(h)(2)(iii)(a) and 1926.1417(t).
6. Crush marks at a repeating interval on the rope. Inspect the drum and the spooling before the rope is condemned, and re-spool under tension with the seating verified per 1926.1417(m) if the layers are crossed.
7. New rope of the wrong size or construction. Check the selection against 1926.1414(a) and, on overhead cranes, 1910.179(h)(2)(viii), which requires replacement rope of the same size, grade and construction as the original unless a wire rope manufacturer recommends otherwise for the actual working conditions.

Where a rope in any of the three categories is required to be removed from service, 1926.1413(a)(4)(iv) requires the equipment or the hoist to be tagged out under 1926.1417(f)(1), with a tag in the cab or in a conspicuous position at the function, until the rope is repaired or replaced, and a crane that comes out of service on a sheave finding follows the same road as any other failed item, described in what happens when a crane fails inspection.

What gets documented

The retention rules are short. Under 1926.1412(f)(7), the annual inspection record states the items checked and the results, and the name and signature of the person who conducted the inspection and the date, retained for a minimum of 12 months. The monthly record under (e)(3) carries the same content for a minimum of three months.

1910.179(m)(1) requires a thorough inspection of all running ropes at least once a month with a certification record including the date, the inspector’s signature and an identifier for the ropes, and (j)(2)(iii) requires the same monthly certification for hooks. The rules for the monthly file are in monthly crane inspection records.

What the rules do not require, and what makes the record useful, is the number. “Sheaves and drums: satisfactory” satisfies (f)(7)(i) and tells the next inspector nothing. A useful entry names each sheave by position, the gauge used and the rope size it was cut for, whether the worn-groove profile seated, the rotation and play check, the flange condition, and for the drum the anchor type, the wrap count at the lowest position and the layer condition.

Rope entries state the measured diameter and where it was measured, the lay length, and the broken-wire count per lay at the worst location, with that location identified by distance from the dead end. That is what lets an owner see that the boom-tip groove went from seating the worn profile to not seating it over two annuals, which is the trend that predicts the rope bill.

The general principles are in crane inspection documentation, and how to read the priorities on the report that comes back is in reading a crane inspection report.

Where a finding is monitored rather than corrected, 1926.1412(f)(6) requires that it be checked in the monthly inspections, and 1926.1413(b)(2) puts the same duty on the monthly rope inspection for deficiencies the annual inspector flagged. A sheave groove that seats the worn profile with a little light showing is the classic monitor item, and the monthly entry should say what was seen, not “checked.”

The same gauging is the first thing done on a used machine with an unknown rope history, since every groove tells you what the last owner’s rope bill looked like and why (see buying a used crane). On a crane coming out of storage, where 1910.179(m)(2) requires a thorough inspection of any rope idle for a month or more before it is used again (see return to service after storage).

And after the shock loading, overloading or corrosive exposure that makes 1926.1412(g) stop the machine until a qualified person has looked at it (see severe service).

On a third-party annual inspection, gauging every sheave and the drum is part of the 12-month scope, and the report says what each groove measured and what it was measured against, so that a condemned rope comes with the reason it died.

Common questions

What are the wire rope standards for cranes?

For construction cranes under Subpart CC, 1926.1413 sets the inspection frequencies and the removal criteria, and 1926.1414 sets selection, installation and design factors. For overhead and gantry cranes in general industry, 1910.179(h)(2) covers rope selection, drum anchoring and replacement and 1910.179(m) covers the monthly rope inspection; 1910.180(g) carries the monthly rope inspection and certification record for crawler, locomotive and truck cranes in general industry.

On the consensus side, ASME B30.30 covers ropes across the B30 equipment volumes, and each equipment volume (B30.5 for mobile cranes, B30.2 for top-running overhead and gantry cranes) keeps its own rope inspection and replacement section. The rope manufacturer’s established removal criterion, or one it has approved in writing for that specific rope, is recognized by 1926.1413(a)(4)(ii)(A) as an alternative to OSHA’s Category II counts.

How often do sheaves and drums have to be inspected, compared with hooks and operating mechanisms?

Under 1910.179(j)(2), functional operating mechanisms are inspected for maladjustment daily, air and hydraulic systems for leakage daily, and hooks and hoist chains visually every day with a monthly inspection and certification record. Running ropes get a thorough monthly inspection with a certification record under 1910.179(m)(1). Those are the frequent-inspection items, at daily-to-monthly intervals. The periodic items, which include sheaves and drums, run at 1-to-12-month intervals, with the interval set under (j)(3) by the crane’s activity, severity of service and environment.

Under Subpart CC, 1926.1412(d) requires a visual inspection begun before each shift, (e) a documented monthly inspection, and (f) a 12-month inspection by a qualified person. The wider schedule is in annual versus frequent versus periodic inspections.

Does OSHA set a wear limit for sheave grooves?

No. 1926.1412(f)(2)(ii) says “cracks or major wear,” 1910.179(j)(3)(iii) says “cracked or worn,” and 1910.179(h)(1)(i) says “smooth and free from surface defects which could cause rope damage.” The dimensional limit is the crane manufacturer’s, the sheave manufacturer’s, or the rope manufacturer’s groove tolerance, and the inspection report should name which one was used.

What are the crane wire rope rejection criteria?

1926.1413(a)(2) sorts them into three categories. Category I is major distortion of the rope structure (kinking, crushing, unstranding, birdcaging, core failure or core protrusion), major corrosion, electric arc or heat damage, and improperly applied or damaged end connections. Category II is the broken-wire counts (six in one lay or three in one strand in one lay for running rope. Two in six diameters or four in 30 diameters for rotation resistant rope.

More than two in a lay beyond an end connection or more than one at an end connection for pendants and standing rope) plus a diameter reduction of more than 5% from nominal. Category III is core protrusion or other distortion indicating core failure in rotation resistant rope, prior electrical contact with a power line, and a broken strand. A rope that contacted an energized power line may not be repaired at all. 1910.179(m)(1) uses a descriptive list without counts.

Is there a crane wire rope replacement period?

Not in the regulations. Removal is condition-based. The rules fix inspection intervals, not rope life. Where the 12-month inspection is not feasible because of the crane’s set-up or the site, 1926.1413(c)(2)(iii) allows it as soon as feasible, but no more than an extra 6 months for running ropes. Rope idle for a month or more because the crane was shut down or stored is inspected before use under 1910.179(m)(2). The crane or rope manufacturer may recommend a change interval, and duty cycle is what sets it in practice.

How many wraps of rope must stay on the drum?

Two. 1910.179(h)(2)(iii)(a) requires no less than two wraps on the drum when the hook is in its extreme low position; 1926.1417(t) and 1910.180(h)(3)(x) say the same for the load and the boom on their respective drums, and a rope shortened under 1926.1413 to remove a damaged section must still leave them.

What is ASME B30.30?

The volume of the ASME B30 safety standard that covers ropes. The edition ASME currently lists is B30.30-2023, and it covers wire rope, hybrid rope and synthetic fiber rope, and rope lifting components, from selection and installation through inspection, repair and replacement, for the equipment in the other B30 volumes. It sits alongside the equipment volumes rather than replacing their rope sections, and OSHA’s Subpart CC incorporates B30.5-2004 rather than B30.30.

Do plastic or nylon sheaves change the rope removal criteria?

No. OSHA stated in the 2010 Subpart CC preamble that the broken-wire criteria do not depend on the type of sheave and apply regardless of the material of which the sheave is made. Rope run on plastic sheaves tends to show fewer surface breaks, so many inspectors put more weight on diameter and lay-length measurements, but the counts in 1926.1413 still decide.

What is the crane wire rope safety factor?

For overhead cranes, 1910.179(h)(2)(i) requires that the rated load divided by the number of parts of rope not exceed 20 percent of the rope’s nominal breaking strength, which is a design factor of 5. Under 1926.1414(e)(2), rotation resistant ropes need an operating design factor of no less than 3.5, and Type I no less than 5 unless the rope and equipment manufacturers approve the design factor in writing; Types II and III below 5 are limited to non-duty-cycle, non-repetitive lifts under (e)(3).

Other rope under 1926.1414(b) follows either B30.5-2004 section 5-1.7.1 (less its paragraph (c)) or a design factor high enough that the 1926.1413 inspections are an effective means of preventing sudden failure.

Does the hook get inspected with the sheaves?

It is on the same block and the same visit, but under different rules and different numbers. Hooks have their own throat-opening and twist limits and their own monthly certification record under 1910.179(j)(2)(iii), covered in crane hook inspection limits, and lifting devices below the hook are inspected under their own B30 volume, described in below-the-hook device inspections.

Who is qualified to gauge sheaves and condemn rope?

The shift and monthly rope inspections under 1926.1413 are competent-person work. The 12-month inspection of sheaves, drums and rope under 1926.1412(f) and 1926.1413(c) is qualified-person work, and the qualified person makes the safety-hazard determination. Third-party inspectors holding CCO Crane Inspector certification, which is offered in mobile, tower, overhead and articulating crane designations, are one way an employer documents that qualification. The terms themselves are untangled in competent versus qualified versus certified.

Gauge the groove before you order the rope, and write down what it measured.

Measure the sheaves before you buy more rope

Rope that keeps dying young is telling you about the reeving, not the rope. Ask us to gauge the sheaves and drum on the next periodic inspection — groove profiles, drum condition, and bearing checks, recorded with the numbers so the replacement rope lasts the way the manufacturer said it would.