Safe working load markings

The safe working load (SWL), the minimum angle to the horizontal at which that SWL may be applied, and the date of the test must be plainly marked at the heels of all booms. This is required by 1919.21(a).

• Include the SWL value, the minimum working angle, and the test date together at the boom heel so operators can see the limit and when it was last verified.
• If the gear is certificated for use under a union purchase rating, that union purchase SWL must also be plainly marked on the boom heel per 1919.21(a).

The rule requires that any restrictions or special conditions affecting the gear’s safe working load be recorded in the vessel’s official documentation (the vessel’s papers). See 1919.21(a).

• "Vessel's papers" refers to the shipboard records or certification files where equipment limitations and certificates are kept so inspectors and crew can review operational constraints.
• Markings on the gear show the limits on the equipment itself, while the vessel’s papers must carry any additional limitations or clarifications required by the standard.

All blocks used in hoisting or lowering must have the safe working load plainly marked on them, as required by 1919.21(b).

• That includes single-, double-, or multiple-sheave blocks and similar hoisting blocks that form part of the lifting assembly.
• Ensure the marking remains legible and durable under shipboard conditions so crew and inspectors can read the SWL at a glance.

When a boom’s capacity is rated by radius variation, the maximum safe working loads for the various working angles and the maximum and minimum safe radii must be conspicuously posted near the controls and visible to the crane operator, per 1919.21(c).

• The posted chart or plate should be easy to read from the operator’s station so the operator can select safe loads for the boom angle and radius in use.
• Ratings may be shown in pounds or in tons of 2,000 pounds; if shown in tons of 2,000 pounds this must be clearly indicated on the posting, as stated in 1919.21(c).

Yes — boom ratings may be stated in pounds, and if they are stated in tons of 2,000 pounds you must indicate that fact on the posting, as required by 1919.21(c).

• Make the units explicit on the capacity plate or chart (for example, “lbs” or “tons (2,000 lb)”) so there is no confusion about load limits.
• A clearly marked unit prevents mistakes when operators read rated capacities under changing boom angles or radii.

If gear is certificated for use under a union purchase rating, that union purchase safe working load must also be plainly marked at the heels of the booms, as required by 1919.21(a).

• Include both the normal certificated SWL and the union purchase SWL on the boom heel so crews know which rating applies under union purchase conditions.
• Keep any related limitations or instructions in the vessel’s papers per 1919.21(a).

The standard requires that the safe working load be "plainly marked," so a worn or illegible marking would not meet 1919.21. You must restore or replace markings so they remain plainly legible.

• Practical steps include repainting or refastening metal capacity plates and recording the date of the test again if required by your vessel’s procedures.
• While [1919.21] specifies the content and location of markings, ship operators should maintain legibility as part of overall compliance and safe operation; see also the maritime applicability discussion in the OSHA applicability letter at https://www.osha.gov/laws-regs/standardinterpretations/1991-02-19 for context on maritime standards application.

The maximum safe working loads for the various working angles and the maximum and minimum radii must be conspicuously posted near the crane or derrick controls and must be visible to the crane operator, according to 1919.21(c).

• “Near the controls” means the operator should be able to read the load chart or plate without leaving the operator’s station.
• Postings should be durable, clearly labeled with units (pounds or tons of 2,000 pounds), and positioned to avoid obstruction by other equipment or weather exposure.

The standard itself requires that the markings and postings exist on the gear and near controls, so the vessel owner/operator or the party responsible for maintaining the vessel’s certificated gear must ensure compliance with 1919.21.

• Maritime standards at Part 1919 apply to vessel cargo gear; the employer or vessel operator should maintain markings and vessel papers in accordance with those rules. You can refer to the general applicability guidance in OSHA’s 1991 interpretation at https://www.osha.gov/laws-regs/standardinterpretations/1991-02-19 which explains how maritime standards like Part 1919 apply to vessel operations.
• Practical compliance includes periodic inspection of markings, recordkeeping of tests, and updating vessel papers with any limitations.

The standard requires that the date of the test be plainly marked at the heel of the boom, but it does not specify testing intervals or frequency in 1919.21(a).

• Because [1919.21(a)] mandates placing the test date on the boom, keep that date current per your vessel’s inspection and certification program or other governing rules.
• If your operation or classification society sets specific test intervals, follow those requirements and record the test dates on the boom and in the vessel’s papers; the competent-person and accreditation guidance in OSHA’s April 26, 1977 letter at https://www.osha.gov/laws-regs/standardinterpretations/1977-04-26 may be relevant when determining who performs or approves certification-related work.

1919.21(b) requires the safe working load to be marked on all blocks used in hoisting or lowering. If a block is not used for hoisting or lowering (for example, a fixed guide that never carries load), that specific text does not require an SWL marking.

• However, if the guide block is ever used in a lifting or lowering operation or could be substituted into a load path, it should be treated as a hoisting block and have an SWL marking.
• When in doubt, mark and document the SWL or keep the block out of service for lifting until it is certified and marked to avoid noncompliance or unsafe use.

Limitations that affect safe working loads must be noted in the vessel’s papers and the required markings must be plainly displayed on the gear, as specified in 1919.21(a).

• Keep written limitations in the vessel’s official documentation (vessel’s papers) so they are available during inspections and to crew.
• Complement written records with durable markings or capacity plates on the equipment and with conspicuous load charts near operator controls when required by 1919.21(c).

Yes — when the boom capacity is rated by radius variation, the maximum and minimum radii at which the boom may be safely used must be posted along with the maximum safe working loads for the various working angles, as required by 1919.21(c).

• A complete chart helps the operator select the correct load limit for the combination of boom angle and radius in use.
• Make sure the radius values are conspicuous and consistent with the units used for the load ratings.

Part 1919 is the specific maritime standard for certification of vessels’ cargo gear, and 1919.21 sets the marking requirements for that gear. Employers must follow the maritime standard where it applies rather than general industry rules, as discussed in OSHA’s applicability guidance at https://www.osha.gov/laws-regs/standardinterpretations/1991-02-19.

• The 1991 OSHA interpretation explains that maritime-specific standards (such as Part 1919) apply to vessel operations when relevant, so follow the maritime marking requirements in [1919.21] for vessel cargo gear.
• If a situation overlaps sectors, apply the standard that specifically addresses the operation under inspection.

The standard requires that the safe working load be "plainly marked" at the heels of booms and on blocks used in hoisting or lowering (1919.21(a) and 1919.21(b)). For booms rated by radius, the standard requires that the maximum loads and radii be conspicuously posted near the controls (1919.21(c)).

• In practice, this means SWLs on booms and blocks can be stamped, plate-mounted, or durably painted, as long as they are plainly legible on the equipment itself.
• Radius-based ratings should be provided as a conspicuous chart or plate near the controls so the operator can read the various loads and radii per [1919.21(c)].

1919.21(a) requires the date of the test to be marked on the boom, but it does not specify who must perform the test. OSHA’s April 26, 1977 letter of interpretation discusses accreditation and the role of persons who certify gear under Part 1919, noting that certain maritime certification tasks have been performed by persons accredited under Part 1919 procedures (see https://www.osha.gov/laws-regs/standardinterpretations/1977-04-26).

• Use qualified or accredited persons when your governing rules or classification society require accredited certification; the 1977 interpretation at https://www.osha.gov/laws-regs/standardinterpretations/1977-04-26 provides context about accreditation for Part 1919-related certification.
• Maintain the test date on the boom and the supporting certification records in the vessel’s papers so inspectors can verify who performed the test and when.