Equipment modifications requirements

Modifications or additions that affect the capacity or safe operation of the equipment are prohibited unless the conditions in 1926.1434(a) are met. See the general prohibition and requirements in 1926.1434(a) for details.

• This covers any change that could alter how much load the equipment can carry or how safely it operates (for example, structural changes, adding counterweights, changing boom geometry).
• It does not mean minor, non-safety-related cosmetic changes, but when in doubt treat the change as safety-related and follow the requirements in 1926.1434(a).

Yes — an employer may make a modification that affects capacity or safe operation if the manufacturer approves the modification in writing and the other conditions in 1926.1434(a)(1) are met. See the manufacturer review and approval requirements in 1926.1434(a)(1).

• The approval must be in writing (1926.1434(a)(1)(i)).
• Load charts, manuals, and decals must be updated as necessary (1926.1434(a)(1)(ii)).
• The original safety factor of the equipment must not be reduced (1926.1434(a)(1)(iii)).

If the manufacturer refuses to review the modification or fails to acknowledge or begin a review within 30 days, the employer may proceed only if a registered professional engineer approves the modification and other conditions in 1926.1434(a)(2) are met. See the manufacturer refusal rule in 1926.1434(a)(2).

• A registered professional engineer who is a qualified person for that equipment must approve the modification and specify the applicable equipment configurations (1926.1434(a)(2)(i)(A)).
• The engineer must also update load charts, manuals, and decals as needed (1926.1434(a)(2)(i)(B)).
• The original safety factor must not be reduced (1926.1434(a)(2)(ii)).

If the manufacturer is unavailable, the employer may proceed only if the same requirements in 1926.1434(a)(2)(i) and (ii) are met — namely engineer approval, updates to documentation, and no reduction in original safety factor. See the unavailable manufacturer provision in 1926.1434(a)(3).

• "Unavailable" means the manufacturer cannot be contacted or no longer exists; employers must obtain approval from a registered professional engineer who is qualified for the equipment.
• The engineer must specify which configurations the approval covers and revise load charts, manuals, and markings accordingly.

If the manufacturer agrees to review but fails to complete the review within 120 days after receiving the detailed description, the employer may treat the situation like a manufacturer refusal and proceed if the engineer approval and other 1926.1434(a)(2) conditions are met. See the 120-day delay provision in 1926.1434(a)(4).

• The employer must provide the manufacturer a detailed description and give it an opportunity to review before invoking this rule.
• The registered professional engineer must approve and document the changes, update paperwork, and ensure the equipment's original safety factor is preserved.

For equipment designed for marine work sites that contains major structural components from more than one manufacturer, modifications may proceed if the requirements of 1926.1434(a)(2)(i) and (ii) are met — engineer approval, documentation revisions, and no reduction in safety factor. See the multiple-manufacturer/marine provision in 1926.1434(a)(5).

• Because no single manufacturer may take full responsibility, the standard requires a registered professional engineer's approval and corresponding updates to load charts and manuals.

If the manufacturer reviews and rejects the proposed modification and explains the reasons in writing, the modification is prohibited. See the manufacturer rejection rule in 1926.1434(b).

• If the manufacturer rejects the proposal but does not explain the reasons in writing, the employer may treat that outcome as a refusal to review and follow the steps in 1926.1434(a)(2) (engineer approval and documentation updates).

After an approved modification, the load charts, procedures, instruction manuals, and instruction plates/tags/decals must be modified as necessary to reflect the change. See the documentation update requirement in 1926.1434(a)(1)(ii).

• Updates should clearly show new capacities, limits, operating procedures, and any new restrictions.
• Markings and decals on the equipment must match the revised load charts so operators have accurate, on-equipment guidance.

It means the modified equipment must maintain at least the same minimum margin of safety (strength and design factor) that it had before the change; modifications cannot weaken components or reduce required safety margins. See the safety factor preservation requirements in 1926.1434(a)(1)(iii) and 1926.1434(a)(2)(ii).

• Practically, engineers must demonstrate through calculations, analysis, or testing that the change does not reduce the original design safety factor.
• If the modification would lower the safety factor, it is not permitted under these provisions.

The engineer must approve the modification in writing and specify the equipment configurations to which that approval applies. See the engineer approval detail in 1926.1434(a)(2)(i)(A).

• The approval should identify serial numbers, model numbers, or other identifiers and list any limits, operating conditions, or configurations for which the approval is valid.
• Vague or generic approvals that don't define applicable configurations do not meet the standard's requirement.

Yes — when an engineer approves a modification because the manufacturer refused or failed to review, the engineer must modify load charts, procedures, manuals, and plates/tags/decals as necessary. See the engineer-update requirement in 1926.1434(a)(2)(i)(B).

• The revised load chart must clearly reflect new capacities and limits for every configuration covered by the approval.
• Ensure the updated charts and labels are placed on the equipment and in operator materials so users have accurate information.

Yes — if the manufacturer rejects the proposal but does not explain the reasons in writing, the employer may treat this as a manufacturer refusal to review under 1926.1434(a)(2). See the rejection/no-reason guidance in 1926.1434(b).

• In that case, the employer must follow the 1926.1434(a)(2) path: obtain engineer approval, update documentation, and preserve the original safety factor.

No — the provisions in paragraphs (a) and (b) do not apply to modifications made or approved by the U.S. military. See the military exception in 1926.1434(c).

• If equipment is modified or approved by the U.S. military, it is exempt from the specific manufacturer/engineer approval paths described in 1926.1434(a) and (b).

An employer should prepare and provide a detailed description of the proposed modification so the manufacturer can review the technical merits; this is required for the manufacturer-review and refusal pathways. See the requirement to provide a detailed description referenced in 1926.1434(a)(2).

• Include drawings, calculations, purpose of modification, equipment identification (model/serial numbers), and anticipated operating configurations to give the manufacturer adequate information to review.
• Keep records of the date the detailed description was sent and any communications; timing matters (30- and 120-day rules).

The employer may treat the manufacturer as refusing to review if the manufacturer declines to review or fails, within 30 days, to acknowledge the request or initiate the review; then the employer may follow the engineer-approval path in 1926.1434(a)(2). See the 30-day timing provision in 1926.1434(a)(2).

• Document when the detailed description was provided and any attempts to contact the manufacturer to show the 30-day period elapsed.

Yes — if the manufacturer agrees to review but fails to complete the review within 120 days after receiving the detailed description, the employer may proceed under the engineer-approval path provided the 1926.1434(a)(2)(i) and (ii) requirements are met. See the 120-day completion provision in 1926.1434(a)(4).

• Again, maintain records showing the date the manufacturer received the detailed description and that 120 days elapsed without a completed review.

A qualified person must be a registered professional engineer with demonstrated qualifications and experience relevant to the specific type of equipment being modified so they can competently approve the change and specify applicable configurations. See the registered professional engineer requirement in 1926.1434(a)(2)(i).

• Employers should hire an engineer whose registration and practice area match the equipment type (for example, a structural or mechanical P.E. experienced with cranes).
• The engineer's approval should be documented in writing and include the technical basis for accepting the modification.

The rule 1926.1434 is part of Subpart CC, which covers cranes and derricks in construction, so it applies to equipment regulated under that subpart. See the standard header for 1926.1434 within Subpart CC, Cranes and Derricks in Construction.

• If other equipment is covered by different OSHA standards, those standards' modification rules would apply; always check the specific standard for the equipment in question.

If a modification or addition does not affect the capacity or safe operation of the equipment, 1926.1434's approval and documentation rules do not apply; the prohibition in 1926.1434(a) targets changes that affect capacity or safe operation. See the scope statement in 1926.1434(a).

• However, employers should still ensure that procedural changes do not inadvertently affect safety or capacity, and update manuals and training as needed.

Practical examples include structural changes to the boom or frame, adding or removing counterweights, changing the rated boom length or angle limits, installing aftermarket load-moment indicators that change operating limits, or altering hydraulic systems that affect lift capacity. These all could affect capacity or safe operation and would trigger 1926.1434's requirements. See the prohibition and approval requirements in 1926.1434(a).

• For any such change, obtain manufacturer written approval or follow the manufacturer-refusal/engineer-approval path and update load charts and markings accordingly.

Employers should keep written manufacturer approvals (if any), the detailed description provided to the manufacturer, written engineer approvals specifying configurations, and records of updated load charts, manuals, and on-equipment decals. These documents demonstrate compliance with 1926.1434 requirements. See the documentation and approval provisions in 1926.1434(a)(1) and (a)(2) and 1926.1434(a)(2).

• Keep communication records showing dates the manufacturer received the detailed description and any responses to support reliance on the 30- or 120-day rules.

No — while required operator training is important, it does not substitute for the written modification approval and updates to load charts, manuals, and decals required by 1926.1434(a)(1). The employer must obtain the manufacturer's written approval and make the necessary documentation changes. See the manufacturer-approval and documentation requirements in 1926.1434(a)(1).

• Training can be an additional condition imposed by the manufacturer, but employer compliance requires the written approval and matching equipment documentation.

No — if the manufacturer, after reviewing the technical safety merits, rejects the proposal and explains the reasons in writing, the modification is prohibited under 1926.1434(b). You cannot override a documented manufacturer rejection; however, if the manufacturer rejects without stating reasons in writing, you may treat it as a refusal and follow 1926.1434(a)(2). See the manufacturer rejection rule in 1926.1434(b).

• If the manufacturer provides written reasons, consider addressing those concerns and re-submitting a revised proposal or engaging with the manufacturer further rather than proceeding without their documented consent.