The person who oversees and directs crane assembly and disassembly is the A/D director (assembly/disassembly director). Under 29 CFR 1926.1404(a), the A/D director must be both a competent person and a qualified person, or a competent person who is assisted by one or more qualified persons. Where one person does the whole job, that person must meet both tests and is the A/D director.
If you found this page through a fill-in-the-blank question such as “the ____ oversees and directs all crane assembly and disassembly operations”, the answer is “A/D director”. The rest of the page covers what the role involves under the US OSHA crane standard, checked on 1 Nov 2026.
Who counts as competent and qualified
| Term | Definition in 29 CFR 1926.1401 | What it means for the A/D director |
|---|---|---|
| Competent person | One who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them | Can spot the hazards of the assembly and has the authority to stop work and fix them |
| Qualified person | A person who, by possession of a recognized degree, certificate or professional standing, or by extensive knowledge, training and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter, the work or the project | Has the technical knowledge to deal with the crane, its components and the procedures |
The standard does not require a particular license or course for the A/D director. The employer decides, and has to be able to show, that the person meets both definitions for the crane being assembled. The role is defined by what the person does, not by a job title, and it can be filled by management or non-management personnel (1926.1401). NCCCO launched a voluntary A/D Director certification in January 2026, with mobile crane and tower crane tracks. It is one way to show the knowledge, not an OSHA requirement.
What the A/D director must do
| Duty | What 1926.1404 requires | Paragraph |
|---|---|---|
| Know the procedures | Understand the applicable assembly and disassembly procedures | (b) |
| Review them | Review the procedures immediately before work starts, unless the director already understands them and has applied them to the same type and configuration of equipment | (c) |
| Brief the crew | Before work starts, make sure crew members understand their tasks, the hazards of those tasks and the hazardous positions to avoid. Repeat this before a crew member takes a different task and when new people join | (d) |
| Protect people out of the operator’s view | A crew member going to a place out of the operator’s view must tell the operator first. The operator then does not move any part of the equipment or load until told, by a pre-arranged system, that the person is safe | (e) |
| Keep people from under the boom | When pins or similar devices are being removed, employees must not be under the boom, jib or other components, with a narrow exception where site constraints require it and the director sets procedures that limit risk and exposure | (f) |
| Respect capacity limits | Rated capacity limits for loads on the equipment, components, rigging, lifting lugs and accessories must not be exceeded in any phase | (g) |
| Address specific hazards | The twelve hazards listed in the next section | (h) |
| Follow the manufacturer | Select components and configure the equipment according to manufacturer instructions, prohibitions, limitations and specifications. If these are unavailable, a registered professional engineer familiar with the equipment must approve the selection and configuration in writing | (m)(1) |
| Inspect after assembly | After assembly, the equipment is inspected to confirm the configuration complies. See 1926.1412(c) | (m)(2) |
| Set outriggers and stabilizers correctly | Outriggers and stabilizers fully extended or, if manufacturer procedures permit, deployed as specified in the load chart. Outriggers set to remove the equipment weight from the wheels, floats attached, each visible to the operator or a signal person while it is extended and set, and blocking that meets (h)(2) and (h)(3) | (q) |
| Rigging | The rigging work is done by a qualified rigger and synthetic slings are protected from abrasive or sharp edges and from distortion or compression that would reduce capacity | (r) |
The twelve hazards the A/D director must address
Paragraph (h) lists the hazards the director supervising the work must address:
- Site and ground bearing conditions must be adequate to support the equipment during assembly and disassembly.
- Blocking material must be big enough, in good condition and stacked so it sustains the loads and stays stable.
- Proper location of blocking under lattice booms or components, to protect structural integrity and prevent dangerous movement and collapse.
- Verifying assist crane loads at each phase before assembly or disassembly begins, when an assist crane is used.
- Boom and jib pick points suitable for preventing structural damage and for safe handling.
- Center of gravity identified where the method of keeping the load stable depends on it, or measures taken against an inaccurate estimate.
- Stability upon pin removal: boom sections, suspension systems and components rigged or supported so they stay stable when pins come out.
- Snagging: suspension ropes and pendants must not catch on boom or jib connection pins or cotter pins.
- Struck by counterweights: unintended movement from inadequately supported counterweights and from hoisting counterweights.
- Boom hoist brake failure: the brake is tested each time reliance is placed on it, and if it is not sufficient another method such as a pawl, backup brake, blocking or an assist crane is used.
- Loss of backward stability before swinging the upperworks, traveling, and attaching or removing components.
- Wind speed and weather: their effect on the equipment.
Manufacturer or employer procedures
Under 1926.1403 the employer must follow all manufacturer prohibitions and use either the manufacturer’s assembly and disassembly procedures or the employer’s own. Employer procedures may be used only if the employer can show they meet 1926.1406. Those procedures must prevent unintended dangerous movement and collapse of any part of the equipment, give adequate support and stability to all parts, and position employees so their exposure to unintended movement or collapse is minimized. A qualified person must develop them. When synthetic slings are used in assembly or disassembly rigging, the manufacturer’s procedures must be followed.
Pin rules when dismantling booms and jibs
1926.1405 adds rules that apply whether manufacturer or employer procedures are used. In short, pins must not be removed, partly or completely, in these cases:
- any pin in the pendants while the pendants are in tension;
- pins (top or bottom) on boom sections between the pendant attachment points and the crane body while the pendants are in tension;
- pins on boom sections between the uppermost boom section and the crane body while the boom is supported by the uppermost section resting on the ground or another support;
- top pins on the cantilevered part of the boom being removed until that cantilevered section is fully supported.
Cantilevered boom sections also have a limit: the manufacturer’s limit on the amount of boom supported only by cantilevering must not be exceeded. Where it is unavailable, a registered professional engineer must set the limit in writing (1926.1404(j)).
Assembly and disassembly checklist
Use this as a starting point for the job. It follows the paragraphs above and is not a substitute for the manufacturer’s procedures.
- The A/D director is named, and the employer can show they meet both the competent and the qualified person definitions.
- Manufacturer procedures, or employer procedures developed by a qualified person, are on site and have been reviewed just before the start.
- The weight of each component is readily available (1926.1404(k)).
- Ground conditions are checked and blocking is sized, stacked and placed for the loads.
- If an assist crane is used, its loads at each phase are verified before work begins.
- The crew has been briefed on tasks, hazards and positions to avoid, and is briefed again when tasks or people change.
- A pre-arranged communication system exists for crew members who are out of the operator’s view.
- Pick points, center of gravity, counterweights and backward stability have been addressed.
- The boom hoist brake has been tested before anyone relies on it.
- Nobody is under the boom or jib when pins are removed, unless the exception procedure is in place.
- Outriggers and stabilizers are fully extended or set per the load chart, with floats attached and blocking that meets (h)(2) and (h)(3).
- Rigging is done by a qualified rigger and synthetic slings are protected.
- Wind and weather limits are set and checked.
- Shipping pins, straps and links are removed and stowed so they cannot fall.
- After assembly, the configuration is inspected against the manufacturer’s requirements.
For the signals used on the job, see rigging hand signals. Posting warning signage is part of site setup.
Common mistakes
- Treating the A/D director as a general supervisor. The standard names a person who is both competent and qualified for this equipment, or a competent person assisted by qualified persons.
- Skipping the procedure review because the crew has done it before. The exception only applies to the same type and configuration of equipment.
- Not repeating the briefing when a crew member changes task or a new person arrives.
- Working under the boom or jib during pin removal without the written-out exception procedure.
- Relying on the boom hoist brake untested.
- Not verifying assist crane loads at each phase.
- Ignoring wind and weather. The standard lists it among the hazards the director must address.
- Letting an unqualified person rig components. Rigging for assembly must be done by a qualified rigger.
Outside the US
In Great Britain, regulation 8 of the Lifting Operations and Lifting Equipment Regulations 1998 requires every lifting operation to be properly planned by a competent person, appropriately supervised and carried out safely. Other countries use their own terms for the role. The A/D director title and the paragraph numbers above are specific to US OSHA.
Frequently asked questions
Who oversees and directs all crane assembly and disassembly operations?
The A/D director (assembly/disassembly director). 29 CFR 1926.1404(a) requires assembly and disassembly to be directed by a person who meets the criteria for both a competent person and a qualified person, or by a competent person assisted by one or more qualified persons.
Who can be an A/D director?
Anyone who meets the requirements, whatever their job title and whether they are management or non-management (1926.1401). The employer decides, and has to be able to show, that the person meets both definitions for the crane being assembled.
Is the A/D director the same as the competent person, the qualified person or the signal person?
No. Competent person and qualified person are two definitions that the A/D director must satisfy together. A signal person gives signals to the crane operator and does not direct assembly. In the fill-in-the-blank question, A/D director is the answer.
Can one person assemble a crane alone?
Yes, if that person meets both the competent person and the qualified person criteria. That person is then the A/D director (1926.1404(a)(2)).
Does the A/D director need a certificate?
OSHA does not require a particular certificate. NCCCO launched a voluntary A/D Director certification in January 2026, with mobile crane and tower crane tracks. NCCCO also says a Washington State rule taking effect in 2026 requires certified professionals for crane assembly and disassembly, so check the rule in your state.
Is the A/D director the same as the lift director?
No. The A/D director is the role in 1926.1404 for assembly and disassembly. The signal rules in Subpart CC refer to a lift director, where there is one, for lifting operations (for example 1926.1419(c)(2) and 1926.1421(a)).
Related guides
- Rigging hand signals and signal person rules
- Crane safety signs
- Crane safety: OSHA rules and site practices
- Mobile crane lifting plan template
- What a construction safety officer does
- Safe distance from overhead power lines
- Types of slings
- Types of mobile cranes
- Crane hazards and control measures
- Crane safety toolbox talk
Sources
- eCFR, 29 CFR 1926.1403, 1926.1404, 1926.1405, 1926.1406 and 1926.1401 (definitions), current to 29 Oct 2026, read 1 Nov 2026.
- UK Lifting Operations and Lifting Equipment Regulations 1998, regulation 8, read 1 Nov 2026.
- NCCCO, Introducing CCO’s New A/D Director Certification (press release dated 21 Oct 2025, certification launching January 2026), read 1 Nov 2026.
- OSHA, Cranes and Derricks in Construction (OSHA 3433) and the Subpart CC A/D director fact sheet (definition of A/D director and the twelve hazards), read 1 Nov 2026.