If your facility runs an overhead crane with a rated capacity exceeding three tons, California law requires that crane to be inspected and certified annually by an accredited third-party certificating agency. The certification must result in a Plate V certificate per Title 8, Section 5021, and a copy of that certificate must be available with each crane or at the project site (Title 8, Section 5025). If you cannot produce a current one, the crane cannot legally be used.
A surprising number of facilities are out of compliance and don't realize it. Some let their certificates lapse by a few months. Others assume their in-house maintenance team covers the requirement. It doesn’t. Annual certification must come from an independent agency accredited under Title 8, Section 344.60. There is no self-certification path in California.
And if your insurance carrier ever asks for documentation of your crane's compliance after an incident, a lapsed or missing Plate V is the last thing you want to have
Proof Load Testing
Beyond the annual certification, Title 8, Section 5022 requires proof load tests at specific intervals.
New cranes must complete a quadrennial proof load test before initial use and every four years after. Previously uncertificated cranes already in service must be tested at the time of initial certification and every four years after that. If certificated equipment has been out of service for six months or more past its certification due date, a full examination equivalent to initial certification, including a proof load test, is required before the crane can re-enter service.
For overhead cranes, the proof load must not exceed 125 percent of the manufacturer's load rating, and the loaded crane must traverse the full length of the track, bridge, runway, and crossovers in all operable directions where practicable (Title 8, Section 5022(c)).
One exception to note: cranes with a rated capacity greater than one ton but not exceeding three tons must undergo an initial proof load test before first use, but the recurring quadrennial proof load test is not required for this capacity range (Title 8, Section 5022, Exceptions to Subsection (a)).
What About Cranes Three Tons and Under?
Cranes three tons and under are not subject to the Plate V certification requirement under Section 5021. However, they are not exempt from inspection entirely. Title 8, Section 4886 applies general safety orders to all overhead cranes with a rated capacity exceeding one ton. Federal OSHA standard 29 CFR 1910.179 further requires both frequent and periodic inspections on all overhead and gantry cranes regardless of capacity.
Frequent inspections cover daily to monthly intervals depending on usage. Periodic inspections, which are more comprehensive, are required at intervals ranging from one to twelve months depending on how hard the crane works (29 CFR 1910.179(j)).
Equipment in this capacity range tends to be the most neglected because the state doesn't mandate third-party certification. That doesn't make it safe. It makes it invisible to regulators until something goes wrong.
Who Can Perform What
Not every inspection requires a licensed certificating agency. Understanding where the line falls helps you stay compliant without overspending and helps you recognize where you may be falling short.
Frequent inspections (daily to monthly, depending on service classification) are the responsibility of the crane operator or a qualified person on staff. These are in-house checks covering functional mechanisms, controls, hooks, wire rope condition, and safety devices. They are required under 29 CFR 1910.179 and Title 8 Article 100 for all cranes, regardless of capacity. If your operators are not performing and documenting these, you have a gap.
Periodic inspections (one to twelve month intervals, depending on service classification) require a more thorough examination by a qualified person. For cranes three tons and under, this can be done in-house if your facility has someone with the training and experience to qualify. Most facilities do not, which is where a third-party inspection provider adds value even when the law doesn't explicitly require one. There's also a practical reason to use a third-party provider on equipment that doesn't require it by law. An inspection performed by an independent certificating agency carries more weight in any liability dispute than one performed internally. If a crane is involved in an incident and the only documentation you can produce is your own operator's checklist, the question becomes whether that inspection was truly objective. When a licensed third-party agency documents the condition of your equipment, that record stands on its own. Insurance carriers recognize the difference, and so do attorneys. For the cost of a single inspection visit, you create a paper trail that protects the facility in ways an internal check never will.
Annual certification (cranes over three tons only) must be performed by a Cal/OSHA Approved Bridge and Gantry Surveyor employed by a licensed certificating agency, such as AC3, under Title 8, Section 5021. Resulting document is The Plate V certificate. No in-house option exists.
Quadrennial proof load test (cranes over three tons only) must be performed by a licensed certificating agency. 125 percent of rated capacity, full traverse of the runway. No in-house option exists.
How Service Classification Affects Frequency
Both OSHA 1910.179 and ASME B30.2 tie the required inspection frequency to how your crane actually operates.
A crane that sits idle most of the year and runs only a handful of times should be inspected before each use, with a full periodic inspection at minimum annually.
A crane running two to five lifts per hour at loads well below rated capacity requires monthly frequent inspections and annual periodic inspections.
A crane averaging five to ten lifts per hour at around fifty percent of rated capacity requires monthly frequent inspections and semi-annual periodic inspections.
A crane running ten to twenty lifts per hour near rated capacity requires weekly frequent inspections and semi-annual periodic inspections.
A crane running twenty or more lifts per hour at or near rated capacity requires daily frequent inspections and quarterly periodic inspections.
Many crane owners have never classified their equipment by service. If your crane runs harder than your inspection schedule accounts for, you may be in compliance on paper with your annual certification but under inspecting relative to how the equipment is actually being used.
Why It Matters Before It Has To
Worn wire ropes, degraded brakes, structural fatigue in runway beams, and electrical failures all develop gradually. Routine inspection catches these when they are maintenance items with lead time. Without one, they surface as emergency shutdowns during the weeks you need the crane most.
For facilities that depend on cranes seasonally, the risk compounds. Equipment that sits idle in weather does not improve with time. The longer it sits, the more likely something has corroded, seized, or deteriorated. The crane that worked last season is not guaranteed to start this season.
If you are unsure whether your Plate V is current, if your crane falls in the one to three ton range and hasn't been looked at in over a year, or if your operators aren't performing documented frequent inspections, now is the time to address it. Contact AC3 for more information on how we can help you determine where your equipment stands and what it needs to stay compliant, operational, and protected.
AC3 is a Cal/OSHA accredited third-party certificating agency (CA-231) performing inspections, certifications, and proof load testing on all types of overhead, gantry, and mobile cranes throughout California. Contact us to schedule an inspection or learn about our preventive maintenance programs.