Who Can Run a Digger Derrick, and What Overload Looks Like

Key Takeaways

A digger derrick is a crane. The person on the controls needs training for that machine.
Pole work has a narrow OSHA exception. Loading cargo in a yard does not.
On March 7, 2024, a lead mechanic lifted a mower that was chained to a trailer. The line snapped.
The crew never added up the mower, the trailer, and the tractor. That total was 48,000 pounds.
Washington requires a written, dated, signed inspection record every month for brakes, hooks, and ropes. This crane had no line inspection on record for five years.
The load chart has to be in the cab. If you cannot read the capacity, you do not lift.
Digger derrick training is where load charts, setup, and pole work get practiced before a live pick.

A trained operator runs a digger derrick. An overload is any lift past the chart. In a Washington yard, a crew picked a mower, a trailer, and a tractor at once. The line snapped.

The Washington FACE report is dated October 10, 2026. The lift happened on March 7, 2024. The findings are preliminary. They still show how a normal yard move becomes a fatal pick.

Who is allowed to run a digger derrick?

Washington’s crane rule is plain. Cranes are run by regular crane operators. An authorized substitute may run one after real training under a competent operator. A crane repair person or an inspector may also run one. That rule is WAC 296-24-23529.

Shop time on the truck is not that training. The mechanic in this report had been the lead mechanic and shop manager for 11 years. Investigators still found he was not qualified by training or experience to run the truck crane.

On a construction site, the federal rule is stricter when the crane standard applies. The employer must make sure each operator is trained, certified or licensed, and evaluated before the lift. That is 29 CFR 1926.1427.

The credential ATS prepares students for is the NCCCO digger derrick operator card. You must be at least 18. You pass a written exam and a practical exam. The card lasts five years. The written exam has 75 questions and a 90-minute limit. About 17 percent of that test is the manufacturer’s load chart. You have 12 months after the first exam to pass the other one.

When does the pole-work exception apply?

OSHA leaves some digger derrick work outside the construction crane standard. The exception covers three jobs:

Augering holes for poles that carry electric or telecom lines
Setting those poles and pulling them
Handling the hardware that goes on those poles, or comes off them

Other work covered by the power-line construction rules can qualify too. The employer still has to follow those power-line rules in full. The section is 29 CFR 1926.1400(c)(4).

Loading a purchased mower onto a lowboy is outside that list. So is a general pick in a yard, a sign, or a construction load that is not pole hardware. Once the job leaves the exception, the crane rules apply.

A mechanic’s truck can also sit outside the crane standard when the hoist is used for repair work. That is a different exclusion. It does not turn every mechanic into a crane operator.

What did the October report find?

A telecom contractor sent a four-person crew to a heavy equipment yard. They were picking up a flail mower the company had just bought. Two foremen were on the crew. The lead mechanic ran the crane and the rope winch.

He stood on a platform at the right rear corner of the truck. The truck was backed up to the side of the trailer. The crew hooked a braided synthetic winch line to the mower, lifted it, and set it on the deck.

The mower was too wide. The wheels stuck out past the deck, past legal width for the road. The crew moved the wheels into a gap near the middle of the deck. They chained the mower to the trailer frame so it would stay put.

The foreman in charge stepped away. The mechanic had the rest of the crew lift again, to stand the mower on its wheels in that gap. The boom was extended over him and over the people on the deck. The wheels came up about two feet. The line snapped. The mower dropped on the mechanic. He died at the scene.

Investigators listed three failures:

What went wrong	What the crew did	What the rule requires
Untrained operator	A lead mechanic ran the crane	A regular operator, or a substitute trained under a competent operator
Bad hookup	A loose drift pin in a larger hole	A sling or another approved device on the hook
Unknown weight	No one added the mower, trailer, and tractor	Stay inside the rated load, and know the weight first

The pin was 3/4 to 7/8 inch thick. The hole in the mower was 1.5 inches. The pin was not secured. WAC 296-24-24015 says the load goes on the hook by a sling or another approved device. The same rule says no one stands or passes under a load on the hook.

The crane and the aged line had no documented inspection for five years. Washington requires a written, dated, signed record every month on critical items in use, including brakes, hooks, and ropes. That is WAC 296-24-24007(5).

What does an overload look like?

The crew did not pick a mystery weight in the air and hope. They chained the mower to the trailer. When the winch took weight, it tried to lift the mower and the trailer it was tied to. The tractor was part of that same mass. The report puts the mower, trailer, and tractor at 48,000 pounds. That total was past the crane and past the winch line.

You can see the overload before the line breaks.

The load is tied to something you did not mean to lift.
The wheels, frame, or deck start to rise with the hook.
The line goes bar-tight and the boom is working hard at a long reach.
Nobody has a weight, and nobody has opened the chart.

Washington bars a lift past the rated load, except for a test done under the test rule. On a construction crane, 29 CFR 1926.1417(o) says the same thing. The equipment must not be operated past its rated capacity. The operator must not be told to do that anyway.

The report says to use an overhead crane, such as a gantry, for a yard load like this. A truck crane is a poor tool for standing a wide machine up on a trailer.

How do you check the load before you lift?

On a construction job, the load chart, the speeds, the warnings, and the operator’s manual stay in the cab. If the chart is only on a screen and the screen dies, the operator stops. That is 29 CFR 1926.1417(c).

The weight check has two legal paths:

Get the weight from the manufacturer, from a standard calculation, or from another reliable source. If the operator asks, that number comes before the lift.
Or start the hoist and read a load-weighing device, a load moment indicator, or a rated-capacity limiter. If the load is over 75 percent of the maximum rated capacity at the longest radius you will use, stop. Confirm the weight the first way before you go on.

Radius matters as much as pounds. A load the chart allows close to the truck can be illegal once the boom is out. Outriggers down, the truck level, and the right chart for that setup are part of the same check.

The line has its own limit. A winch rope can fail while the boom chart still looks fine. The monthly rope record exists so a worn line is retired before the pick, not after.

Rigging is a separate skill from running the crane. A drift pin in a loose hole is not a sling. Rigging certification covers how the load is attached and how the signal is called. The person under the boom cannot be the only one watching the hook.

What should the crew agree on first?

The report asks for a cargo plan before anyone rigs, loads, or shifts the machine. Cover four points out loud:

The hazards, including a load that can get away from you.
The load limits, read off the crane chart.
The rigging method, and a look at the line, hook, and hardware.
Who does what. One person runs the crane. One person calls the lift.

If the person in charge leaves, the plan does not change from the rear platform. The pick waits.

Power lines are a separate check. Treat them as live until the utility says otherwise. The distances are in the crane power line clearance guide.

On the Sun Prairie yard, the habit is the same one a pole job needs. Read the chart for that radius. Know the weight. Hook the load with a sling. Keep people out from under the hook. Digger derrick training is where that sequence gets practiced. Students also work the auger, set poles, and prepare for the NCCCO written and practical exams. The card you are training for is an NCCCO credential.

Conclusion

The person on a digger derrick is a crane operator, or a substitute who was trained to be one. Pole work can sit outside the construction crane standard. A yard lift of cargo does not.

The October report shows what an overload looks like. The mower was chained to the trailer. The hook picked up more than the mower. The line had no inspection record for five years. The operator was standing under the load.

Want that practice before you are the person on the platform? See training dates, apply for training, or call ATS at (800) 383-7364. Questions can go through contact ATS.

Frequently Asked Questions

Q: Can a mechanic run a digger derrick?
A: Only with the training the crane rule requires. Years in the shop do not replace it. Washington allows regular operators, trained substitutes, crane repair people, and inspectors. The October report found this lead mechanic was not qualified to run the truck crane.

Q: Does pole work skip the crane certification rule?
A: Some digger derrick work sits outside OSHA’s construction crane standard. That work is augering pole holes, setting and pulling those poles, and handling pole hardware. The employer must still follow the power-line rules. Other lifts stay under the crane rules. Loading equipment on a trailer is one of those lifts.

Q: What is a digger derrick overload?
A: A lift past the rated capacity of the crane or the winch line. In this case the crew chained a mower to a trailer and picked. The mower, trailer, and tractor together weighed 48,000 pounds, which was past the crane and the line.

Q: How often does the winch line need an inspection record?
A: Washington requires a written, dated, signed inspection record every month for critical items in use, including ropes. The crane and the line in this report had no documented inspection for five years.

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