Crane Safety Through Alabama Hurricanes, Thunderstorms and Tornado Season

What OSHA requires when the weather turns

Alabama is a federal OSHA state, so private construction employers here follow 29 CFR 1926 Subpart CC without any state add-ons. Subpart CC does not print one wind speed at which every crane must stop. Instead it hands the decision to people and documents. Under 29 CFR 1926.1417(n), the competent person must adjust the equipment, the operation or both to account for the effect of wind, ice and snow on stability and rated capacity. Under 1926.1417(h), once a local storm warning is issued, the competent person must decide whether the manufacturer's recommendations for securing the equipment need to be put into effect.

The anchor for both duties is 1926.1417(a), which requires the employer to follow all manufacturer procedures for the crane's operational functions. That makes the operator's manual and load chart the controlling documents for wind. If neither the chart nor the manual gives wind speeds and derating information, OSHA's guidance is to get that information from the manufacturer. Tower cranes carry a parallel rule in 1926.1435: wind may not exceed the manufacturer's recommended speed, or, where the manufacturer is silent, a speed set by a qualified person.

• Competent person: decides when to slow, derate, stop or secure the crane based on current conditions.
• Manufacturer limits: in-service and out-of-service wind speeds for the exact configuration on site.
• Storm warning: triggers the decision on securing; it is not optional paperwork after the fact.

Reading your crane's wind numbers

A vendor blog or a toolbox talk may quote a single cutoff, such as 20 mph, as if it were law. It is not. Permissible wind depends on the machine, the boom length, the jib, the load's surface area and the radius. Manitowoc's published wind guidance for its crawler cranes, for example, lists in-service limits that vary by configuration and sets separate out-of-service procedures for when the anticipated wind exceeds those limits. Your chart may also require reduced capacity at lower wind speeds than the stop limit.

Two practical points matter on Alabama jobs. First, the wind you feel at the outriggers is not the wind at the boom tip; gusts at 150 feet can be much stronger than ground readings, which is why many fleets fit boom-tip anemometers. Second, a big, light load such as a roof panel bundle, an HVAC unit with a shroud or a precast wall piece acts like a sail. The chart's wind figures usually assume a standard load profile, so a high-surface-area pick may need its own limit from the manufacturer or a qualified person. Our self-paced mobile crane operator prep covers wind derating, and the guide on how to read a crane load chart shows where the notes usually hide.

Getting ready for a Gulf hurricane

Hurricanes give crews days of notice, and that time should go into a written securing plan rather than a last-minute scramble. Hurricane Sally showed how long a storm can linger: it crawled ashore near Gulf Shores on September 16, 2020 as a Category 2 hurricane moving at about 3 mph, raking the coast from Pensacola Beach to Dauphin Island for hours. Across the state line, construction barges working on the new Pensacola Bay Bridge broke loose from their moorings, and one barge reported to be carrying a crane brought down a span of the bridge, which stayed closed for months.

Florida now requires a hurricane preparedness plan for tower and mobile cranes and requires hoisting equipment to be secured no later than 24 hours before hurricane impacts are expected. That statute does not apply in Alabama, but its checklist is a sensible model for any Baldwin or Mobile County site: follow the manufacturer's high-wind recommendations, lay fixed booms down where feasible, retract and stow hydraulic booms, and strip rigging from the hook blocks.

• Set a trigger point, such as a hurricane watch for your county, for starting crane securing work.
• Finish all lifts and lower or retract booms well before sustained winds approach in-service limits.
• Remove tag lines, slings, spreader bars and banners that catch wind or turn into projectiles.
• Check ground conditions: saturated sand and clay can soften under outrigger pads and crawler tracks.

Leaving mobile and tower cranes in a safe configuration

For mobile cranes, the manufacturer's out-of-service instructions usually come down to two options: park the crane in a specified position with the boom at a set angle and hooks secured, or lower the boom onto blocking at ground level. Telescopic booms are normally fully retracted and boomed down. Lattice booms on crawlers may need the boom laid on the ground, and some long-boom configurations call for the mast to be lowered as well once forecast winds pass a manufacturer threshold.

Tower cranes work the opposite way. They are not boomed down; they are left free to weathervane. With the slewing brake released, the jib swings like a weather vane until it points downwind, which keeps wind loads within what the structure was designed to resist. The UK Health and Safety Executive investigated tower crane failures in which the slew brake had not been released, or had only been partly released, before the crane was left out of service, and it traced some cases to poorly lubricated brake release mechanisms. The lesson applies anywhere: confirm the brake is actually free, park the trolley at the manufacturer's out-of-service radius, and keep the jib's swing path clear of other cranes and structures. Candidates preparing for the tower crane operator exam should know this procedure cold.

Lightning and tornado days

Summer storms in Alabama build fast, and a crane boom is the tallest metal object on most sites. Subpart CC has no lightning-specific paragraph, so lightning falls under the manufacturer's procedures that 1926.1417(a) makes mandatory and under the site's emergency plan. The National Weather Service's guidance for people outdoors is short: if you can hear thunder, you are within striking distance, and you should wait 30 minutes after the last thunder before going back out. Stop lifts early, land the load and follow your manual and company plan on whether the operator stays in the cab or leaves the machine; safety sources disagree on that point, so the plan should settle it before the storm, not during it.

Tornadoes leave little time for securing anything. On April 27, 2011, dozens of tornadoes crossed Alabama in a single day, including the EF4 that tore through Tuscaloosa and into the Birmingham area and the long-track Hackleburg tornado in the northwest. On days when the Storm Prediction Center highlights a severe risk, the useful steps happen in the morning: plan smaller lifts, keep booms short, identify real shelter for the crew, and assign someone to monitor warnings so the competent person can make the 1926.1417(h) call quickly.

Inspecting a crane after the storm

A crane that rode out a hurricane or a near-miss tornado should not go straight back to work. Wind can shift a crane on its pads, flood water can wash out cribbing and reach electrical and hydraulic components, and flying debris can dent boom chords or lacing. 29 CFR 1926.1412 already requires a competent person's shift inspection before use, and its severe-service provision tells the employer to stop using equipment and have a qualified person inspect for structural damage where conditions make damage or excessive wear reasonably probable.

A post-storm walkaround should look at the foundation and outrigger supports first, then the boom, jib, mast ties and connections, wire rope and sheaves, limit devices and anemometers, and the cab's electrical systems. Tower cranes deserve a close look at mast ties to the structure and the base. Anything found goes to the qualified person before the crane lifts again.

Storm-restoration lifting

After a major storm, Alabama sees a surge of crane work: tree removal off houses, setting replacement utility poles and transformers, lifting roof trusses and HVAC units on rebuilt homes, and moving debris. That work brings its own hazards. Downed and re-energized power lines are everywhere, so treat every line as live until the utility says otherwise; our power line safety guide covers the clearance rules. Ground is often saturated or undermined, so mats and cribbing matter more than usual.

Out-of-state crews and rental cranes arrive quickly, which is when certifications and employer evaluations get skipped. The 1926.1427 certification and evaluation rules still apply to covered construction work during cleanup; whether a given tree-removal job is construction or general industry depends on the facts, so ask your safety department. Restoration crews often need rigger level 1 and signal person qualifications alongside the operator card, and line crews can review the digger derrick operator material. The Alabama crane certification requirements page shows how the federal rules fit together.