Hurricane Irma showed yet again that cranes can collapse in high winds. Know the manufacturer’s recommendations, and watch for regulation changes.
Hurricane Irma proved that tower cranes and high winds often don't mix. When the storm hit South Florida on Sept. 10, 2017, two construction sites in Miami and one in Fort Lauderdale suffered more damage from the collapse of crane booms than the high winds.
The causes of the crane collapses are being investigated. The contractors say the cranes had been inspected and secured before the hurricane hit. The cranes were designed to withstand winds as high as 145 mph — and yet according to the Washington Post, wind gusts in Miami topped out at 100 mph. Now there’s talk about tightening regulations for crane operation.
OSHA defers to manufacturer recommendations
The most critical step in securing a crane ahead of high winds is understanding the wind speed the crane is manufactured to withstand. Talk to your manufacturer’s representative about the company’s recommendations for securing the crane. If you rent, make sure you have those recommendations.
OSHA’s standard for rail-mounted cranes used in marine terminals requires employers to post operating instructions for high wind conditions in the cab of each crane — good advice for any crane. By and large, however, OSHA defers to the manufacturer’s instructions for securing cranes.
For some models, manufacturers recommend the crane be entirely secured and lowered by a certain number of tower sections. But often, there’s simply not enough time to lower the crane, so “weathervaning” is the primary means of safeguarding many cranes. It means releasing the swing brake so the boom can spin freely on its turntable. In some cases, locking the boom can make it more resistant to the wind and increase the risk of breakage.
Experts also recommend checking bolts and tightening them as needed, ensuring power cables are securely fastened and removing any advertising banners and loose items on top, such as tools. It’s also important to inspect any tie-down or stowage system on a regular basis to ensure all parts are in working order and show no signs of damage.
The latest recommendations
While OSHA sets the standards for safe crane operation, they have little to say on the matter of high winds, other than to follow the manufacturer’s instructions. But some cities and states have looked at creating their own regulations aimed at avoiding potential catastrophe.
In 2016, the New York City Council implemented a working group recommendation that the city ban any type of crane that is unable to operate in winds of 20 miles per hour or less. The recommendation came after a crane collapse. Cranes that must stop operating in winds between 20 and 30 miles per hour are allowed only in non-public areas or if a safety plan is approved by the city. The city is also working to phase out use of older cranes that don’t come equipped with an anemometer to measure wind speeds.
Florida had its own discussion of how to improve the safety of crane operations in high winds back in 2008. In fact, Miami-Dade County passed an ordinance that year requiring any tower crane used in the city be manufactured to withstand winds up to 140 mph. But the ordinance was pushed back by a legal appeal from construction industry stakeholders. The appeal won on the grounds that regulating cranes is OSHA’s job and, according to OSHA, the maximum wind speed a crane must withstand is best determined by the manufacturer.
Depending on the outcome of the investigation into the most recent crane failures in Florida, the county may take a fresh look at the rejected ordinance.