Knucklebooms 101

By Jennifer Oredson, Technical Writer | September 28, 2010

Articulating cranes are unquestionably more popular overseas than they are in North America. That explains why dozens of overseas companies manufacture knucklebooms, but only two North American companies make them.

The question about why articulating cranes are more prevalent overseas has many answers. One of the big reasons is the number of material-handling methods available in North America that aren't as practical for Europe.

"Our two main competitors are telescopic cranes and piggyback forklifts," says Jim Darr, product specialist for material-handling systems at Iowa Mold Tooling Co. (IMT), which is one of the North American manufacturers of articulating cranes. "Those material-handling methods don't work well for Europe, so they aren't taking some of the market share away from knucklebooms."

The Way It Is

One of the main reasons telescopic cranes and piggyback forklifts — or forklifts that ride on the backs of trucks — aren't practical for Europe is the truck length laws. European trucks have to be much shorter than those in the United States, so they simply don't have the space to store a telescopic crane or a forklift.

Tradition has a lot to do with it as well. "Europe was in the knuckleboom business long before the United States, so the industry just kind of grew that way," Darr says. "The knuckleboom market has grown a lot since they first showed up in the United States in 1960, but because of the prevalence of telescopic cranes here, the growth has been slow and steady. And the growth is definitely going to continue because we're always finding new markets."

Also, changing state and federal regulations are leading to more requests for smaller articulating cranes. The laws that require operator training for any crane that has more than 25 feet of reach or more than 15,000 pounds of lift are making customers look twice at knucklebooms.

Nonetheless, the bottom line is that the list of European markets in which knucklebooms are the standard is very long, but that list becomes shorter in the United States. That said, there are a fair number of industries in North America in which articulating cranes are the best solution.

Articulating or Telescopic?

One reason many people don't spend much time thinking about articulating cranes is because they are so comfortable using telescopic cranes. But if a crane operator were to step out of his comfort zone, he might find that there's no reason to be intimidated by a knuckleboom and that it might, in fact, be a perfect fit for his company.

The first task is figuring out whether an articulating crane is right for you. What essentially differentiates a telescopic crane from an articulating crane — other than the obvious straight boom versus knuckleboom — is reach capability and payload transportation ability.

"One of the big differences between our cranes and the big telescopic cranes is that telescopic cranes don't primarily haul payload, whereas our cranes are designed to haul payload from Point A to Point B," Darr says.

A truck-mounted articulating crane is designed to place payload on the truck bed, haul it to the job site and then place the payload where it ultimately needs to go. That's not the case with telescopic cranes, which are designed to be stored over the truck bed, leaving little room for product transportation. When an articulating crane is stored, it's folded up tightly in a "figure four" position, leaving plenty of bed space for payload.

"A good way to sum up the difference is that the big telescopic cranes have one purpose — placing payload — while the truck-mounted articulating cranes have a dual purpose: transporting product and then placing it," Darr says. "A customer would choose an articulating crane rather than a telescopic crane primarily because he wants the ability to haul the product to the job with no interference from the stored boom. It's the ability to pick up the load, deliver the load to the job site, and place it with no conflict due to boom storage."

Also, articulating cranes don't usually have the reach capabilities that telescopic cranes do, so they're typically used on job sites where vertical reach isn't a major concern. It was this very thing that made Utility Lines Construction, a subsidiary of Asplundh Construction, a perfect candidate for articulating cranes.

Utility Lines specializes in installing underground and overhead power lines and does directional drilling for power companies in Georgia, and this type of work doesn't typically have much of a height requirement. The company used to do its heavy lifting with backhoes, which were technically supposed to be doing the digging, not lifting heavy components during utility line construction.

"Moving our reels of wires and transformers with backhoes was terribly inefficient and not particularly safe," says Rick Chrissley, field supervisor with Utility Lines. "Those backhoes are meant for digging, and so when we used to move our heavy items around with them, they'd have to stop what they were doing, and we lost productivity."

Also, depending on the size of the transformers, Chrissley says the backhoes were unable to handle the payload. So it didn't take a rocket scientist to notice they were experiencing too much downtime, and that's when Utility Lines decided to purchase some articulating cranes and leave the heavy lifting to them.

"Now we can move payload with the cranes, and the backhoes can keep digging, which is what they're supposed to be doing," Chrissley says.

As soon as Utility Lines started using IMT articulating cranes — they currently own about 10 of the 11/76 series — the backhoes could focus on their task, and Utility Lines saw productivity skyrocket.

"So far with the IMT cranes, I haven't lost production or time, and I've been able to handle the task at hand without fail," Chrissley says, adding that all of their cranes are out in the field working about eight hours a day. "We're getting use out of them, that's for sure, because they're out there being used all day, every day," he says.

The Knucklebooms Market

Even though knucklebooms work best in markets that have lower height requirements, that doesn't mean we're still living in the days when someone who had a reach requirement of more than 25 feet would be relegated to a telescopic crane.

"People aren't aware that articulating cranes come with the reach they do today," Darr says. "They're used to the idea that if they want something with an 80-foot reach, they're going to have to use a telescopic crane, and they don't realize that articulating cranes have that kind of reach these days."

In general, the types of businesses that most commonly use articulating booms are building suppliers — everything from wallboard companies to brick and concrete block companies — utility companies, railroad construction, mining companies, and equipment dealers. Knucklebooms are also great in construction markets where reach requirements are no more than about 80 feet, but telescopic cranes are better for construction markets that need higher reach.

Provided by: Iowa Mold Tooling Co., Inc. (IMT)