The Tower Cranes North America Conference held in Miami, FL in June 2018 attracted manufacturers and customers alike who wanted to learn about all things tower cranes. Kelly Hadland, president of Compass Equipment based in Phoenix, AZ, gave an in-depth presentation on the pros of self-erecting tower cranes, speaking to the growing popularity of these efficient lifting machines.
“Once erected, these machines take up a very small footprint, much less than a mobile crane,” Hadland said. “They cover a large area of a project from one location, and don’t require an expensive concrete foundation.”
But first, it’s important to break down the mechanics of a self-erecting tower crane, Hadland said.
“Self-erecting tower cranes swing from the bottom, hence they are bottom slewing tower cranes,” said Hadland. “They are also set up on outriggers, so instead of using a concrete foundation, they are set up much like a mobile crane does, and you can adjust the height of the outriggers to get the crane perfectly level. Another big difference is that there is no counter jib. So with these cranes, the jibs are held up by the suspension going up the rear of the tower instead of a large counter jib sticking out the back.”
Kelly Hadland, President, Compass Equipment
These cranes also typically use wireless remote controls, or wired remote controls, depending on the model. But one of the most impressive attributes of a self-erecting tower crane is it folds up into the size of a semi-trailer, making it easy to transport going down the road.
Self-erecting tower cranes are safer and more cost effective when compared to other crane and material handling options, Hadland explained. He estimated that the machine population in the U.S. is sitting between 500 and 600, compared to 15,000 self-erecting tower cranes in Germany alone. But while self-erecting tower cranes are not as heavily utilized in North America as they are in Europe, the market is improving as more users see their advantages on the jobsite. With significant cost savings to customers, a self-erecting tower crane provides a strong return on investment, Hadland said.
Ranging from smaller units (approximately 85 foot radius) to extra-large (around 164 foot radius), the versatility of self-erectors plays a huge role in their benefits. Small models often have self-contained counterweights, and axle sets are possible with the smaller range, making fast erection and onsite moves possible. Small self-erectors are ideal for two- to three-story apartments with multiple buildings.
Small self-erecting tower cranes are easy to train operators to erect and dismantle, and in most cases are cheaper and safer than a boom truck. Hadland estimated that a two-month long project costs around $55,000 with a boom truck, while an 85-foot self-erecting tower crane with a full-time operator costs only $25,000, with 75 percent of this cost going to the operator. The crane only ends up costing as little as $30 per hour over this period of time.
A medium-sized self-erecting tower crane comes with counterweights and the axle set, but it is not permanently attached to the axle set. Medium-sized units can be erected in just two hours with three men and two semi-trucks. They have a radius of up to about 130 feet. These machines are ideal for three- to six-story wood-framed structures. They can be moved on the jobsite in three to four hours. For this size range, Hadland provided the example of a self-erecting tower crane in comparison to a fork lift.
In 2017, Liebherr launched 81 K.1 fast-erecting crane, an upgrade of its popular 81 K.
“When building a four-story building, a conventional method would include two or three large reach fork lifts, and extensive labor to move material around, in addition to a mobile crane to set heavy pieces and trusses,” said Hadland.
When utilizing a medium-sized self-erector to place material where it’s needed, only one small reach fork lift would be required, and in most cases, a mobile crane would not be needed. With less labor required and a much faster project completion time, this process is ultimately safer and more cost effective, he said. While estimated cost savings are conservative numbers based on customer survey averages, Hadland approximates that a three-month project using only fork lifts versus using a self-erector can save $45,000.
When it comes to large self-erectors, some models ship tower sections separately to the jobsite. They can be erected in around four hours with four men and three semi-trucks. With a radius of up to 148 feet, large self-erectors can be moved onsite in six to eight hours.
Finally, extra large self-erectors are faster to erect than a standard tower crane and may require the use a small assist crane. With a radius of up to 160 feet, they typically require four men, six to eight hours of set up time and five semi-trucks for transportation.
Often a contractor will need to decide whether the jobsite requires a larger, standard tower crane or a self-erector. If a self-erecting tower crane can get the job done, that means lower trucking costs, shorter set up times and safer erection. Additional benefits include eliminating double handling of materials that shortens the schedule and reduces costs, green operations that are better for the environment and hurricane-proof when folded up. However, as far as disadvantages, there are a few. According to Hadland, self erecting tower cranes can be more difficult to move around on a jobsite than a mobile crane. Limited capacities and reach can pose an issue. These are sophisticated machines that require hydraulics or rope and pulleys for folding, he said.
Safety also plays a critical role in the success of self-erecting tower cranes. Because the machines do not drive around the jobsite all day, there’s less chance for an incident. Operator proficiency is achieved quickly, and there are fewer choices to make about configuration.
“A self-erecting tower crane is a fantastic product that in the right application, is unbeatable,” Hadland, said.
Believing there was a market for the self-erecting tower crane, Hadland started Compass Equipment in 2007 with one unit. Today the company has branches in five states and serves multiple markets with self-erectors, tower cranes and conventional mobile and crawler cranes.
Despite the fact that self-erectors in the U.S. don’t have the following they do in Europe, the market is growing. Leading OEMs of these machines report steady demand.
Terex manufactures the CBR 32 PLUS and the CBR 40H self-erectors, which are both prominent models in the market. The CBR 32 PLUS features a maximum jib length of 105 feet, with a capacity at maximum length of 1.1-tons and a maximum capacity of 4.4-tons. The CBR40H self-erecting tower crane has a maximum capacity of 4.4-tons and a jib tip capacity of 1.1 tons but features a 131-foot jib length.
In 2017, Liebherr launched the 81 K.1 fast-erecting crane, an upgrade of the 81 K. The crane is more powerful and flexible, Liebherr said. The lifting capacity of the 81 K.1 can be temporarily increased by up to 20 percent when using the Load-Plus function. There is no need to use an additional larger crane for heavyweight hoists. The jib can be extended by 9.84 feet without much effort and increasing the maximum radius to 157 feet.
Also making its debut in 2017 was the Potain Hup 40-30, which has become the most popular self-erecting crane in the range, according to Manitowoc. The Hup 40-30 shines in both versatility and agility, with several configuration options, a high-performance slewing radius and the best transport package ever designed for a self-erecting crane, according to Potain. Its launch followed the introduction of the Hup 32-27 in mid-2016. Jean-Pierre Zaffiro, global product director for Potain self-erecting cranes at Manitowoc, said the Hup 40-30 represents a profound transformation in self-erecting crane technology.
“The use of self-erecting cranes is growing in the region because there are several advantages to using these compact and versatile cranes,” Zaffiro said. “Often companies save significant money when using them on a long-term project. And because the new Hup cranes are very versatile, customers can handle a wide range of projects with just one crane. We fully expect the use of the cranes to continue growing in North America.”
The Hup 40-30 has a 131-foot jib and 16 configurations. The crane has a maximum capacity of 4.4 tons, while it can lift 1.1 tons at its jib end of 131 feet. The crane features a telescopic mast for a range of working heights.