By D.Ann Shiffler01 March 2017
“The crane made us money,” said Chuck Paulson, crane manager for St. Cloud, MN, USA-based Landwehr Construction, Inc., after completing back-to-back cooling tower installation and petro vessel removal projects using its newest crane, a Terex AC 350/6 all terrain crane.
A little more than six months ago, Landwehr jumped up to the 400-ton crane capacity with the new AC 350/6. “Without this crane, we could not have competitively bid these jobs,” said Paulson. Prior to the purchase, Landwehr had a crane fleet ranging from 30 to 275 tons capacity. However, increasing competition and changes in the market necessitated the increase in crane capacity. Since the 400-tonner was delivered, the crane has not seen much of Landwehr’s yard
“We were missing out on the next level of work, the jobs with longer reaches and heavier lifts,” said Pat Herron, crane division manager for Landwehr, a fifth generation family company. “We were a little hesitant to make the jump at first, but with our headquarters within about an hour’s drive of Minneapolis, there is much competition in the lower capacity classes. Once you get to the 400-ton class, there is less competition, especially when heading west toward the Dakotas, and we have a customer base where we will travel up to 500 miles for a lift project.”
Landwehr completes a broad range of construction work, ranging from utility and excavation and site development to environmental remediation and solar services. For decades, the crane and rigging division’s primary work stemmed from lifts to support Landwehr’s construction divisions. But its 275-ton cranes did not offer enough capacity for the growing body of construction work.
“Precast tilt-up walls for commercial building construction projects were getting bigger and heavier, and the radius and panel size were increasing,” Paulson said. “We recently finished a department store construction project where the wall panels were 120,000 pounds.”
The combination of the AC 350/6’s long luffing jib and Superlift configurations helped Landwehr to land and profitably complete the two back-to-back industrial lifts.
Reach flexibilityLandwehr mobilized the AC 350/6 45 miles from its headquarters to Melrose, MN for a cooling tower lifting project at a dairy processing facility. Due to the tower’s weight, the facility’s wall height and how deep into the roof supporting materials had to be placed, the pick required 157.5 feet of luffing jib.
“The crane can be equipped with up to 236.2 feet of luffing jib to increase machine flexibility,” said Ben Steege of RTL Equipment, the supporting Terex distributor.
The crane’s full 257,300-pound counterweight package was required to lift the 30,000-pound cooling tower. Mobilizing the crane, luffing jib and counterweight required seven truckloads.
“The base crane goes out with one basic counterweight and rigging truckload,” said Paulson. “Full counterweight requires an additional five trucks, and we needed one additional truck for the luffing jib. The way the counterweight slabs and jib segments are designed helps us to maximize truckloads, which helps us to keep trucking costs down to remain price competitive.”
Within about an hour, the crane and truckloads arrived at the dairy facility. It took Landwehr’s four-person rigging crew plus two operators five hours to configure the AC 350/6 crane with maximum counterweight and luffing jib for the lift. Including the tower unit, supporting structure pieces, catwalks and ladder, the crane made 12 picks for the job. By far, the most complex part of the lift was the 30,000-pound cooling tower critical pick.
“Lift planning for the cooling tower was one of the biggest challenges,” Paulson said. “We had to devise a flight plan to minimize worker evacuation for the cooling tower pick, since this was an active factory during work hours.”
To clear the 25-foot-high factory wall while lifting the 12-foot wide, 24-foot long, 10-foot tall cooling unit, the crane’s center pin was positioned 26 feet away from the building. Crews initially used 74-feet of main boom with the 157.5 feet of luffing jib positioned at 73 degrees.
“At this configuration, the AC 350/6 crane offers a 36,200-pound capacity at a 150.9-foot radius,” said Steege. Some of the structural steel had to be placed an additional 80 feet into the building’s roof. For this, the crane operator telescoped the main boom to 178 feet and changed the luffing jib’s angle to 65 degrees.
“This gave us a 6,000-pound capacity when we were working at a 230-foot radius,” said Paulson. “The ability to change main boom length during the lift was the key to economically using this crane and winning the bid.”
Within eight hours, all the lifts were made. Afterwards, Landwehr’s crew had the crane derigged in about five hours and prepped to move for its next project. The crane then made a 45-mile trek to Little Falls, MN to lift and remove a 60,000-pound vessel at an ethanol plant. This time, Landwehr called on the crane’s Superlift structure to boost main boom lift capacities. Using 211,000-pounds of counterweight, the operator needed 177.8 feet of main boom to lift the 113-foot-tall vessel. The crane worked at a 72-foot radius to maneuver the vessel into its final position.
“The Superlift boosts the crane’s capacity to 76,700 pounds, which was more than enough to make this lift,” said Paulson. Compact and agileWith space tight at the refinery, the AT’s size and close radius working capabilities proved to be a significant benefit.
“At a mere 54.8-foot total length, the AC 350/6 is the most compact six-axle crane in its capacity class, and it offers six different steering modes to easily maneuver the carrier into tight spots,” said Steege.
The ability to boom up and work in as little as a 26.2-foot radius in this configuration made removal of the vessel in tight quarters go smoothly, Paulson added.
“By being able to quickly change from the luffing jib configuration to main boom with SL configuration, we were able to use the same crane to win bids for two different applications,” said Paulson. The type of 400-ton capacity crane to add to Landwehr’s fleet was made easier from previous experience of another all terrain crane. Sixteen years ago, when Paulson joined the Landwehr team, the company had five cranes in its fleet. In 2016 the company owned 23 cranes.
“We have quite a few Terex cranes, including 30- and 60-ton RTs and other ATs,” said Herron. Impressive track recordThe longevity delivered by Landwehr’s 2005 Terex AC 140 helped to tip the scales in favor of purchasing the larger AC 350/6.
“That AC 140 crane has more than 167,770 miles on it, and it is still hammering down the road from site to site. We’ve only had to put one set of tires on it, and we have not had to put a lot of maintenance in it.”
The versatility of the AC 350/6 was key. Using different counterweight configurations, the crane is used on multiple jobs, and, depending on how much counterweight is needed to complete a lift, Paulson can send additional supporting truckloads for the full counterweight package.
“While we always want jobs with maximum counterweight, the ability to adjust counterweight packages keeps this crane busy,” he said. “We will go out with a basic 39,900-pound counterweight package and one supporting truckload, and for 275-ton capacity jobs we use 76,500 pounds of counterweight. The ability to vary our counterweight keeps trucking costs down.”
Multiple boom options increase the project adaptability. The AC 350/6 offers a maximum 210-foot main boom and multiple luffing jib options give Landwehr a maximum 412.4-foot system length. The crane’s Superlift structure for the main boom increases lift capacities when working at extended radius. The crane’s ability to adapt to a variety of lift configurations has Landwehr expanding the types of applications it is bidding. While a true economic benefit for Landwehr, it serves to extend the times the crane is required in the field, making the Terex AC 350/6 increasingly homesick for Landwehr’s yard, Paulson said.