This article published on September 1, 2022 on CranesandLifting.com.
Action Cranes, a for hire crane service in Australia, has been serving Sydney and the surrounding market since 1971. The company recently purchased its first set of engineered outrigger pads.
“Attention to ground conditions and crane setup is becoming highly scrutinized, especially on Tier 1 and Tier 2 projects. Our company policy is to always exceed regulatory requirements,” said Clinton Forner, General Manager. Action Cranes previously used hardwood timbers under outriggers, but when Forner saw other crane rental companies chatting about a new engineered crane pad on an industry Facebook page, he became interested in learning about a better solution.
Action Cranes purchased a set of four FiberTech FTR48-1 (48”x1”), which is the largest standard size FRP (Fiber Reinforced Polymer) pads DICA manufactures. Each 4 ft. round FiberTech pad weighs 140 lbs., which is considerably less than the 450 lb. weight of the hardwood timbers Action Crane used before.
“I wanted to make setup safer and easier for our crane crews,” said Forner. “These engineered pads can be rolled into place by one person. One pad is the equivalent of placing down 10 hard wood timbers—40 timbers total,” he explained. The result is much less physical handling by personnel, which reduces strain and makes setup more efficient.
FiberTech outrigger pads are made of 13 layers of quad axial continuous glass fibers and polyester resin, which gives them exceptional strength and stiffness to distribute loads. They do not absorb water, chemicals or contaminants, and are easy to clean.
“Action Cranes has a high commitment to safety,” said Kris Koberg, CEO of DICA. “The company was looking for the lightest weight solution available that would also reduce risk and provide them with the peace of mind they need when it came to setting up cranes in a variety of ground conditions.”
“The selection process was really easy. I just gave DICA the crane models I was planning to use the pads with and they gave me several options with reports showing performance projections. I then compared that to typical ground loading limits that I knew I wanted to stay under,” explained Forner.
Action Cranes sought recommendations for three crane models—Liebherr LTC 1050-3.1 50 metric ton city crane, Liebherr LTM 1060-3.1 60 metric ton all terrain crane, and a Grove GMK 4100 100 metric ton all-terrain crane. DICA presented Forner with 11 different models of SafetyTech, FiberTech, and FiberMax outrigger pads that would target the average allowable ground bearing objectives.
“We work with customers to identify options that have the appropriate strength and stiffness needed for their applications. When determining outrigger pad types and sizes many crane companies embrace DICA’s strategy of selecting a set of outrigger pads that meet the needs of most everyday lifting scenarios,” said Koberg. He explains that most crane companies have critical lift thresholds, such as a maximum allowable percentage of the chart. “Based on this information and the outrigger reaction forces, we calculate the minimum pad area needed. When operating in the 70-80 percent range, it is unlikely the crane will generate outrigger reaction forces that would exceed the threshold,” said Koberg.
This approach allows owners to choose a pad type and size that aligns with the planned use of the crane, which is often smaller than if sized for the maximum outrigger reaction forces. “The benefit is that everyday pads will weigh less and cost less,” said Koberg. “Or course, anytime the lift exceeds the chart thresholds set by the owner then the crane company should create a specific lift plan that may require a different outrigger pad type, size, and thickness than the assigned everyday pad.”
To narrow down the final selection, DICA assisted Forner in evaluating the performance characteristics of different products and surface conditions. Based on the pad stiffness and pad to ground interaction, charts were provided demonstrating load displacement based on soft, hard, and concrete ground conditions.
“Forner wanted to understand the data so that he could put that info to use to solve his unique setup scenarios,” said Koberg. “He was looking for the lightest weight solution based on his ground bearing pressure requirements. Of the three products he evaluated—two SafetyTech and one FiberTech pad—the FiberTech FTR48-1 was the option that met his needs,” said Koberg.
“FiberTech was more expensive, but the stiffness to weight ratio was the best for a variety of soil types,” said Forner. Weight savings was an important factor in Forner’s decision. A 1” thick FiberTech pad is equivalent in stiffness and performance to a 3” thick SafetyTech pad, but weighs about 25% less.
“They are much lighter weight, easier to store, and easier to handle, which makes it less likely that crane crews will take short cuts by using small timber pads.” The response from crews? “We absolutely love these DICA FiberTech outrigger pads,” said Forner.
Putting FiberTech to work
Shortly after receiving the FiberTech outrigger pads, Action Cranes put them to use on two projects. The first project involved lifting materials in a skip bin from 50 meters below the Warragamba dam. The company’s LTC 1050-3.1 was set up on concrete on the top of the dam. The second project, using the same crane, involved lifting steel beams on a residential construction project in Balmain, Sydney. In one position, the crane was set up on hard packed dirt, and in the other, it was set up on asphalt. “I was worried about small, hard blue metal rocks damaging the pads, but the pads are really hard and the rocks were just crushed with no damage to the pad,” said Forner. Since then, Action Cranes has had a chance to use their new FiberTech outrigger pads in softer ground conditions with equal success.
Although Forner considers the purchase of the FiberTech outrigger pads to be an investment, he is already predicting that their life expectancy will at least double that of the hardwood timbers he used to use. Even more important was choosing an outrigger pad that made life easier for his crews. “It was refreshing to work with a company that cares so much about their people, their equipment, and their reputation,” said Koberg.