Crane Pads

Crane Pads Buying Guide

What separates a crane pad from a smaller outrigger pad. The two do the same physics, spread a concentrated leg load over more ground, but they work in different weight classes. The outrigger pads one level up handle service trucks, aerial lifts, and digger derricks, where the float is small and the reaction sits in the tens of thousands of pounds. A crane pad is what goes under an all-terrain, rough-terrain, or boom truck crane, where a fully extended outrigger can drive a single float into the ground at well over a hundred thousand pounds, and no foot-square steel foot spreads that safely. The pads here are correspondingly larger and thicker, several feet on a side and 6 to 12 inches deep, heavy enough that footprint and handling weight become part of the buying decision. If you are matching pads to a specific machine, start from the crane and its load chart, not from what happens to fit in the truck box.

Size to the worst-case reaction, and remember it moves. Sizing is arithmetic: take the maximum outrigger reaction from the crane's load chart and divide it by the allowable ground bearing pressure of the surface, and the result is the minimum pad area. The wrinkle that catches crews is that the reaction is not one fixed number. As the crane swings and the boom moves, the load shifts across the four outriggers, so the leg carrying the most on a pick over the side is not the leg that carried the most a quarter turn earlier. Size every pad to the worst case any leg will see through the full working arc, not to the reaction at setup. Ground bearing pressure is the other half and it is unforgiving: firm compacted gravel might carry several thousand pounds per square foot, while soft or saturated clay carries a small fraction of that, which is why the same crane needs a much larger pad on bad ground. When you cannot get a real number for the soil, that uncertainty is an argument for more pad, not less.

FiberMax: composite that acts like steel and weighs far less. DICA's FiberMax pads are molded from continuous sheets of fiber-reinforced polymer, and the point of the material is stiffness. A FiberMax pad delivers the rigidity of steel while weighing roughly 60 percent less, which matters because a pad a crew cannot move is a pad that gets left in the yard. The line carries a 1,000 psi crush rating and comes in 6, 6.75, 10, and 12 inch thicknesses; capacity climbs with thickness, from around 100,000 lb on the thinner pads to 325,000 lb at 10 inches and 400,000 lb at 12. The thicker, larger pads reach into the high five figures on our site, and they carry a long factory warranty because the composite does not rot, rust, absorb fluids, or delaminate the way wood cribbing and some plastics do. This is the tier for lattice, all-terrain, and the heaviest boom truck work.

Fully supported or bridged: the number changes with what is underneath. A crane pad only carries its headline rating when the whole underside is bearing on the ground. Set it so the center spans a rut, a curb, or a soft spot with only the ends supported, and the pad is now loaded in bending, which is a different and lower rating entirely. DICA's EcoMax pad is explicit about this, publishing a standard fully-supported capacity and a separate lower bridge rating for the ends-supported case, with only the fully-supported and one bridged orientation approved inside the operating area. Rated at 160,000 lb across 24 square feet, the EcoMax suits cranes up to about the 150 ton class and is the recycled-composite value pick in the collection, pairing steel-like stiffness with a lower price than the FiberMax mats. Whichever pad you run, the honest move is to prepare the ground so the pad is fully supported and buy on the fully-supported number.

Center the float, and know the standards you set up under. Two things finish a good setup. First, center the outrigger float on the pad: the EcoMax carries a built-in center target for exactly this, because a float parked at the edge drives load into one corner instead of spreading it, and DICA rates its pads to level a fully supported float up to 10 degrees in two planes. Second, know the rules. ASME B30.5 requires that outrigger blocking have enough strength to resist crushing, bending, or shear, and enough thickness, width, and length to completely support the float, carry the load to the supporting surface, and prevent the machine from shifting or settling under load, which is the standard a rated pad meets and scrap lumber does not. On construction sites, OSHA 1926.1402 puts the ground itself on the controlling entity, requiring conditions firm, drained, and graded enough to support the crane with the pads and cribbing in use. The pad is one link in that chain; the ground under it is the other.