Tower Cranes

Several crane accidents received unusually broad news coverage in 2010 because they reached beyond the construction site. The mechanics of a hammerhead tower crane are relatively straightforward. The vertical mast section is typically anchored in a large concrete footing, which provides a firm foundation upon which the weight of the crane and anything it might lift can bear. The amount of material that a tower crane can lift depends on how far from the tower pivot the load is located. The farther from the supporting mast, the greater the tendency of a load to overturn the crane. There are as many as 3,000 tower cranes operating in the US, making over 105,000 lifts daily without incident. Construction cranes tend to be remarkable but ignorable parts of the built environment until an incident in which something goes terribly wrong.