Materials in Motion

INTRODUCTION TO CONSTRUCTION CRANES

Treadwheel CraneCranes are some of the most important pieces of equipment in the construction industry. Modern construction cranes include fixed tower cranes, huge shipyard gantry cranes, drivable truck-mounted cranes, and more. Different kinds of cranes work in very different ways, so every construction crane is perfectly suited to the job it is designed to do.

The earliest cranes were built by the Ancient Greeks, who used them to build huge theaters, monuments, and temples, such as the Parthenon in Athens. Early Greek cranes were capable of lifting stone blocks weighing up to 20 tons. Roman engineers further developed Greek crane designs, using complex pulley systems and large treadwheels to lift over 60 tons.

By the Middle Ages, cranes were used to build the giant gothic cathedrals that became an iconic part of medieval architecture. As crane technology grew and the use of steam power became more widespread, they contributed to the rapid growth of industry in the 18th and 19th centuries. Today, there is a huge variety of construction cranes to build all kinds of structures around the world.

Fixed Cranes

Some of the most impressive and recognizable construction cranes are tower cranes. These giant machines can often be seen in cities, rising hundreds of feet in the air to construct huge skyscrapers. Most tower cranes have a cab mounted to a long horizontal boom, which rotates around the top of a large mast. Like other fixed cranes, tower Tower Cranecranes remain in one place while working and are not designed to move.

Other types of fixed cranes include jib cranes and some gantry cranes. Jib cranes are similar to tower cranes, with a horizontal boom that rotates at the top of a vertical mast in a fixed location. Jib cranes are much smaller than tower cranes, but they can often be used to load and unload construction materials at construction sites.

Many shipyards use large gantry cranes to construct ships and ship parts. Gantry cranes consist of long booms that span between two support legs and one or more hoists that travel the length of the boom. The support legs travel along the ground, which allows large parts and modules to be taken from the dock and installed on ships that under construction on the water.

Mobile Cranes

There are many types of mobile cranes that are also used in modern construction applications, including truck-mounted cranes, railroad cranes, and aerial cranes. Truck-mounted cranes come in a few variations, such as off-road cranes and all-terrain cranes. Truck-mounted cranes drive on large rubber tires and can be maneuvered around a worksite through self-propulsion. This kind of crane also requires horizontal outriggers for stability when lifting, and unstable rigging can cause catastrophic results.

Crawler CraneSome other types of mobile cranes do not require outriggers for stability. Crawler-style cranes are equipped with wide crawler tracks that make the crane both mobile and stable. Unlike truck-mounted cranes, crawler cranes cannot travel on roads and must be transported to worksites by trucks. However, the all-terrain capabilities of large crawler tracks make them extremely useful when construction sites are on soft or uneven terrain.

Many railcar-mounted cranes are also designed to operate without outriggers by using counterweight mechanisms. Railroad cranes generally consist of a rotating crane body mounted on a large railcar, and they can often be used for railroad construction or repairs. Aerial cranes are typically mounted to helicopters, and the helicopter’s rotors provide the lift and stability to carry loads. Helicopter cranes are frequently used in applications where loads need to be carried in remote locations that can’t be reached by truck-mounted cranes or jobs that are otherwise inaccessible.

Light-Duty Cranes

Spanco PF Series Gantry CraneThere are also many construction services that require smaller, lighter-duty cranes. Spanco Freestanding Jib Cranes can provide ideal permanent solutions for construction maintenance needs. Spanco PF Series Gantry cranes for modular or vehicle construction that require more maneuverability than larger construction cranes can provide.

Lifting heavy construction material along at the height of a building is one of the most important steps in construction. Cranes have been designed to fit the specific needs of every kind of construction project, from high-rise office buildings to modular home construction. Whether the job requires a sky-scraping tower crane, a light-duty mobile gantry crane, or anything in between, there is a crane for every application.