While all mobile cranes have almost identical end goals— moving heavy materials safely from one location to the next— there are different types and devices on each one that characterize the individual kinds. Most basic cranes consist of at least a truss (or boom) that lengthens to allow for its use on tall structures, a mobile platform for the operator, and the wire and attachment that is able to grab the item to be moved. But, there are also more specialized devices for slightly different purposes.
A truck-mounted crane is the most commonly used type of mobile crane. It is characterized by its platform's location— on a truck bed. The upper part of the crane, including the boom, swivels on a turntable that allows it to be compactly folded on the back of a truck for safe transportation on local roads.
Containing a single engine that powers both the moving undercarriage and crane itself, this truck-mounted device also contains an inner hydraulic system to propel the boom outward.
Because these are able to travel on highways or narrower roads, they are the chosen favorite of many construction workers or building contractors. The counterweights that can be seen on the opposite side of the boom may need to be removed and transported separately but as a whole, the cost of use is far less than similar alternatives.
Rough Terrain Crane
Used in more rural, off-road type situations, a rough terrain crane is mounted on an all-wheel drive vehicle with heavy-duty rubber tires. Ideal for rural projects in less-than-ideal terrain, these machines are normally smaller but come with all-wheel drive for easier operation, steering, and traction.
Pick and Carry Crane
A popular option in Australia for job sites that are hundreds of kilometers a part, a pick and carry crane is another alternative to the classic mobile crane. With shorter booms, the main benefit of this type of machine is its ability to lift a heavy load and carry it to its next destination (within a small area). They are also compactable and can be driven on public roads to allow for easy access and versatility.
Because the set-up time is next to none, pick and carry cranes have generally replaced smaller truck cranes because they are sturdier and overall more efficient.
If you're contemplating renting a crane for your next construction project or wondering about those you have seen on sites before, chances are, one of the above three types will be what you're looking for.