In construction terms, a boom (like one found on a crane or digger derrick) is normally used to help with the loading and unloading of cargo from a delivery vehicle, or from one location to another. Before the advent of these equipment items, workers had to manually load and unload the cargo, a time-consuming and difficult process. The mounting of a boom on a truck chassis made the process much faster and more efficient.
Sometimes other equipment is installed on the boom to help with other jobs. For example, a grapple may be installed to move brush or logs. An auger may be added, which transitions the equipment from a boom truck into a digger derrick. A bucket can also be added, allowing workers to accomplish aerial tasks, like changing bulbs in lights or signs.
The crane truck is a standard truck chassis with a boom installed on the rear, making it useful for hoisting heavy objects or moving items or personnel up to approximately 160 feet in the air. It is easy to recognize because the vehicle portion looks like a typical heavy truck, along with a crane installed on a flatbed or body with bin doors. Equipment like this is built to be easily driven from one location to another, and in some cases it can even haul small loads on the truck bed. The crane truck uses a combination of a winch system and hydraulics to move its load effectively, together with outriggers (sometimes called stabilizer jacks) to remain stable, while lifting.
A digger derrick is essentially the same as a truck mounted crane, with the exception that the digger derrick has a hydraulic motor installed, together with an auger. That combination, mounted on the side of the boom enables operators to swing the boom out, drop the auger, and dig a vertical hole in which something like a power pole may be placed. In the case of utility pole installation, the digger/auger is stowed after creating the hole and the boom and winch line are used to lift, position and install the utility pole. Similar to a crane truck, the digger derrick truck uses a combination of a winch system and hydraulics to move its load effectively, together with outriggers (sometimes called stabilizer jacks).
The mobile crane is an enormous piece of equipment that is solely dedicated to hoisting heavy objects to great heights. It is most notable for its large telescopic boom (and many times also a lattice boom) and massive overall profile. This equipment is designed to be massive so it is heavy enough to counter the weight of its load and avoid tipping over. Another characteristic that makes this equipment unique is that it does not have space for hauling loads. It is only used for lifting heavy cargo on the work site. Another key difference with this equipment is that (because it is massive) it is not as easily moved. You will notice these equipment items sometimes remain on a job site for a longer period of time.
Auctions are a great way to buy used digger derrick trucks, used crane trucks, and used mobile cranes. Contact us, if we can assist.