A crane truck, in layman’s terms, is a truck with crane equipment attached to a mobile platform. The crane is hydraulically powered for the purpose of lifting and lowering heavy objects. The crane truck operation requires a well-trained, skillful operator who is knowledgeable in safety procedures necessary to avoid major accidents and prevent serious injuries from happening.
The crane truck has become a very essential piece of equipment in many industries. In the construction industry, it would be hard to imagine building a high-rise building without the benefit of such equipment. The crane on a crane truck operates in three basic ways: it can operate as a balance crane with a horizontal beam that pivots about a fulcrum to lift a load; it can operate as a jib crane with a pulley system that winds cables to enable the lifting or lowering motion; and it can operate as a mobile hydraulic crane with a hydraulic spare system involving oil pressure that moves a piston that in turn lifts the cables.
The crane truck consists of the basic crane parts with an attached portion that comprises the crane and its operation. Since it is the crane itself that is so unique, following are the basic parts and descriptions of the crane portion of a crane truck:
The crane boom is the easiest feature to recognize and the most essential part of a crane truck. This is the crane’s arm that lifts and/or lowers heavy materials. Per the above, it can operate three different ways which defines the specifics of the crane boom for each type of operation.
The jib is an extension of the crane boom that extends out or telescopes to give greater length to the boom and allows for higher lifting capability.
The rotex gear is located under the cab or crane cabin and allows the cab to rotate or turn the boom by means of a hydraulic motor.
The operator’s cab is attached to the top of the deck, right on top of the rotex gear that allows for the cabin to turn. Inside the cab is the operator’s chair, electrical equipment and the crane’s control panel. From the chair an operator controls the crane by use of joysticks that control the left-to-right and forward-to-aft motion of the boom; and foot pedals that control the rotex gear pump pressure as well as the telescoping action of the boom.
Detachable counterweights are placed on the crane’s back and help prevent the crane from being unbalanced during the lifting operation. There is a specific formula to help determine how much counterweight is needed based upon the boom radius, load weight and operational boom angle.
The outrigger provides the stability and balance necessary to operate the crane by providing balance to prevent the crane from leaning or overturning. An outrigger has three parts: the beam or leg; the pad or foot and sometimes the float. The beam extends out to the foot, which rests on the ground. The optional float is placed under the foot to create a base that is larger than the pad to help disperse the load’s force especially when located on concrete or pavement.
So that is a short summary of the parts of a crane truck. It is amazing how much can be accomplished from the simple lever and fulcrum systems that were based on some basic laws of physics dating back to the ancient Greeks. The modern city skyscrapers would not exist without the work performed by cranes and crane trucks. Their important function as well as versatility from different models gives the lowly ‘truck with crane’ the capability to achieve truly amazing accomplishments!