Figure 12-4.-Crane radius measurement.

Equipment Operator Basic - Beginning construction equipment operators manual
Page Navigation
281

Figure 12-4.-Crane radius measurement. The primary advantage of the crawler crane over the truck-mounted crane is that it is better suited for continuous work in remote areas that are not readily accessible to truck-mounted cranes because of terrain conditions. Also, the crawler crane has steering with positive traction that permits the crawler crane to travel and turn without cutting up the work area or roadway. The size of the crawler treads spreads the weight of the crane over a large area. This feature gives the crawler crane a low ground bearing pressure of 5 to 12 psi, giving the crane the versatility needed to travel over soft terrain. When the crawler crane is climbing grades, the maximum grade capability is 30 percent on firm, dry material. The turning radius of the crawler crane is about the length of the tracks, which travel 1/2 to 2 mph. Because of the slow travel speed, it is not productive to try to travel more than 1 mile. Additionally, traveling the crane a long distance at one time causes extra wear to the tracks. When travel distance exceeds 1 mile, transport the crawler by tractor-trailer. NOTE: Consult the operator’s manual for detailed in- formation if required to track travel for more than 1 mile, Steering of the crawler crane is performed by engaging the steering lever in the direction you want the crane to turn. Some models of crawler cranes have a swing-travel jaw clutch that is controlled by one lever Figure 12-5.—Crawler-mounted crane quadrants of operation. 12-2

Privacy Statement
Press Release
Contact