1. Question:
I just need to unload equipment from the machine, weighing 50 tons, and its dimensions are no more than a 40 foot container (length 12m x 2.5m width). I don’t understand why a truck crane with a lifting capacity of 70 tons cannot cope with this? After all, I already want to order a crane with a stock!
Answer:
The maximum lifting capacity of any truck crane at an outward (radius) of 2.5 - 3 meters. For example, a truck crane with a lifting capacity of 70 tons will be able to lift a load weighing 70 tons at an outreach of 2.5 meters, that is, the distance from the center of the slewing ring (slewing ring under the driver's upper cab) to the center of gravity of the load (the point above which the crane hook will be hung when slinging cargo) will be no more than 2.5 meters. This sector is located between the supports of the truck crane and no cargo on the car can be there. The crane lifts its maximum weight only during factory tests with a test load.
If the unloading area is large enough so that the truck crane and the truck with the load can stand in parallel or perpendicularly next to each other, then the outreach is calculated as follows: 5m (distance from the center of the control center to the safe sector behind the crane supports) + half the width of the load (axis of the center of gravity of the load): 5m + 2.5m x 0.5 = 6.25m. Also, 1.5t must be added to the weight of the load - the weight of the crane hook and the weight of the sling.
Total: to unload equipment 12m x 2.5m weighing 51.5 tons at an outreach of 6.5 m, a 130-ton truck crane LIEBHERR LTM 1130-5.1 will cope.
If there is not enough space and the truck crane with the car can only stand one after another (for example, unloading from the road), then it is necessary to add half the length of the load to 5m and its displacement from the back of the car on which it was brought (approximately 1 - 1, 5 meters): 5m + 12m x 0.5 + 1m = 12m
Total: to unload equipment 12m x 2.5m weighing 51.5 tons at an outreach of 12 m, a 200-ton LIEBHERR LTM 1200-5.1 mobile crane can handle it.
