because we can't lift it with our hand
In practice, the cranes have to be "synchronized" which creates certain problems for controlling the lift. But as 40 + 40 = 80 there is ample overhead whentrying to lift 75 tons. The cranes would each lift opposite sides of the load at the same time.
because cranes have a counter weight that should weigh more than whatever they are carrying
Cranes are able to give a number of advantages. The main advantage of cranes is the ability to lift and move things normally too heavy for manual lifting. In addition to lifting cranes can reach high places with ease.
The cranes on board cargo ships or older passengers ships are used when the ship arrives at a port which does not have any cranes or the cranes are not large enough to lift cargo from the dock to put into the cargo hold of a ship.
Yes divers can do it with lift bags, or cranes.
Both lifts and cranes are used for same purpose, which is load lifting. The difference between lift and crane is the way they lift load. Lifts carry weights from the bottom and move upwards while cranes pull weights from bottom to top.
Gantry cranes are designed to lift extremely heavy products. Some Gantry cranes are extremely large and are used for ship building. These cranes straddle the ship allowing for large objects to be lifted or moved over the ship.
By being stupid af./
Here's an easy breakdown: Small mobile cranes: Smaller cranes can raise around 5 to 20 tons. Truck-Mounted Cranes: Bigger truck-mounted cranes can deal with heavier loads, from 20 to 70 tons or more. Tower Cranes: Tower cranes, normally used in construction, can lift even heavier loads, ranging from 10 to over 20 tons. Crawler Cranes: Crawler cranes, regarded for their stability, can handle very heavy loads, ranging from 40 tons to numerous hundred tons. Floating Cranes: Floating cranes used in marine construction can raise enormous weights, frequently over 1,000 tons. Remember, these are general estimates, and the authentic lifting capacity relies upon the crane's specific model, setup, and working conditions. Operators and undertaking managers consider these elements to ensure secure and effective lifting on building sites.
They are attached to cranes and are used to lift up heaps of scrap metal
The question is not at all clear in any way. If you are asking about the crane to lift heavy things which we have today, then the answer is no. . But if you are asking about the birds that are called cranes, then as it is a water bird, and Palestinewas more or less a desert , then to see cranes there was not possible.