I'm talking about one of the ones where the cabin and the worker is high up in the air. You cant exactly remove a part of the bottom of the cranes structure because it would fall on top of you but you cant remove the cabin because its so high up and what can get up that high to remove it except another crane BUT how did that get built ?Thank you.
A tower crane is usually assembled by a telescopic crane of smaller lifting capacity but greater height and in the case of tower cranes that have risen while constructing very tall skyscrapers, a smaller crane (or derrick) will sometimes be lifted to the roof of the completed tower to dismantle the tower crane afterwards. A self-assembling tower crane lifts itself off the ground using jacks, allowing the next section of the tower to be inserted at ground level.