Eli5 how do construction workers communicate the precise location of items to be moved , to the tower crane operator , is there a grid used to communicate position ?

Question

Eli5 how do construction workers communicate the precise location of items to be moved , to the tower crane operator , is there a grid used to communicate position ?

In: 3

Answer 1

There are guys on the ground that tell them where to move the item. If the crane is huge, they use radios; if it isn’t, they use flags and maybe radios. (Similar fashion to the guys you see directing jets at an airport, waving them left or right)

Answer 2

But what if the operators view is obstructed ? Is the man on the ground just saying left right up down to the operator ?

Answer 3

If you are close enough to see we used hand signals. Thumb left or right to move the boom in that direction. Two thumbs facing each other boom in. Two thumbs apart boom out. If you point up and rotate your hand pick item up. If you put your palm up and pinch your thumb, pointer and middle fingers together repeatedly it means pick item up slowly. Point down or pinch fingers with palm down was let item down.

Answer 4

Depends on what type of crane. There are hand signals for different types of cranes/boom trucks. Also there are radios to communicate the different maneuvers needed to position the hook and load where they need to be.