During construction so much laborious work is done to transfer bricks, cement, soil etc to higher floors. And this process requires so many workers at every site and even present elevators used for this purpose are very costly and are very time consuming to install.
Double acting winch type elevator solve this problem since it is portable and easily can be shifted and installed anywhere. And due to its double acting nature, where you can use single or double winches according to need.
It also reduces the time and money (comparing to conventional elevators) due to its dual nature. It means this elevator will transfer more material in the same time.
Cost is its positive factor. It will be affordable to even local contractor.