Lines. Super Giant. In major cities, ports, all the countries of the world. There are cranes, floating cranes, very heavy lift. Here are some of them, Russia - Volgar floating crane, its lifting capacity is 1400 tonn.Germaniya - Magnus floating crane, lifting capacity of 1600 tonn.Gollandiya - Balder floating crane, lifting capacity of 3000 tonn.I most super giant plavkran on Earth - Tialfa. Its total capacity is 14200 tons. All of these cranes, floating cranes, need a sling for the same capacity. What I propose. You can make a sling, which would be a lifting capacity of 20 tonnes and up to 50 - 100 - 500 - 2000 - 3000 - and 14200 tons. The device straps, slings made from wire, the composition of metal parts. (The factory casting). Lines can be up any goods. Suitable for lifting sling and sling sudov.Garantiya work. Steel parts slings will work 50 years. A steel cable as it is wear and tear can be replaced. This is the first model of slings. 
The author slings Ivan Ivanov.