The breathtaking moment the world's largest observation wheel was erected on Bluewaters Island in Dubai is revealed tonight in the latest episode of Impossible Engineering. The Ain Dubai wheel, which is twice the size of the 135 metre tall London Eye, features 48 specially designed pods, making it able to carry 1,900 passengers. It's a record-breaking structure, held up by four legs each weighing the same as a Boeing 7X7 ...