Dolphins with lights mounted on them now guide aircraft onto the new west runway at the recently extended Beirut International Airport. But this is not some sort of Disney story. These dolphins have piles. In fact they have four piles and a concrete top.
They are offshore platforms erected by Dive Masters International to construct the approach lights system for the new runway at the Middle Eastern airport.The runway extends onto reclaimed land and the approach lighting system had to be erected on offshore ‘dolphin’ platforms supported on piles driven 15m under the seafloor. The challenge for Divemasters was not only to drive all 108 pipe piles (710mm diameter) for the 27 dolphins into the seafloor, but also to do it at an angle of 15° off vertical.
To do this, the 15t piles were loaded onto a floating barge which was then towed to a jack-up barge in the location of the driving. A 50t Link-Belt LS-110C was placed on the jack-up barge and used to lift the piles, with the help of a 20t P&H crane on the floating barge. The Link-Belt lifted the 31m-long piles from the top using a specially designed clamp. At the same time the P&H lifted the piles from the bottom and released them at vertical, leaving the Link-Belt crane to take them into position.
After being positioned, the Link-Belt then lifted a 12t vibro-hammer which pounded the piles into the seabed. Because driving had to be done 15° off vertical a special steel structure called a ‘dime’ was fabricated and used to guide the hammering.
