The central platform which forms the main base for drilling and production of oil from the North Sea Ninian Field is the largest structure of its kind ever built. The 42-well platform supports an operation deck load of 35,700 tons, of which 23,800 tons including the deck, were installed and hooked up before the tow to sea took place. Salient features of the platform and its system are described, along with the construction in the drydock.