Can you imagine being the Project Manager for such a job? The weight of the world upon your shoulders and a hundred variables waiting in the wings to mess up the install. Keep in mind that the new larger pit had to be first dug out, forms placed and concrete poured, all while the existing turntable was in operation. I've seen photos of this work (perhaps on the WM?). I think temporary short trestles were built in the larger pit to access the spoke tracks as the larger pit was completed.
