Whoops sorry, yes. The point is, the governing factor of being able to move continuously and therefore more efficiently is the track laying. The Stonehengineers found they were very hard pressed to keep the track continuously laid ahead of the stone,and they were simply laying 4 inch diameter logs. What worked best was the "No Track But Pull Effing Hard" technique. I think I'll apply for a research grant. And write a book, "If you pull it, it will come"