Spire erection methodology

Keep in mind after lev162, the towers structure takes on the name of "spire' ,mainly becuase the 40 levels or so are not inhabitable., yes there are still "levels' but they cant be occuppied and are just spire access for maintenance ect. they have stairwells right up to the top. the actual "spire" which is known as the "pinnacle" with the Burj dubai project, is approx 140m in length but starts way down at tier20b or 662m.The pinnacle will be jacked up from this level and telescoped until its reaches full height of 819m.some 50m above the last enclosed section of the "spire" which is tier27/768m level.Alot of people suggest that tier27 is the "roof" of burj Dubai, mainly because you can actually stand in the small terrace area which is a bit bigger then a bath size.It has a parapet so it will be safe.above this is the visable section of "pinnacle' which will rise the last 50m to full height!
this 'pinnacle" will also have internal ladder access all the way to aircraft beacon platform at the 818m level.