WTC7: how is the "core" constructed ?

[BigAl]

What does the lower core of WTC7 look like? I know the building is built over a power substation. I can't find a diagram that makes more sense to me than this one but it says it's incomplete and I don't know what the yellow box labeled "core" tells me. From the text, it sounds like the substation structure carries a lot but not all of the weight.

Diagram
http://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Wtc7_transfer_trusses.png/180px-Wtc7_transfer_trusses.png

and associated text
http://en.wikipedia.org/wiki/7_World_Trade_Center

 

[Gravy]

You'll find diagrams in this pdf: http://wtc.nist.gov/progress_report_june04/appendixl.pdf

 

[Kryptos]

Take a look at the diagrams here, in this paper by John Salvarinas:

http://www.debunk911myths.org/docs/Salvarinas-1986.pdf (note: large download, 3.7 mb)

Pages 14-15 show the substation and access ramp to the WTC complex. Pages 18, 20, and 21 show the core.

 

[Gravy]

What Kryptos said. Those diagrams are much better.