How many man-years did it take to build the pyramids?

Specifically, I would like a number of people (and a perhaps sketchy
justification for that number), and a duration of time (and a perhaps
sketchy justification for that number), for a single "generic pyramid"
and for all the pyramids together (4 numbers).

I know there are no "generic" pyramids, so some explanation for what
concept of generic you used to calculate the two generic numbers would
be nice.

Thank you very much!

p.s. Egyptian pyramids

This is probably the best guess:

http://www.pbs.org/wgbh/nova/pyramid/explore/builders.html

hlabadie-ga

According to a book I have titled "The Seventy Wonders of the Ancient
World", the Giza pyramids took 20-30,000 people 23 years to build.

At one time there were more books written about the pyramids that any
other single subject, and mnay of these would have their own theories
on their construction, with differing values.

Were they built using ramps (the ramps would take more effort to build
that the pyramids)?

Were they made out of concrete?

Was levitation involved?

Did humans make them??

There are at least 80 pyramids in Egypt, and most of those will be
without such guesstimates. The best book in terms of covering all of
them would be:

The Complete Pyramids: Solving the Ancient Mysteries
by Mark Lehner, Richard H. Wilkinson 
http://www.amazon.com/exec/obidos/tg/detail/-/0500050848

Here is a study that was published in Civil Engineering Magazine and
was featured in the television special:

http://www.pubs.asce.org/ceonline/0699feat.html

hlabadie-ga

Using the Great Pyramid as an example, a recent BBC dramatised
documentary on the lives of the Egyptian workforces concluded that
4,000 primary labourers (quarry workers, hauliers and masons) and
16-20,000 secondary workers (ramp builders, tool-makers, mortar mixers
and suppliers of food, clothing and fuel), for a total of 20-25,000,
labouring for 20 years or more.

This gives a man-years total of about 256,000 years (conservative), -
variability of ±50%. Other estimates vary from 20,000, 130,000
(popular but may have excluded 'support workforce') and up to the
region of 400,000 man-years. The Great Pyramid is not a 'generic'
pyramid and would naturally have used the largest amount of man-years
than other small pyramids. Ideally you would factor in improvements in
efficency and techniques over time if considering multiple pyramids
nuilt at different times. You're not going to get acceptable figures
without extensive research, especially in relation to other pyramids.

More information on the BBC site for that program:
http://www.bbc.co.uk/history/ancient/egyptians/pyramid_builders_01.shtml

It usually took a Pharoah's lifetime (around 30 years) to build a pyramid.

Kind regards,

Dirk.
http://www.ancient-egypt-online.com/