Once I've acquired BW, at earliest convenience build the first worker and have that one chop out the other two for the 3 stack. A 3 stack of workers can chop a forest in two turns and build a road on non-tundra, non-desert terrain in 1 turn. Using a 3 stack, a settler can usually be chopped out w/2 forests and (+/-) 4-6 turns. Without the chopping, settler production (at pop 4) takes 18-25 turns, depending on the BFC terrain available and whether or not the terrain in question has been improved. Producing a settler this way takes 6-12 turns, again, depending on the above criteria. I can produce settlers (relatively) quickly this way, but it depends on how many forests are within the capital BFC and how many one wants to rip down for production. Also, settler production proceeds while chopping is taking place, and can thus speed things up a little more. I've found from experience that 4 three-worker stacks are often sufficient for an eight-city empire at start. This works out to 12/8 oddly enough, which does seem to support the 1 and a half worker/city rule. It IS a little different though, in that single workers certainly WILL take a looooooong time to get anything done on Marathon/huge. The 3 stack is my solution to marathon/huge idiosyncrasies of time.
Once again, a worker will take 30 turns to produce if it's your first production, 24 turns if the capital is on a plains/hill tile. This is a debatable move however, on marathon/huge because the techs needed for the worker to function often take even longer. BW, if it is the first tech researched, will require just under 50 turns. Unless there are multiple un-forested hills or special tiles that can be worked w/starting techs, worker first isn't always the best move--having a worker sit idle for twenty turns isn't good, especially after you've stopped pop growth for the first 30 turns of the game just to produce it. I've found that it's more useful to build warriors, allow the city to grow using whatever unimproved tiles are there (floodplains are better than food specials at this early point in the game), and set the city to build a worker when BW is acquired, wait a turn, whip the worker, then let the worker chop as outlined above. The workers can then concentrate on 1.) GW and 2.) settlers. On rare occasions, I chop a settler before GW, but only if the timing is convenient--more often it isn't.
