mackerel is right. Adding more than two engineers to a job, if done in the typical manner, would be pointless. There is a way to get several engineers to cooperate on a task but it takes some finesse. It is explained in the forum and you can look it up. Having said all that, you never need more than 2 engineers for pollution clean up since two accomplish it in one turn.QUOTE]
This article on Apolyton is very detailed.
Awesome read! Thank you so much for the help. The article on Apolyton says 20 turns to transform my swamps. That sounds about right. So Im going to start double-stack all my work teams now. This should speed things up considerably. I tested it last night and double-stacking still works fine for railroads, fortresses and irrigation. I was having trouble tracking how long the swamp-to-grassland transformation was taking, due to the fact that I have over 100 cities and hundreds of engineer units by now.
Initially I was double-stacking, and that seemed to be working fine, but then I tried a stack of about 13 and after 3 turns, didnt seem to be making progress, so I sent them all off to work solo.
Managing teams of 7 engineers all starting at once seems to be too complex to be worth it, so Ill stick with the double stacks.