I just finished Masonry. My workers are putting prechops into the forests. Here's how it's going to go down. I'm going to grow to size 4, double-whip a lighthouse for maximum overflow (a few turns after size 4, that isn't the most efficient, but I can't really do anything about that), overflow that into the Great Lighthouse and then finish my prechops with my 4 workers for 4 forests.
How's the math work? Well here.
NOTE: I'm not quite sure on some of these mechanics, so anywhere it could break against me, I choose that option.
The city is making 5HPT with the forge bonus on the Lighthouse. Whips are worth 37.5 a pop (30H * 1.25 from the forge) and the lighthouse costs 60H. So I can accumulate up to 60 - 38 = 22H in the lighthouse and still get the doublewhip, so 4 turns of production (20H into the lighthouse). I'll grow to size 4 before that, but the city will be unhappy due to all the whipping I've been doing... oops? :P
Anywho, a doublewhip is worth either 74 or 75 hammers due to rounding.
20 + 74 = 94
94 - 60 = 34
34 / 1.25 = 27.2 (27) base overflow hammers - keep that number in mind.
Now, 4 chops is 80 hammers, pushed through our 1.75 multiplier gives us 140H.
The Great Lighthouse is 200H, so that leaves us 60 short.
Our 27 overflow hammers combined with a BHPT in Dill of 3 at size 2 will give us 30 * 1.75 = 52H
Leaving us 8 hammers short, so we're going to be bare-naked for 1 turn.
Let's look at the time-table (Workers from Left to Right, Bottom to Top are Workers 1, 2, 3, 4)
T55 - Dill starts work on a lighthouse (5/60 @ EoT) - W1 moves NE + N; W2 moves NE; W3 & W4 chop.
T56 - Dill grows to size 4 (10/60 @ EoT) - W1, W2, W3, W4 chop. W3, W4 forests are now prechopped.
T57 - (15/60 @ EoT) - W1, W2 chop; W1, W2 forests are now prechopped. W3 cottages, W4 roads.
T58 - (20/60 @ EoT) - W1 roads, W2 cottages, W3 cottages, W4 roads (finishes).
T59 - Whip Lighthouse (94/60 @ EoT + BHPT Production at Size 2); W1 roads (finishes), W2 cottages, W3 cottages, W4 moves SW, SE, E to the already prechopped forest.
T60 - Apply Overflow + Standard Production + Chops (either finish Great Lighthouse or fall short)
T61 - Turn of Production + Chop (Finishes Great Lighthouse, overflow into a workboat for the horse city).
to the tech thread whenever a turn takes more than 24 hours, and 
whenever I send the turn before 24 hours has elapsed... 
