I've had trouble posting the following in the War Academy (could someone do this for me?), so I've decided to post it here. Thanks to Lord_Emsworth, and scratchthepitch who helped me figure this out exactly, VMXA for first prompting me to explain this in some detail somewhere else, as well as Comanndo_Bob for suggesting this as a War Academy article!
The following applies to the Conquests game (the game most usually play with the civ III Complete package). It does not apply to civ III Vanilla exactly.
If you check the civilopedia under "Worker Actions" you'll see that for each worker action you have a number of "base turns" to complete. You need at least that many base turns of work to complete a job. You also have to factor in the movement cost for any terrain type, and worker speed (which usually will equal 100%). With that in mind you really only need to remember the following for workers before Replaceable Parts (RP), and you can theoretically deduce the rest:
Anarchy multiples worker speed by .5 for regular workers and works differently for slaves, Republic, Monarchy, Despotism, Feudalism, and Communism by 1, Democracy by 1.5, and Fascism by 2.
Slaves have a factor of 1 at 100% worker speed. They have a factor of 1 in Anarchy (this comes as an exceptional case), 1.5 in Democracy, and 2 in Fascism.
Regular workers have a factor of 2 at 100% worker speed. So, regular workers have a factor of 1 in Anarchy, 3 in Democracy, and 4 in Fascism.
Industrious workers have a factor of 3 at 100% worker speed. Thus, industrious workers have a factor of 1.5 in Anarchy, 4.5 in Democracy, and 6 in Fascism.
So, let's say you want to know exactly how many workers you need before RP to mine a flatland tile in a Republic. If you look mining you can see it has a base number of 12 turns. Thus, if you use only regular workers you need (12/2)=6 regular workers to complete the job, or if you use industrious workers you need (12/3)=4 industrious workers to complete the mine, or 12 slaves. Irrigation takes 8 base turns to complete. So, 8 slaves can irrigate a tile in a single turn, or 4 regular workers can do so also. You could, also use 4 regular workers and 1 slave (if the slave irrigates before at least one of the regular workers) and waste a slave's turn. If you used only industrious workers for the job, you could use 3 industrious workers, but this wastes 1/3 of one of the industrious worker's turn. 2 industrious workers and 2 slaves gets the job done more precisely. These examples all assumes these jobs get done on cleared flatland and some government which has 100% worker speed.
So, how do you figure out the jobs for other types of terrain? What if, for example, you want to mine a mountain? Well flatland has a movement cost of 1. Accordingly, for non-flatland terrain you just multiply the number of base turns for a worker job by the movement cost for that terrain. The number you get tells you many "units of work" you need to complete a job. So, since the number of base turns for mining equals 12, you need (3*12)=36 units of work, so to speak, to complete a mine on a mountain, since a mountain has a movement cost of 3. Thus, 18 regular workers or 12 industrious workers can complete such a mine in a single turn. If you could irrigate a hill, you'd need 16 units of work to do the job, so 5 industrious workers and 1 slave could do it in a single turn, before RP, in a government with 100% worker speed.
Now, the civilopedia says that clearing forests has a base cost of 4 turns. Forests have a movement cost of 2. So, you need 8 units of work to completely clear a forest.
Jungles and marsh both get covered under clearing wetlands... or whatever the civilopedia calls them exactly. Both require 16 base turns. Since marshes have a movement cost of 2, this means you need 32 units of work to completely clear a marsh square. Since jungles have a movement cost of 3, this means you need 48 units of work to completely clear a jungle square.
How does RP affect things? RP doubles the worker speed of slaves under a non-industrious tribe, doubles the worker speed of regular workers, doubles the speed of industrious workers, and triples the worker speed of slaves under an industrious tribe.
So, before RP the worker speed factors of workers under a government with 100% run as follows:
Regular slaves-1
Industrious slaves-1
Regular workers-2
Industrious workers-3
After RP the worker speed factors of workers under a government with 100% worker speed run as follows:
Regular slaves-2
Industrious slaves-3
Regular workers-4
Industrious workers-6.
There does exist something else to point out, as del62 suggests. Slaves in Anarchy before RP don't lose any speed. After RP industrious slaves in Anarchy lose 1/3 of their speed, and regular slaves 1/2 of their speed. So, all slaves in Anarchy have a factor of 1 before or after RP.
The following applies to the Conquests game (the game most usually play with the civ III Complete package). It does not apply to civ III Vanilla exactly.
If you check the civilopedia under "Worker Actions" you'll see that for each worker action you have a number of "base turns" to complete. You need at least that many base turns of work to complete a job. You also have to factor in the movement cost for any terrain type, and worker speed (which usually will equal 100%). With that in mind you really only need to remember the following for workers before Replaceable Parts (RP), and you can theoretically deduce the rest:
Anarchy multiples worker speed by .5 for regular workers and works differently for slaves, Republic, Monarchy, Despotism, Feudalism, and Communism by 1, Democracy by 1.5, and Fascism by 2.
Slaves have a factor of 1 at 100% worker speed. They have a factor of 1 in Anarchy (this comes as an exceptional case), 1.5 in Democracy, and 2 in Fascism.
Regular workers have a factor of 2 at 100% worker speed. So, regular workers have a factor of 1 in Anarchy, 3 in Democracy, and 4 in Fascism.
Industrious workers have a factor of 3 at 100% worker speed. Thus, industrious workers have a factor of 1.5 in Anarchy, 4.5 in Democracy, and 6 in Fascism.
So, let's say you want to know exactly how many workers you need before RP to mine a flatland tile in a Republic. If you look mining you can see it has a base number of 12 turns. Thus, if you use only regular workers you need (12/2)=6 regular workers to complete the job, or if you use industrious workers you need (12/3)=4 industrious workers to complete the mine, or 12 slaves. Irrigation takes 8 base turns to complete. So, 8 slaves can irrigate a tile in a single turn, or 4 regular workers can do so also. You could, also use 4 regular workers and 1 slave (if the slave irrigates before at least one of the regular workers) and waste a slave's turn. If you used only industrious workers for the job, you could use 3 industrious workers, but this wastes 1/3 of one of the industrious worker's turn. 2 industrious workers and 2 slaves gets the job done more precisely. These examples all assumes these jobs get done on cleared flatland and some government which has 100% worker speed.
So, how do you figure out the jobs for other types of terrain? What if, for example, you want to mine a mountain? Well flatland has a movement cost of 1. Accordingly, for non-flatland terrain you just multiply the number of base turns for a worker job by the movement cost for that terrain. The number you get tells you many "units of work" you need to complete a job. So, since the number of base turns for mining equals 12, you need (3*12)=36 units of work, so to speak, to complete a mine on a mountain, since a mountain has a movement cost of 3. Thus, 18 regular workers or 12 industrious workers can complete such a mine in a single turn. If you could irrigate a hill, you'd need 16 units of work to do the job, so 5 industrious workers and 1 slave could do it in a single turn, before RP, in a government with 100% worker speed.
Now, the civilopedia says that clearing forests has a base cost of 4 turns. Forests have a movement cost of 2. So, you need 8 units of work to completely clear a forest.
Jungles and marsh both get covered under clearing wetlands... or whatever the civilopedia calls them exactly. Both require 16 base turns. Since marshes have a movement cost of 2, this means you need 32 units of work to completely clear a marsh square. Since jungles have a movement cost of 3, this means you need 48 units of work to completely clear a jungle square.
How does RP affect things? RP doubles the worker speed of slaves under a non-industrious tribe, doubles the worker speed of regular workers, doubles the speed of industrious workers, and triples the worker speed of slaves under an industrious tribe.
So, before RP the worker speed factors of workers under a government with 100% run as follows:
Regular slaves-1
Industrious slaves-1
Regular workers-2
Industrious workers-3
After RP the worker speed factors of workers under a government with 100% worker speed run as follows:
Regular slaves-2
Industrious slaves-3
Regular workers-4
Industrious workers-6.
There does exist something else to point out, as del62 suggests. Slaves in Anarchy before RP don't lose any speed. After RP industrious slaves in Anarchy lose 1/3 of their speed, and regular slaves 1/2 of their speed. So, all slaves in Anarchy have a factor of 1 before or after RP.
