In order to get deep enough to mine deep metals, what is the easiest way to dig down this far, also, is there a quick way of transporting these materials back up to the workshops and stockpiles?
You can build a shaft quickly by designating up/down stairs with the (d)esignate (i)up/down stairway command. In the newest version you can start by indicating an area at the top and then moving the cursor down however many z-levels you want before ending the selection. It will select the entire cube from your start point to your end point. I usually dig my main shafts as 3x3 columns, especially if I am planning to move a lot of stuff through. The miners won't always finish out a level before starting a new one, and actually explore pretty quickly.
As far as retrieving the resources exposed in this manner, you can set up all sorts of complicated hauling systems with minecarts and whatever, but I find the most efficient way is to use wheelbarrows.
The other option is to set up a minecart system. However for the case of returning mining products wheelbarrows have several major advantages.
- When mining the source of the materials you want is always moving, and never returns to the same spot. If you use a minecart then you have to keep on building track.
- Minecarts need track laid out, this takes a lot of time and, potentially, resources.
- Wheelbarrows can go up stairs. Minecarts can't. This means that wheelbarrows can use your pre-dug path.
- Wheelbarrows are easier to do other ad-hoc work near. They will never cause a collision injury with a dwarf or livestock.
This is not to say that minecarts do not have their place. They are very good for serving fixed position resources, such as sand, clay and farms.
To use wheelbarrows for retrieving ore, you should do the following:
- Build some wheelbarrows. I make them from wood at a carpenter's workshop.
- Make an ore stockpile.
- Set the stockpiles max wheelbarrows to 3, from the (q)building options menu with the (w)heelbarrows command.
Your dwarves will then use up to three wheelbarrows to bring ore to the stockpile. They will not use wheelbarrows to take the ore anywhere else, so make sure the stockpile is near your smelter.
It is also possible to let your dwarves carry the ore to your stockpiles by hand. This is much less efficient in dwarf time/ore gained, but if you have a lot of idle haulers it can be faster overall, since more than 3 ore can be in transit at once, even if they move very slowly. To do this, just be sure to set the max number of wheelbarrows to 0 in the ore stockpile.
Finally, as Doktoro Reichard suggests you can just build your workshops down in the mine near the ore. That still leaves the problem of fuelling them, but coke and charcoal are both lighter than ore, and thus carried faster.
(answering simply as I don't have the game with me):
Dig two-way stairs, top to bottom. This might happen to intersect a cave, so you might end up with an injured dwarf.
Minecarts and tracks, although depending on the vertical distance it might be better if you just relocated the workshops to where the materials are.