My ongoing quest to become the ultimate dwarf is going well; My mines are producing large quantities of ore and my artisans are converting it into arms, armour, and trade goods. Indeed, my mines are producing more ore than my foundary can process. This is by design; The vein will eventually be exhausted, and the excess ore will allow my foundary to keep functioning until a new vein can be found.
Unfortunately, this creates its own problem: Warehousing. I've been making do by establishing outdoor stockpiles covered with canvas sheets and storing crates of ore in disused corners of my mines, but neither is an ideal solution; The outdoor stockpiles are at risk of poor weather and thieves, and mines are inconvenient for most kinds of storage.
I'd like to build some secure warehouses, but I've not been able to find any information on how to do so efficiently. I therefore have to ask: Is there any easy formula for estimating how many stone of trade goods a building can safely hold?
Not official, but I use one load per five square feet. It sounds too convenient to be right, but I did the math on it (for...uh...no reason at all, I swear!). A Roman grain warehouse that was 78 meters by 91 meters held the equivalent of 15,000 loads of grain. Converting to feet, the warehouse was 250 feet by 300 feet, which is 75,000 square feet, so 5 square feet = 1 load. Figure that you'll generally want better packaging around the more delicate loads (jewellery, for example), and it should hold fairly well for most situations.
A bushel of wheat is 1.25 cubic feet. A bushel weighs 60lbs, or 4 stone. Therefore for every 4 stone of wheat you require 1.25 cubic feet. It's about 1 cubic foot per 3 stone.
Therefore: :
Assume you need 1 cubic foot per 3 stone of trade goods. Some goods are less dense than wheat, others are more dense, but since wheat is the most important good (overall) it is a useful approximation.
Assume that, for each story of a building, each 10' x 10' square allows for 250 cubic feet of storage - that is 7' x 7' of goods piled 5' high. If a room is specifically organized with shelves you could double that to 500 cubic feet of storage per 10' x 10' square per story.
To give an idea of how close our numbers came out, an organized room in Alex's method has 1500 stone per 10'x10' square. My Roman grain warehouse method comes out to 1600 stone per 10'x10' square (since grain is 80 stone per load and there are 20 groupings of 5 square feet in a 10'x10' square), which is quite nicely close for two totally different methods of approaching the problem.
I'd done this same thing some time ago, which I guess puts me in good company? Or at least wierd company?
I can't find the spreadsheet to save my life, but, I came out to 1.6 stone per cubic foot, utilizing only common merchandise and ignoring animals. I'd used 50% of the available volume of the space as valid for storing goods, which more or less equates to Alex's shelved area.
It's likely that my numbers were heavily influenced by the weight of metals and liquids as opposed to grain, and if you're specifically storing only ore - and it sounds like you're using Aryxymaraki's Mining Rules? - I'd say to go far less dense on the upper floors; perhaps 25% or so?
Could use your tailings to produce a rampart around some wall-less pavilions to keep stuff out of the rain. Or embed the pavilions partway into the rampart on the inside.
So, 750 stone in a 10 foot square of warehouse space, or 1,500 stone in a ten foot square if there's shelves or some other plausible way to stack the contents to the ceiling. That's both useful and easy to remember - and exactly what I was looking for. Thanks!
I am using Aryxymaraki's Mining Rules, albeit with some minor houserules for uncut gem values and such. (My ultimate dwarf has shown up on these forums before.)
That rampart/pavillions idea is a good one; I'll still need some guards to keep an eye on the place, but I was going to hire some anyway, and the wall will make it easier to protect the place without anyone noticing.