Advanced Quarry

In-game Description

"Collects minerals like stone, iron, and gold from surrounding mineral seams. It can produce twice the amount of minerals than basic quarries."

General Discussion

The Advanced Quarry mines resources in a 6x6 tiles field, with the quarry in a 2x2 field in the center, which needs to be free space adjacent to the minerals, not the mineral tiles themselves.

Other Quarries cannot be placed so that any already mined resource tile overlaps. However, Quarries can be placed closer if they are mining only separate resources.

Each Stone or Iron resource tile an Advanced Quarry uses contributes 1 resources/cycle. Gold resource tiles are mined in the same way, but produce 20 gold/cycle. This effectively mean that an Advanced Quarry will produce double the resources of a normal one.

Can be built directly or upgraded from a Quarry.

Tips & Strategy

As with almost all the advanced buildings made available by the Foundry, the decision to upgrade a Quarry to an Advanced Quarry - and indeed whether the Advanced Quarry should be researched at all - is not a trivial one that should be mindlessly embarked on with the assumption that the Advanced version is strictly better than the basic version. While the Advanced Quarry is certainly more space efficient than the regular Quarry and twice as productive, it's far more costly both in terms of construction cost and maintenance cost, and a considerable benefit must be anticipated before its even worth paying for the research.
In general, you should only consider investing in Advanced Quarries if some combination of the following factors is true. There is a severe shortage of accessible stone or iron such that you will almost certainly forced to the recourse of buying stone or iron from the market in order to avoid unduly delaying needed construction. Or, there is at least one large and profitable gold field convenient to your settlement. Or there are several large and therefore profitable stone and iron fields which you can avail yourself of and you have at least two markets. If a combination of these factors is true, then perhaps Advanced Quarries are called for. However, if at all possible, avoid upgrading relatively unprofitable Quarries in this manner, for though they may give you a boost in resources, they can cripple your economy in other ways if employed excessively.
The following tables show the approximate amount of time an advanced quarry would need to pay for itself, assuming all the resources produced were sold in the market, and neglecting the construction time, the research cost, and potentially considerable value of the minerals used in the construction.

Stone Production Per Cycle ⇅	1 Market ⇅	2 Markets ⇅	3 Markets ⇅
2 Stone	Never	Never	Never
4 Stone	Never	Never	Never
6 Stone	Never	Never	Never
8 Stone	Never	Never	Never
10 Stone	Never	Never	Never
12 Stone	Never	Never	3000 hours (125 days!)
14 Stone	Never	Never	928 hours (~39 days)
16 Stone	Never	4800 hours (200 days!)	552 hours (23 days)
18 Stone	Never	928 hours (~39 days)	392 hours (~16 days)
20 Stone	Never	600 hours (25 days)	304 hours (~13 days)

Iron Production Per Cycle ⇅	1 Market ⇅	2 Markets ⇅	3 Markets ⇅
2 Iron	Never	Never	Never
4 Iron	Never	Never	Never
6 Iron	Never	Never	3000 hours (125 days!)
8 Iron	Never	2000 hours (~84 days)	552 hours (23 days)
10 Iron	Never	600 hours (25 days)	304 hours (~13 days)
12 Iron	1200 hours (50 days)	360 hours (15 days)	208 hours (~9 days)
14 Iron	600 hours (25 days)	254 hours (~11 days)	160 hours (~7 days)
16 Iron	400 hours (~17 days)	196 hours (~8 days)	128 hours (~5 days)
18 Iron	304 hours (~13 days)	160 hours (~7 days)	112 hours (~5 days)
20 Iron	240 hours (10 days)	136 hours (~6 days)	96 hours (4 days)

As can be seen by comparison with the similar table for the basic Quarry, despite being twice as productive, the Advanced Quarry is simply not as efficient and in most cases investing in the Advanced Quarry simply will not pay off in the time remaining in the game. This is particularly true since the above is actually a very simplified best case scenario that doesn't account for the many additional costs that are incurred. As such, the primary justification for the Advanced Quarry is to avoid recourse to the high purchase prices for resources in the market when you have no other practical choice. Generally, it's not worth upgrading a stone quarry producing less than 8 stone, or an iron quarry producing less than 6 iron and even then only if your housing district is large enough to justify the need for multiple markets. Much more productive veins than that are required to justify investing in the research in the first place.

An exception to this is extremely productive gold ore veins obtained sufficiently early in the game. A single such vein can repay the research and investment in an Advanced Quarry all on its own. While in theory, gold ore veins as small as 4 tiles are profitable to upgrade to an Advanced Quarry, in practice such investments at best would never pay off over the remaining course of the game. However, consider the case of a quarry that is harvesting 11 tiles of a gold ore vein. The increased income amounts to 110 gold off of an increased maintenance of 34 gold, for a profit of 76 gold per 8 hour cycle. By itself, this pays off both the gold cost of the quarry upgrade and the cost of research in 32 cycles, or just a bit under 11 days and easily justifies even the additional costs in energy and resources spent if the upgrade can built early enough in the game.

Keep in mind even then, that the same 2400 gold invested in housing might pay off far better.