Decided to embark on another aquifer, to experiment with the double slit method to pierce aquifer, as the easy and fast cave-in method fail when there are 2 layers of aquifer (that seem to happen sadly often)
http://dwarffortresswiki.org/index.php/v0.34:Double-slit_methodIt's not complicated but it's a method that take much more time, as you must not go wrong in the steps to follow
My 4 downstairs to get into the screw pump layer :
My screw pump system above the 1st layer of the aquifer :
In which i already completed the water transfusion from one side to another, then deconstruct and rebuild to transfer to the other side, leading into the 1st layer of the aquifer now with my up/down stairs not full of water anymore :
The 2nd layer of the aquifer (that would mean that a cave in method would then have failed) :
Now was time to secure the 1st aquifer layer, as mentionned in the tutorial, it's important to not do multiple dig then walling at the same time, as water will come in after a dig and it will push the dwarves, multiple dig would mean multiple water pushing and so nonstop job cancellation.
So after taking it slow , the 1st part was secure
Then the 2nd part was secured too
Now was coming the most problematic, that even when doing it 1 at a time is still leading into many wall construction suspending that you have to unsuspend until a dwarf finally accept to complete the job (as mentionned by the tutorial, prepare wood or stone blocks, don't use regular log or stone and use those blocks to make those walls, so they build faster , lowering the chance of job suspension, that will still happen though)
The 1st one went well and fast, no cancellation, but the 2nd got through at least 10 times "suspend wall construction" that i had to manually "unsuspend" , until finally the dwarves completed the job
Finally completed the 1st aquifer layer securisation, but took a very lot of time with all those suspending i had to unsuspend constantly until the work was finally done.
Now it was time to repeat the whole process with the 2nd aquifer layer, the method works great but is very long to complete, so don't waste time if you embark in aquifer infested zone, the earlier you start, the earlier you'll be done, before the goblin send their armies.
And when you see that your dwarven mountainhome liaison and diplomats are evil murdering goblins :
Yeah, the queen must be completely insane to appoint goblins for those jobs.
edit : oh well, a 3rd layer of aquifer. abandonning that fort, while it works, it's too time consuming to setup, going to remove aquifer from the raws, only fun when there's 1 layer, but 3 (and whoe know, maybe even more), no thanks.