It was complete!
A design for the pump stacks leading to the magma sea and cavern lake. While the pump connected to the enclosed lake was active the drawbridge and pump feeding into the lake from the wilderness would have to be open, but the pumps drawing straight from the magma sea would have their own inlet complete with a drawbridge system to cut off flow. The magma here was very felsic, viscous, and wrought with dissolved gasses that posed a serious threat to the machinery, so it would be decompressed in a tower leading to a vent on the surface - another weak point in the design to be covered with a drawbridge when under siege and a serious health hazard should the winds blow the wrong way, which it never seemed to. Eric had a vague recollection of a community game he'd participated in so many years ago; years before he'd awoken at the foot of a mountain, surrounded by nigh-complete strangers. That game took place in the world of Aluonra, or "The Windy World." This was a very windy forest indeed, but it wasn't in The Windy World.
Here, in under a week after embark, he was about to make the first designations that would make or break their future. The mountainhomes had provided a workforce, the earth itself, the body and soul of this monolithic monument to their ingenuity. The pump stacks would rise from the ground at opposite ends of the structure on the East and West sides. They would pour over the walls that would be erected next into a 55x55x50 tile, or 165mx165mx150m, hollow. They outer 33 meters on every side of every level, excluding the three stories nearest the ground, would house various ballistae, marksdwarves, and any new weapons or automations that could be designed. The center of the structure wouldn't be hollowed out until he actually had a plan for it, but for now this fortress would present an enormous tower of death to any invading armies.
Today, he and a dozen of the stoutest dwarves would strike the earth!