> Really curious how a door like this opens. If it's just a standard blast door, captured hinges with grease. You just pull it open, and a cam pulls it closed

> Really curious how a door like this opens. If it's just a standard blast door, captured hinges with grease. You just pull it open, and a cam pulls it closed tight. If it's a sliding door, you can use bearings, cams and screw gears. For very large doors that swing open they'll still use captured hinges, with hydraulics to actuate it, but humans can still close it themselves. > And curious about the purpose/logistics of a 320,000 gallon water tank. The same purpose as towns that have water tanks. You'll still pump water into the tank slowly, but you need a much smaller pump capacity to slowly fill it. And it's way more efficient to distribute the water using the force of gravity; it would be very difficult to distribute lots of water at the speed needed to maintain adequate water pressure. The tank's excess capacity allows you to service peak usage easily, and operates in the absence of electricity. Work smarter, not harder.