2 ms·
look at the underside of an overpass. it's not a flat surface, but has thick ribs; lots of room for airflow even if the blades were 1" from the underside of th
by naikrovek 5y ago
look at the underside of an overpass. it's not a flat surface, but has thick ribs; lots of room for airflow even if the blades were 1" from the underside of the bridge.
- efreak 5y agoI'm in a bus under a freeway overpass as I type this. I pass under here twice a day. The underside is smooth, possibly to keep it easier to clean. I've definitely seen overpasses that are not smooth underneath, but certainly not all overpasses and tunnels have space in the ceiling.