Flat Earth Inquiry: Did the Eurotunnel forget about the Curve?

Good grief. What a pointless video.

For one thing: for a 23 mile tunnel, the linear curvature (at 8 inches per mile) is just over 15 feet, for the whole length. That’s about 7 and a half feet for halfway.

And linear curvature is the only kind you need to worry about here. Not side to side. Not the curvature of a sphere.

And the tunnel follows the rock layer. The video-maker doesn’t even know the details of slope and distance from sea level.