In message
-sept
ember.org, at 09:32:59 on Sun, 26 Mar 2017, Recliner
remarked:
Roland Perry wrote:
In message
-sept
ember.org, at 08:56:48 on Sun, 26 Mar 2017, Recliner
remarked:

One limiting factor on tunnel size is that they have to bear the weight of
575 tonne A380s a few metres above.

You've not seen the highway tunnels with their portals only metres away
from the runways at Schiphol? https://goo.gl/maps/K5NbbmjqqL42

Seen and travelled through them.

Good. You'll therefore note that much wider and much shallower tunnels
don't collapse under the weight of huge planes.

Yes, I do have engineering degrees,

You don't need an engineering degree to see there isn't a Jumbo jet in a
big hole over the tunnel!

and am familiar with the concept of
load-bearing beams. But the greater the span, the deeper the beams.

Incidentally, CDG also has public vehicle and passenger tunnels under
taxiways.

So does AMS also have those. The one above is under a runway.

And Heathrow has a lot more vehicle and rail tunnels than the
public ones from the M4 and A4 to the central area.

It does, but this subthread is only about the people mover.
--
Roland Perry