In message , at 16:20:48 on Sun, 17 Nov
2019, Recliner remarked:
Based on a 2015 FOI request, the following platforms are at least 15
metres below sea level (numbers are metres above LU datum, which is
exactly 100 metres below the OS datum at Newlyn):
*Above* the LU datum? Why did they choose something so deep as a base point?

So that all the numbers are positive. They could have used 50 or 30
metres, but this way they're unlikely to ever need to change it.

Similarly the Eurotunnel zero point is around the 63 milepost west of
Westenhangar, rather than at the concession boundary.

74.0 Waterloo (Jubilee)
84.4 Bank (Northern)

Looks like the actual deepest railway platform in London is a toss up between
jubilee waterloo and Bank DLR which is way beneath the northern line platforms.
Anyone know how deep the DLR is?

74.20 metres LU datum.

It's interesting that the next station from the more-or-less the deepest
station is on a viaduct (Shadwell). It's quite a climb.

Yes, it's almost as good as a ride at a theme park (if you get a front
seat).
--
Roland Perry