On Fri, 19 Aug 2005 14:19:45 +0200, "Alan \(in Brussels\)"
wrote:

Yes and no, because although those are indeed examples of what the OP of the
text meant, what he actually wrote (as he clarified subsequently) referred
to the construction of tunnels *to replace* surface or elevated lines.

The Circle line through Barbican almost fits this description - it was
in open cutting before being rebuilt in tunnel when the Barbican
Centre was built.