On Sat, 10 Nov 2007 11:28:43 GMT, wrote:

On another note, what is the deal for a prospective tunnel connection to
Ireland? I seem to recall talk about this in times past but, because the
earth between the two islands is largely sand, it is quite difficult to
build any sort of subterranean structure there.

A tunnel from Holyhead to Dublin would be nearly twice the length of
the channel tunnel, though proposals do get raised every now and then.
The shortest Irish Sea crossing, and so the easiest place to build a
tunnel is between Scotland and Northern Ireland (eg Stranrear-Larne).
even with trains running at TGV speed on both sides of the Irish Sea
this would be a long enough way round for many journeys, including
London-Dublin, for rail to remain uncompetitive with air.

Somewhere I also remember reading that the Irish Sea is much deeper
than the English Channel, which makes tunnelling more difficult than
the tunnel length would suggest, but I haven't been able to verify
that

Martin