On Sun, 25 Jan 2009, James Farrar wrote:

The Sunday Times reports
(http://www.timesonline.co.uk/tol/new...e5581066.ece):

BORIS JOHNSON, the London mayor, has unveiled detailed proposals for a
£40 billion airport spanning the Thames estuary in a move aimed at
presenting a credible alternative to the government’s plans for expanding
Heathrow.

So where are these detailed proposals, then? Oh, hang on - according to:

http://www.london.gov.uk/view_press_...eleaseid=20639

"Doug Oakervees report is expected to be completed around the end of
March."

So maybe the Times has jumped the gun on the detail. Still, the good news
is that we thus have free rein to come up with whatever mad schemes we
like to fill in the blanks. Hurrah!

The bold scheme entails splitting the airport in two, with runways
placed on two separate islands in the mouth of the Thames.

Passengers would shuttle between the islands in a tunnel below the river
bed, running from Essex on the north bank, to Kent on the south.

Based on what the article says about Southend and Sheerness being the
closest towns, i'd guess that the islands would be built on either side of
the Medway channel, at about 45-50 minutes east of the meridian.

I've prepared this small map of buoyage in the estuary, showing the
Yantlet and Medway channels:

http://maps.google.co.uk/maps?q=http... es_Buoys.kml

The islands would have to be clear of those, so perhaps one off the tip of
Grain, and one off Sheernes/Minster.

Douglas Oakervee, who masterminded the engineering of Hong Kong’s
international island airport in the 1990s, said that splitting the
airport in two would reduce disruption to local wildlife. It would also
enable the airport to connect to high-speed rail routes to the
Continent.

I don't see how splitting the island is a prerequisite for the latter. Not
that i'm complaining - more smaller islands means more coastline, which i
hope will be constructed as ecologically vital saltmarsh.

Underwater turbines, built into ducts running through the body of the
islands, would generate nearly all the airport’s electricity needs by
harnessing the tide .

Nice.

Speaking to The Sunday Times aboard a dredger, Johnson

Not something you read very often!

The two estuary terminals would be served by road and rail links. The
larger terminal, in Kent, would be connected to Crossrail and the high-
speed Channel tunnel rail link, whisking passengers to central London in
about 35 minutes. The rail connections to Europe would cut out the need
for many short-haul flights.

Given the position i hypothesise above, i assume the link would be to
Grain, and then along the route of the existing freight branch from there
to Hoo junction. I don't know what the plan is from there - carry on along
the North Kent line, to Northfleet/Ebbsfleet? New tracks long that
alignment? A new tunnel? Would Crossrail trains run through to the
airport? How would this route help get people to the Continent? Would
there be a new alignment (what i insist be called the Thong chord) across
the countryside to a junction and/or station near M2 junction 1, on the
edge of Rochester?

And what happens on the Essex side? A connection to one of the existing
Southend stations? Somehow connecting to Stansted - two sides of a
triangle via Stratford, or some new line running along the M25/M11 to join
the existing line at Harlow?

tom

--
In the long run, we are all dead. -- John Maynard Keynes