Recliner wrote:

There's also the little matter of London City airport -- high bridges
simply aren't an option anywhere close to its flight path.

I'd like to see a pair of curved swing bridges, forming a circle across the
river. Normally you'd have two lanes northbound on one and two lanes
southbound on the other, but when a boat comes you'd open one and switch the
other to two-way. When the boat is between them you'd shut the open one and
switch the two way traffic to that, and then open the other.

--
We are the Strasbourg. Referendum is futile.

In article , (David A
Stocks) wrote:

I seem to recall Albert Bridge (a structure of similar age to the
oldest of these tunnels) being closed at weekends in the past.

It's closed in the New Year for quite a time, I gather. I now cycle that
way to work when I'm staying in Putney and will be doing so in the morning.

--
Colin Rosenstiel

wrote:
In article , (David A
Stocks) wrote:

I seem to recall Albert Bridge (a structure of similar age to the
oldest of these tunnels) being closed at weekends in the past.

It's closed in the New Year for quite a time, I gather. I now cycle
that way to work when I'm staying in Putney and will be doing so in
the morning.

Good luck cycling tomorrow morning... the roads are an ice-rink. No grit or
salt on the roads!

--
We are the Strasbourg. Referendum is futile.

On Tue, 15 Dec 2009 16:24:23 -0000, "Basil Jet"
wrote:
Recliner wrote:

There's also the little matter of London City airport -- high bridges
simply aren't an option anywhere close to its flight path.

I'd like to see a pair of curved swing bridges, forming a circle across the
river. Normally you'd have two lanes northbound on one and two lanes
southbound on the other, but when a boat comes you'd open one and switch the
other to two-way. When the boat is between them you'd shut the open one and
switch the two way traffic to that, and then open the other.


How often would they need to open to allow vessels to pass?

In article ,
(Basil Jet) wrote:

wrote:
In article , (David
A Stocks) wrote:

I seem to recall Albert Bridge (a structure of similar age to the
oldest of these tunnels) being closed at weekends in the past.

It's closed in the New Year for quite a time, I gather. I now cycle
that way to work when I'm staying in Putney and will be doing so in
the morning.

Good luck cycling tomorrow morning... the roads are an ice-rink. No
grit or salt on the roads!

No problems at all this morning. There was no sign of ice by the time I
left Putney (08:50). The morning queues on Albert Bridge have been bad the
last few times i've been that way. I wonder what it will be like when the
bridge is closed? I took the District Line to Putney last night but there
was no ice in Putney at about 9.

--
Colin Rosenstiel

On Tue, 15 Dec 2009 09:53:41 -0000, Bruce wrote:
Bridges aren't an option for the Blackwall and Rotherhithe tunnel
routes. The bridges would have to offer full navigable clearance so
that tall ships could enter the Pool of London. So they would have to
be as tall as the bridge that forms the southbound Dartford-Thurrock
crossing, with very long approach ramps. There's no land available
for all that.

It all depends how you want your bridge to be used. Most big bridges are
designed for motorway speeds, with shallow gradients to ensure that most
motor vehicles can sustain them. Older bridges had to be possible for
horses to get up pulling carts. In East London, in 2010, neither motorway
speeds nor horses need to be provided for.

It would be quite possible to design a bridge with a gradient of 1 in 5,
which would allow the ramps, even to get up to mast-clearing height, to be
largely or entirely over the river. Traffic would cross at 20 mph or less
- but even at 10mph crossing would only take about a minute.

This would not solve the problem of the London City flightpath, of course.

Colin McKenzie

--
No-one has ever proved that cycle helmets make cycling any safer at the
population level, and anyway cycling is about as safe per mile as walking.
Make an informed choice - visit www.cyclehelmets.org.

On Sat, Dec 19, 2009 at 10:12:28AM -0000, Colin McKenzie wrote:
On Tue, 15 Dec 2009 09:53:41 -0000, Bruce wrote:
Bridges aren't an option for the Blackwall and Rotherhithe tunnel
routes. The bridges would have to offer full navigable clearance so
that tall ships could enter the Pool of London...
It all depends how you want your bridge to be used. Most big bridges are
designed for motorway speeds, with shallow gradients to ensure that most
motor vehicles can sustain them. Older bridges had to be possible for
horses to get up pulling carts. In East London, in 2010, neither motorway
speeds nor horses need to be provided for.

This would not solve the problem of the London City flightpath, of course.

Perhaps that can be solved by asking whether we still need to allow
tall boats into the Pool of London. It's not like there's any actual
working dock there any more that takes large vessels! Yes, HMS Belfast
would have to be moved. But I hardly think that the IWM's convenience
is that important.

--
David Cantrell | Nth greatest programmer in the world

Fashion label: n: a liferaft for personalities
which lack intrinsic buoyancy

David Cantrell wrote on 06 January 2010 13:16:23 ...
On Sat, Dec 19, 2009 at 10:12:28AM -0000, Colin McKenzie wrote:
On Tue, 15 Dec 2009 09:53:41 -0000, Bruce wrote:
Bridges aren't an option for the Blackwall and Rotherhithe tunnel
routes. The bridges would have to offer full navigable clearance so
that tall ships could enter the Pool of London...
It all depends how you want your bridge to be used. Most big bridges are
designed for motorway speeds, with shallow gradients to ensure that most
motor vehicles can sustain them. Older bridges had to be possible for
horses to get up pulling carts. In East London, in 2010, neither motorway
speeds nor horses need to be provided for.

This would not solve the problem of the London City flightpath, of course.

Perhaps that can be solved by asking whether we still need to allow
tall boats into the Pool of London. It's not like there's any actual
working dock there any more that takes large vessels! Yes, HMS Belfast
would have to be moved. But I hardly think that the IWM's convenience
is that important.

It's not just the IWM. Tower Bridge is raised about 1000 times a year
to let tall boats through.

--
Richard J.
(to email me, swap 'uk' and 'yon' in address)

Speaking of tunnels, apparently the Faroes contains 14 tunnels between 760
metres and 6300 metres long, some of which link islands beneath the sea.
More are proposed, to link up all the main villages in the archipelago.
Considering that the Faroes only contain 49000 people, it shines a new light
on the ongoing failure to link east and southeast London.

http://en.wikipedia.org/wiki/List_of..._Faroe_Islands

--
We are the Strasbourg. Referendum is futile.

On Wed, 6 Jan 2010 17:35:00 -0000
"Basil Jet" wrote:
Speaking of tunnels, apparently the Faroes contains 14 tunnels between 760
metres and 6300 metres long, some of which link islands beneath the sea.
More are proposed, to link up all the main villages in the archipelago.
Considering that the Faroes only contain 49000 people, it shines a new light
on the ongoing failure to link east and southeast London.

http://en.wikipedia.org/wiki/List_of..._Faroe_Islands

No doubt all paid for by Denmark.

B2003