In message
Roland Perry wrote:

In message , at 22:50:32 on Fri, 10
Mar 2006, Graeme Wall remarked:
I believe they will be using the two service tunnels each side of the main
road tunnels.

Sorry, yes, it does say that in the article :-(

Are those the tunnels that are currently used by taxis, and have a
"loading gauge" hanging over the entrance?

AFAIK yes those are they. I believe they were originally pedestrian tunnels
when built. There have been various suggestions of what they could be used
for over the years.

Or are the service tunnels in addition to those? The area between the
airport end of the tunnels and T1 is currently somewhat full of roads and
car parks, it will be interesting to see how they weave this pod-track
through it all and up to the terminal building (currently the frontage is
occupied by the car drop-off zone).

I wonder if they are going to try to move the drop-off point out of the
central area? Would certainly help reduce the amount of traffic there.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

In message , at 13:23:03 on Sat, 11 Mar 2006,
Nick Leverton remarked:
It's always a bit sad when a scheme mentions the benefits (fewer buses)
and omits the drawbacks (more taxis in the central bores). Makes you
wonder what else they "forgot" to mention...

Bicycles ? Don't know if they still are, but the taxi tunnels used to
be signposted for cycles too.

Originally, weren't they exclusively for bicycles (and essential
maintenance/emergency use).
--
Roland Perry

In message
Roland Perry wrote:

In message , at 12:01:42 on Sat, 11 Mar
2006, Paul Terry remarked:
Are those the tunnels that are currently used by taxis, and have a
"loading gauge" hanging over the entrance? Or are the service tunnels
in addition to those?

It looks like it. A proposed route is shown on page 3 of ...

http://www.atsltd.co.uk/media/casest...se_studies.pdf

Page 4 shows (somewhat surprisingly) that it is possible to fit four
people-mover tracks inside one service tunnel -

I'm astonished that there's so much room! Must have a better look next
time I'm there. All I remember is the loading gauge and a general
feeling of claustrophobia when approaching even in a car, that made me
choose the main tunnel instead.

although it doesn't explain what will be done with the displaced taxi
traffic!

It's always a bit sad when a scheme mentions the benefits (fewer buses)
and omits the drawbacks (more taxis in the central bores). Makes you
wonder what else they "forgot" to mention...

As I theorised in my other post, looks like they could be looking at drop off
points for taxis outside the CTA.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

On Sat, 11 Mar 2006, Roland Perry wrote:

It's always a bit sad when a scheme mentions the benefits (fewer
buses) and omits the drawbacks (more taxis in the central bores).
Makes you wonder what else they "forgot" to mention...

The fact that the side tunnels are the only cycle route?

In message c.uk, at
14:02:18 on Sat, 11 Mar 2006, Alan J. Flavell
remarked:
It's always a bit sad when a scheme mentions the benefits (fewer
buses) and omits the drawbacks (more taxis in the central bores).
Makes you wonder what else they "forgot" to mention...

The fact that the side tunnels are the only cycle route?

Maybe you'll have to cycle to the car park and get a free "Pod". (I
assume they are free, it talks about a journey costing 80p, which hardly
seems worth collecting).
--
Roland Perry

In message , Roland Perry
writes

I'm astonished that there's so much room! Must have a better look next
time I'm there. All I remember is the loading gauge and a general
feeling of claustrophobia when approaching even in a car, that made me
choose the main tunnel instead.

I think the part that is currently used is only the upper deck shown in
the ATS cross-section (2642mm high) - IIRC it is a couple of metres
above the main roadway, as shown.

It looks as though they are intending to put the bottom pair of tracks
on the lower deck, which was originally the pedestrian route through
from the Bath Road when the tunnel opened in 1955.

--
Paul Terry

On Sat, 11 Mar 2006, Roland Perry wrote:

Originally, weren't they exclusively for bicycles (and essential
maintenance/emergency use).

I don't know about "originally", but, quite some years back, as I
recall, they weren't well signposted (possibly as a deliberate
policy), and the route to them was a bit of a dog-leg, but some of the
drivers who took us from Rutherford Lab to LHR would know the way, and
would use the side tunnel when the traffic in the main tunnel looked
heavy. It appeared to me that any car driver who could find the way
there was free to use them (provided they gave way to cyclists...).

More recently they did seem to be better signposted, and quite busy.

The picture in the cited PDF file suggests that there's a double-deck
side tunnel. If that's so, then it comes as a surprise to me, I have
to admit.

Paul Terry wrote:

In message , Roland Perry
writes

I'm astonished that there's so much room! Must have a better look next
time I'm there. All I remember is the loading gauge and a general
feeling of claustrophobia when approaching even in a car, that made me
choose the main tunnel instead.

I think the part that is currently used is only the upper deck shown in
the ATS cross-section (2642mm high) - IIRC it is a couple of metres
above the main roadway, as shown.

It looks as though they are intending to put the bottom pair of tracks
on the lower deck, which was originally the pedestrian route through
from the Bath Road when the tunnel opened in 1955.


As a regular visitor to Heathrow (eight times in the past month) I
wonder what assessments have been made of the additional road
congestion that will be caused by closing the "taxi tunnels" to cars.

It is some time since the taxi tunnels were used only for taxis (and
cycles) because the road layouts were changed a few years ago to allow
them to be used by cars. There are now three lanes into the Central
Area for cars and three lanes out. This proposal will reduce that to
two because the taxi tunnels will be used for ATS vehicles.

If ATS results in a reduction of road traffic through the tunnel
system that is greater than the capacity lost by closing the taxi
tunnels to cars, all will be well. But I cannot see that happening,
and there will be horrendous problems while ATS is constructed.

I must admit a personal interest, in that the taxi tunnels form part
of my alternative routes in and out of Heathrow that miss most of the
congestion most of the time.

On Sat, 11 Mar 2006 12:01:42 +0000, Paul Terry
wrote:

In message , Roland Perry
writes

Are those the tunnels that are currently used by taxis, and have a
"loading gauge" hanging over the entrance? Or are the service tunnels
in addition to those?

It looks like it. A proposed route is shown on page 3 of ...

http://www.atsltd.co.uk/media/casest...se_studies.pdf

Page 4 shows (somewhat surprisingly) that it is possible to fit four
people-mover tracks inside one service tunnel - although it doesn't
explain what will be done with the displaced taxi traffic! I wonder if
there might be room to retain a taxi-way below the upper pair of tracks?

The maps on pages 59-62 of the Heathrow Masterplan (big download) ...

http://www.heathrowairport.com/asset...MasterPlan.pdf

show more extended systems, with different routes, to take account of
the third runway proposal.

IIRC, the top of the 'Service Tunnels' - currently used by taxis and
no longer available to cyclists or pedestrians - is at the same level
as that of the main tunnel. The floor level however, is somewhat
higher than that of the the road tunnels. Some excavation will be
required.
Regards
JonH

wrote:

IIRC, the top of the 'Service Tunnels' - currently used by taxis and
no longer available to cyclists or pedestrians - is at the same level
as that of the main tunnel. The floor level however, is somewhat
higher than that of the the road tunnels. Some excavation will be
required.


If you looked at the .pdf document (the URL was in the section of text
you quoted in your post) all would become clear.

The former taxi tunnels, which are no longer limited to taxis and are
freely available for cars, are in the upper half of a two cell
structure. The lower cell is not currently in use.

The proposed new transit system would use both the upper and lower
halves.

As I said, it is all in the .pdf document. All you need to do is
click on the link, which you included in your post:

http://www.atsltd.co.uk/media/casest...se_studies.pdf

Look at the diagram on Page 4.