Sh*r*d use bridge.

[Tom Crispin]

5Mb PDF download
www.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf

[Martin Dann]

Tom Crispin wrote:
> 5Mb PDF download
> www.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf

"
Pedestrians and cyclists alike need to rise approximately ten metres
from the level of the river bank to the
end of the opening span of the bridge; a large distance for a pedestrian
bridge, equivalent to three flights of
stairs or 200 metres of ramp, rising at 1 in 20. This is not a problem
for cyclists, and will in fact increase their
enjoyment and delight in using the bridge.
"

So making cyclists cycle up a 200m ramp will increase our enjoyment.

The question is, will we be able to pedal down the other side, without
any needless braking, and without any junctions at the bottom that we
will need to slow for after claiming back all that P.E. that we have
worked for.
Or will the silly spiral just mean that we have to brake all the way down?

Martin.

[vernon[_2_]]

"Tom Crispin" > wrote in message
...
> 5Mb PDF download
> www.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf

and your opinion of it is....?

[Tom Crispin]

On Fri, 25 Apr 2008 06:47:19 +0100, "vernon"
> wrote:

>
>"Tom Crispin" > wrote in message
...
>> 5Mb PDF download
>> www.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf
>
>and your opinion of it is....?

Fantastic.

The Rotherhithe Tunnel is very uncomfortable to cycle through. Tower
Bridge is 20 minutes upstream. Cycling in the Greenwich Foot Tunnel
is prohibited, the lifts are only open 7am - 7pm and the lifts are
frequently closed. The Woolwich Ferry is 40 minutes downstream, and,
again, has limited opening hours and is frequently closed. The wait
for a Crossing Patrol lift over the Queen Elizabeth II bridge or
through the Dartford Tunnel can be up to one hour and is a good 2
hours downstream following the Thames Path, though faster along the
A2.

I would prefer a cycle tunnel parallel to the Greenwich Foot Tunnel as
it is more local to me, the Greenwich foot tunnel is 15.2 m below mean
high water, so a 1:20 ramp to take cyclists to that level suggests a
ramp about a quarter of a mile long. The Durand's Wharf to Impounding
Lock location for a bridge makes a great deal of sense and would take
a lot of sustainable traffic over the River.

The downside is the need for the bridge to close for up to 2 hours
about 30 times per years. This length and frequency of closure would
be unacceptable for a road or rail tunnel - though the trade off is
that cycling over a bridge is far more enjoyable then through a
tunnel, and a bridge height of 45 metres (which would allow large
ships to pass safely without opening) suggests a ramp length of over
half a mile each end. When closed, the Rotherhithe Tunnel is a local
alternative. The proposed deck width of 9m seems unusually generous
for a shared use path, with the cycle ramps leading to the main deck
being 3 - 4m wide.

[Colin McKenzie]

Tom Crispin wrote:
> The downside is the need for the bridge to close for up to 2 hours
> about 30 times per years. This length and frequency of closure would
> be unacceptable for a road or rail tunnel

Is this in addition to closures to let ships through? Tower Bridge
seems to close a few times a day for about 15 minutes at a time.

The new bridge, further downstream, would be passed by more ships -
but it sounds as if the deck is a bit higher. So I'd expect it to have
to open about as much.

I agree that the ability to go fast down from the bridge would make it
much more attractive. Maybe uphill cyclists and pedestrians should be
segregated from downhill cyclists.

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.

[[email protected]]

On Apr 24, 10:23 pm, Tom Crispin
> wrote:
> 5Mb PDF downloadwww.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf

Having a quick skim though I noticed a picture of the Gateshead
Millennium bridge.

I've never cycled across it but I've walked across it lots of times.
The surface of the cycling deck appears to be metal but also appears
to be non-slippery, even when wet.

Does anyone know any more details about this surface and can it be
used on manhole covers or does it need to rely on rain being able to
drain through and into the river?

Tim.

[Tom Crispin]

On Fri, 25 Apr 2008 08:03:34 +0100, Colin McKenzie
> wrote:

>Tom Crispin wrote:
>> The downside is the need for the bridge to close for up to 2 hours
>> about 30 times per years. This length and frequency of closure would
>> be unacceptable for a road or rail tunnel
>
>Is this in addition to closures to let ships through? Tower Bridge
>seems to close a few times a day for about 15 minutes at a time.

No.

>The new bridge, further downstream, would be passed by more ships -
>but it sounds as if the deck is a bit higher. So I'd expect it to have
>to open about as much.
>
>I agree that the ability to go fast down from the bridge would make it
>much more attractive. Maybe uphill cyclists and pedestrians should be
>segregated from downhill cyclists.

Pedestrians and, I expect, wheelcahir and push chair users, have an
alternative route - using a lift This would be the main ramp for
pedestrians. 3 - 4m seems sufficiently wide for uphill and downhill
cyclists to pass, though at 75cm each, overtaking downhillers passing
overtaking uphillers would be very tight.

[Nick[_4_]]

Tom Crispin wrote:
> On Fri, 25 Apr 2008 06:47:19 +0100, "vernon"
> > wrote:
>
>> "Tom Crispin" > wrote in message
>> ...
>>> 5Mb PDF download
>>> www.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf
>> and your opinion of it is....?
>
> Fantastic.
>
> The Rotherhithe Tunnel is very uncomfortable to cycle through. Tower
> Bridge is 20 minutes upstream.

5 minutes. Maybe 10.



> Cycling in the Greenwich Foot Tunnel
> is prohibited, the lifts are only open 7am - 7pm and the lifts are
> frequently closed.

The stairs aren't that bad. Running up the stairs carrying a bike is
still easier than cycling up the hill by Greenwich park.


> The Woolwich Ferry is 40 minutes downstream, and,
> again, has limited opening hours and is frequently closed. The wait
> for a Crossing Patrol lift over the Queen Elizabeth II bridge or
> through the Dartford Tunnel can be up to one hour and is a good 2
> hours downstream following the Thames Path, though faster along the
> A2.
>
> I would prefer a cycle tunnel parallel to the Greenwich Foot Tunnel as
> it is more local to me, the Greenwich foot tunnel is 15.2 m below mean
> high water, so a 1:20 ramp to take cyclists to that level suggests a
> ramp about a quarter of a mile long. The Durand's Wharf to Impounding
> Lock location for a bridge makes a great deal of sense and would take
> a lot of sustainable traffic over the River.
>

It would only be worthwile for cyclists living locally or coming from
the west. Even then I think it might be quicker to go over Tower Bridge.

> The downside is the need for the bridge to close for up to 2 hours
> about 30 times per years. This length and frequency of closure would
> be unacceptable for a road or rail tunnel - though the trade off is
> that cycling over a bridge is far more enjoyable then through a
> tunnel, and a bridge height of 45 metres (which would allow large
> ships to pass safely without opening) suggests a ramp length of over
> half a mile each end. When closed, the Rotherhithe Tunnel is a local
> alternative. The proposed deck width of 9m seems unusually generous
> for a shared use path, with the cycle ramps leading to the main deck
> being 3 - 4m wide.

[Nick[_4_]]

Colin McKenzie wrote:
> Tom Crispin wrote:
>> The downside is the need for the bridge to close for up to 2 hours
>> about 30 times per years. This length and frequency of closure would
>> be unacceptable for a road or rail tunnel
>
> Is this in addition to closures to let ships through? Tower Bridge seems
> to close a few times a day for about 15 minutes at a time.
>

The great thing about Tower Bridge closures is the race when it opens.
50-100 cyclists, there are always a few going your way home willing to play.

> The new bridge, further downstream, would be passed by more ships - but
> it sounds as if the deck is a bit higher. So I'd expect it to have to
> open about as much.
>
> I agree that the ability to go fast down from the bridge would make it
> much more attractive. Maybe uphill cyclists and pedestrians should be
> segregated from downhill cyclists.
>
> Colin McKenzie
>

[Ian Jackson]

In article >,
Tom Crispin > wrote:
>5Mb PDF download
>www.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf

I don't see any analysis of the suitability of the spirals for
descending cyclists. There needs to be estimates of the speed at
which a cyclist would prefer to travel down a 1:20 400m slope and what
the minimum curve radius and width for that speed ought to be.

This plus an estimate of the total journey time across the bridge, as
part of a comparision of this new bridge vs. other routes.

Sustrans's consultants thinking that cyclists like going up and down
hills (pdf page 17, RHS, 2nd para) is only to be expected (given how
useless Sustrans are in general).

--
Ian Jackson personal email: >
These opinions are my own. http://www.chiark.greenend.org.uk/~ijackson/
PGP2 key 1024R/0x23f5addb, fingerprint 5906F687 BD03ACAD 0D8E602E FCF37657

[Paul Boyd]

Colin McKenzie said the following on 25/04/2008 08:03:

> Is this in addition to closures to let ships through? Tower Bridge seems
> to close a few times a day for about 15 minutes at a time.

Shouldn't that be "Tower Bridge seems to open a few times a day..."? :-)

--
Paul Boyd
http://www.paul-boyd.co.uk/

[Ian Jackson]

In article >,
Ian Jackson > wrote:
>In article >,
>Tom Crispin > wrote:
>>5Mb PDF download
>>www.sustrans.org.uk/webfiles/london/Thames_Bridge_Feasibility_2.pdf
>
>I don't see any analysis of the suitability of the spirals [...]

Reading it more carefully I've become more convinced that the
consultants who wrote that report were muppets. An obvious big source
of inconvenience and trouble to bridge users is the high deck, 10m
above ground level. The engineering proposals, and the analysis, are
very poor from this point of view: they fail to treat this question as
a major consideration when making the tradeoffs necessary in any
engineering design.

The analysis where the required clearance (when the bridge is
closed[1]) is determined is on pdf pages 6 and 19 and is very scanty.
They compare with Tower Bridge which they say opens[1] 1000 times a
year, and apparently assume without justification that this is too
often for the proposed new bridge; they assume without a clear
justification that the height of the Royal Victoria Dock Bridge is
more appropriate.

Having observed that this initial assumed height causes problems for
bridge users, the designers ought to have reconsidered that initial
choice.

If instead the bridge were built with a lower closed position, say
8.6m air clearance like Tower Bridge rather than the 15m they assume,
the need for bridge users to climb and descend would be practically
eliminated. I think most bridge users would prefer this approach even
if it meant several openings a day, particularly as it would be quite
feasible to require boats to give a reasonable notice so that ground
travellers who care can have warning that when the bridge is going to
be open and adjust their plans accordingly.

Also, even something as simple as the structural engineering of the
span appears not to have considered the need to keep the bridge deck
low. It's a simple triangular truss below the deck, which uses a
considerable degree of vertical space - which corresponds to extra
vertical distance that the bridge users have to climb. No effort
appears to have been made to choose a structural design which avoids
or minimises the below-deck structure.

The various figures in the report are not very accurate or consistent
- for example the spiral ramps vary from 250m (pdf page 22 RHS) to
200m (pdf page 17 RHS), and the height above the river from 15m (pdf
page 6 RHS) to 12m (pdf page 22 RHS; I think this latter is a mistake
and actually represents height above the bank and not above the mean
water level - so it looks like a more detailed calculation was carried
out here but the results not fed back to the rest of the report).

Sustrans should ask for their money back.

[1] Throughout I use `open' to mean the position of a bridge where it
is raised or moved aside and thus does not connect the banks for
ground traffic and `closed' to mean the position where it is lowered,
or deployed, or whatever, and does. That is, the `road' across the
bridge is closed when the bridge is open; the bridge opens for the
passage of boats and closes for pedestriand and cyclists. I think
this terminology is conventional for bridges.
--
Ian Jackson personal email: >
These opinions are my own. http://www.chiark.greenend.org.uk/~ijackson/
PGP2 key 1024R/0x23f5addb, fingerprint 5906F687 BD03ACAD 0D8E602E FCF37657

[David Hansen]

On 25 Apr 2008 15:42:38 +0100 (BST) someone who may be Ian Jackson
> wrote this:-

>Reading it more carefully I've become more convinced that the
>consultants who wrote that report were muppets.

I hope you have fed this back to Sustrans.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

[[email protected]]

On 25 Apr, 09:28, Nick > wrote:
> Tom Crispin wrote:

> >> and your opinion of it is....?
>
> > Fantastic.
>
> > The Rotherhithe Tunnel is very uncomfortable to cycle through. Tower
> > Bridge is 20 minutes upstream.
>
> 5 minutes. Maybe 10.

10 I'd say. The tunnel isn't that bad if you ride on the pavement -
it's
about the only place where, in the interests of avoiding conflict, I
do
that for any sustained period.

> > Cycling in the Greenwich Foot Tunnel
> > is prohibited, the lifts are only open 7am - 7pm and the lifts are
> > frequently closed.
>
> The stairs aren't that bad. Running up the stairs carrying a bike is
> still easier than cycling up the hill by Greenwich park.

True, if your bike is unloaded. It becomes grim if you have panniers.

John

[Ian Jackson]

In article >,
David Hansen <> wrote:
>On 25 Apr 2008 15:42:38 +0100 (BST) someone who may be Ian Jackson
> wrote this:-
>>Reading it more carefully I've become more convinced that the
>>consultants who wrote that report were muppets.
>
>I hope you have fed this back to Sustrans.

No, I don't have any respect for Sustrans.

If there is someone who does have such respect or thinks at the very
least that they might be susceptible to constructive critical input,
they're welcome to pass it on to. Feel free to CC me, give them my
email address, etc., or to hack my text about (provided you then take
my name off it).

--
Ian Jackson personal email: >
These opinions are my own. http://www.chiark.greenend.org.uk/~ijackson/
PGP2 key 1024R/0x23f5addb, fingerprint 5906F687 BD03ACAD 0D8E602E FCF37657

[David Hansen]

On 25 Apr 2008 16:33:59 +0100 (BST) someone who may be Ian Jackson
> wrote this:-

>>I hope you have fed this back to Sustrans.
>
>No, I don't have any respect for Sustrans.

Your personal opinions are not particularly important. I have
recently sent feedback two three organisations that I have no
respect for. In the future, when I expect them to claim that nobody
criticised their plans, I will be able to point out that their
assertion is incorrect.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

[Danny Colyer]

On 25/04/2008 19:48, David Hansen wrote:
> Your personal opinions are not particularly important. I have
> recently sent feedback two three organisations that I have no
> respect for.

You make me think of Burt giving feedback to S Glos.

> In the future, when I expect them to claim that nobody
> criticised their plans, I will be able to point out that their
> assertion is incorrect.

Yup, he seems to do that a lot.

--
Danny Colyer <http://www.redpedals.co.uk>
Reply address is valid, but that on my website is checked more often
"The plural of anecdote is not data" - Frank Kotsonis

[Colin McKenzie]

Ian Jackson wrote:
> In article >,
> David Hansen <> wrote:
>>I hope you have fed this back to Sustrans.
>
> No, I don't have any respect for Sustrans.
>
> If there is someone who does have such respect or thinks at the very
> least that they might be susceptible to constructive critical input,
> they're welcome to pass it on to. Feel free to CC me, give them my
> email address, etc., or to hack my text about (provided you then take
> my name off it).

I suggest Roger Stocker, cycling officer at Southwark council.

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.

[Tom Crispin]

On Fri, 25 Apr 2008 20:35:32 +0100, Colin McKenzie
> wrote:

>Ian Jackson wrote:
>> In article >,
>> David Hansen <> wrote:
>>>I hope you have fed this back to Sustrans.
>>
>> No, I don't have any respect for Sustrans.
>>
>> If there is someone who does have such respect or thinks at the very
>> least that they might be susceptible to constructive critical input,
>> they're welcome to pass it on to. Feel free to CC me, give them my
>> email address, etc., or to hack my text about (provided you then take
>> my name off it).
>
>I suggest Roger Stocker, cycling officer at Southwark council.

Is he? He's also chair of Lewisham Cyclists.

[Tim Hall]

On Fri, 25 Apr 2008 08:30:54 -0700 (PDT), wrote:

>On 25 Apr, 09:28, Nick > wrote:
>> Tom Crispin wrote:
>

>
>> > Cycling in the Greenwich Foot Tunnel
>> > is prohibited, the lifts are only open 7am - 7pm and the lifts are
>> > frequently closed.
>>
>> The stairs aren't that bad. Running up the stairs carrying a bike is
>> still easier than cycling up the hill by Greenwich park.
>
>True, if your bike is unloaded. It becomes grim if you have panniers.
>
Or if it's a tandem.



--

Tim

I understand very little of what's being discussed
but for some reason it's fascinating.

(Jon Thompson, urs)

[Tom Crispin]

On Fri, 25 Apr 2008 08:30:54 -0700 (PDT), wrote:

>True, if your bike is unloaded. It becomes grim if you have panniers.

Plans are at an advanced stage to have 'rails' fitted so that bikes
can be rolled up and down the stairs. I'm not quite sure what the
protocol will be when an unhill pusher meets a downhill pusher. The
design of the rails, I am told, is quite complex because at every 12
steps there is a landing.

[Clive George]

"Tim Hall" > wrote in message
...
> On Fri, 25 Apr 2008 08:30:54 -0700 (PDT), wrote:
>
>>On 25 Apr, 09:28, Nick > wrote:
>>> Tom Crispin wrote:
>>
>
>>
>>> > Cycling in the Greenwich Foot Tunnel
>>> > is prohibited, the lifts are only open 7am - 7pm and the lifts are
>>> > frequently closed.
>>>
>>> The stairs aren't that bad. Running up the stairs carrying a bike is
>>> still easier than cycling up the hill by Greenwich park.
>>
>>True, if your bike is unloaded. It becomes grim if you have panniers.
>>
> Or if it's a tandem.

Whereas escalators are great - stairs are fine on foot, but escalators make
getting a bike, even laden, up and down really easy. Contrary to the
opinions of the security people in Las Vegas airport. "but I just bought it
up there" - and they're not actually listed in the banned items (nor are
bikes). Fortunately the people in Liverpool are rather more sensible, coz at
least there's decent sized lifts at the airport. And Liverpool trains still
take tandems, hoorah - though catching the eye of the guard is probably a
poor thing to do - get on at the other end.

cheers,
clive

[Rob Morley]

In article >, Tom Crispin
says...
> On Fri, 25 Apr 2008 08:30:54 -0700 (PDT), wrote:
>
> >True, if your bike is unloaded. It becomes grim if you have panniers.
>
> Plans are at an advanced stage to have 'rails' fitted so that bikes
> can be rolled up and down the stairs. I'm not quite sure what the
> protocol will be when an unhill pusher meets a downhill pusher.

This will never happen, because you don't push downhill. :-)

[Nick[_4_]]

Tom Crispin wrote:
> On Fri, 25 Apr 2008 08:30:54 -0700 (PDT), wrote:
>
>> True, if your bike is unloaded. It becomes grim if you have panniers.
>
> Plans are at an advanced stage to have 'rails' fitted so that bikes
> can be rolled up and down the stairs. I'm not quite sure what the
> protocol will be when an unhill pusher meets a downhill pusher. The
> design of the rails, I am told, is quite complex because at every 12
> steps there is a landing.

I'll believe that when I see it. Pushing a bike sounds dangerous.

Why not just make the lifts user operated.

[Nick[_4_]]

wrote:
in the Greenwich Foot Tunnel

>> The stairs aren't that bad. Running up the stairs carrying a bike is
>> still easier than cycling up the hill by Greenwich park.
>
> True, if your bike is unloaded. It becomes grim if you have panniers.
>
I knew there had to be a reason I always use a ruck sack.

[_[_2_]]

On Sat, 26 Apr 2008 10:05:43 +0100, Nick wrote:

> Tom Crispin wrote:
>> On Fri, 25 Apr 2008 08:30:54 -0700 (PDT), wrote:
>>
>>> True, if your bike is unloaded. It becomes grim if you have panniers.
>>
>> Plans are at an advanced stage to have 'rails' fitted so that bikes
>> can be rolled up and down the stairs. I'm not quite sure what the
>> protocol will be when an unhill pusher meets a downhill pusher. The
>> design of the rails, I am told, is quite complex because at every 12
>> steps there is a landing.
>
> I'll believe that when I see it. Pushing a bike sounds dangerous.
>

If they are like those in the Netherlands, they work quite well.

[Paul Boyd]

Nick said the following on 26/04/2008 10:05:

> I'll believe that when I see it. Pushing a bike sounds dangerous.

There used to be something like that on the bridge at the end of Five
Mile Lane a few miles east of Lincoln. It worked quite well. The whole
bridge works even better now that it's been completely rebuilt!

--
Paul Boyd
http://www.paul-boyd.co.uk/

[[email protected]]

On 26 Apr, 10:07, Nick > wrote:
> wrote:
>
> in the Greenwich Foot Tunnel
>
> >> The stairs aren't that bad. Running up the stairs carrying a bike is
> >> still easier than cycling up the hill by Greenwich park.
>
> > True, if your bike is unloaded. It becomes grim if you have panniers.
>
> I knew there had to be a reason I always use a ruck sack.

That rather depends what you're carrying. With me it's often two full
panniers and a toolbag (or alternatively four panniers) - don't fancy
that
lot on my back.

John

[[email protected]]

On 26 Apr, 10:05, Nick > wrote:

> Why not just make the lifts user operated.

That would address the issue of staff shortage leading to unplanned
closures, but do nothing about the lifts' unreliability. South lift
closed
again at 5ish this evening - inevitably, I was going North-South,
so got the lift down but had the length of the tunnel to resign myself
to carrying bike and bags up.

It's a funny business how the original lifts can last until the early
'90s
from installation at the turn of the century, but their replacements
are
already tired. Guess they don't make 'em like they used to ...

John

[Tom Crispin]

On Sat, 26 Apr 2008 14:16:07 -0700 (PDT), wrote:

>On 26 Apr, 10:05, Nick > wrote:
>
>> Why not just make the lifts user operated.
>
>That would address the issue of staff shortage leading to unplanned
>closures, but do nothing about the lifts' unreliability. South lift
>closed
>again at 5ish this evening - inevitably, I was going North-South,
>so got the lift down but had the length of the tunnel to resign myself
>to carrying bike and bags up.

The North lift at the Woolwich Foot Tunnel is on long term closure.

>It's a funny business how the original lifts can last until the early
>'90s
>from installation at the turn of the century, but their replacements
>are
>already tired. Guess they don't make 'em like they used to ...