"derek" wrote in message
...
On Tue, 4 Nov 2003 18:42:40 -0000, "iantheengineer"
wrote:


Not everything works on the same principles are you so stupid??? Water
flows
under gravity does that mean rock will too???

Certainly does as anyone who has studied civil engineering *ought*
*to* *know*. ;-)


There are some examples in Professor James Edward Gordon's books, (The
New Science of Strong Materials or Why You Don't Fall Through the
Floor, "Structures" was another one ), and there plenty for all to see
around here where stone walls have deflected in areas of mining
subsidence, The stones have bent over 50-100 years where the ground
has subsided beneath them. There are also many examples in the
medieval cathedrals you just need to look out for them.

According to Steve yes, so
when we build culverts for rocks we need to design them the same as for
water??!???

You don't need to rush!

DG

As an engineer I do know that many fundamental principles can be applied to
many different materials, however what isnt being accepted is that different
problems require different solutions and the same principles do not apply to
all things, Steve seems to think that all problems can be solved through
increasing capacity, which they can be solved, but at what expense???,
however he is not considering the problem from all aspects to increase
conveyance is only one way of solving the problem. I am by original training
a drainage engineer and for many years (before my time) the only solutions
to drainage problems were to increase the conveyance or capacity of the
system. This has resulted (along with different rainfall patterns) in the
floods that we experienced in 1998 and 2000. Engineers now look at this
problem more holistically looking at the source of the rainfall and how it
runs off the ground, in an attempt to attenuate the flow to more greenfield
states.

We cant as yet at least prevent rainfall falling at high intensity during
the summer months and for long durations during the winter months, but we
can slow its journey to the river system and reduce the peak flows in the
river.

Unlike rainfall we have another alternative with traffic we can restrain the
source if we choose, which along with the other tools including where
necessary road building will help the road system cope with the traffic.

As for your example of stones deflecting well thats a new one on me.
Subsidence is due to the mines or other underground tunnel etc gradually
collapsing and what normally happens is failure of the foudation leaving a
crack visible in the supported wall either through the blocks or the mortar
joints whichever is the weakest. Stone and concrete are strong in
compression but weak in tension so as you get a force acting on one side
causing compression in one face through bending, you get tensiile forces on
the other face which normally resulst in cracking and subsequent failure. I
daresay that stone will deflect to a degree but this would be unmeasurable
to the naked eye.

On Fri, 07 Nov 2003 22:23:48 +0000, iantheengineer wrote:

It doesnt need to for most of the commute

Ahh, so the bus splits into 72 parts at each end?

"iantheengineer" wrote in message
...

I am by original training
a drainage engineer and for many years (before my time) the only solutions
to drainage problems were to increase the conveyance or capacity of the
system.

In that case you ought to be able to recognise that de-bottlenecking is a
vital part of traffic management, whereas the tendency has been to provide
constrictions, leading to excessive congestion.
--
Terry Harper
http://www.terry.harper.btinternet.co.uk/

"iantheengineer" wrote in message
...

"Nick Finnigan" wrote in message
...
"iantheengineer" wrote in message
...

"Nick Finnigan" wrote in message
...
"iantheengineer" wrote in message
...

To continue to build roads will continue the problem. The answer is
puvblic
transport, but public transport cannot cater for all journeys and
therefore
over time journeys will need to become more corridored. For example
go
into
any city during the am peak and the tidality of the flow is there to
be
seen. IF we were to get all of the people from their cars onto
public
transport, or even better living nearer to the workplace, the
congestion
would be far less.

cars. Without cars on the urban road network public transport would
be
faster and more reliable.

How fast would urban public transport be with no cars
on the road? (and no vans, cycles, taxis etc. if that helps).

Is this a question, is it not obvious enough.

It will be exactly the travel time + the stops for pick up/drop off,
without
any delay occurring due to congestion,

And what will the travel speed be, and who long will
each stop take, and how frequently will the stops occur?
Or, alternatively, how fast would a typical journey be?

Well this depends upon the usage the frequency of buses, the congestion
levels.

Under the assumption that there are no cars, vans, bikes
would there still be congestion? Assume the usage is the
same as the total passenger km as on an urban bus route
at the moment, and whatever bus frequency is optimal
(which I expect to be at least 30 buses in the peak hour).

"Nick Finnigan" wrote in message
...
"iantheengineer" wrote in message
...

"Nick Finnigan" wrote in message
...
"iantheengineer" wrote in message
...

"Nick Finnigan" wrote in message
...
"iantheengineer" wrote in message
...

To continue to build roads will continue the problem. The answer
is
puvblic
transport, but public transport cannot cater for all journeys
and
therefore
over time journeys will need to become more corridored. For
example
go
into
any city during the am peak and the tidality of the flow is
there to
be
seen. IF we were to get all of the people from their cars onto
public
transport, or even better living nearer to the workplace, the
congestion
would be far less.

cars. Without cars on the urban road network public transport
would
be
faster and more reliable.

How fast would urban public transport be with no cars
on the road? (and no vans, cycles, taxis etc. if that helps).

Is this a question, is it not obvious enough.

It will be exactly the travel time + the stops for pick up/drop off,
without
any delay occurring due to congestion,

And what will the travel speed be, and who long will
each stop take, and how frequently will the stops occur?
Or, alternatively, how fast would a typical journey be?

Well this depends upon the usage the frequency of buses, the congestion
levels.

Under the assumption that there are no cars, vans, bikes
would there still be congestion? Assume the usage is the
same as the total passenger km as on an urban bus route
at the moment, and whatever bus frequency is optimal
(which I expect to be at least 30 buses in the peak hour).





Its an unanswerable question as it depends upon link and junction capacities
so each location is different., but it is fair to say that the throughput of
people would be greater so congestion would a lot less than it is at present

"Paul Weaver" wrote in message
news
On Fri, 07 Nov 2003 22:23:48 +0000, iantheengineer wrote:

It doesnt need to for most of the commute

Ahh, so the bus splits into 72 parts at each end?

No not at all, and I would think that the theory behind it is obvious, the
key to bus usage is modal interchange, ie facilities to allow transfer from
opne mode of travel to another. Fotr the most part of the commute menay
people are travelling in the same direction however upon reaching the very
last section of the journey and at the very start of the journey we all live
and work in slightly different places, but we use the same main corridors.
In cities, it is generally the case that most people can walk from their bus
stop to their office. Complications arise for people who work to site etc,
but for the most part many people are 9-5 approx and stay office bound. IF
you carry out any o-d survey you will see that certain routes are trafficked
by people from the same areas going to the same areas, and it is for these
that public transport works. The main problem with public transport is the
effective routing. In order to make it profitable a bus must collect x
punters to make the service profitable, in order to do this sometimes it is
necessary to protract the route to serve a certain catchment and by doing
this it incurrs delays compared to the direct route of using the car, but ,
by many people using their cars they create delays through traffic
congestion. Bus lanes assist to redress this balance a litlle, but at
present do not provide sufficient advantage to make the bus seem attractive.

"Terry Harper" wrote in message
...
"iantheengineer" wrote in message
...

I am by original training
a drainage engineer and for many years (before my time) the only
solutions
to drainage problems were to increase the conveyance or capacity of the
system.

In that case you ought to be able to recognise that de-bottlenecking is a
vital part of traffic management, whereas the tendency has been to provide
constrictions, leading to excessive congestion.
--
Terry Harper
http://www.terry.harper.btinternet.co.uk/


As I explained I have made a career out of drainage and traffic enginering
so I am full aware of what works. What happens when you de-bottleneck as you
put it, you send the problem downstream, this exactly what I was saying with
the drainage problems. You remove one obstruction letting more traffic
through and then it hits the next one and so on and so on. At some point you
have to step back from the problem and say well this isnt really solving the
problem just transferring it, how do we solve it. With traffic we can change
the way that the demand is satisfied through public transport which
effectively increases the passengers that can be got ionto the town without
increasing infrastructure. We could keep going down the road of improving
junctions but where would it end, we have been doing this for the past 100
or so years and we still havent solved it this way.

"PeterE" wrote in message
...
Robin May wrote:

It's completely obvious that's not what he means. It's true that
people use their cars too much. It's ridiculous that people think
it's ok to commute 50 or 100 or whatever miles to work each day in a
car with only one person in it. Obviously people have to get to
places some distance away from their home but there's no need for
them to be so ridiculously far away just so some rich **** can live
in a quiet little village.


Most really long-distance commuting is done by train, not car. How many
season tickets do GNER issue from Grantham and Newark to London? Is that
somehow better?

--
http://www.speedlimit.org.uk
"If laws are to be respected, they must be worthy of respect."

Dont take this the wrong way but do we have figures on the commute as I
would be interested to see them.

I would be interested to see if this is the case, as a train ticket to
London when I last went in 1998 (not long enough in my view) cost me £45
return when I could have driven and parked for a lot less. I chose to use
the train as I was going to an important meeting and neded time to prepare,
but I am sure many more use their cars.

On Sat, 8 Nov 2003 13:39:59 -0000, "iantheengineer"
wrote:

As I explained I have made a career out of drainage and traffic enginering
so I am full aware of what works. What happens when you de-bottleneck as you
put it, you send the problem downstream, this exactly what I was saying with
the drainage problems. You remove one obstruction letting more traffic
through and then it hits the next one and so on and so on. At some point you
have to step back from the problem and say well this isnt really solving the
problem just transferring it, how do we solve it. With traffic we can change
the way that the demand is satisfied through public transport which
effectively increases the passengers that can be got ionto the town without
increasing infrastructure. We could keep going down the road of improving
junctions but where would it end, we have been doing this for the past 100
or so years and we still havent solved it this way.

You're a TRAFFIC ENGINEER?

God save us all.
--
Paul Smith
Scotland, UK
http://www.safespeed.org.uk
please remove "XYZ" to reply by email
speed cameras cost lives

"Clive" wrote in message
...
In message , iantheengineer
writes

Speed humps are used to prevent speeding idiots and save lives. Do you
REALLY think that a local authority with limited funds would waste it n
putting in humps for the sake of it.

Come on now get real!!
In my neck of the wood, West Cumbria, yes. We have restricted parking
next to a school in term time, 100yds. Away we have a 24/7/365 20mph.
Limit next to a school. The road planners just don't know what
they're doing, they just have to spend the available money. So we get
speed humps on our roads and very little salt/grit in the winter.
--
Clive

Have you ever thought beyond the parking restrictions and speed humps. Speed
humps slow drivers down thus making accidents less likely and less severe.
The placement of parking restrictions prevents children from running between
parked cars into the road as they are visible to drivers and the cars are
visible to the children.

If you have children these inconveniences are nothing compared to the saftey
of your child.


As for speed limit in force at all times well if it wasnmt drivers would get
confused, and is travelling at 20 over that distance such a problem??.

Gritting / salting should only be undertaken when absolutely necessary. The
only guide that is given is the weather forecast, so occasionaly it gets
salted when it doesnt needs it ans not salted when it should. Salting has to
be done when the ice is forming, not before or after. If you salt too early
it gets washed and trafficked off. If you salt too late you need 40g/m2 as
opposed to 15g/m2. Local authorities normally have a limited stock for the
whole winter ( blame the accounting systems of the country) so they can
normally only go out a limited number of times a year (ridiculous I know)
so the decisions are not taken lightly.

I hope that explains things a little and restores at least a little
confidence in your lha.