David Bradley wrote:
On 06 Nov 2005 20:34:10 GMT, Adrian wrote:

David Bradley ) gurgled happily, sounding
much
like they were saying :

Progress would have been served if
the route had been electrified with zero polluting,

Such a thing doesn't yet exist.

Please explain further. In my book a trolleybus IS zero
polluting.

Your book is - at best - skimpy.

Where does the electricity come from?

As a former CEGB / NGC employer I can answer that question in
exceptional detail. In can see where you are coming from by
suggesting that the production of electricity is sometimes less
than enviromental friendly but equally can be derived from
renewable sources such as wind power or hydro sources. The power
might even have been provided from another country but however it
was produced, and where ever it originated from, the product does
not come with any kind of labelling for your average user to be
able to determine its source.

EDF in France, who I believe supply some electricity to the UK via the
cables under the Channel, do in fact declare on their bills to customers
in France the source of the electricity they provide. The 2004 figures
which appear on this year's bills make interesting reading:
83.4% nuclear
7.6% hydro-electric
3.8% gas
3.1% coal
1.3% oil
0.5% "other renewables" (presumably tides, wind)
0.3% other

--
Richard J.
(to e-mail me, swap uk and yon in address)

In message , Richard J.
writes
Clive wrote:
In message , David
Bradley writes
On Sun, 6 Nov 2005 17:31:23 +0000, Clive
wrote:

In message , David
Bradley writes
Then I am one ofthe few because there is no such thing as a clean
diesel, only a less dirty one. Progress would have been served
if the route had been electrified with zero polluting,
Such a thing doesn't yet exist.

Please explain further. In my book a trolleybus IS zero polluting.

David Bradley

Not only do trolley buses pollute, (carbon from motor brushes
asbestos from brake pads etc.) but there is also the pollution
from the source of the traction current supplied.

Asbestos is no longer used in brake pads. From the DfT website:
"Regulations introduced under the Consumer Protection Act, the Road
Vehicles (Brake Linings Safety) Regulations 1999, prohibited the
manufacture, supply or fitting of asbestos-based brake linings."

If I accept that and the juice is generated somewhere, car to explain
how, and why are there no losses between power plant and consumer?
--
Clive

In article ,
(Richard J.) wrote:

Clive wrote:
In message , David
Bradley writes
On Sun, 6 Nov 2005 17:31:23 +0000, Clive
wrote:

In message , David
Bradley writes
Then I am one ofthe few because there is no such thing as a clean
diesel, only a less dirty one. Progress would have been served
if the route had been electrified with zero polluting,
Such a thing doesn't yet exist.

Please explain further. In my book a trolleybus IS zero polluting.

David Bradley

Not only do trolley buses pollute, (carbon from motor brushes
asbestos from brake pads etc.) but there is also the pollution
from the source of the traction current supplied.

Asbestos is no longer used in brake pads. From the DfT website:
"Regulations introduced under the Consumer Protection Act, the Road
Vehicles (Brake Linings Safety) Regulations 1999, prohibited the
manufacture, supply or fitting of asbestos-based brake linings."

and modern electric motors don't use carbon brushes either.

--
Colin Rosenstiel

In message ,
Colin Rosenstiel writes
and modern electric motors don't use carbon brushes either.
Then how do you energise the rotor commutator or slip rings?
--
Clive

On Sun, 06 Nov 2005 17:10:40 +0000, David Bradley
wrote:

Few would be complaining if the buses were replaced with a new design
of modern Routemaster, "clean"-engined and accessible while retaining
the open platform and conductor.

Then I am one ofthe few because there is no such thing as a clean diesel,

Hence the quotation marks. I was deliberately avoiding delving into
the details of the various emissions standards.

On Sun, 6 Nov 2005 23:32:21 +0000, Clive wrote:

In message , Richard J.
writes
Clive wrote:
In message , David
Bradley writes
On Sun, 6 Nov 2005 17:31:23 +0000, Clive
wrote:

In message , David
Bradley writes
Then I am one ofthe few because there is no such thing as a clean
diesel, only a less dirty one. Progress would have been served
if the route had been electrified with zero polluting,
Such a thing doesn't yet exist.

Please explain further. In my book a trolleybus IS zero polluting.

David Bradley

Not only do trolley buses pollute, (carbon from motor brushes
asbestos from brake pads etc.) but there is also the pollution
from the source of the traction current supplied.

Asbestos is no longer used in brake pads. From the DfT website:
"Regulations introduced under the Consumer Protection Act, the Road
Vehicles (Brake Linings Safety) Regulations 1999, prohibited the
manufacture, supply or fitting of asbestos-based brake linings."


Modern trolleybuses [and trams] use brushless AC motors - the amounts of
carbon dust released into the environment by traditional trolleybus [and tram]
DC motors was hardly enough to be any kind of issue anyway.

Both trams and trolleybuses need to make some use of friction braking
material. Fundamentally modern trolleybuses and trams have rather similar
friction braking arrangements and are about equally polluting at a level which
in practice must be considered as negligible, particularly because both trams
and trolleybuses do most of their braking electrically, unlike diesel buses
which depend heavily on friction braking systems.

Yes - there is pollution "from the source of the traction current" for all
electric vehicles, trams and trolleybuses. But this pollution is NOT directly
dumped into the air breathed on the streets AND the levels are much lower than
from diesel vehicles, a fraction by comparison in fact, even if the power is
generated by burning fossil fuels in thermal power stations.

A study done in Sweden comparing the emission levels into the environment as a
whole for Netherlands trolleybuses, which are powered from an electricity grid
with a similar generation mix of coal, gas, etc., to our own, showed the
following comparison for pollutants emitted directly by diesel buses and
indirectly from power stations on behalf of trolleybuses:-

NOX - trolleybus 7% of diesel
CO - trolleybus 3% of diesel
HC - 0% of diesel
Particulates - 2% of diesel
CO2 - 73% of diesel

If I accept that and the juice is generated somewhere, car to explain
how, and why are there no losses between power plant and consumer?

There are power losses between power plant and consumer. In the UK grid,
these losses have been quoted as 9%. The above pollution figures factor in
all losses between power station and trolleybuses.

d wrote:
..... You can't just look at the weight and make
all your conclusions from that. The engines on the new busses, and all the
bits connecting them to the wheels, are brand new designs (compared to the
RMs). "Wasted time and fuel in traffic"? Bendy busses can overtake traffic
RMs would struggle to. I've used lots of RMs and lots of bendy busses, and
the two aren't even comparable when it comes to speedy driving. Bendy
busses out-accelerate RMs, which counts for everything in London traffic.

Force = mass x acceleration. Ye canna break the laws of Physics. I
already knew there's lots more mass in a bendy - now you're saying
there's more acceleration too?

I'd be surprised if they get as much as 5mpg. In Central London buses
almost never travel at constant speed.

Colin McKenzie

In article ,
(Clive) wrote:

In message ,
Colin Rosenstiel writes
and modern electric motors don't use carbon brushes either.
Then how do you energise the rotor commutator or slip rings?

Have you not heard of induction motors?

--
Colin Rosenstiel

In message ,
Colin Rosenstiel writes
Have you not heard of induction motors?
Yes, but how much of the total electric traction in our country uses
these? I suspect it is only the newest solid state controlled equipment.
--
Clive

David Bradley ) gurgled happily, sounding much
like they were saying :

Please explain further. In my book a trolleybus IS zero polluting.

Your book is - at best - skimpy.

Where does the electricity come from?

As a former CEGB / NGC employer I can answer that question in
exceptional detail. In can see where you are coming from by
suggesting that the production of electricity is sometimes less than
enviromental friendly but equally can be derived from renewable
sources such as wind power or hydro sources.

And what percentage of UK grid electricity is?

http://www.dti.gov.uk/energy/inform/...ity/dukes05_5_
6.xls

2004 -
Coal - 36.9%
Oil - 1.34%
Gas - 34.24%
Nuclear - 21.49%
Renewable Thermals - 3.34% (Burning biofuels and non-biodegradable
waste)
Other Thermals - 1.83% (Coke oven gas, Blast furnace gas, Waste products
from chemical processes)
Hydro - Natural Flow - 0.5%
Hydro - Pumped Storage - 0.27%
Other Non-Thermal - 0.2% (Wind, Wave, Solar)

So somewhere in the region of sod all. Or, to put a number on it,
renewables make 4.31% of the UK's electricity.

A lot better than I expected, I will admit. But still not much.
Especially as any ramp-up in demand will be met by the non-renewables,
as the renewables are stretched to provide the current amount.

The power might even have been provided from another country but
however it was produced, and where ever it originated from, the
product does not come with any kind of labelling for your average user
to be able to determine its source.

Indeed. So it's not quite right to say it's "zero-polluting", is it?

The right combination of circumstances can therefore have a trolleybus
operating on a fuel that can be considered to be entirely zero
polluting and to suggest that can't happen is bunkum.

Indeed.

However, to suggest that it's *likely* to happen is equally bunkum.

In any event I would certainly prefer a trolleybus service running
past my front, especially at night, rather than the cleanest of
diesel buses.

Ah, the "I don't live next door to a powerstation, so they don't
matter" NIMBY line.