On Sat, 17 Sep 2011 08:31:22 -0700 (PDT), 77002
wrote:

On Sep 17, 8:22*am, Andy Breen wrote:
On Sat, 17 Sep 2011 07:44:04 -0700, 77002 wrote:
On Sep 17, 7:39*am, "Peter Masson" wrote:
"Andy Breen" wrote in message

...

On Sat, 17 Sep 2011 15:21:58 +0100, Peter Masson wrote:

"allantracy" wrote

The future for cars looks very bleak unless they can be persuaded
to run on electricity.

Though there was a steam car around a while ago how ironic would
that be?

Battery technology can never be made efficient,

Define the meaning you are picking for "efficient" in this context..

so even with nuclear or
other renewable generation of electricity, battery cars can never be
made efficient.

See above. What do you mean by this? Cost? Energy density? Charge
cycling efficiency? Lifespan? Charging time?

charge cycle efficiency. The other issues can in principle be overcome,
but the laws of physics will not let you charge and discharge a battery
without significant energy losses.

Are there not also weight, and size issues with batteries. *Gasoline/
petrolium is fairly light and very efficient. *A trunk full of batteries
is heavy, even if we are talking about the recent battery developments.

But the break point between the two is a moving thing, not least because
IC engines have been getting more complex as additional pollution control
gear has been added.

Example, from the bottom end of the power range I'll admit. Small electric
outboard motors for boats are now getting very competitive with small
petrol outboards. They cost more, but they are much lighter and easier to
handle and much cheaper to run. In fact, a local builder offers them as
their preferred option on boats up to 23'...

http://www.torqeedo.com/en/hn/home.html

Five years ago none of that would have been true - electric outboards
back then were very much what they'd been for the previous 90-odd years.
These things really are a different world (and yes, I've seen one in use,
and they do seem to have run-times comparable with a small petrol engine
with integral tank. When I need to replace the 6bhp o/b I have then I'll
be seriously considering one).

That's a low-power example, but it's not going to stop there.

Often wondered if there is an application for a streetcar/tram or
electric/trolly bus that runs under wires where practical, but
utilizes batteries for stretches where wires are not practical, or
unsightly.

Somewhere in France IIRC where they did not want overhead wires strung
up across a historic square, distinct from systems with no OHLE at
all. Not forgetting shunting batteries as found with some trolleybuses
(or at least one system which also has part-time diesel generators on
the trolleybuses).

An electro diesel tram train might be another possibility.

On 18/09/2011 00:41, Charles Ellson wrote:
On Sat, 17 Sep 2011 08:31:22 -0700 (PDT),
wrote:

On Sep 17, 8:22 am, Andy wrote:


Often wondered if there is an application for a streetcar/tram or
electric/trolly bus that runs under wires where practical, but
utilizes batteries for stretches where wires are not practical, or
unsightly.

Somewhere in France IIRC where they did not want overhead wires strung
up across a historic square, distinct from systems with no OHLE at
all.

Nice I believe (well they certainly have that system there - just not
sure of the exact reason)

Someone Somewhere wrote on 18 September 2011 09:16:16 ...
On 18/09/2011 00:41, Charles Ellson wrote:
On Sat, 17 Sep 2011 08:31:22 -0700 (PDT),
wrote:

On Sep 17, 8:22 am, Andy wrote:


Often wondered if there is an application for a streetcar/tram or
electric/trolly bus that runs under wires where practical, but
utilizes batteries for stretches where wires are not practical, or
unsightly.

Somewhere in France IIRC where they did not want overhead wires strung
up across a historic square, distinct from systems with no OHLE at
all.

Nice I believe (well they certainly have that system there - just not
sure of the exact reason)

Yes, in 2007 Alstom supplied Citadis trams to Nice which can run on
batteries in streets where overhead wires would spoil the view of
historic buildings or interfere with carnival processions.

Alstom have an alternative technology for 'heritage' streets which they
use in Bordeaux and elsewhere. This is APS ('alimentation par le sol'
or 'ground-supply') which is effectively a third rail set into the road
surface. It is made up of short sections, each of which is only
energised when the tram is over it. This allows longer sections of
route without overhead wires, but is more expensive than the battery
option, which can cope with sections up to 1 km long.

More details at http://www.railway-technology.com/projects/nice-trams/
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)

Richard J.:
Alstom have an alternative technology for 'heritage' streets which they
use in Bordeaux and elsewhere. This is APS ('alimentation par le sol'
or 'ground-supply') which is effectively a third rail set into the road
surface. It is made up of short sections, each of which is only
energised when the tram is over it.

This is the "stud" system that was tried in London and a number of
other places about 100 years ago. And the reason you've probably
never heard of it is that all too often the studs remained live when
the tram had moved on. One hopes that things are more reliable now.
--
Mark Brader "I like to think of [this] as self-explanatory."
Toronto "I hope *I* think of [it] that way."
-- Donald Westlake: "Trust Me On This"

My text in this article is in the public domain.

In article ,
(Charles Ellson) wrote:

Somewhere in France IIRC where they did not want overhead wires strung
up across a historic square, distinct from systems with no OHLE at
all. Not forgetting shunting batteries as found with some trolleybuses
(or at least one system which also has part-time diesel generators on
the trolleybuses).

London trolleybuses had traction batteries. I can't say I ever saw them in
use, mind.

--
Colin Rosenstiel