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Home > Archive > Alternative Power sources > November 2006 > someone reduce my ignorance
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someone reduce my ignorance
|
|
| no spam 2006-11-14, 5:25 pm |
| My biggest ignorance is in regenerative braking. How can a few seconds of
braking put any significant charge in a battery pack? My only thought was
if it was used to charge capacitors.
Now thinking about how it worked this morning got me wondering if an
electric school bus would work.
A couple of my thoughts on this. First let's forget any dangers associated
with mixing large batteries, kids and accidents.
Second, a school bus has a lot of space below the cab to store batteries.
Therefore no loss of passenger or cargo space.
Third, school busses have a lot of roof space for solar cells. Might they
be able to recharge themselves on most days with the 6-8 hours between the
morning run and the afternoon?
Fourth, busses do a lot of stop and go. This is where my ignorance of regen
braking comes in, would using it help in an electric bus.
| |
| Joe Fischer 2006-11-14, 5:25 pm |
| On Tue, 14 Nov 2006 "no spam" <no@spam.net> wrote:
>My biggest ignorance is in regenerative braking. How can a few seconds of
>braking put any significant charge in a battery pack? My only thought was
>if it was used to charge capacitors.
It takes as much energy to stop a bus as it does
to get it going. Ultracapacitors can deliver power
faster to the motor than most batteries, and can be
charged faster without damage, and last 20 times
as long.
It takes no energy to keep moving, think of
a satellite in orbit, and a vehicle has wind resistance
and rolling friction, but most of the energy is used
to accelerate.
>Now thinking about how it worked this morning got me wondering if an
>electric school bus would work.
There are lots of electric buses in operation, but
most are real expensive demonstration projects.
>A couple of my thoughts on this. First let's forget any dangers associated
>with mixing large batteries, kids and accidents.
>
>Second, a school bus has a lot of space below the cab to store batteries.
>Therefore no loss of passenger or cargo space.
The weight of the batteries below the floor might
make it more difficult to turn over.
>Third, school busses have a lot of roof space for solar cells. Might they
>be able to recharge themselves on most days with the 6-8 hours between the
>morning run and the afternoon?
Still not enough space, and too expensive at this time,
but hopefully the price will come down.
>Fourth, busses do a lot of stop and go. This is where my ignorance of regen
>braking comes in, would using it help in an electric bus.
All hybrid vehicles are electric vehicles, and they
get better mileage for two reasons, the power source can
be smaller and more efficient, and regenerative braking
can recapture some of the energy used to accelerate.
http://www.nyserda.org/Press_Releas...sp?i=133&d=2006
Double click the link and see just one of many projects
getting under way.
Too bad most of them are just demo projects,
searching google for electric school bus will show many more.
Joe Fischer
| |
| Ashley Clarke 2006-11-14, 5:25 pm |
| "no spam" <no@spam.net> wrote in message
news:%3q6h.350$eb5.178@newsreading01.news.tds.net...
> My biggest ignorance is in regenerative braking. How can a few seconds of
> braking put any significant charge in a battery pack? My only thought was
> if it was used to charge capacitors.
You are not ignorant here, the alternator over this time period will only
regenerate a fraction (?) of the full braking potential.
> Now thinking about how it worked this morning got me wondering if an
> electric school bus would work.
It has been tried and tested by at least one School in the States I recall
from some Web browsing I did about a year ago, as a science project for
the School.
> A couple of my thoughts on this. First let's forget any dangers associated
> with mixing large batteries, kids and accidents.
They just don`t mix, the whole project is usually overseen by a senior.
> Second, a school bus has a lot of space below the cab to store batteries.
> Therefore no loss of passenger or cargo space.
This space was originally designed for Suitcases, now where do we put these?
> Third, school busses have a lot of roof space for solar cells. Might they
> be able to recharge themselves on most days with the 6-8 hours between the
> morning run and the afternoon?
As stated above, this has been Field-tested...
> Fourth, busses do a lot of stop and go. This is where my ignorance of regen
> braking comes in, would using it help in an electric bus.
Every little helps but as I said earlier it is just a small amount.
A better idea would be to introduce a more efficient temporary storage
mechanism
such as Clockwork where the energy can be released from it over a longer period
of time for the Alternator to chew on. Contemporary Compressed Air is also
viable.
Waddaya think?
Ashley Clarke
| |
| R.H. Allen 2006-11-14, 5:25 pm |
| no spam wrote:
> My biggest ignorance is in regenerative braking. How can a few seconds of
> braking put any significant charge in a battery pack? My only thought was
> if it was used to charge capacitors.
As Joe said, it takes as much energy to get a vehicle moving as it does
to stop it. I seem to recall seeing 30% as a figure for regenerative
braking efficiency, meaning that regeneratively braking a car from 55
mph to a standstill will recover 30% of the energy it took to accelerate
it from a standstill to 55 mph. That means that roughly every fourth
time you stop the energy for your next acceleration is provided by
regenerative braking. Whether the energy is stored in batteries or
capacitors makes no difference, provided the storage medium can handle
the current.
Now, that explanation is rather simplified. Strictly speaking, the
actual efficiency of regenerative braking depends upon the battery's
state of charge and other details of the charging system. In addition,
the regenerative braking system can only recover the vehicle's kinetic
energy -- it can't recover energy used to overcome wind resistance,
rolling resistance, etc. And obviously it can only recover energy while
you're braking. Add it all up and it means that regenerative braking can
add a lot range to a car driving in city traffic with low speeds and
lots of stopping and starting, but it isn't so significant for highway
driving.
> Now thinking about how it worked this morning got me wondering if an
> electric school bus would work.
>
> A couple of my thoughts on this. First let's forget any dangers associated
> with mixing large batteries, kids and accidents.
Yeah, because there's no danger at all in mixing large gasoline tanks,
kids, and accidents. Granted, batteries are a different *kind* of
danger, and possibly a less *familiar* kind of danger, but still....
> Fourth, busses do a lot of stop and go. This is where my ignorance of regen
> braking comes in, would using it help in an electric bus.
That's exactly the kind of situation when regenerative braking would be
*most* useful.
| |
| no spam 2006-11-14, 8:25 pm |
| >> A couple of my thoughts on this. First let's forget any dangers
>
> They just don`t mix, the whole project is usually overseen by a senior.
I just didn't want to get a "It'll kill the kids if a truck hits the bus."
line started.
>
>
> This space was originally designed for Suitcases, now where do we put
> these?
Not on a school bus. I know I own one. Most of the space below the floor
is wasted. A little used for drive train, fuel tank and air tanks. AAMOF,
the wife has great plans on how -=I=- can convert the bus into a grand
camper including parts of the floor so we can have a stand up shower.
>
> Every little helps but as I said earlier it is just a small amount.
I was thinking that, when behind it, a bus seems to spend 50% of its time
slowing down.
> A better idea would be to introduce a more efficient temporary storage
> mechanism
> such as Clockwork where the energy can be released from it over a longer
> period
> of time for the Alternator to chew on. Contemporary Compressed Air is also
> viable.
> Waddaya think?
To much loss to heat using air compression. Maybe a really big fly wheel 
| |
| Vaughn Simon 2006-11-14, 8:25 pm |
|
"Joe Fischer" <joe@westpointracing.com> wrote in message
news:s6ckl2pvorb87hosnillpbdpbk4p4gmefq@4ax.com...
> It takes no energy to keep moving,
Nonsense. There are important uses of energy within the vehicle, plus you
grossly underestimate wind and rolling and mechanical resistance. We have been
over this ground before. If what you insist on saying were true, then there
would be no top limit on the speed of vehicles. They would just be able to
accelerate indefinitely until they either became airborne or the engine flew
apart from the RPMs.
> but most of the energy is used to accelerate.
That depends on the type of trip. I recently took a 500-mile trip in my
car and I found that my gas gauge sometimes dropped dramatically while I was
keeping a very constant speed with my cruise control (for hours at a time on the
interstate) ;-)
> All hybrid vehicles are electric vehicles
Not necessarily so,( although all present mass-market hybrid autos have
electric as part of the drive system.) Hydraulics is another possible
competitive technology and flywheels have also been considered.
Vaughn
| |
| no spam 2006-11-14, 8:25 pm |
| > Now, that explanation is rather simplified. Strictly speaking, the actual
> efficiency of regenerative braking depends upon the battery's state of
> charge and other details of the charging system. In addition, the
> regenerative braking system can only recover the vehicle's kinetic
> energy -- it can't recover energy used to overcome wind resistance,
> rolling resistance, etc. And obviously it can only recover energy while
> you're braking. Add it all up and it means that regenerative braking can
> add a lot range to a car driving in city traffic with low speeds and lots
> of stopping and starting, but it isn't so significant for highway driving.
Which seem to scream SCHOOL BUS doesn't? Ever seen anything do more slow
speed driving with that many stops and starts?
>
> Yeah, because there's no danger at all in mixing large gasoline tanks,
> kids, and accidents. Granted, batteries are a different *kind* of danger,
> and possibly a less *familiar* kind of danger, but still....
Ain't been a gasoline school bus built in the US in many, many years. They
are all, except for a few 'demo models', run on diesel. Have you ever tried
to start a fire with diesel? It'll burn hot once you FINALLY get it
burning.
Also, I would much rather be sprayed with diesel from a busted tank than
anything the would pop out of a battery in an accident.
| |
| Eeyore 2006-11-14, 8:25 pm |
|
no spam wrote:
> My biggest ignorance is in regenerative braking. How can a few seconds of
> braking put any significant charge in a battery pack? My only thought was
> if it was used to charge capacitors.
It's a significant amount of energy when you're braking quite often as in town /
city driving as all those little bits add up.
An ultracap is used since the instantaneous current from regenerative braking
can be rather high ( beyond the battery's capability of accepting charge ).
Graham
| |
| Eeyore 2006-11-14, 8:25 pm |
|
no spam wrote:
> Third, school busses have a lot of roof space for solar cells. Might they
> be able to recharge themselves on most days with the 6-8 hours between the
> morning run and the afternoon?
Not a hope in hell. Solar cells produce very little power.
> Fourth, busses do a lot of stop and go. This is where my ignorance of regen
> braking comes in, would using it help in an electric bus.
Regenerative braking is ideally suited to stop and go driving.
Graham
| |
| Joe Fischer 2006-11-14, 8:25 pm |
| On Tue, 14 Nov 2006 23:37:02 GMT, "Vaughn Simon"
<vaughnsimonHATESSPAM@att.FAKE.net> wrote:
>"Joe Fischer" <joe@westpointracing.com> wrote in message
>news:s6ckl2pvorb87hosnillpbdpbk4p4gmefq@4ax.com...
>
> Nonsense. There are important uses of energy within the vehicle,
Some, but there was a time when I had a gasoline
heater because the car did not come with a heater.
>plus you
>grossly underestimate wind and rolling and mechanical resistance.
I don't under estimate it, up to 30 MPH wind
resistance isn't a big energy eater.
While any wheel is difficult for a human to turn
very fast, even a bicycle wheel, good bearings make a
big difference. I bought a cordless lawnmower from
B & D, and can't use it because it has plastic sleeve
bearings, and it is too much for an old man to push.
(am I the only one here with a lawnmower that
doesn't use fossil fuel?)
>We have been over this ground before.
Yes, and the engineers want to keep the motor
connected to the wheels all the time.
>If what you insist on saying were true, then there
>would be no top limit on the speed of vehicles. They would just be able to
>accelerate indefinitely until they either became airborne or the engine flew
>apart from the RPMs.
Nonsense, air resistance is the limiting factor,
and it becomes substantial at about 40 MPH.
>
> That depends on the type of trip. I recently took a 500-mile trip in my
>car and I found that my gas gauge sometimes dropped dramatically while I was
>keeping a very constant speed with my cruise control (for hours at a time on the
>interstate) ;-)
On that trip, regenerative braking wouldn't
make much difference.
>
> Not necessarily so,( although all present mass-market hybrid autos have
>electric as part of the drive system.) Hydraulics is another possible
>competitive technology and flywheels have also been considered.
>Vaughn
But electric has the big advantages, the only problem
is the supply and price of copper.
I really would like to see all electric cars in the US
be compatible with household power, just like I only buy
12 volt cordless tools and lanterns.
Joe Fischer
| |
| Eeyore 2006-11-14, 8:25 pm |
|
no spam wrote:
>
> I just didn't want to get a "It'll kill the kids if a truck hits the bus."
> line started.
That'll happen when they start using hydrogen fuelled buses in California !
It'll also take out the truck driver and half the damn block too.
Graham
| |
| Eeyore 2006-11-14, 8:25 pm |
|
Joe Fischer wrote:
> "Vaughn Simon" <vaughnsimonHATESSPAM@att.FAKE.net> wrote:
>
> Some, but there was a time when I had a gasoline
> heater because the car did not come with a heater.
>
>
> I don't under estimate it, up to 30 MPH wind
> resistance isn't a big energy eater.
Try moving a surface the size of the front of a school bus @ 30 mph and you'll
retract that statement.
Graham
| |
| Joe Fischer 2006-11-14, 8:25 pm |
| On Wed, 15 Nov 2006 00:09:59 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>That'll happen when they start using hydrogen fuelled buses in California !
>It'll also take out the truck driver and half the damn block too.
>Graham
How does something explode without being
mixed with oxidizer, and being contained?
Joe Fischer
| |
| clare at snyder.on.ca 2006-11-14, 8:25 pm |
| On Tue, 14 Nov 2006 23:50:28 GMT, "no spam" <no@spam.net> wrote:
>
>Which seem to scream SCHOOL BUS doesn't? Ever seen anything do more slow
>speed driving with that many stops and starts?
>
>
>
>Ain't been a gasoline school bus built in the US in many, many years. They
>are all, except for a few 'demo models', run on diesel. Have you ever tried
>to start a fire with diesel? It'll burn hot once you FINALLY get it
>burning.
>
>Also, I would much rather be sprayed with diesel from a busted tank than
>anything the would pop out of a battery in an accident.
>
If hydrogen, in metal hydride tanks, had been invented/used back when
the automobile was young, there is NO WAY they would allow gasoline
today. Hydride storage of hydrogen is MUCH safer than bulk storage of
gasoline
--
Posted via a free Usenet account from http://www.teranews.com
| |
| Joe Fischer 2006-11-14, 8:25 pm |
| On Wed, 15 Nov 2006 00:13:41 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>Joe Fischer wrote:
>
>Try moving a surface the size of the front of a school bus @ 30 mph and you'll
>retract that statement.
>Graham
Try streamlining it.
Joe Fischer
| |
| clare at snyder.on.ca 2006-11-14, 8:25 pm |
| On Tue, 14 Nov 2006 21:42:48 -0000, "Ashley Clarke"
<aclarke2005@toucansurf.com> wrote:
>"no spam" <no@spam.net> wrote in message
>news:%3q6h.350$eb5.178@newsreading01.news.tds.net...
>
> You are not ignorant here, the alternator over this time period will only
>regenerate a fraction (?) of the full braking potential.
>
>
> It has been tried and tested by at least one School in the States I recall
>from some Web browsing I did about a year ago, as a science project for
>the School.
>
>
> They just don`t mix, the whole project is usually overseen by a senior.
>
>
> This space was originally designed for Suitcases, now where do we put these?
>
>
> As stated above, this has been Field-tested...
>
>
> Every little helps but as I said earlier it is just a small amount.
>
> A better idea would be to introduce a more efficient temporary storage
>mechanism
>such as Clockwork where the energy can be released from it over a longer period
>of time for the Alternator to chew on. Contemporary Compressed Air is also
>viable.
>
> Waddaya think?
>
> Ashley Clarke
>
Put a set of pedals at each seating position and let the little
rascals pedal. No need for Phys ed and it will keep the little
monsters fit and trim.
--
Posted via a free Usenet account from http://www.teranews.com
| |
|
| ..
>
> Which seem to scream SCHOOL BUS doesn't? Ever seen anything do more slow
> speed driving with that many stops and starts?
yeah, garbage trucks. Hard acceleration for 40 feet then hard on the brakes
for 20 feet, stop for about 3 seconds to emtpy the bin, repeat a few 1000
times a day. If they cant make it work on a garbage truck they better give
up now.
http://www.permo-drive.com/tech/index.htm
| |
| Eeyore 2006-11-14, 8:25 pm |
|
Joe Fischer wrote:
> On Wed, 15 Nov 2006 00:09:59 +0000, Eeyore
> <rabbitsfriendsandrelations@hotmail.com> wrote:
>
>
> How does something explode without being
> mixed with oxidizer,
That's what happens when the truck collides with the bus. Air = oxidiser.
> and being contained?
Containment is not required. Here's an example. Supposedly the largest explosion
in Europe since WW2 !
http://news.bbc.co.uk/1/hi/uk/4517962.stm
Graham
| |
| Eeyore 2006-11-14, 8:25 pm |
|
Joe Fischer wrote:
> On Wed, 15 Nov 2006 00:13:41 +0000, Eeyore
> <rabbitsfriendsandrelations@hotmail.com> wrote:
>
>
> Try streamlining it.
A bus ? There'll still be a significant drag coefficient.
As for rolling losses, just trying pushing a bus even at walking speed.
Graham
| |
| Eeyore 2006-11-14, 8:25 pm |
|
Ashley Clarke wrote:
> A better idea would be to introduce a more efficient temporary storage
> mechanism
> such as Clockwork where the energy can be released from it over a longer period
> of time for the Alternator to chew on. Contemporary Compressed Air is also
> viable.
>
> Waddaya think?
Honestly ?
I think you're a nutter.
Graham
| |
| Frank Cusack 2006-11-14, 9:25 pm |
| On Wed, 15 Nov 2006 02:17:07 +0000 Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
> As for rolling losses, just trying pushing a bus even at walking speed.
I wouldn't think that is too difficult. We used to push rail cars
around by hand. Of course steel wheels on track has much less friction.
-frank
| |
| OldNick 2006-11-15, 3:25 am |
| On Tue, 14 Nov 2006 20:56:27 GMT, "no spam" <no@spam.net> wrote:
>My biggest ignorance is in regenerative braking. How can a few seconds of
>braking put any significant charge in a battery pack? My only thought was
>if it was used to charge capacitors.
That few seconds is very intense. It needs ther same energy to stop
the bus as it did to get it up there. However batteries are not ther
answer. You use ultra capacitors, which _are_ available....at a price
:-<
>Third, school busses have a lot of roof space for solar cells. Might they
>be able to recharge themselves on most days with the 6-8 hours between the
>morning run and the afternoon?
>
>Fourth, busses do a lot of stop and go. This is where my ignorance of regen
>braking comes in, would using it help in an electric bus.
The figures below are as rough as heck. Thisngs change all the time in
all areas of this. But they will be well within realistic ranges,
unless I have ballsed it up.
Area of the sides of a bus = roughly 72m^2
windows = 1/3 of this (can't keep the little dears in the dark now,
can we)
so nett = 48m^2
The sun will fall on these at an extreme angle, either because the bus
is facing or rearing the sun, or because the bus is side on and only
one side gets it, or the sun is high in the sky and the angle is so.
Sunlight = 1Kw/m^2
Peak solar cell efficiency at best in real life is, say, 15%
Because of the sun's angle, the intensity and thus power of the sun on
the bus sides will be maybe 15% of the "square on" power.
48 * 1 * .15 *.15 = About 1Kw
from the bus sides.
Over the 8 hours of school + travel this is 8 KW-hr
Area of top of bus = 30m^2
From the sides, we could maybe double the effectiveness and energy
input / m^2.
(30 / 48)m^2 * 8 KW-hr * 2
= 10 KW-hr per running day.
Because the bus is accelerating for a large portion of the time,
compared to a "150HP (115 KW)" bus it will use probably 25 KW to run
on average. Guessing. So in two hours it will use 50 KW-hr.
I base this figure on the fact that you need a much "lower power"
electric motor to run any vehicle, especially under heavy loads, than
the "HP" that is needed from an internal combustion engine. A 6 hp
electric motor on a boat would equal "30-40 HP" of IC engine.
Regen braking will give back 30% (efficiency) of _maybe_ 1/3rd
(braking input) of that = 5KW-hr
Defficiency (generous I feel) = (50 -5) - (8 + 10) = 27 KW-hr or over
half the daily energy. You are still going to need very effective
charging and storage.
The trouble is the cost. The panels as shown above would be _peak _
power (KWp)
120 m^2 * 0.15 efficiency * 1 KW / m^2 solar energy = 18 KWp. This
would cost maybe $5000 / KWp = $90,000. Then there are the batteries
and Ultra Capacitors.
| |
|
|
"Frank Cusack" <fcusack@fcusack.com> wrote in message
news:m2ac2ts9b5.fsf@sucksless.local...
> On Wed, 15 Nov 2006 02:17:07 +0000 Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>
> I wouldn't think that is too difficult. We used to push rail cars
> around by hand. Of course steel wheels on track has much less friction.
>
> -frank
the only numbers i could find
http://science.howstuffworks.com/question523.htm
400lbs? i dont know about you but i wouldnt be pushing it very far
| |
| Eeyore 2006-11-15, 3:25 am |
|
Frank Cusack wrote:
> On Wed, 15 Nov 2006 02:17:07 +0000 Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
>
> I wouldn't think that is too difficult.
You reckon ?
> We used to push rail cars
> around by hand. Of course steel wheels on track has much less friction.
Very much less ! Thank you for making my point.
Graham
| |
| nicksanspam@ece.villanova.edu 2006-11-15, 3:25 am |
| OldNick <nsremovable@iinet.net.au> wrote:
>"no spam" <no@spam.net> wrote:
>
>
>... That few seconds is very intense. It needs ther same energy to stop
>the bus as it did to get it up there. However batteries are not ther
>answer. You use ultra capacitors, which _are_ available....at a price :-<
How many kWh to stop a busful of 50 kids from 30 mph? After a 500' hill?
How many dollars for these ultracaps?
Nick
| |
|
|
nicksanspam@ece.villanova.edu wrote:
> OldNick <nsremovable@iinet.net.au> wrote:
>
> How many kWh to stop a busful of 50 kids from 30 mph? After a 500' hill?
>
> How many dollars for these ultracaps?
>
> Nick
Apart from Braking the advantage of regenerative braking is when
descending hills, when the energy used climbibg the hill is put back
into the batteries (less losses). These losses are however quite
large. With lead acid batteries you have to put three times the power
in as what you get out. (due to heating and hydrogen vent losses)
In days of yore trolley buses and trams (some of them) used to time
their journeys so that one descending a hill would regenerate to help
another one simultaneously climbing the hill. Hard to arrange though.
Some again had "coasting brakes" for descending hills which
regenerated but the electricty was run through large resistors ,
dissipating the energy as heat. This slowed the bus without wearing
out mechanical brakes. (No engine braking from electric motor as with
a diesel engine.)
Re school buses, there was a very serious accident, in Kentucky I think
it was, involving a petrol driven school bus which caught fire. I
think about thirty kids were killed. Since then no diesel engines on
school buses. We've never had petrol engnes in buses in the UK. Not for
at least sixty years anyway,.
http://en.wikipedia.org/wiki/Carrollton_bus_disaster
| |
| Ignoramus18503 2006-11-15, 5:25 pm |
| On 15 Nov 2006 11:20:15 -0800, Harry <susan.armitage@virgin.net> wrote:
> Re school buses, there was a very serious accident, in Kentucky I
> think it was, involving a petrol driven school bus which caught
> fire. I think about thirty kids were killed. Since then no diesel
> engines on school buses. We've never had petrol engnes in buses in
> the UK. Not for at least sixty years anyway,.
> http://en.wikipedia.org/wiki/Carrollton_bus_disaster
>
Um, the bus that caught fire had a gasoline engine.
i
| |
| Trygve Lillefosse 2006-11-15, 5:25 pm |
| On Tue, 14 Nov 2006 20:56:27 GMT, "no spam" <no@spam.net> wrote:
>My biggest ignorance is in regenerative braking. How can a few seconds of
>braking put any significant charge in a battery pack? My only thought was
>if it was used to charge capacitors.
>Now thinking about how it worked this morning got me wondering if an
>electric school bus would work.
With a bus-system. I would rather think that trolley busses would be
better. Since the busses follows the same route each day. The
regenartion power can be fed directly back into the system without
problem.
http://en.wikipedia.org/wiki/Trolleybus
The only problems with theese, that I can see is
1 All those ugly powerlines. Maybee it's possible to use induction and
have them under the road surface.
2. When they are rerouted to an area without lines, due to roadworks
etc. But is should be possible to have a small engine that will make
it run inbetween lines.
2.2 It has to be easy to switch from fuel to electricity without the
driver having to go out of the bus. Preferably when the bus is moving.
--
SEE YA !!!
Trygve Lillefosse
AKA - Malawi, The Fisher King
| |
| no spam 2006-11-15, 5:25 pm |
|
"Ignoramus18503" <ignoramus18503@NOSPAM.18503.invalid> wrote in message
news:fcg62.ps6.19.1@news.alt.net...
> On 15 Nov 2006 11:20:15 -0800, Harry <susan.armitage@virgin.net> wrote:
>
>
> Um, the bus that caught fire had a gasoline engine.
True but:
1: it was in the US not UK
2: this was almost 20 years ago: 1988
3: the bus was 11 years old at the time of the accident (1977 Ford B-700)
4: it was a FROMER school bus then a church bus
As I stated in MY post there haven't been any gasoline powered school busses
for many, many years.
| |
| no spam 2006-11-15, 5:25 pm |
| > On Tue, 14 Nov 2006 20:56:27 GMT, "no spam" <no@spam.net> wrote:
>
> With a bus-system. I would rather think that trolley busses would be
> better. Since the busses follows the same route each day. The
> regenartion power can be fed directly back into the system without
> problem.
>
> http://en.wikipedia.org/wiki/Trolleybus
>
> The only problems with theese, that I can see is
>
> 1 All those ugly powerlines. Maybee it's possible to use induction and
> have them under the road surface.
> 2. When they are rerouted to an area without lines, due to roadworks
> etc. But is should be possible to have a small engine that will make
> it run inbetween lines.
> 2.2 It has to be easy to switch from fuel to electricity without the
> driver having to go out of the bus. Preferably when the bus is moving.
3. A large rural population
| |
| R.H. Allen 2006-11-15, 5:25 pm |
| Eeyore wrote:
>
> Joe Fischer wrote:
>
>
> A bus ? There'll still be a significant drag coefficient.
The drag coefficient for a school bus is much lower than I would have
expected, in the range of 0.46-0.55, and tends to the low end of the
range at speeds above 10 mph. That's roughly the same as a delivery
truck or a Hummer, and not much higher than a pickup truck. Most cars
are in the 0.30-0.40 range.
So aggressively streamlining a bus might reduce aerodynamic drag by a
maximum of about 25%. It might also require making the bus much longer,
which might make it difficult or impossible to drive, or dramatically
shortening the part of the bus that carries kids. From an aerodynamic
perspective, reducing the frontal area of the bus would have the same
effect as streamlining it, but that would reduce the number of kids it
could carry. If you streamline the bus *and* reduce the frontal area you
can make huge strides in the aerodynamics, but then you have less of a
bus and more of a limousine. In the end, if you make the bus more
fuel-efficient but reduce the number of kids it carries, you've gained
nothing.
That said, given the high mass of the bus, the surprisingly low drag
coefficient, and the high percentage of stop-and-go driving and I
suspect Joe is correct that aerodynamic drag is responsible for a rather
small portion of the energy consumption of a school bus. I haven't run
any numbers on it, but if it were a major loss mechanism I suspect bus
manufacturers would have been on it long ago. If I'm wrong about that,
there's probably a tremendous opportunity waiting for somebody in
selling streamlined buses with improved gas mileage to cash-strapped
school districts looking to save pennies in any way they can.
> As for rolling losses, just trying pushing a bus even at walking speed.
Ever see those world's strongest man competitions they show on the cable
channels (here in the U.S., anyway)? :-)
| |
| Trygve Lillefosse 2006-11-15, 5:25 pm |
| On Wed, 15 Nov 2006 16:15:04 -0500, "R.H. Allen" <kkarie@hotmail.com>
wrote:
>Eeyore wrote:
>
>The drag coefficient for a school bus is much lower than I would have
>expected, in the range of 0.46-0.55, and tends to the low end of the
>range at speeds above 10 mph. That's roughly the same as a delivery
>truck or a Hummer, and not much higher than a pickup truck. Most cars
>are in the 0.30-0.40 range.
>So aggressively streamlining a bus might reduce aerodynamic drag by a
>maximum of about 25%. It might also require making the bus much longer,
>which might make it difficult or impossible to drive, or dramatically
>shortening the part of the bus that carries kids. From an aerodynamic
>perspective, reducing the frontal area of the bus would have the same
>effect as streamlining it, but that would reduce the number of kids it
>could carry. If you streamline the bus *and* reduce the frontal area you
>can make huge strides in the aerodynamics, but then you have less of a
>bus and more of a limousine. In the end, if you make the bus more
>fuel-efficient but reduce the number of kids it carries, you've gained
>nothing.
Would it not be possible to make the bus quite a bit lower?
In another post there were talks about how mutch space there were
below the floor. If the floor and roof were lowered a bit, it should
give less drag.
The classical scool-bus looks like it has a lot of potential for
streamlining. AFAIK Both the front and the rear could have been
rounded without changing the basic design.
--
SEE YA !!!
Trygve Lillefosse
AKA - Malawi, The Fisher King
| |
| Joe Fischer 2006-11-15, 8:25 pm |
| On Wed, 15 Nov 2006 23:47:44 +0100, Trygve Lillefosse
<trygve@lillefosse.NOSPAM.org> wrote:
>Would it not be possible to make the bus quite a bit lower?
Most of the school buses in the US are built on a
truck chassis designed for about a 10 ton straight truck.
I can't think of any other reason they are so high,
but it may be safer in an accident, although they are
bound to turn over easier.
>In another post there were talks about how mutch space there were
>below the floor. If the floor and roof were lowered a bit, it should
>give less drag.
It should be easy to streamline the front on the ones
with the motor compartment sticking out, if they are
fuel cell or hybrid electric, then the shape can change and
the grille openings are not needed.
>The classical scool-bus looks like it has a lot of potential for
>streamlining. AFAIK Both the front and the rear could have been
>rounded without changing the basic design.
I don't see why all vehicles still have the front grille
if they have an electric radiator fan, the ram air cooling
is no longer needed and the drag must be a lot more
than the energy needed to run the fan.
But it takes time, and the designers will all be
crying because they have to learn something new,
which may be more what is holding back large
scale production of hybrid electrics than the
cost or technology.
I think it takes about 5 years to make a major
change in an engine plant, that may also delay the
change to hybrid and a smaller ICE.
For the school buses, along each side under
the floor would be the ideal location for the batteries
all in a row, with an interlock cover so that servicing,
testing and changing would be easy.
Joe Fischer
| |
| Eeyore 2006-11-15, 9:25 pm |
|
Harry wrote:
> With lead acid batteries you have to put three times the power
> in as what you get out. (due to heating and hydrogen vent losses)
No you don't.
Graham
| |
| Eeyore 2006-11-15, 9:25 pm |
|
Ignoramus18503 wrote:
> On 15 Nov 2006 11:20:15 -0800, Harry <susan.armitage@virgin.net> wrote:
>
>
> Um, the bus that caught fire had a gasoline engine.
He said *in the UK*. I'm not sure the 60 years is quite right though.
Graham
| |
| Eeyore 2006-11-15, 9:25 pm |
|
Trygve Lillefosse wrote:
>
> The only problems with theese, that I can see is
>
> 1 All those ugly powerlines. Maybee it's possible to use induction and
> have them under the road surface.
No. Not technically practical.
Graham
| |
| Eeyore 2006-11-15, 9:25 pm |
|
"R.H. Allen" wrote:
> If you streamline the bus *and* reduce the frontal area you
> can make huge strides in the aerodynamics, but then you have less of a
> bus and more of a limousine.
Hey, we had these things in the 50s !
http://www.vectis.co.uk/images/vectis/111000/459.jpg
Graham
| |
| Eeyore 2006-11-16, 3:25 am |
|
Trygve Lillefosse wrote:
> Would it not be possible to make the bus quite a bit lower?
If it weren't based on a truck chassis yes.
> In another post there were talks about how mutch space there were
> below the floor. If the floor and roof were lowered a bit, it should
> give less drag.
Yes.
> The classical scool-bus looks like it has a lot of potential for
> streamlining. AFAIK Both the front and the rear could have been
> rounded without changing the basic design.
Americans are clueless about good design.
Graham
| |
| R.H. Allen 2006-11-16, 1:25 pm |
| Joe Fischer wrote:
> On Wed, 15 Nov 2006 23:47:44 +0100, Trygve Lillefosse
> <trygve@lillefosse.NOSPAM.org> wrote:
>
> It should be easy to streamline the front on the ones
> with the motor compartment sticking out, if they are
> fuel cell or hybrid electric, then the shape can change and
> the grille openings are not needed.
The biggest challenge in streamlining a school bus would be on the back
end, not the front. With that big, blocky back end you're essentially
creating a vacuum behind the bus so that the air in front literally
tries to push the bus backwards. However, it would be difficult to taper
the back in aerodynamic fashion without either significantly lengthening
the bus or sacrificing a number of seats on board.
In the end, though, it comes down to whether the fuel savings would make
it worth the effort. If the bus spends most of its time accelerating and
decelerating and rarely exceeds 20 mph then streamlining is most likely
a waste of time and money -- and believe me, streamlining would take a
lot of both. You'd get a lot more bang for your buck by increasing fuel
efficiency or reducing the weight of the bus.
>
> I don't see why all vehicles still have the front grille
> if they have an electric radiator fan, the ram air cooling
> is no longer needed and the drag must be a lot more
> than the energy needed to run the fan.
Before the electric radiator fan most cars had a belt-driven radiator
fan, so I don't see how the fan makes a difference. Besides, if you
close off the front grille it becomes much more difficult for the fan to
blow air over the radiator, and the air it draws will be warm (if not
hot) air from the engine compartment. The end result will be an
overheated engine. If you don't believe me, block the grille on the
front of your car and see what happens. No matter what you do, you need
cool air from outside the car in order to cool the radiator.
> But it takes time, and the designers will all be
> crying because they have to learn something new,
> which may be more what is holding back large
> scale production of hybrid electrics than the
> cost or technology.
Believe me, designers don't cry about having to learn something new --
in fact, most of them rather enjoy it. Their managers, however, are
loathe to be the first to do something. Risk-taking is highly
discouraged in the auto industry. I've had to sell a major automaker on
using a microchip that was designed with automotive applications in
mind, but since it had never actually been used a mass-produced vehicle
they wanted no part of it (yet they wanted the same functionality at
microchip prices...).
> I think it takes about 5 years to make a major
> change in an engine plant, that may also delay the
> change to hybrid and a smaller ICE.
Five years is the typical timeline for an auto manufacturer to develop
and launch a new model. If pressed they can do it a little faster, and
I've seen relatively simple *components* of cars go from sketches on a
cocktail napkin to full production in as little as 18 months. I doubt
you'll ever seen anything as complex as an engine get done in 18 months,
though.
| |
| R.H. Allen 2006-11-16, 1:25 pm |
| Eeyore wrote:
>
> "R.H. Allen" wrote:
>
>
> Hey, we had these things in the 50s !
>
> http://www.vectis.co.uk/images/vectis/111000/459.jpg
By the looks of them I'll bet they had lower drag coefficients and
frontal areas than a school bus, too.
| |
| clare at snyder.on.ca 2006-11-16, 1:25 pm |
| On Thu, 16 Nov 2006 11:40:52 -0500, "R.H. Allen" <kkarie@hotmail.com>
wrote:
>In the end, though, it comes down to whether the fuel savings would make
>it worth the effort. If the bus spends most of its time accelerating and
>decelerating and rarely exceeds 20 mph then streamlining is most likely
>a waste of time and money -- and believe me, streamlining would take a
>lot of both. You'd get a lot more bang for your buck by increasing fuel
>efficiency or reducing the weight of the bus.
Put voertex generators on the back. Google Air tabs for more
information. I've seen what they do on trailers.
--
Posted via a free Usenet account from http://www.teranews.com
| |
| William Mcfadden 2006-11-16, 1:25 pm |
| >> Add it all up and it means that regenerative braking can
>
>Which seem to scream SCHOOL BUS doesn't? Ever seen anything do more slow
>speed driving with that many stops and starts?
Garbage truck. Certain construction vehicles.
Nevertheless, the point is well taken that these kinds of applications would
benefit most from regenerative braking.
--
Bill McFadden billmc@agora.rdrop.com http://www.rdrop.com/users/billmc
CAUTION: Don't look into laser beam with remaining eye.
| |
| Joe Fischer 2006-11-16, 5:25 pm |
| On Thu, "R.H. Allen" <kkarie@hotmail.com> wrote:
>Joe Fischer wrote:
>
>The biggest challenge in streamlining a school bus would be on the back
>end, not the front. With that big, blocky back end you're essentially
>creating a vacuum behind the bus so that the air in front literally
>tries to push the bus backwards. However, it would be difficult to taper
>the back in aerodynamic fashion without either significantly lengthening
>the bus or sacrificing a number of seats on board.
I heard some time ago that the back can be blunt and
it doesn't add drag, there should be a technical discussion
of that some place.
>In the end, though, it comes down to whether the fuel savings would make
>it worth the effort. If the bus spends most of its time accelerating and
>decelerating and rarely exceeds 20 mph then streamlining is most likely
>a waste of time and money -- and believe me, streamlining would take a
>lot of both.
It would cost to make the change, but once the
design is stable, it shouldn't cost any extra, streamlining
usually takes less metal.
>You'd get a lot more bang for your buck by increasing fuel
>efficiency or reducing the weight of the bus.
With regenerative braking, I don't see the weight
as much of an issue, a heavier vehicle with the same drag
will roll a lot farther, so the driving habits may make the
big difference.
My car will coast more than 1000 feet from
10 miles per hour, and at higher speeds the weight
increases momentum or kinetic energy and that
overwhelms the drag (compared to a lighter car
with the same wind resistance.
>
>Before the electric radiator fan most cars had a belt-driven radiator
>fan, so I don't see how the fan makes a difference. Besides, if you
>close off the front grille it becomes much more difficult for the fan to
>blow air over the radiator, and the air it draws will be warm (if not
>hot) air from the engine compartment. The end result will be an
>overheated engine.
With a fan, it shouldn't matter if the air comes up
from the bottom or from one side to another, the front
grille isn't needed, but as designed, the fan only runs
when the coolant is above a certain temperature.
>If you don't believe me, block the grille on the
>front of your car and see what happens. No matter what you do, you need
>cool air from outside the car in order to cool the radiator.
I don't have a radiator fan, but if I did, I would be
tempted to put the radiator someplace else and streamline
the grille area.
>
>Believe me, designers don't cry about having to learn something new --
>in fact, most of them rather enjoy it.
If they can figure it out for themselves they enjoy it,
but scream bloody murder when told that what they have
been doing is not as good as something else.
>Their managers, however, are
>loathe to be the first to do something. Risk-taking is highly
>discouraged in the auto industry. I've had to sell a major automaker on
>using a microchip that was designed with automotive applications in
>mind, but since it had never actually been used a mass-produced vehicle
>they wanted no part of it (yet they wanted the same functionality at
>microchip prices...).
There shouldn't be any risk taking, they see the
sales numbers and the poll results on hybrid electrics,
so there is no reason to not be all hybrid electric in
5 years or less.
But copper supplies may be a problem.
>
>Five years is the typical timeline for an auto manufacturer to develop
>and launch a new model. If pressed they can do it a little faster, and
>I've seen relatively simple *components* of cars go from sketches on a
>cocktail napkin to full production in as little as 18 months. I doubt
>you'll ever seen anything as complex as an engine get done in 18 months,
>though.
I would think a 20 HP motor should be easy,
with bore and stroke for an optimum 3000 RPM,
and a good muffler.
The only problem is with fools that want to
drive 80, they would need an extra 20 HP.
Raising the speed limit in the US was a big
mistake, an extra 10,000 lives lost each year, and
no telling how much fuel wasted.
Joe Fischer
| |
| OldNick 2006-11-17, 3:25 am |
| On Wed, 15 Nov 2006 19:43:29 +0000 (UTC), Ignoramus18503
<ignoramus18503@NOSPAM.18503.invalid> wrote:
>On 15 Nov 2006 11:20:15 -0800, Harry <susan.armitage@virgin.net> wrote:
>
>driven school bus which caught
>
>Um, the bus that caught fire had a gasoline engine.
um, I think it was typo. Read the whole post and try again.
| |
| no spam 2006-11-17, 5:25 pm |
| > Raising the speed limit in the US was a big
> mistake, an extra 10,000 lives lost each year, and
That was the cry before it was raised but the last numbers I saw didn't
support it. Kind'a like when the a state passes concealed carry law; "The
streets will run with the blood from all of the old west type shoot outs
that will happen!". In reality crime drops. Opposite has been proven in
England and Australia.
| |
| R.H. Allen 2006-11-17, 5:25 pm |
| Joe Fischer wrote:
> On Thu, "R.H. Allen" <kkarie@hotmail.com> wrote:
>
>
> I heard some time ago that the back can be blunt and
> it doesn't add drag, there should be a technical discussion
> of that some place.
I'm pretty far removed from my aerodynamics experience at this point so
I won't say it's impossible, but what you *would* have to do is "fill
in" the area behind the bus with air at a similar pressure to the air in
front of the bus. Tapered designs (like airplane wings) typically do
that while non-tapered designs don't (or do it poorly).
>
> It would cost to make the change, but once the
> design is stable, it shouldn't cost any extra, streamlining
> usually takes less metal.
But the price of the bus will have to be increased for awhile to pay for
the streamlining. If the increase in price is more than the fuel savings
it's a waste of money.
>
> With regenerative braking, I don't see the weight
> as much of an issue, a heavier vehicle with the same drag
> will roll a lot farther, so the driving habits may make the
> big difference.
The amount of energy required to accelerate the bus is directly
proportional to its weight. Regenerative braking will recover at most
30% of the kinetic energy of the bus, meaning net discharge of the
batteries will be proportional to 70% of the bus's weight. Better than
if it's proportional to 100% of the bus's weight to be sure, but weight
is still going to be a major issue. Considering how often a bus starts
and stops, it's likely to be *the* major issue where energy consumption
is concerned.
> My car will coast more than 1000 feet from
> 10 miles per hour, and at higher speeds the weight
> increases momentum or kinetic energy and that
> overwhelms the drag (compared to a lighter car
> with the same wind resistance.
I have no idea what you mean by "overwhelms the drag," but two cars with
different weights and the same aerodynamic properties will require
*exactly* the same amount of energy as one another to maintain a
constant speed (neglecting mechanical losses like rolling resistance,
which is a function of vehicle weight). The only time their energy
requirements will differ is during acceleration.
>
> With a fan, it shouldn't matter if the air comes up
> from the bottom or from one side to another, the front
> grille isn't needed, but as designed, the fan only runs
> when the coolant is above a certain temperature.
Where the air comes from makes no difference, as long as it's cool
enough to cool the radiator. Ensuring that is difficult to do without a
grille. And it's generally not that difficult to draw air inside the
vehicle without significantly affecting the vehicle's aerodynamics anyway.
>
> There shouldn't be any risk taking, they see the
> sales numbers and the poll results on hybrid electrics,
> so there is no reason to not be all hybrid electric in
> 5 years or less.
But all it takes is one model of hybrid to be repeatedly recalled to set
them back years in terms of the public's appetite for them. That's the
kind of risk the automakers are looking at.
| |
| Joe Fischer 2006-11-17, 5:25 pm |
| On Fri, 17 Nov 2006 19:56:07 GMT, "no spam" <no@spam.net> wrote:
>
>That was the cry before it was raised but the last numbers I saw didn't
>support it.
Those were the wrong numbers. :-)
A full 40 percent of traffic fatalities are at speeds
above 60 MPH. Stats show fatalities per mile are
down, etc., but that doesn't say anything about what
the number of fatalities would be if _nobody_ went
over 55 MPH.
But it is certain that fuel is wasted pushing
air at higher speeds.
Joe Fischer
| |
| Anthony Matonak 2006-11-17, 8:25 pm |
| Joe Fischer wrote:
> On Fri, 17 Nov 2006 19:56:07 GMT, "no spam" <no@spam.net> wrote:
>
> Those were the wrong numbers. :-)
As I understand it, raising the speed limit didn't result in more
fatalities because speed wasn't the main factor in traffic accidents.
Tougher enforcement of drunk driving laws did lower fatalities.
> A full 40 percent of traffic fatalities are at speeds
> above 60 MPH. Stats show fatalities per mile are
> down, etc., but that doesn't say anything about what
> the number of fatalities would be if _nobody_ went
> over 55 MPH.
Most highways around here are posted at 65 mph and some have
a speed limit of 75 mph. Someone would have to be driving
5 to 15 mph slower than the speed limit to have an accident
at a speed less than 60 mph.
> But it is certain that fuel is wasted pushing
> air at higher speeds.
Fuel is wasted pushing cars at any speed. Cars are one of
the least efficient and most expensive ways to move people.
Anthony
| |
| clare at snyder.on.ca 2006-11-17, 8:25 pm |
| On Fri, 17 Nov 2006 18:03:03 -0500, "R.H. Allen" <kkarie@hotmail.com>
wrote:
>
>I have no idea what you mean by "overwhelms the drag," but two cars with
>different weights and the same aerodynamic properties will require
>*exactly* the same amount of energy as one another to maintain a
>constant speed (neglecting mechanical losses like rolling resistance,
>which is a function of vehicle weight). The only time their energy
>requirements will differ is during acceleration.
Not completely true. How about climing a grade?
--
Posted via a free Usenet account from http://www.teranews.com
| |
| Joe Fischer 2006-11-17, 8:25 pm |
| On Sat, 18 Nov 2006 01:17:50 GMT, Anthony Matonak
<anthonym40@nothing.like.socal.rr.com> wrote:
>Joe Fischer wrote:
>
>As I understand it, raising the speed limit didn't result in more
>fatalities because speed wasn't the main factor in traffic accidents.
Speed has always been the main factor in traffic accidents.
>Tougher enforcement of drunk driving laws did lower fatalities.
Many things have been effective in lowering fatalities
per vehicle mile, better designed cars, more SUVs (larger,
heavier vehicles are safer for occupants, not for other vehicles),
more driver education, better highways, larger percentage
of older more experienced drivers, and other things.
>
>Most highways around here are posted at 65 mph and some have
>a speed limit of 75 mph.
There are far more roads and streets and far more
traffic where speed limits are 50 or less.
>Someone would have to be driving
>5 to 15 mph slower than the speed limit to have an accident
>at a speed less than 60 mph.
If they all did, there might be a big reduction
in accidents. In fact, there are so many really bad
accidents now where the car totally disintegrates,
and that only happens at very high speeds.
>
>Fuel is wasted pushing cars at any speed. Cars are one of
>the least efficient and most expensive ways to move people.
>Anthony
Cars are more efficient than transit systems for
90 percent of people because the bus doesn't stop here,
and it doesn't go there and it only runs at the wrong time
of day. Missing the last bus to go home is something
that will discourage transit riders.
The 55 speed limit was to save fuel, it worked, and
it is needed now more than ever. The problem is,
the same people that drive over 55 now are the same
ones that would drive over 55 even if it was the limit.
Joe Fischer
| |
|
|
<clare at snyder.on.ca> wrote in message
news:v3psl2lb27ck95ijhvh9j562b27lk83k5g@4ax.com...
> On Fri, 17 Nov 2006 18:03:03 -0500, "R.H. Allen" <kkarie@hotmail.com>
> wrote:
>
>
> Not completely true. How about climing a grade?
>
unless it's up hill both ways it doesnt matter(unless of course the hills
are very steep)
| |
| clare at snyder.on.ca 2006-11-18, 1:25 pm |
| On Fri, 17 Nov 2006 20:52:37 -0500, Joe Fischer
<joe@westpointracing.com> wrote:
>On Sat, 18 Nov 2006 01:17:50 GMT, Anthony Matonak
><anthonym40@nothing.like.socal.rr.com> wrote:
>
>
> Speed has always been the main factor in traffic accidents.
Absolutely NOT true. It is the main factor in the SEVERETY of
accidents, not the number - and even then the DIFFERENCE in speed is
often more relevant than the absolute speed.
The main CAUSE of accidents is driver inattention, and that can be
more of a problem at low speeds (urban driving) than at high speeds.
>
>
> Many things have been effective in lowering fatalities
>per vehicle mile, better designed cars, more SUVs (larger,
>heavier vehicles are safer for occupants, not for other vehicles),
>more driver education, better highways, larger percentage
>of older more experienced drivers, and other things.
>
>
> There are far more roads and streets and far more
>traffic where speed limits are 50 or less.
>
>
> If they all did, there might be a big reduction
>in accidents. In fact, there are so many really bad
>accidents now where the car totally disintegrates,
>and that only happens at very high speeds.
>
>
> Cars are more efficient than transit systems for
>90 percent of people because the bus doesn't stop here,
>and it doesn't go there and it only runs at the wrong time
>of day. Missing the last bus to go home is something
>that will discourage transit riders.
>
> The 55 speed limit was to save fuel, it worked, and
>it is needed now more than ever. The problem is,
>the same people that drive over 55 now are the same
>ones that would drive over 55 even if it was the limit.
>
>Joe Fischer
--
Posted via a free Usenet account from http://www.teranews.com
| |
| clare at snyder.on.ca 2006-11-18, 1:25 pm |
| On Sat, 18 Nov 2006 21:36:19 +1100, "stu" <nowhere@justyet.com> wrote:
>
><clare at snyder.on.ca> wrote in message
>news:v3psl2lb27ck95ijhvh9j562b27lk83k5g@4ax.com...
>unless it's up hill both ways it doesnt matter(unless of course the hills
>are very steep)
>
A few long grades up, and ons short steep down makes a big
difference. I drove electric for a few years.
--
Posted via a free Usenet account from http://www.teranews.com
| |
| no spam 2006-11-18, 1:25 pm |
|
"Joe Fischer" <joe@westpointracing.com> wrote in message
news:cffsl2d4824mcdo5oat7q75pit5e2sc01q@4ax.com...
> On Fri, 17 Nov 2006 19:56:07 GMT, "no spam" <no@spam.net> wrote:
>
>
> Those were the wrong numbers. :-)
>
> A full 40 percent of traffic fatalities are at speeds
> above 60 MPH. Stats show fatalities per mile are
> down, etc., but that doesn't say anything about what
> the number of fatalities would be if _nobody_ went
> over 55 MPH.
That doesn't prove a causal effect between the greater speed and more
deaths. It could just be that 40% of deadly accidents happen on the
interstate, or other high speed, highways. You'd have to check the
percentages of death on the theses highways before and after the the speed
increase.
> But it is certain that fuel is wasted pushing
> air at higher speeds.
Depends on your definition of "wasted". I drive 55 mph probably 90% of the
time to reduce my gas consumption but there are other times I 'spend' more
fuel to drive 70 to save time. Its not a waste its just a trade of fuel for
time.
| |
| (PeteCresswell) 2006-11-18, 5:25 pm |
| Per Anthony Matonak:
>As I understand it, raising the speed limit didn't result in more
>fatalities because speed wasn't the main factor in traffic accidents.
>Tougher enforcement of drunk driving laws did lower fatalities.
I cannot cite, but somebody I trust that lives in Germany says that their
autobahn death rate per mile driven is significantly lower than the USA's
divided-highway rate.... and over there you've got Porsches doing 150+ mixing it
up with triple tractor trailers pulling out to pass at 45.... Not to mention the
many people in-between cruising at anywhere from 85 to 105...
When I'm driving over there the thing that *really* stands out is that everybody
seems to be playing by the same rules:
-----------------------------------------------------------------------
- Never cross any kind of line unless you're turn signal's been
flashing for at least several blinks
- Always yield the hammer lane to closing vehicles - before they
have to slow down for you.
- Never, ever, under any circumstances pass on the right.
- Come down the on-ramp at lane speed.
-----------------------------------------------------------------------
There are probably more, but those are the really obvious ones that contrast
with what's going on US highways.
--
PeteCresswell
| |
| Joe Fischer 2006-11-18, 5:25 pm |
| On Sat, 18 Nov 2006 "(PeteCresswell)" <x@y.Invalid> wrote:
>There are probably more, but those are the really obvious ones that contrast
>with what's going on US highways.
There are definitely more, and a lot of contrast with
other roads than one super highway.
The road I travel most is not a divided highway,
part way it has a center turn lane, but the rest of the
way it is 4 lanes with just a double yellow line separating
opposite direction traffic, and no warning sign saying
"center lane ends".
The speed limit is 50 part way, and 55 part way,
but most people drive 65 or 70 where it is 55.
The mindset of the speeders is, if something
gets in the way, don't use the brakes, steer around it,
and that seems to be why so many cars are entering
houses and business places at high speed.
I have been wondering if there is much difference
if a front wheel drive car engine locks up compared to
rear wheel drive, the number of cars crossing the center
media or hitting trees way off to the side at speeds of
60 or greater is really scary.
The state is even installing cables in the center
of 80 foot wide center media to stop the head on
crashes of cars out of control.
And speed is the factor in all of these accidents.
I find everybody tries to justify speed, and I
simply don't see any justification for it.
Joe Fischer
| |
| Jesse Spencer 2006-11-18, 8:25 pm |
|
> Fourth, busses do a lot of stop and go. This is where my ignorance of regen
> braking comes in, would using it help in an electric bus.
IC coming out with hybrid buses in 07 I believe.
Hybrids have to be enticing to any service thats stop and go...from
school buses to delivery vans.
Regen braking is quite effective because the amount of energy needed to
stop is close to that needed to accelerate. A reasonable percentage of
energy recaptured is free-o.
Regen braking is why the counter intuitive higher mpg in city for hybrids.
| |
| Joe Fischer 2006-11-18, 8:25 pm |
| On Sun, 19 Nov 2006 00:56:28 GMT, Jesse Spencer
<spencerfdnydelete@netscape.net> wrote:
>
>IC coming out with hybrid buses in 07 I believe.
>Hybrids have to be enticing to any service thats stop and go...from
>school buses to delivery vans.
>Regen braking is quite effective because the amount of energy needed to
>stop is close to that needed to accelerate. A reasonable percentage of
>energy recaptured is free-o.
>Regen braking is why the counter intuitive higher mpg in city for hybrids.
Part of it, but not having an engine running while
waiting in traffic is the rest, plus not pushing air so fast.
Joe Fischer
| |
| (PeteCresswell) 2006-11-18, 8:25 pm |
| Per Joe Fischer:
> The road I travel most is not a divided highway,
>part way it has a center turn lane, but the rest of the
>way it is 4 lanes with just a double yellow line separating
>opposite direction traffic, and no warning sign saying
>"center lane ends".
> The speed limit is 50 part way, and 55 part way,
>but most people drive 65 or 70 where it is 55.
>
> The mindset of the speeders is, if something
>gets in the way, don't use the brakes, steer around it,
>and that seems to be why so many cars are entering
>houses and business places at high speed.
Germany?
--
PeteCresswell
| |
| Joe Fischer 2006-11-18, 8:25 pm |
| On Fri, "R.H. Allen" <kkarie@hotmail.com> wrote:
>Joe Fischer wrote:
>
>But all it takes is one model of hybrid to be repeatedly recalled to set
>them back years in terms of the public's appetite for them. That's the
>kind of risk the automakers are looking at.
So there will never be hybrids? I think the fear
factor should be forgotten, and go electric hybrid all the way,
it doesn't matter if it is IC, fuel cell, flow battery or what.
If they don't Honda and Toyota will have all the market.
Joe Fischer
| |
| Joe Fischer 2006-11-18, 8:25 pm |
| On Sat, "(PeteCresswell)" <x@y.Invalid> wrote:
>Per Joe Fischer:
>
>Germany?
No, Fort Knox.
Joe Fischer
| |
| Eeyore 2006-11-19, 3:25 am |
|
"(PeteCresswell)" wrote:
> Per Joe Fischer:
>
> Germany?
European accident rates are a fraction of US rates despite higher speeds. Auto
accidents are caused primarily by *bad driving* !
Graham
| |
| (PeteCresswell) 2006-11-19, 1:25 pm |
| Per Joe Fischer:
>
> No, Fort Knox.
Thanks. I was having a little cognitive dissonance over it because it sounded
very un-German.
--
PeteCresswell
| |
| daestrom 2006-11-19, 1:25 pm |
|
"Joe Fischer" <joe@westpointracing.com> wrote in message
news:a33vl21gc0rj5chbpcrsnet0li4qpijrnr@4ax.com...
> On Sat, 18 Nov 2006 "(PeteCresswell)" <x@y.Invalid> wrote:
>
>
> There are definitely more, and a lot of contrast with
> other roads than one super highway.
>
> The road I travel most is not a divided highway,
> part way it has a center turn lane, but the rest of the
> way it is 4 lanes with just a double yellow line separating
> opposite direction traffic, and no warning sign saying
> "center lane ends".
> The speed limit is 50 part way, and 55 part way,
> but most people drive 65 or 70 where it is 55.
>
> The mindset of the speeders is, if something
> gets in the way, don't use the brakes, steer around it,
> and that seems to be why so many cars are entering
> houses and business places at high speed.
> I have been wondering if there is much difference
> if a front wheel drive car engine locks up compared to
> rear wheel drive, the number of cars crossing the center
> media or hitting trees way off to the side at speeds of
> 60 or greater is really scary.
>
> The state is even installing cables in the center
> of 80 foot wide center media to stop the head on
> crashes of cars out of control.
>
> And speed is the factor in all of these accidents.
>
> I find everybody tries to justify speed, and I
> simply don't see any justification for it.
>
Reminds me of the last time I went through PA. They've given up on law
enforcement apparently. Several areas are posted with large black/yellow
signs that state, "Warning, Agressive Drivers" and "Dangerous Driver Area".
What's up with that??
I wonder if there's a study that shows a correlation between traffic law
enforcement and accident fatalities?
daestrom
| |
| daestrom 2006-11-19, 1:25 pm |
|
"Harry" <susan.armitage@virgin.net> wrote in message
news:1163618415.113603.109690@f16g2000cwb.googlegroups.com...
>
> nicksanspam@ece.villanova.edu wrote:
>
> Apart from Braking the advantage of regenerative braking is when
> descending hills, when the energy used climbibg the hill is put back
> into the batteries (less losses). These losses are however quite
> large. With lead acid batteries you have to put three times the power
> in as what you get out. (due to heating and hydrogen vent losses)
Power or energy? Lead acid batteries typically can return 70-80% of the
energy put into them.
> In days of yore trolley buses and trams (some of them) used to time
> their journeys so that one descending a hill would regenerate to help
> another one simultaneously climbing the hill. Hard to arrange though.
Not so 'yore' in San Francisco. The cable cars are still operated using a
similar technique. The cable house is not capable of pulling all the cars
up hills at the same time, some cars must be going down hills to help pull
others up.
> Some again had "coasting brakes" for descending hills which
> regenerated but the electricty was run through large resistors ,
> dissipating the energy as heat. This slowed the bus without wearing
> out mechanical brakes. (No engine braking from electric motor as with
> a diesel engine.)
This technique is called 'dynamic braking' and is used in modern railroad
locomotives (the diesel-electric type used in the US). The energy of
coasting down grades is converted to electricity in the traction motors,
then converted to heat in the dynamic brake resistor bank (and rejected to
the air by a fan blowing on the resistor bank).
daestrom
| |
| Joe Fischer 2006-11-19, 5:25 pm |
| On Sun, 19 Nov 2006 17:38:21 GMT, "daestrom"
<daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:
>"Joe Fischer" <joe@westpointracing.com> wrote in message
>news:a33vl21gc0rj5chbpcrsnet0li4qpijrnr@4ax.com...
>
>Reminds me of the last time I went through PA. They've given up on law
>enforcement apparently. Several areas are posted with large black/yellow
>signs that state, "Warning, Agressive Drivers" and "Dangerous Driver Area".
>
>What's up with that??
It is possible to drive aggressively and dangerously,
and stay within traffic laws. I have been guilty at times
of driving aggressively, but have been very lucky, but
most of the time I practice good defensive driving, and
it saves gas.
>I wonder if there's a study that shows a correlation between traffic law
>enforcement and accident fatalities?
>daestrom
I am sure there is, but google gives so many hits
it makes my eyes burn.
But because damage, injury, and stopping distance
are all a function of the square of the speed, an extra
ten miles per hour can mean the difference between
a month in the hospital or a funeral.
It has been 24 years since I was in PA, and I
suspect people drive differently now.
In that time, the cars have gotten lighter and
quicker, my weight hasn't changed, but I have
gotten slower.
Joe Fischer
| |
| R.H. Allen 2006-11-20, 1:25 pm |
| clare at snyder.on.ca wrote:
> On Fri, 17 Nov 2006 18:03:03 -0500, "R.H. Allen" <kkarie@hotmail.com>
> wrote:
>
>
> Not completely true. How about climing a grade?
That's the sort of thing I meant by "mechanical losses." Read it in
context -- the point was to emphasize that vehicle weight has absolutely
nothing to do with aerodynamic drag.
| |
| R.H. Allen 2006-11-20, 1:25 pm |
| Joe Fischer wrote:
> On Fri, "R.H. Allen" <kkarie@hotmail.com> wrote:
>
>
> So there will never be hybrids?
I didn't say that, only that there's tremendous institutional inertia in
the auto industry.
> I think the fear
> factor should be forgotten, and go electric hybrid all the way,
> it doesn't matter if it is IC, fuel cell, flow battery or what.
> If they don't Honda and Toyota will have all the market.
With the economics of early hybrids they would have been content to let
Honda and Toyota have the market. And while they've improved
considerably from an economic standpoint, it is my distinct impression
that they still aren't very profitable (and note the small numbers of
them that are built despite the long wait lists for them). You're going
to have a hard time convincing the Big Three to build an unprofitable
vehicle -- especially one they perceive as risky -- when they're
bleeding money and shedding jobs.
Don't get me wrong, I'm not saying hybrids are bad or that IC engines
are good. But building hybrids in large numbers is not a simple decision
when you're the one putting up the billions of dollars and years of
development that are required.
| |
| Joe Fischer 2006-11-20, 5:25 pm |
| On Mon, "R.H. Allen" <kkarie@hotmail.com> wrote:
>Joe Fischer wrote:
>
>I didn't say that, only that there's tremendous institutional inertia in
>the auto industry.
I don't see the big deal, they have built electric cars,
they can use almost any chassis and body, just build the
car as electric, and add a generator.
I just saw a Chevy SS-R for the first time yesterday,
the market for those can't possibly be 10 percent of what
the hybrid market could be for even an unengineered model.
>
>With the economics of early hybrids they would have been content to let
>Honda and Toyota have the market. And while they've improved
>considerably from an economic standpoint, it is my distinct impression
>that they still aren't very profitable (and note the small numbers of
>them that are built despite the long wait lists for them).
If a long waiting list doesn't do it, somebody is psycho.
>You're going
>to have a hard time convincing the Big Three to build an unprofitable
>vehicle -- especially one they perceive as risky -- when they're
>bleeding money and shedding jobs.
Because they are not building a car to compete with
the 50 and 60 MPG hybrids.
>Don't get me wrong, I'm not saying hybrids are bad or that IC engines
>are good. But building hybrids in large numbers is not a simple decision
>when you're the one putting up the billions of dollars and years of
>development that are required.
At this point in time, if it takes Billions of dollars
to tool and get a hybrid in production, they need to fire
about 3000 engineers and give one guy a free hand.
The F-117 Stealth fighter cost less than 1 Billion
to get into production, a hybrid car is not a stealth fighter,
and GE sells electric motors and generators, so I just
don't see why they have the fear and reluctance.
Maybe the stockholders will force the issue
before the companies go broke building gas guzzlers.
I have been a GM dealer mechanic, and have
always preferred GM, but I am at the point where
I don't even want to bother working on an ICE,
it is the worse possible prime mover.
Joe Fischer
| |
| clare at snyder.on.ca 2006-11-20, 5:25 pm |
| On Mon, 20 Nov 2006 11:07:34 -0500, "R.H. Allen" <kkarie@hotmail.com>
wrote:
>clare at snyder.on.ca wrote:
>
>That's the sort of thing I meant by "mechanical losses." Read it in
>context -- the point was to emphasize that vehicle weight has absolutely
>nothing to do with aerodynamic drag.
I'll agree with your last ten words.
--
Posted via a free Usenet account from http://www.teranews.com
| |
| Eeyore 2006-11-20, 8:25 pm |
|
"R.H. Allen" wrote:
> clare at snyder.on.ca wrote:
>
> That's the sort of thing I meant by "mechanical losses." Read it in
> context -- the point was to emphasize that vehicle weight has absolutely
> nothing to do with aerodynamic drag.
Climbing a 'grade' isn't a mechanical loss.
The energy is recovered going back down it.
Graham
| |
| Joe Fischer 2006-11-20, 8:25 pm |
| On Tue, 21 Nov 2006 00:04:42 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:
>"R.H. Allen" wrote:
>
>Climbing a 'grade' isn't a mechanical loss.
>
>The energy is recovered going back down it.
>Graham
This requires some thought, driving down
a hill into a valley and up the other side would
allow the energy going down to be used going
up the other side.
But when considering batteries, the energy
should be considered recovered even though it is
used for something else besides going back up the
hill.
This may illustrate the difficulty of moving
from a wasteful ICE with the engine running all
the time to renewable or alternate energy with
batteries (ultracapacitors) and regenerative braking.
The energy has to be considered for each
specific input and output, acceleration, air drag,
rolling friction, etc.
And with the wasteful ICE everybody is
accustomed to, there is a tendency to think that
energy input is needed constantly because the
engine runs all the time.
Joe Fischer
| |
| R.H. Allen 2006-11-21, 1:25 pm |
| Joe Fischer wrote:
> On Mon, "R.H. Allen" <kkarie@hotmail.com> wrote:
>
>
> I don't see the big deal, they have built electric cars,
> they can use almost any chassis and body, just build the
> car as electric, and add a generator.
>
> I just saw a Chevy SS-R for the first time yesterday,
> the market for those can't possibly be 10 percent of what
> the hybrid market could be for even an unengineered model.
You're right about the small market for the SSR. Chevy quit producing it
last spring after building only about 25,000 of them. But if that's 10
percent of what the hybrid market *could* be then you've just given
automakers an excellent reason not to bother with them -- the Toyota
Camry alone sells more than 400,000 units/year in the U.S.
>
> If a long waiting list doesn't do it, somebody is psycho.
Toyota built some 55,000 Priuses last year (and lost money on every one
of them). Most estimates I've heard are that they could have sold double
that. That would be 110,000 vehicles -- a medium seller at best. Psycho
would be inferring from a waiting list that represents a very small
number of vehicle sales that flooding the market with millions of
hybrids is a sound business decision.
>
> Because they are not building a car to compete with
> the 50 and 60 MPG hybrids.
>
>
> At this point in time, if it takes Billions of dollars
> to tool and get a hybrid in production, they need to fire
> about 3000 engineers and give one guy a free hand.
Toyota spent about $1 billion in development costs on the Prius, which
is about average for a new car. That doesn't count the cost of the
manufacturing plant. I don't know what the Prius plant cost, but the
plant Chrysler used to build the Cirrus/Stratus platform was more than a
billion dollars itself (though it was churning out 300,000+
vehicle/year, as opposed to the 55,000 for the Prius).
> The F-117 Stealth fighter cost less than 1 Billion
> to get into production, a hybrid car is not a stealth fighter,
> and GE sells electric motors and generators, so I just
> don't see why they have the fear and reluctance.
That may be, but that particular stealth fighter went into production in
the late '80s and would most certainly cost in excess of a billion
dollars to develop now. And more recent stealth fighters have cost much,
much more than that....
| |
| R.H. Allen 2006-11-21, 1:25 pm |
| Eeyore wrote:
>
> "R.H. Allen" wrote:
>
>
> Climbing a 'grade' isn't a mechanical loss.
Well, it's not an electrical loss or an aerodynamic loss. The energy is
lost to gravity (or to potential energy, if you prefer) -- sounds like a
mechanical loss to me.
> The energy is recovered going back down it.
Immaterial. The energy can't be used to help maintain constant speed on
the way up the hill. Now maybe it's just semantics because we're talking
about different time scales, but in the context of my comment there is
no way to recover the energy lost when climbing a grade.
| |
|
|
"R.H. Allen" <kkarie@hotmail.com> wrote in message
news:mqWdnZjphrhVgP7YnZ2dnUVZ_s2dnZ2d@giganews.com...
> Joe Fischer wrote:
>
> You're right about the small market for the SSR. Chevy quit producing it
> last spring after building only about 25,000 of them. But if that's 10
> percent of what the hybrid market *could* be then you've just given
> automakers an excellent reason not to bother with them -- the Toyota Camry
> alone sells more than 400,000 units/year in the U.S.
>
>
> Toyota built some 55,000 Priuses last year (and lost money on every one of
> them).
The Prius has been available for 9 years. Are you saying this company for 9
years has lost money and continues to do so? In know BMC, drew even on the
original Mini. It enabled them to buy more parts cheaper in bulk and make
more money on other models.
> Most estimates I've heard are that they could have sold double that. That
> would be 110,000 vehicles --
> a medium seller at best.
It is made in Japan, USA and China. They also make other hybrid models too.
55,000 maybe only in the USA.
| |
| R.H. Allen 2006-11-21, 8:25 pm |
| News wrote:
>
> "R.H. Allen" <kkarie@hotmail.com> wrote in message
> news:mqWdnZjphrhVgP7YnZ2dnUVZ_s2dnZ2d@giganews.com...
>
> The Prius has been available for 9 years. Are you saying this company
> for 9 years has lost money and continues to do so?
Upon further investigation, I can find evidence that Toyota made a
razor-thin profit margin on U.S. sales of the Prius in 2004 (it seems
they've been able to charge more, and thus make a profit sooner, on
vehicles sold in Japan, but about half them are sold in the U.S.). I
suspect they're still making a profit and that it is part of the reason
that they've ramped up production over the last couple of years. But
otherwise, yes, I'm saying they sold the car at a loss -- in the U.S.,
at least -- for five or six years. That's hardly unprecedented,
especially for a Japanese company.
> In know BMC, drew
> even on the original Mini. It enabled them to buy more parts cheaper in
> bulk and make more money on other models.
I have no idea what you're trying to say there.
>
> It is made in Japan, USA and China. They also make other hybrid models
> too. 55,000 maybe only in the USA.
You're right. Earlier this year worldwide sales of the Prius reached
500,000. For the entire 9 years of its existence. That's an average of
55,000/year worldwide. Not too long ago they were on a pace to exceed
100,000 U.S. sales in 2006, so they're headed in the right direction.
Still not nearly enough to justify the sort of all-out hybrids-or-bust
campaign that Joe seems to favor.
| |
| Joe Fischer 2006-11-22, 3:25 am |
| On Tue, "R.H. Allen" <kkarie@hotmail.com> wrote:
>Joe Fischer wrote:
>
>You're right about the small market for the SSR. Chevy quit producing it
>last spring after building only about 25,000 of them. But if that's 10
>percent of what the hybrid market *could* be then you've just given
>automakers an excellent reason not to bother with them -- the Toyota
>Camry alone sells more than 400,000 units/year in the U.S.
And the Hybrid Camry is being made now near Cincinnati.
>
>Toyota built some 55,000 Priuses last year (and lost money on every one
>of them). Most estimates I've heard are that they could have sold double
>that. That would be 110,000 vehicles -- a medium seller at best. Psycho
>would be inferring from a waiting list that represents a very small
>number of vehicle sales that flooding the market with millions of
>hybrids is a sound business decision.
They are needed, people can not afford to pay $2
a gallon in the US, so they need 50 MPG cars, and the
hybrid is the only way to do that in city traffic.
>
>Toyota spent about $1 billion in development costs on the Prius, which
>is about average for a new car. That doesn't count the cost of the
>manufacturing plant. I don't know what the Prius plant cost, but the
>plant Chrysler used to build the Cirrus/Stratus platform was more than a
>billion dollars itself (though it was churning out 300,000+
>vehicle/year, as opposed to the 55,000 for the Prius).
There are many assembly plants, and more and more
will have to switch to hybrids or close.
Ford has had to start reducing the workforce on the
most popular product, too bad they didn't foresee the hybrid
market and the fact that hybrids can get better mileage in
the city than on the highway.
>
>That may be, but that particular stealth fighter went into production in
>the late '80s
No, late 1970s, first flight in 1981.
..and would most certainly cost in excess of a billion
>dollars to develop now. And more recent stealth fighters have cost much,
>much more than that....
But they are more capable, faster, and have longer range.
There is a big market for a car that gets good mileage
and looks sharp. It doesn't need high technology, just
an electric motor, and a generator or fuel cell to charge
the batteries.
In the evacuation of Houston many people ran
out of gas only 100 miles north, and with a good hybrid,
they would not have.
If the reason for building cars is to make $5000
profit on each, then both the public and the auto makers
are in big trouble.
Joe Fischer
| |
| Joe Fischer 2006-11-22, 3:25 am |
| On Tue, "R.H. Allen" <kkarie@hotmail.com> wrote:
>Eeyore wrote:
>
>Immaterial. The energy can't be used to help maintain constant speed on
>the way up the hill. Now maybe it's just semantics because we're talking
>about different time scales, but in the context of my comment there is
>no way to recover the energy lost when climbing a grade.
There is, just come back down the hill.
It may not be the same energy, but one is
as good as the next.
Joe Fischer
| |
| no spam 2006-11-22, 1:25 pm |
| >> | | |