What is the "Optimal" Speel Limit?
John Gilmer
Since in other threads it has been asserted the Physics is the source of all
knowledge (and I have given up my counter-claim that the source of all
knowledge is Electrical Engineering) perhaps you can apply your collective
brillance to the following questions:
WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate Highways
used as commuter roads. By optimum I mean, carries the greatest number of
vehicles. How would one go about determining it? What data would it be
necessary to obtain? Would strict enforcement of "minimum speed" make a
major difference.
NO CHEATING. You can't say, the optimum speed limit is ZERO. Let people
walk, bike, or ride the transit system to be constructed in the right of
way.
From a NG in Virginia, a poster wrote me that to a first approximation,
the speed limit doesn't make any difference. Each car would stay 2 seconds
behind the car in front. The lane capacity becomes 2 seconds/car (ok, the
car doesn't have zero lenght) but this is clearly a good first order guess.
Thirty plus years ago a lot of simulation work was done in this area.
Since then speed limits have gotten involved in politics and I don't think
it is possible to get an objective (let alone honest) answered from studies
paid for by the government.
_______________________
President Clinton is a Rapist! -- But, that's OK.
John Gil...@Crosslink.net
Joe Fischer
: WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate Highways
: used as commuter roads. By optimum I mean, carries the greatest number of
: vehicles. How would one go about determining it? What data would it be
: necessary to obtain? Would strict enforcement of "minimum speed" make a
: major difference.
You have to consider the extra lives lost and
the time lost to extra accidents at higher speeds.
I drive 55, and keep a good distance behind
other cars, and I get there about as fast as anybody.
: NO CHEATING. You can't say, the optimum speed limit is ZERO. Let people
: walk, bike, or ride the transit system to be constructed in the right of
: way.
: Thirty plus years ago a lot of simulation work was done in this area.
: Since then speed limits have gotten involved in politics and I don't think
: it is possible to get an objective (let alone honest) answered from studies
: paid for by the government.
:
: President Clinton is a Rapist! -- But, that's OK.
Driving 55 is optimum for all considerations,
any faster and there is more stress, and more problems
with wheel balance, motor overheating, and a lot of
other troubles, in addition to worse accidents because
of the ability to stop depends on the square of the
speed. At 55 you have a chance to brake to below
30 MPH before colliding, and at higher speeds, forget it.
I was on an underused freeway yesterday where
the posted speed limit is 65, and saw one bad accident,
and about one abandoned car every mile.
You just won't believe how much extra distance
is required to stop at the higher speeds. And since
most people drive over the speed limit, the reason for
the increasing fatalities is very clear.
At 55 you move 60 feet in the time it takes
to get your foot to the brake pedal. Then it takes
at least 120 feet to stop on good pavement in dry
weather. The number of cars the highway will carry
is not a big issue, lives lost is.
Joe Fischer
Lorenz [to_email_see_my_sig] Borsche
<gil...@crosslink.net> wrote:
>WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate Highways
>used as commuter roads. By optimum I mean, carries the greatest number of
>vehicles.
Any speed as long as cars ride bumber to bumper. What you really ask
for is this: at which speed the greatest number of people are
transported from A to B (meaning personal A to personal B, otherwise
busses would be the answer :-). Methinks, the number is close to what
you are allowed to drive on US highways, 80-100 km/h. This speed
allows for relative short distances between cars, which solely depends
on the virtue of the drivers. Driven by microchips, we may double the
speed and shorten distances to one car length, which will generate a
nice throughput.
--
Lorenz Borsche http://www.borsche.de
eMail? Name: LBsys Provider: dinx Extension: de
-----------------------------------------------------
All professions are conspiracies against laymen (GBS)
John Gilmer
One: You are "defining away the problem" which is a form of cheating.
Two: Many, if not most, interstate highways are parellel to the older,
unlimited access route. When the interstate and the local HW have the same
speed limit more people use the less safe road. Thus, even if safety is
your ONLY concern, raising the speed limit on the interstate may be a good
idea.
Three: Since Richard Nixon pulled the "double nickel" out of his ass back
in 1974 both the cars and the highways have improved. If only because of
this the question of what the "best" speed should be should be re-opened!
Yours,
John Gil...@crosslink.net
Joe Fischer wrote in message <36fd2...@news.iglou.com>...
>John Gilmer (gil...@crosslink.net) wrote:
>: WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate
Highways
>: used as commuter roads. By optimum I mean, carries the greatest number
of
Paul Lutus
This is not the whole story. The two-second interval is meant to allow time
to react to the sight of a car braking in front of you. It won't work if the
car in front collides with something solid, as so often happens in fog. In
this case, the two-second interval won't prevent your joining the pileup.
People generally don't know this, and that is one reason why fog (or heavy
rain, darkness, curves) is so dangerous -- people falsely believe they are
safe if they can see a two-second interval ahead.
Also, because the energy in a moving object is proportional to mass times
velocity squared, each increase of about 41% in speed doubles the energy of
the vehicles, energy that must be dissipated against something -- brakes
(cost, materials), objects or people (cost of damage, death, medical care).
These considerations should not be left out of a discussion of optimum
highway speed.
--
Paul Lutus
www.arachnoid.com
John Gilmer wrote in message <36fcd34a$1$1...@mojo.crosslink.net>...
>WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate Highways
>used as commuter roads. By optimum I mean, carries the greatest number of
>vehicles
<snip>
John Gilmer
Paul Lutus wrote in message ...
><< Each car would stay 2 seconds behind the car in front. >>
>
>This is not the whole story. The two-second interval is meant to allow time
>to react to the sight of a car braking in front of you. It won't work if
the
>car in front collides with something solid, as so often happens in fog. In
>this case, the two-second interval won't prevent your joining the pileup.
Of course, you are right: You should be able to stop in time if the highway
is blocked.
The two second rule works just fine in normal circumstances. It only
works if you do more than just look at the bumper of the car in front of
you. In other words, just because the guy in front of you runs into a
stopped truck, that doesn't mean you have to run into him.
Another point: cars that are running normally can stop faster than cars
that are out of control.
My orginial question still stands: Scientifically, what is the most
efficient speed in terms of cars/hour/lane?
JLG
Paul Lutus
efficient speed in terms of cars/hour/lane? >>
Because of the numerous factors involved, I do not think there is a
defensible scientific answer, any more than there is for a question such as,
"Will it rain next week?"
If you only use the two-second interval rule and disregard other factors,
there is no single answer -- all speeds are the same. If you include other
factors, the question quickly leaves the analytical realm.
--
Paul Lutus
www.arachnoid.com
John Gilmer wrote in message <36fd660c$0$1...@mojo.crosslink.net>...
<snip>
Wolfram Schmied
wrote:
On a well-constructed road system, it usually just depends on how fast
you want to go. Example:
Here in Germany, on a stretch of the A5 near Frankfurt I used to
frequent a lot, you have the choice between four lanes for each
direction. Rightmost, trucks and other slow vehicles go 50mph. Middle
left, average speed 70, middle right 90-110. Leftmost, anything below
130mph is a roadblock. So, except for rush hour (3-6pm), which slows
speed down to 50mph on average, the optimum speed depends on the
individual traveller.
You say 'accidents?' I reply, Germany is and has been for decades in
the international average.
Way to go
Wolfram 8-)#
Paul Lutus
cars follow a rule about distance based on a time interval, say two seconds,
speed drops out of the equation as a factor in traffic volume. Other factors
have to be considered, those not having strictly speaking to do with
maximizing traffic volume.
There are some experimental sensor/braking systems that road-follow and
detect the car in front, keeping a relatively short, constant distance. This
kind of arrangement is the focus of active research because the interval
between cars is obviously a more productive area of study than increasing
speeds.
<< You say 'accidents?' I reply, Germany is and has been for decades in the
international average. >>
I know some of the reasons. If you met some selected American drivers, and
saw the methods by which they are "qualified" to operate large, heavy metal
objects, you would probably fly home right away.
Guess how many American drivers know that a car's stopping distance varies
as the square of its speed (neglecting reaction time)? I have been
performing an unofficial poll, during my lecture series. Virtually no
American drivers know this.
--
Paul Lutus
www.arachnoid.com
Wolfram Schmied wrote in message <36fe4937...@news.blinx.de>...
Joe Fischer
: There are some experimental sensor/braking systems that road-follow and
: detect the car in front, keeping a relatively short, constant distance. This
: kind of arrangement is the focus of active research because the interval
: between cars is obviously a more productive area of study than increasing
: speeds.
That is a hair-brained idea, many accidents are from
vehicles crossing the center median and from accidents in
adjacent lanes.
In order to stop, the speed must be low enough to
stop in the distance needed _ to _ stop, and for humans
driving this usually is worded as "driving within headlights"
at night, or if there is glaze ice (black ice) the car
must stop before getting to the ice.
A computer will never be able to drive a car in
traffic, although it could be of considerable assistance
to a human driver.
Joe Fischer
Mark Folsom
news:36fcd34a$1$1...@mojo.crosslink.net...
> Greetings:
>
> Since in other threads it has been asserted the Physics is the source of
all
> knowledge (and I have given up my counter-claim that the source of all
> knowledge is Electrical Engineering) perhaps you can apply your collective
> brillance to the following questions:
>
Highways
> used as commuter roads.
The optimum is no speed limit, since that gets the self-appointed speed
limit nannies out of blocking mode in the left lane. Traffic often clumps
behind multiple slow cars driving abreast leaving gaps in which few or no
cars pass by for varying intervals.
>By optimum I mean, carries the greatest number of
> vehicles.
Why is that the optimum? Maximizing the number of vehicles at 10 mph
doesn't make a freeway serve my purposes optimally. I'm more concerned with
how long it takes me to get from one point to another.
>How would one go about determining it? What data would it be
> necessary to obtain? Would strict enforcement of "minimum speed" make a
> major difference.
Probably not, but strict lane discipline would help a lot, since it would
help to eliminate clumping.
>
> NO CHEATING. You can't say, the optimum speed limit is ZERO. Let
people
> walk, bike, or ride the transit system to be constructed in the right of
> way.
>
> From a NG in Virginia, a poster wrote me that to a first approximation,
> the speed limit doesn't make any difference. Each car would stay 2
seconds
> behind the car in front.
I don't think people drive like that in heavy traffic. My experience is
that in heavy traffic, people follow more closely.
>The lane capacity becomes 2 seconds/car (ok, the
> car doesn't have zero lenght) but this is clearly a good first order
guess.
>
> Thirty plus years ago a lot of simulation work was done in this area.
> Since then speed limits have gotten involved in politics and I don't think
> it is possible to get an objective (let alone honest) answered from
studies
> paid for by the government.
NHTSA published fatality rate figures for all German freeways while giving
the impression that the figures were for the West German Autobahns. They
were found out and confronted with the fact that the fatality rate for the
Autobahns is the same as for US Interstates and they agreed that they would
stop publishing the figures, but refused to issue a retraction. Also, the
old study that showed that the lowest accident rate on interstates is for
drivers going 12 mph above average appears to be unavailable from the
government.
>
> _______________________
> President Clinton is a Rapist! -- But, that's OK.
>
> John Gil...@Crosslink.net
>
>
--
Mark Folsom, P.E.
Consulting Mechanical Engineer
http://www.redshift.com/~folsom
Lorenz [to_email_see_my_sig] Borsche
(Wolfram Schmied) wrote:
>Here in Germany, on a stretch of the A5 near Frankfurt I used to
>frequent a lot, you have the choice between four lanes for each
>direction. Rightmost, trucks and other slow vehicles go 50mph. Middle
>left, average speed 70, middle right 90-110. Leftmost, anything below
>130mph is a roadblock. So, except for rush hour (3-6pm), which slows
>speed down to 50mph on average, the optimum speed depends on the
>individual traveller.
But he wanted to know the optimum of the road. That is given where it
balances under full load: at 50 mph as you rightly say. The limiting
factor of course is human reaction time. Chip driven we could rise
that to 150 mph with problems (chips talking to each other, thus
looking in advance a few hundred cars..)
>You say 'accidents?' I reply, Germany is and has been for decades in
>the international average.
Much better than that actually. A few figures from here for our
american friends to compare: 30 years ago we had some 18 million cars
driving an averaged 9.000 km/a and a death toll of 8000 per year. Now
we have 40 million cars, averaging 13.000 km and a death toll of 7300
last year. Well-defined crash zones, ABS, airbag and safety belts are
responsible for that. The numbers include all sorts of streets, in
town and out of town and all fatalities (i.e. pedestrians being run
over, dead bikers etc.) where a car was involved.
Lorenz [to_email_see_my_sig] Borsche
[to_email_see_my_sig] Borsche) wrote:
>factor of course is human reaction time. Chip driven we could rise
>that to 150 mph with problems (chips talking to each other, thus
-----------------^^^^
Should have been 'without' of course.
Paul Lutus
could be of considerable assistance to a human driver. >>
Never say "never" :) Statistically speaking, and assuming something about
your age, you will see it happen in your lifetime.
The key to the systems being tested is that the driver's reaction time is no
longer a factor. It is not a hair-brained idea. Also, barring mechanical
failure, the system maintains the car's lane position, enters and leaves the
highway, and so forth.
--
Paul Lutus
www.arachnoid.com
Joe Fischer wrote in message <36fec...@news.iglou.com>...
<snip>
Lorenz [to_email_see_my_sig] Borsche
><< A computer will never be able to drive a car in traffic, although it
>could be of considerable assistance to a human driver. >>
>
>Never say "never" :) Statistically speaking, and assuming something about
>your age, you will see it happen in your lifetime.
>
>The key to the systems being tested is that the driver's reaction time is no
>longer a factor. It is not a hair-brained idea.
I'd second that. Although I'd only believe in statistics I have
forged myself :-)
Mark Folsom
Lorenz [to_email_see_my_sig] Borsche <pub...@usa.net> wrote in message
news:36fff...@news.farside.net...
> In article <vGPL2.1302$fb4....@news2.giganews.com>, "Paul Lutus"
> <nos...@nosite.com> wrote:
> ><< A computer will never be able to drive a car in traffic, although it
> >could be of considerable assistance to a human driver. >>
> >
> >Never say "never" :) Statistically speaking, and assuming something about
> >your age, you will see it happen in your lifetime.
> >
> >The key to the systems being tested is that the driver's reaction time is
no
> >longer a factor. It is not a hair-brained idea.
>
> I'd second that. Although I'd only believe in statistics I have
> forged myself :-)
>
You should be more honest and only fudge statistics. Forging is very bad.
Lorenz [to_email_see_my_sig] Borsche
<fols...@redshift.com> wrote:
>> I'd second that. Although I'd only believe in statistics I have
>> forged myself :-)
>>
>
>You should be more honest and only fudge statistics. Forging is very bad.
Thanks! I'll remember that! I probably meant fudging anyway. That's
the bad thing not being a native speaker - you can't break even, not
even on very hot days...
Speaking of hot days: At 10 am we switched on the solar panels. At
11:30 (summertime, i.e. ~10.00 solar time) on an overcast day it
delivered 650 Watt already. Not bad for the end of march.
Paul Lutus
11:30 (summertime, i.e. ~10.00 solar time) on an overcast day it
delivered 650 Watt already. Not bad for the end of march. >>
Das ist phantastisch! How many panels? What kind?
--
Paul Lutus
www.arachnoid.com
Lorenz [to_email_see_my_sig] Borsche wrote in message
<3700a...@news.farside.net>...
<snip>
Thomas Jaworowski
Cars are not really all that aerodynamic. At around 200 MPH drag becomes an
issue. Most production cars can't even surpass 130 MPH.
If cars drove at 130 MPH, then they would be burning lots of fuel and since
they are redlining their engines, their engines would blow.
I would have to say that the optimal would be where it is not the most
efficient way to move cars, but how safe is it to move the cars. Deaths from
automobile accidents is the leading cause of death by injury. If cars could
be automated and controlled by computer, then I think that we could reduce
the number of accidents caused by human error (i.e. drunk driving, sleeping
at the wheel, "rubber necking"...) and even raise the speed limits on the
road.
Many intelligent systems have been invented and tested that can actually
drive a car by following the white lines that are painted on the surface of
the road or by sensing magnetic strips placed underneath the road surface.
One day, perhaps, driving might be computer assisted and your car may one
day have an auto pilot.
Lorenz [to_email_see_my_sig] Borsche
><< Speaking of hot days: At 10 am we switched on the solar panels. At
>11:30 (summertime, i.e. ~10.00 solar time) on an overcast day it
>delivered 650 Watt already. Not bad for the end of march. >>
>
>Das ist phantastisch! How many panels? What kind?
It is 24 Kyocera 80wp modules. They give a guarantee of 80% (of that
80 wp) for 20 years and I hope of course they'll last 50 years and
more. Anyway it was a bargain: the Heidelberg community put up a
program financing solar roofs. That means, I invest into the roof
(16.6 K$ at 1% interest guaranteed for 10 years) rate and 80c/kWh
guarantee for 10 years. After 15 years the installation should be
payed back, so even if efficiency drops a bit, there's still not much
risk. After 20 years I have ~1600 kwh/year for free, especially in
summer to run air conditioning.
That's not a hell of a lot, but I tell you, seeing a powermeter
running backwards is pretty impressive!
The transformer has an RS232 interface, and I'd love to put the data
continuously on a web page, but alas, the telephone costs (plus a
computer running) would eat up 20% of what the cells gain in money.
Today is a real nice sunny day and I wonder what the meter will read
tonight (last night it said 3.7 kWh).
jmfb...@aol.com
><nos...@nosite.com> wrote:
>><< Speaking of hot days: At 10 am we switched on the solar panels. At
>>11:30 (summertime, i.e. ~10.00 solar time) on an overcast day it
>>delivered 650 Watt already. Not bad for the end of march. >>
>>
>>Das ist phantastisch! How many panels? What kind?
>
>It is 24 Kyocera 80wp modules. They give a guarantee of 80% (of that
>80 wp) for 20 years and I hope of course they'll last 50 years and
>more. Anyway it was a bargain: the Heidelberg community put up a
>program financing solar roofs. That means, I invest into the roof
>(16.6 K$ at 1% interest guaranteed for 10 years) rate and 80c/kWh
>guarantee for 10 years. After 15 years the installation should be
>payed back, so even if efficiency drops a bit, there's still not much
>risk. After 20 years I have ~1600 kwh/year for free, especially in
>summer to run air conditioning.
>That's not a hell of a lot, but I tell you, seeing a powermeter
>running backwards is pretty impressive!
>
>The transformer has an RS232 interface, and I'd love to put the data
>continuously on a web page, but alas, the telephone costs (plus a
>computer running) would eat up 20% of what the cells gain in money.
>
>Today is a real nice sunny day and I wonder what the meter will read
>tonight (last night it said 3.7 kWh).
>
What happens to your house grid when a surge comes from the
outside?
/BAH
Subtract a hundred and four for e-mail.
Lorenz [to_email_see_my_sig] Borsche
[to_email_see_my_sig] Borsche) wrote:
>(16.6 K$ at 1% interest guaranteed for 10 years) rate and 80c/kWh
>guarantee for 10 years.
sorry, should have been: 80c/kWh (which I get for each kwh delivered)
guaranteed for *20* years. Also it of course is a loan I took for the
installation which has a rate of 1% interest, and after 10 years
they'll give me 4% below market interest rates. So the conditions are
really helpful. All in all I figure that big scale cell prices have to
come down by a factor of four to make it worthwhile under normal
market conditions (if you then consider lifespans of 30 and more years
of course). But that means we need to stimulate mass production -
which is done by these programs. Heck, we shoved heaps of bucks into
nuke power until that got of the ground, didn't we...
BTW: living in Mexico would help also of course ;-)
Cheerio
Lorenz [to_email_see_my_sig] Borsche
wrote:
>>Today is a real nice sunny day and I wonder what the meter will read
>>tonight (last night it said 3.7 kWh).
>>
>What is involved when there's rain, snow, sleet, wind or dust?
The rain will wash away the dust :-)
We have very little snow in HD and it never lasts longer than a few
days. Also the pads are at ~40-45° and very smooth - the snow may
slide down any moment, but wait and see next winter.
Wind or hailstorm we do not fear, the modules are made to withstand
it.
But WTH is sleet?
>What happens to your house grid when a surge comes from the
>outside?
Same as ever. The house of course is still connected to the public
grid. If what is needed surpasses what is produced, the public grid
will give - or take up the surplus otherwise. Only economically it is
strictly separated as I buy at 12c/kWh and sell (what I produce on the
roof) at 80c/kWh. No, there's no way of cheating... :-))
(only if I'd install guided mirrors to enhance production on cloudless
days)
jmfb...@aol.com
>wrote:
>
>>>Today is a real nice sunny day and I wonder what the meter will read
>>>tonight (last night it said 3.7 kWh).
>>>
>>What is involved when there's rain, snow, sleet, wind or dust?
>
>The rain will wash away the dust :-)
It doesn't seem to wash away the dust over here. This place
is a dust bowl created by the stuff they dump on the snow
to make driving harder; it's called salting but I still
don't understand why plowing isn't done first.
>
>We have very little snow in HD and it never lasts longer than a few
>days. Also the pads are at ~40-45° and very smooth - the snow may
>slide down any moment, but wait and see next winter.
>
>Wind or hailstorm we do not fear, the modules are made to withstand
>it.
>
>But WTH is sleet?
Ice. Over here we have sleet and freezing rain. The bottom
line is that one can end up with and inch or two of ice
on every surface.
>
>>What happens to your house grid when a surge comes from the
>>outside?
>
>Same as ever. The house of course is still connected to the public
>grid. If what is needed surpasses what is produced, the public grid
>will give - or take up the surplus otherwise. Only economically it is
>strictly separated as I buy at 12c/kWh and sell (what I produce on the
>roof) at 80c/kWh. No, there's no way of cheating... :-))
I was curious if the surge could blow the wiring in the solar
panals (or whatever makes the electricity). Also black outs
and brown outs have their own hazards. How do you keep the
public grid from sucking out all of your power? Have you
ever experienced a black or brown out?
Jim Carr
pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) writes:
>
>But WTH is sleet?
Sleet is like partially melted hail/snow. It is wet on the outside
with a small frozen core. You get wet and stung at the same time.
Whether it ices up roads depends on ground temperature.
Freezing rain is all water, but right at 0 C -- and usually is forecast
when the air/ground is below freezing so that it turns to ice on contact
with power lines and trees, and sometimes roads.
--
James A. Carr <j...@scri.fsu.edu> | Commercial e-mail is _NOT_
http://www.scri.fsu.edu/~jac/ | desired to this or any address
Supercomputer Computations Res. Inst. | that resolves to my account
Florida State, Tallahassee FL 32306 | for any reason at any time.
Lorenz [to_email_see_my_sig] Borsche
>It doesn't seem to wash away the dust over here. This place
>is a dust bowl created by the stuff they dump on the snow
>to make driving harder; it's called salting but I still
>don't understand why plowing isn't done first.
I see :-)
>>But WTH is sleet?
>
>Ice. Over here we have sleet and freezing rain. The bottom
>line is that one can end up with and inch or two of ice
>on every surface.
Under seldomly occuring circumstances we have that too - but I haven't
sen it in HD, which is an unusually warm spot. It of course would
bring production down to almost zero, but in winter that really
doesn't count.
>I was curious if the surge could blow the wiring in the solar
>panals (or whatever makes the electricity).
No. There's a second double fuse to prevent surges from lightnings.
>How do you keep the
>public grid from sucking out all of your power?
Hein?
>Have you ever experienced a black or brown out?
No. Look, we're in GERMANY. Black out's don't happen over here, this
country is much too well organized for trivialities like that ;-). It
*is* true (installation was perfectly done within three days, anyone
was there when announced and we switched on exactly as foretold) but
perfectionism has its own disadvantages...
Wolfram Schmied
<no...@no.spam.edu> wrote:
>Here's my take:
>
>Cars are not really all that aerodynamic. At around 200 MPH drag becomes an
>issue.
I'd say drag becomes an issue at around 40 mph.
>Most production cars can't even surpass 130 MPH.
That's for lack of demand. Also, see my previous post.
>If cars drove at 130 MPH, then they would be burning lots of fuel and since
>they are redlining their engines, their engines would blow.
[snip]
If you inflate a bull frog beyond its ISO-approved capacity, it is
going to blow, too.
Cars that are produced to go 130 mph are built to last at this speed.
If you properly service the engine, it is virtually impossible to blow
it up. I know of a case in which the owner of a small business tried
to wear down the engines of his car, only to detect it was not worth
the hassle. Here's the background.
Foreign and international newspapers (International Herald Tribune,
Financial Times, Le Monde, Corriere della Sera,...) are printed in a
few places across Europe and distributed by road. Since printing
starts at 11 p.m. and ends around midnight, you've got about 6 to 8
hours to get it to the customers up to 500 miles away. At the time,
the entrepreneur in question started to operate four Renault Espace to
do just that. There was one year warranty with unlimited mileage on
the cars. So our hapless hero guessed, "If the engines get fritzed
just before the warranty runs out, I'll have four one-year-old cars
with new engines." He instructed the drivers to floor it whenever
safety allowed, which they gladly did, since it shortened their
workday by about 45 minutes. Well, the first engine surrendered after
10 months of mistreatment, the second one after 12, and the other two
after 13 months. The kicker is, the first car had covered 230.000
miles in that time, and the other proportionally more! And, even if
his plan had worked out as planned, the plus in gasoline and tyre
consumption would still have cost him more than the new machines.
In this business, a well serviced engine usually survives around
500.000 miles. Tyres vary according to route, but the minimum, barring
damage, is 50.000 miles with a maximum of about 200.000 on short
routes.
Wolfram "faster is better" 8-)#
Lorenz [to_email_see_my_sig] Borsche
(Wolfram Schmied) wrote:
>If you inflate a bull frog beyond its ISO-approved capacity, it is
>going to blow, too.
LOL :-)
>Cars that are produced to go 130 mph are built to last at this speed.
You probably are talking to someone living in a country where going
only 100 mph will put you to jail for quite some time :-)
>If you properly service the engine, it is virtually impossible to blow
>it up.
The gearbox is designed to make sure that top speed (limited b/c of
drag) is not at top revs. You may ruin the engine going in 3rd or
maybe 4th gear but not 5th.
>In this business, a well serviced engine usually survives around
>500.000 miles.
Ahum, you probably meant km and even that is a lot. I'd give 300 as
reasonable average.
jmfb...@aol.com
>
>>>But WTH is sleet?
>>
>>Ice. Over here we have sleet and freezing rain. The bottom
>>line is that one can end up with and inch or two of ice
>>on every surface.
>
>Under seldomly occuring circumstances we have that too - but I haven't
>sen it in HD, which is an unusually warm spot. It of course would
>bring production down to almost zero, but in winter that really
>doesn't count.
It would count a lot here if heating my place depended on the
production.
>
>
>>I was curious if the surge could blow the wiring in the solar
>>panals (or whatever makes the electricity).
>
>No. There's a second double fuse to prevent surges from lightnings.
A fuse or is it a circuit breaker?
>
>>How do you keep the
>>public grid from sucking out all of your power?
>
>Hein?
The electricity the solar panels produce has to be measured
according to your contract. That means that it has to go
through the meter before your appliances. What circuitry
prevents the draw of electricity from going to the public
grid before it goes through your private grid?
>
>>Have you ever experienced a black or brown out?
>
>No. Look, we're in GERMANY. Black out's don't happen over here, this
>country is much too well organized for trivialities like that ;-).
It must be nice to be so confident. I used to be until I kept
getting power interruptions here. I was also the contact point
where/when I was working whenever the electric company decided
that a rolling brownout or rolling blackout had to be enforced.
>It
>*is* true (installation was perfectly done within three days, anyone
>was there when announced and we switched on exactly as foretold) but
>perfectionism has its own disadvantages...
>
I have found that every "fix" produces three new problems. :-)
Wolfram Schmied
[to_email_see_my_sig] Borsche) wrote:
>In article <370295ef...@news.blinx.de>, wsch...@mail.blinx.de
>(Wolfram Schmied) wrote:
>
>>If you inflate a bull frog beyond its ISO-approved capacity, it is
>>going to blow, too.
>
>LOL :-)
>
>>Cars that are produced to go 130 mph are built to last at this speed.
>
>You probably are talking to someone living in a country where going
>only 100 mph will put you to jail for quite some time :-)
I think you're referring to the USA. If so, that's dependent on the
state Thomas lives (and drives) in. In Maryland IIRC, there's no speed
limit at night on interstate highways.
Besides, though the average speed of traffic is lower in the US than
it is in Germany, the fastest street-legal car in the world is
American. It's the Callaway Corvette Sledgehammer, and boy, does it
deserve its name! I read about it in an issue of Exotic Cars Quarterly
a few years ago (Sorry, I don't recall which issue). One fine day, old
Callaway decided, 'let's make a REAL car', and put into one lucky car
the finest parts his shelves had to offer. This resulted in a car with
a twin turbo with a maximum output of 920 (American) hp. On the
Talladega speedway, this beast clocked in at just above 255 mph (408
km/h)! Fittingly, it was sold to a German collector. Just imagine. Son
of Mr. Rich gets brandnew Porsche 959 (Ferrari, ...). Boy meets girl,
wants to impress her, takes her for a ride. Boy & car are straining
not to hit something. Then, out of the blue, something zooms past them
without even breaking a sweat. Wut? A CORVETTE? Yeeee-HAW! ;-)))))
>>If you properly service the engine, it is virtually impossible to blow
>>it up.
>
>The gearbox is designed to make sure that top speed (limited b/c of
>drag) is not at top revs. You may ruin the engine going in 3rd or
>maybe 4th gear but not 5th.
>
>>In this business, a well serviced engine usually survives around
>>500.000 miles.
>
>Ahum, you probably meant km and even that is a lot. I'd give 300 as
>reasonable average.
[snip]
Nope. I wrote 500.000 miles and I meant 800.000 km. That most engines
do not last that long is simply due to lack of servicing. Truck
engines regularly work for more than 800.000 miles (1.28 Mm), and
their tyres for more than 220.000 miles (0.35 Mm).
Surprising, isn't it? Ask a cab driver, they will tell you similar
stories about cab engines. Even if you consider the brag factor, cab
engines can easily make 300.000 miles (0.48 Mm), and this is city
traffic, which is much tougher on the engines than long-distance. This
is demonstrated by tyre life, which ends at about 40.000 miles.
Wolfram "Speed limit? Surely you jest, Mr. Einstein?" 8-)#
Wolfram Schmied
>In article <37024...@news.farside.net>,>>In article <7dt9dj$447$1...@ligarius.ultra.net>, jmfb...@aol.com wrote:
[snip]
>>It *is* true (installation was perfectly done within three days, anyone
>>was there when announced and we switched on exactly as foretold) but
>>perfectionism has its own disadvantages...
>I have found that every "fix" produces three new problems. :-)
"The main source of problems is solutions." Eric Sevareid
Wolfram 8-)#
"Nobody's perfect." proverb
"My name is Nobody." Terence Hill
Lorenz [to_email_see_my_sig] Borsche
wrote:
>>It of course would
>>bring production down to almost zero, but in winter that really
>>doesn't count.
>
>It would count a lot here if heating my place depended on the
>production.
Never you could heat the place with it. That's done with gas.
>>No. There's a second double fuse to prevent surges from lightnings.
>
>A fuse or is it a circuit breaker?
A fuse in both lines (DC current lines).
>The electricity the solar panels produce has to be measured
>according to your contract. That means that it has to go
>through the meter before your appliances. What circuitry
>prevents the draw of electricity from going to the public
>grid before it goes through your private grid?
Ok, there's the lot of four or five meters by now, the main one of
them (Drehstrom = 3 phases, what's that in English) does count what's
coming from the roof and what's coming from the public grid. In fact
it counts the difference between the mains and the house - solar is
plugged in between. If the house uses more than the roof delivers it's
spining as usual, otherwise backwards. And it has two separate
counters. Does that answer your question?
>It must be nice to be so confident. I used to be until I kept
>getting power interruptions here.
The last one I experienced was ... - must have been more than 35 years
ago.
>that a rolling brownout or rolling blackout had to be enforced.
What's a brown out? What's a rolling [colour]out?
>I have found that every "fix" produces three new problems. :-)
That's common and basic programers knowledge :-)
BTW: Last night the meter read an additional 7.4 kWh - as double as
much as the first day. As the sunshine will last over easter, I wonder
what the first week will bring :-)
Lorenz [to_email_see_my_sig] Borsche
wsch...@mail.blinx.de (Wolfram Schmied) wrote:
>In Maryland IIRC, there's no speed
>limit at night on interstate highways.
Driving more than 200 km/h at night, you gotta be young, have
fantastic eyesight, a straight highway and not much traffic. A full
moon is of greatest help actually.
>>>In this business, a well serviced engine usually survives around
>>>500.000 miles.
>>
>>Ahum, you probably meant km and even that is a lot. I'd give 300 as
>>reasonable average.
>[snip]
>
>Nope. I wrote 500.000 miles and I meant 800.000 km.
You wrote about Renault Espace. That's not exactly a truck, is it? And
the Espace sure won't last 800.000 km.
>Surprising, isn't it? Ask a cab driver, they will tell you similar
>stories about cab engines.
Sure. The old Yellow Cab, the London Taxi and the old Mercedes Diesel
engines (which derived from tractor engines). A Fiat Chroma or Opel
Omega won't last that long.
Paul Lutus
It is a dreadful practice in places where the grid is completely overloaded
at certain times of day. The power company simply lowers the voltage rather
than allow a complete failure. Incandescent (weißglühend) lights dim from
white to a sort of brown color, hence "brown-out." Oder "Braun-aus?" I
suspect that sounds very funny in German.
<< (Drehstrom = 3 phases, what's that in English) >>
3-phase current (it's from "three-stream", for English-speakers).
The point he is making is that, if the solar panels have *surplus* power,
power that is not used, it will be provided to the grid, but the grid cannot
draw power not explicitly made available to it.
--
Paul Lutus
www.arachnoid.com
Lorenz [to_email_see_my_sig] Borsche wrote in message
<3703e...@news.farside.net>...
<snip>
Ray Vanlandingham
was the optimum speed, due to internal combustion engines burning fuel most
efficiently at around that speed.
John Gilmer wrote in message <36fcd34a$1$1...@mojo.crosslink.net>...
>Greetings:
>
>Since in other threads it has been asserted the Physics is the source of
all
>knowledge (and I have given up my counter-claim that the source of all
>knowledge is Electrical Engineering) perhaps you can apply your collective
>brillance to the following questions:
>
>WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate Highways
>used as commuter roads. By optimum I mean, carries the greatest number of
>vehicles. How would one go about determining it? What data would it be
Lorenz [to_email_see_my_sig] Borsche
><< What's a brown out? What's a rolling [colour]out? >>
>
>It is a dreadful practice in places where the grid is completely overloaded
>at certain times of day. The power company simply lowers the voltage rather
>than allow a complete failure.
What? I cannot believe that. We have a guarantee for not less than
something (methinks 5%).
>Incandescent (weißglühend) lights dim from
>white to a sort of brown color, hence "brown-out."
Umpf.
>Oder "Braun-aus?" I
>suspect that sounds very funny in German.
None the least, sorry. Its the plural of a village we'd rather like to
forget about.
>The point he is making is that, if the solar panels have *surplus* power,
>power that is not used, it will be provided to the grid, but the grid cannot
>draw power not explicitly made available to it.
But it is. I mean, there's a transformer doing the DC/AC trick. So my
solar roof acts like any other generator plugged into the grid.
Thanks for the clarification though.
Lorenz [to_email_see_my_sig] Borsche
<ray...@javanet.com> wrote:
>I seem to recall some EPA studies back in the eighties that said that 45 mph
>was the optimum speed, due to internal combustion engines burning fuel most
>efficiently at around that speed.
LOL :-)
jmfb...@aol.com
><nos...@nosite.com> wrote:
>><< What's a brown out? What's a rolling [colour]out? >>
>>
>>It is a dreadful practice in places where the grid is
>>completely overloaded at certain times of day. The power
>>company simply lowers the voltage rather
>>than allow a complete failure.
>
>What? I cannot believe that. We have a guarantee for not less than
>something (methinks 5%).
It's what happens when the nuclear plants are shut down and can't
provide the power requested. The reason it's call rolling is to
"share" the deficit across the whole region. It was decided that
that was better than enforcing a black out, subregion by subregion.
<snip>
jmfb...@aol.com
>The point he is making is that, if the solar panels have
>*surplus* power, power that is not used, it will be provided
>to the grid, but the grid cannot draw power not explicitly
>made available to it.
I understand that. What I'm trying to determine is if
a large draw from the public grid can cause power fluctuations
in his private grid, and, if it can't, how is that prevented.
Think about a washing machine that first starts up. It
momentarily pulls quite a bit of power, causing the lights
to dim. The same thing can happen with the public grid. It
happens here quite often now.
jmfb...@aol.com
>wrote:
>
>>>It of course would
>>>bring production down to almost zero, but in winter that really
>>>doesn't count.
>>
>>It would count a lot here if heating my place depended on the
>>production.
>
>Never you could heat the place with it. That's done with gas.
I have oil. I still need electricity to run the damn circulator
and the thermostat. No electricity--no heat.
>>>No. There's a second double fuse to prevent surges from lightnings.
>>
>>A fuse or is it a circuit breaker?
>
>A fuse in both lines (DC current lines).
We're not allowed fuses here (unless I'm confused about the
function). Aren't they fire hazzards?
>
>>The electricity the solar panels produce has to be measured
>>according to your contract. That means that it has to go
>>through the meter before your appliances. What circuitry
>>prevents the draw of electricity from going to the public
>>grid before it goes through your private grid?
>
>Ok, there's the lot of four or five meters by now, the main one of
>them (Drehstrom = 3 phases, what's that in English) does count what's
>coming from the roof and what's coming from the public grid. In fact
>it counts the difference between the mains and the house - solar is
>plugged in between. If the house uses more than the roof delivers it's
>spining as usual, otherwise backwards. And it has two separate
>counters. Does that answer your question?
Not really :-). OK, the meter must be in parallel of both grids
and do their comparison thing; they're also piggybacking the two
grids. The interface between the private and public grid is ...?
And you've got DC in all that mess. Wow. How much does the
electrician cost?
>
>>It must be nice to be so confident. I used to be until I kept
>>getting power interruptions here.
>
>The last one I experienced was ... - must have been more than 35 years
>ago.
>
>>that a rolling brownout or rolling blackout had to be enforced.
>
>What's a brown out? What's a rolling [colour]out?
It's this region's answer to nuclear plant shutdowns with
an electrical requirement greater than production. A
brownout is a lower voltage level. A blackout is no
voltage. The rolling part is sharing the lack of
energy over the area. This way an area will experience
power problems only some of the time instead of all of
the time. They tried the volunteer thing where a call
would go out to shut down everything one could (like I
described in an earlier post) but it didn't work very
well. People have forgotten how to turn things off
when not in use.
Joe Fischer
X-Newsreader: TIN [version 1.2 PL2]
Lorenz [to_email_see_my_sig] Borsche (pub...@usa.net) wrote:
: In article <CcSM2.5065$fb4....@news2.giganews.com>, "Paul Lutus"
: >It is a dreadful practice in places where the grid is completely overloaded
: >at certain times of day. The power company simply lowers the voltage rather
: >than allow a complete failure.
:
: What? I cannot believe that. We have a guarantee for not less than
: something (methinks 5%).
The power company doesn't lower the voltage, the
voltage drops because the power capacity can't hold
the voltage up against demand. When voltage drops
too much, automatic switches drop the load, because
low voltage is very hard on some induction machines.
: >The point he is making is that, if the solar panels have *surplus* power,
: >power that is not used, it will be provided to the grid, but the grid cannot
: >draw power not explicitly made available to it.
:
: But it is. I mean, there's a transformer doing the DC/AC trick. So my
: solar roof acts like any other generator plugged into the grid.
The power flow depends on voltage, if the grid
is at a lower voltage, power flows out, if not, no
power flows. If the grid is down, no power flows,
because the solid state AC wave pattern is taken
from the running grid, simplifying phase sync.
Joe Fischer
jmfb...@aol.com
joe...@iglou.com (Joe Fischer) wrote:
>Distribution:
>X-Newsreader: TIN [version 1.2 PL2]
>
>Lorenz [to_email_see_my_sig] Borsche (pub...@usa.net) wrote:
>: In article <CcSM2.5065$fb4....@news2.giganews.com>, "Paul Lutus"
>: >It is a dreadful practice in places where the grid is completely
overloaded
>: >at certain times of day. The power company simply lowers the voltage
rather
>: >than allow a complete failure.
>:
>: What? I cannot believe that. We have a guarantee for not less than
>: something (methinks 5%).
>
> The power company doesn't lower the voltage, the
>voltage drops because the power capacity can't hold
>the voltage up against demand. When voltage drops
>too much, automatic switches drop the load, because
>low voltage is very hard on some induction machines.
Then how do they do a rolling brownout. It's a controlled
voltage reduction to prevent those automatic switches
from getting tripped.
>
>: >The point he is making is that, if the solar panels have *surplus*
power,
>: >power that is not used, it will be provided to the grid, but the grid
cannot
>: >draw power not explicitly made available to it.
>:
>: But it is. I mean, there's a transformer doing the DC/AC trick. So my
>: solar roof acts like any other generator plugged into the grid.
>
> The power flow depends on voltage, if the grid
>is at a lower voltage, power flows out, if not, no
>power flows. If the grid is down, no power flows,
>because the solid state AC wave pattern is taken
>from the running grid, simplifying phase sync.
This doesn't make sense. I have an alternate power
source, the public grid goes down, my neighbor keeps
pulling for power, and I have some. What prevents the
flow from going over to the neighbor?
Paul Lutus
voltage drops because the power capacity can't hold
the voltage up against demand. >>
This isn't true :)
The power company exercises quite a lot of control over voltage. They
deliberately allow the voltage to fall, in order to prevent a system
failure. The degree to which the voltage falls is also carefully controlled
to accommodate the acceptable range for, as one example, compressor motors
on refrigerators, which won't tolerate too low a voltage.
--
Paul Lutus
www.arachnoid.com
Joe Fischer wrote in message <3704b...@news.iglou.com>...
<snip>
Wolfram Schmied
[to_email_see_my_sig] Borsche) wrote:
>In article <3703b946...@news.blinx.de>,
>wsch...@mail.blinx.de (Wolfram Schmied) wrote:
>>In Maryland IIRC, there's no speed
>>limit at night on interstate highways.
>Driving more than 200 km/h at night, you gotta be young, have
>fantastic eyesight, a straight highway and not much traffic. A full
>moon is of greatest help actually.
accomodation to low light levels. It takes several _weeks_ for your
eyes to get fully used to night driving. I noticed this in a big wy
when I switched back to daywork. For three weeks, daylight was
uncomfortably bright for me, even on cloudy days. Of course, you have
to have good headlights, too, and you wouldn't believe the difference
a thoroughly cleaned windshield makes.
Highways are built as straight as possible, and night traffic is light
almost all the time. Except when the Dutch and Scandinavian holidays
begin! ;-)
BTW, with the light from a full moon you don't really _need_
headlights, it is my experience.
>>>>In this business, a well serviced engine usually survives around
>>>>500.000 miles.
>>>Ahum, you probably meant km and even that is a lot. I'd give 300 as
>>>reasonable average.
>>Nope. I wrote 500.000 miles and I meant 800.000 km.
>You wrote about Renault Espace. That's not exactly a truck, is it?
Yup. That's why I wrote 500.000 iinstead of 800.000.
> And the Espace sure won't last 800.000 km.
You bet it will. Remember, you're conversing with an eyewitness. And,
800.000km means about 2 years in the newspaper business. I myself used
transport the stuff from Frankfurt via Salzgitter and Braunschweig to
Berlin. That's 1273km (796 miles) six days a week.
It's not a job for the timid!
>>Surprising, isn't it? Ask a cab driver, they will tell you similar
>>stories about cab engines.
>Sure. The old Yellow Cab, the London Taxi and the old Mercedes Diesel
>engines (which derived from tractor engines). A Fiat Chroma or Opel
>Omega won't last that long.
The new engines are better than the old ones. You bet they will. Just
ask your friendly neighbourhood cabbie.
Wolfram "K.I.T.T. is S.H.I:T" 8-)#
Wolfram Schmied
[to_email_see_my_sig] Borsche) wrote:
>In article <7dvu28$ouu$3...@antiochus.ultra.net>, jmfb...@aol.com
>wrote:
>
>>>It of course would
>>>bring production down to almost zero, but in winter that really
>>>doesn't count.
>>
>>It would count a lot here if heating my place depended on the
>>production.
>
>Never you could heat the place with it. That's done with gas.
That's disgusting. I'd rather freeze to death.
>>The electricity the solar panels produce has to be measured
>>according to your contract. That means that it has to go
>>through the meter before your appliances. What circuitry
>>prevents the draw of electricity from going to the public
>>grid before it goes through your private grid?
>Ok, there's the lot of four or five meters by now, the main one of
>them (Drehstrom = 3 phases, what's that in English) does count what's
three-phase current (according to my Langenscheidt)
>coming from the roof and what's coming from the public grid. In fact
>it counts the difference between the mains and the house - solar is
>plugged in between. If the house uses more than the roof delivers it's
>spining as usual, otherwise backwards. And it has two separate
>counters. Does that answer your question?
Wolfram 8-)#
Mark William Hopkins
>I seem to recall some EPA studies back in the eighties that said that 45 mph
>was the optimum speed, due to internal combustion engines burning fuel most
>efficiently at around that speed.
Actually, if you turn the car off, get out and push it forward, you'll have
around 100% fuel efficiency, as well as greatly enhancing your muscle tone
and aerobic capacity (especially when you get to the hills). Therefore,
the optimal speed for vehicles should be around 4 MPH.
Lorenz [to_email_see_my_sig] Borsche
>>What? I cannot believe that. We have a guarantee for not less than
>>something (methinks 5%).
[brown out]
>It's what happens when the nuclear plants are shut down and can't
>provide the power requested.
And there's no backup? Over here, there the obligation to have that
(20% for the whole countrywide net actually, thus ~12 NPP (out of ~25)
could go down before anything would happen. Not even then. Old coal
plants are being kept serviced and the market hasn't gown all to
much. In real we could put up with 45% failures...
Lorenz [to_email_see_my_sig] Borsche
>What I'm trying to determine is if
>a large draw from the public grid can cause power fluctuations
>in his private grid,
It sure could, but it could never draw more solar than there is. As I
said: the solar is fed directly into the public grid before I get to
see any single electron. It could be done on my neighbours house and
wouldn't be any different to my washing machine.
>Think about a washing machine that first starts up. It
>momentarily pulls quite a bit of power, causing the lights
>to dim.
What? You are making fun of me?
>The same thing can happen with the public grid. It
>happens here quite often now.
The US a 3rd world country where on first floor you can see by the
flickering lights that the washing machine starts the spin cycle? I'm
not buying that.
Lorenz [to_email_see_my_sig] Borsche
>>Never you could heat the place with it. That's done with gas.
>
>I have oil. I still need electricity to run the damn circulator
>and the thermostat. No electricity--no heat.
Yeah, the circulator is a problem, but it has a bypass, actually
itself is a bypass, so we could run on gravity too, only would need to
run higher temperatures
>>A fuse in both lines (DC current lines).
>
>We're not allowed fuses here (unless I'm confused about the
>function). Aren't they fire hazzards?
Fuses?
>And you've got DC in all that mess.
Nope. There's a smart little box converting 257 Volts DC to 220 V 50
Hz AC. After that box there's the meter.
> Wow. How much does the
>electrician cost?
1500$ for the whole rewiring, that was needed to feed into the net
(inclusive having a 3 phase power line by now plus a new meter/circuit
breaker box with 5 instead of 1 meter, plus new earthing).
BTW: Newest reading: 28 KWh in four days.
Paul Lutus
Aren't they fire hazzards?
Fuses? >>
Both fuses and circuit breakers of poor quality are fire hazards. Many fires
in the US are traced to bad panels populated with substandard circuit
breakers. It is a question of what is considered acceptable here -- answer:
practically anything.
I recently replaced a panel on a relatively new house I bought. The panel's
design was accepted by regulatory agencies, after installation it passed
inspection, but it kept catching fire when the electric clothes dryer was
operated. When asked, electricians confirmed this is a common occurrence.
This means the officially acceptable minimum quality level is far below a
rational standard for safety.
About a decade or two ago, aluminum wire was first permitted here in the US.
Before proper techniques were developed, and before electricians were
retrained to handle the new wire, many houses went up in smoke.
--
Paul Lutus
www.arachnoid.com
Lorenz [to_email_see_my_sig] Borsche wrote in message
<3705d...@news.farside.net>...
<snip>
Lorenz [to_email_see_my_sig] Borsche
(Wolfram Schmied) wrote:
>Eyesight is important, but even more decisive is the eye's
>accomodation to low light levels.
Which is a function of youth. Believe me, as I'm about loosing the
'night hawk eyesight' I once had.. :-((
>It takes several _weeks_ for your
>eyes to get fully used to night driving.
Interesting that it can be trained, but actually - which sense can
*not* be trained...
>[...] night traffic is light
>almost all the time. Except when the Dutch and Scandinavian holidays
>begin! ;-)
LOL.
>BTW, with the light from a full moon you don't really _need_
>headlights, it is my experience.
I second that. Coming down A5 from the last triangle north of
Frankfurt, being alone on 3 lanes under full moon I once switched them
off completely - no difference.
>> And the Espace sure won't last 800.000 km.
>You bet it will. Remember, you're conversing with an eyewitness.
Okayokay :-)
>Braunschweig to Berlin. That's 1273km (796 miles) six days a week.
>It's not a job for the timid!
Yo! Well, then you will know what that means: Hamburg - Heidelberg,
630 km, one stop for gas, 3:50h! And Munich - Heidelberg, 315 km,
1:55. Both *averages* at ~160 km/h including all those 120 km Zones
etc. I couldn't do that no more and I'm sure such drives cost you a
grey hair or two. Every respect for people doing that each night.
>The new engines are better than the old ones. You bet they will. Just
>ask your friendly neighbourhood cabbie.
Well then there's hope. I just decided my 318 (120.000 km) has to go
another 5 years (another 120.000). What else except oil service any
10.000 and an inspection all 20.000 can I do?
Jim Carr
jmfb...@aol.com wrote:
}
} >A fuse in both lines (DC current lines).
}
} function). Aren't they fire hazzards?
In article <3705d...@news.farside.net>
pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) writes:
>
>Fuses?
In this country, fuses are not allowed any more (in distribution
panels, they still exist in other places) because people had a
tendency to replace them with a penny if they blew out too often.
Of course, the ones that blew out too often were exactly the wrong
ones to replace with a penny!
Fuses are used there instead of breakers because of the desired
response time?
>1500$ for the whole rewiring, that was needed to feed into the net
>(inclusive having a 3 phase power line by now plus a new meter/circuit
>breaker box with 5 instead of 1 meter, plus new earthing).
>
>BTW: Newest reading: 28 KWh in four days.
Not bad at all. Didn't know there was ever any sun in Germany. ;-)
When do you estimate breakeven for your capital investment? (I don't
recall if you said what power costs over there.)
--
James A. Carr <j...@scri.fsu.edu> | Commercial e-mail is _NOT_
http://www.scri.fsu.edu/~jac/ | desired to this or any address
Supercomputer Computations Res. Inst. | that resolves to my account
Florida State, Tallahassee FL 32306 | for any reason at any time.
Jim Carr
jmfb...@aol.com wrote:
}
} >What? I cannot believe that. We have a guarantee for not less than
} >something (methinks 5%).
}
}[brown out]
} It's what happens when the nuclear plants are shut down and can't
} provide the power requested.
In article <3705d...@news.farside.net>
pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) writes:
>
>And there's no backup? Over here, there the obligation to have that
>(20% for the whole countrywide net actually, thus ~12 NPP (out of ~25)
>could go down before anything would happen. Not even then. Old coal
>plants are being kept serviced and the market hasn't gown all to
>much. In real we could put up with 45% failures...
Comparing Germany and New England is worse than apples and oranges.
First, in the US the grid is made up of a large number of independent
companies with state regulated rate structures, and which may or may
not wish to pay for the power they could draw from the grid to make
up for their own shortcomings. In some regions there is plenty of
power, but they will charge peak rates for delivery to those areas
that have too little capacity to handle, say, electric heat in winter
or air conditioning in summer. It can be cheaper to brown out than
to pay for the power.
Capacity problems can themselves be due to regulatory issues, bad luck,
or bad management. Parts of New England still have a problem because
of the cancellation of the Seabrook nuclear plant, IIRC. One summer
they had a problem when a major power line failed due to overuse when
drawing from another part of the grid in New York. (We had a wild fire
start when a power line sagged -- from the 100 degree heat plus the high
current draw in mid-afternoon -- so much that it ignited some brush.)
Then there are really strange problems. My parents neighborhood was
developed before anyone thought you needed pools (and pool heaters)
and air conditioning, so the capacity of the neighborhood transformers
and the load balancing is horrible. As a result, they frequently noted
a 5 to 10 volt difference between the two circuits in their house (fed
from different phases, one of which probably ran a few more pool pumps
and air conditioners than the other) along with the overall voltage drop.
The minimum was something like 106 volts instead of 120. Not good for
motors or computers (the power protector was what warned them of it the
first time). Really bad.
Jim Carr
pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) writes:
>
>flickering lights that the washing machine starts the spin cycle? I'm
>not buying that.
It is a free-market economy where minimal regulation can result
in people buying exactly that sort of wiring system.
Lorenz [to_email_see_my_sig] Borsche
<nos...@nosite.com> wrote:
>Fuses? >>
>
>Both fuses and circuit breakers of poor quality are fire hazards.
Okay, so there's the good old fuse (which is a wire melting) and
breakers (which run magnetically). We still have both and at certain
points breakers are not even allowed. As I know a bit about here's how
it goes:
The cable runs into the house and is split up first in a box (usually
located in the basement) one line for each storey and each line has
it's own 'slow' fuse. This is sort of the last barrier. The box is
locked and sealed, no way to buy such fuses and breaking the seal
unauthorized can mean jail. Then comes the panel, today of course with
breakers, the old ones with fuses. Shortening the fuses would have
been a tough job, they're explicitly made in a way that a penny or a
wire wouldn't do. I have never heard of a panel having been the cause
of a fire.
>Many fires
>in the US are traced to bad panels populated with substandard circuit
>breakers. It is a question of what is considered acceptable here -- answer:
>practically anything.
So the free market is not the answer to anything, is it?
>About a decade or two ago, aluminum wire was first permitted here in the US.
>Before proper techniques were developed, and before electricians were
>retrained to handle the new wire, many houses went up in smoke.
And who pays for that? I have the feeling that we don't trust the
individual as much as you do in certain respects
(gas/electricity/driving etc.).
OTOH every one is asked to know that a hot coffee is hot and that you
can't dry a pet in the microwave... :-))
I wonder if there's a connection...
Lorenz [to_email_see_my_sig] Borsche
Carr) wrote:
> In this country, fuses are not allowed any more (in distribution
> panels, they still exist in other places) because people had a
> tendency to replace them with a penny if they blew out too often.
> Of course, the ones that blew out too often were exactly the wrong
> ones to replace with a penny!
See my answer to Paul.
> Fuses are used there instead of breakers because of the desired
> response time?
I think so. Actually they should act in case of thunderstorm
(lightning surges) and protect the panels.
>>BTW: Newest reading: 28 KWh in four days.
>
> Not bad at all. Didn't know there was ever any sun in Germany. ;-)
You are right, you know :-) Just a mere 1600 hrs where I live and we
have bad spots with less than 1200 hrs.
> When do you estimate breakeven for your capital investment? (I don't
> recall if you said what power costs over there.)
It's a combined program and of course it wouldn't break even if not
subsidized. I pay a mere 1% on the investment. I sell the solar kWh
for 6 times as much (~80c) as I buy the regular kWh. Given the
sunshine we have, after 16 years everything should be payed off, but I
do get the nice price for 20 years. After that it just reduces my bill
1:1.
Lorenz [to_email_see_my_sig] Borsche
Carr) wrote:
> Comparing Germany and New England is worse than apples and oranges.
If it comes to electricity, maybe. But having read most of John
Irving, New England must be a pretty place to live, despite all brown
and black outs.
> drawing from another part of the grid in New York. (We had a wild fire
> start when a power line sagged -- from the 100 degree heat plus the high
> current draw in mid-afternoon -- so much that it ignited some brush.)
Couldn't happen here: too much rain ;-)
> The minimum was something like 106 volts instead of 120. Not good for
> motors or computers (the power protector was what warned them of it the
> first time). Really bad.
I agree.
Lorenz [to_email_see_my_sig] Borsche
Carr) wrote:
> It is a free-market economy where minimal regulation can result
> in people buying exactly that sort of wiring system.
You get what you pay for.
Paul Lutus
individual as much as you do in certain respects (gas/electricity/driving
etc.). >>
Off-topic, but the issue of the individual is positively mythical in this
country. According to US popular mythology, there are two moral states of
being -- Shane (a legendary cinema cowboy), riding off into the sunset after
solving the town's problems with his handgun, and everything else.
I can't think of two countries where this issue is quite so diametrically
opposed as the US and Germany. In Germany, cooperating with other people,
with a governmental agency, is admirable behavior. Here, it is looked on as
treason against the cowboy thought to live inside every man.
--
Paul Lutus
www.arachnoid.com
Lorenz [to_email_see_my_sig] Borsche wrote in message
<37064...@news.farside.net>...
<snip>
Joe Fischer
: > It is a free-market economy where minimal regulation can result
: > in people buying exactly that sort of wiring system.
: You get what you pay for.
I don't know what Jim means about "that sort
of wiring system", all wiring is UL approved, and
I don't know of any circuits ever having smaller
than #14 wire, which is 15 AMPS.
The only reason you don't see lights dimming
as much is because of the higher voltage, we have
very few lights on 220 volts.
And single phase 110 volts will suffer some
voltage drop when motors start, because even a
small motor can draw 5 to 8 times as much current
when starting as when running under normal load.
There may be some (older) houses which
have too many wiring runs on the same breaker,
but as long as the breaker is 15 AMPS and not
higher, it should not be less safe. But this
can cause more dimming of lights when motors start.
I would guess you see some change in the
brightness of incandescent lights when motors
start, you just don't notice it as much as you
would on 110 volts.
And I haven't seen anything on the news
about brownouts for several years, although
there has been a lot of people without power
for up to two weeks or more because of storms
and the large number of trees which tear down
power lines and poles, a lot of this country
has too many trees, and other parts don't
have enough.
Joe Fischer
Joe Fischer
: jmfb...@aol.com wrote:
: } >A fuse in both lines (DC current lines).
: }
: } We're not allowed fuses here (unless I'm confused about the
: } function). Aren't they fire hazzards?
: pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) writes:
: >
: >Fuses?
:
: In this country, fuses are not allowed any more (in distribution
: tendency to replace them with a penny if they blew out too often.
: Of course, the ones that blew out too often were exactly the wrong
: ones to replace with a penny!
They only used pennies behind screw-in fuses,
but some of the best safety disconnects are fuses,
because they can be made be fast-blow, slow-blow for
motors, but it is the convenience and no need to
change fuses that made breakers standard.
: Fuses are used there instead of breakers because of the desired
: response time?
Right, and 3-phase motors have special solenoid
contactors that have fuses that drop the solenoid out
when they melt.
You aren't old enough to have seen pennies used
behind fuses, :-). :-)
Joe Fischer
Ray Vanlandingham
Joe Fischer wrote in message <37066...@news.iglou.com>...
<snip>
> They only used pennies behind screw-in fuses,
>but some of the best safety disconnects are fuses,
>because they can be made be fast-blow, slow-blow for
>motors, but it is the convenience and no need to
>change fuses that made breakers standard.
For in-line fuses (what you commonly see these days) you need a screw, or a
bullet if you are stupid.
>: Fuses are used there instead of breakers because of the desired
>: response time?
Circuit breakers also have the advantage of having a much higher
current-interrupting capability, which is very helpful if you have a toddler
sticking forks in electrical outlets. In the navy, I've seen a phase to
phase short arc /across/ a blown F60C500V fuse. It was fairly cool, once we
put the fire out.
> Right, and 3-phase motors have special solenoid
>contactors that have fuses that drop the solenoid out
>when they melt.
Yup. You can reset them if you hold them upside down over a cigarette
lighter, but it's not highly recommended.
> You aren't old enough to have seen pennies used
>behind fuses, :-). :-)
I've seen a roll of quarters used to replace a /large/ DC fuse. Does that
count? It was for a 41kw motor-generator.
Jim Carr
:
: (Jim Carr) wrote:
: > It is a free-market economy where minimal regulation can result
: > in people buying exactly that sort of wiring system.
:
: You get what you pay for.
In article <37066...@news.iglou.com>
joe...@iglou.com (Joe Fischer) writes:
>
> I don't know what Jim means about "that sort
>of wiring system", all wiring is UL approved, and
>I don't know of any circuits ever having smaller
>than #14 wire, which is 15 AMPS.
Well, I had in mind a house we bought when I was a kid where it
seemed like half the outlets were all on one circuit. I think it
was the garage, kitchen, dining room, and part of the living room
(most of the first floor). Then there would be one outlet for a
single lamp in the living room with its very own breaker. Run the
air compressor in the garage and there would be a brownout (if not
a blackout) in that part of the house.
> The only reason you don't see lights dimming
>as much is because of the higher voltage, we have
>very few lights on 220 volts.
Ah, I always forget about that difference.
> There may be some (older) houses which
>have too many wiring runs on the same breaker,
>but as long as the breaker is 15 AMPS and not
>higher, it should not be less safe. But this
>can cause more dimming of lights when motors start.
Or, in the days of fuses, the application of the penny solution
when the fuse blew too often.
Lorenz [to_email_see_my_sig] Borsche
<nos...@nosite.com> wrote:
>Off-topic, but the issue of the individual is positively mythical in this
>country. According to US popular mythology, there are two moral states of
>being -- Shane (a legendary cinema cowboy), riding off into the sunset after
>solving the town's problems with his handgun, and everything else.
:-)
>I can't think of two countries where this issue is quite so diametrically
>opposed as the US and Germany.
I'm sure you are right in this respect.
>In Germany, cooperating with other people, with a governmental
>agency, is admirable behavior. Here, it is looked on as
>treason against the cowboy thought to live inside every man.
And I'm not at all sure what to favor...
wsch...@my-dejanews.com
Please email your replies to ensure I get it.
In article <3705f...@news.farside.net>,
pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) wrote:
> In article <3704fb9b...@news.blinx.de>, wsch...@mail.blinx.de
> (Wolfram Schmied) wrote:
> >Eyesight is important, but even more decisive is the eye's
> >accomodation to low light levels.
> Which is a function of youth. Believe me, as I'm about loosing the
> 'night hawk eyesight' I once had.. :-((
Don't worry. Soon you won't remember that... ;-)
> >It takes several _weeks_ for your
> >eyes to get fully used to night driving.
> Interesting that it can be trained, but actually - which sense can
> *not* be trained...
Common sense?
> >BTW, with the light from a full moon you don't really _need_
> >headlights, it is my experience.
> I second that. Coming down A5 from the last triangle north of
> Frankfurt, being alone on 3 lanes under full moon I once switched them
> off completely - no difference.
There is one.
> >Braunschweig to Berlin. That's 1273km (796 miles) six days a week.
> >It's not a job for the timid!
> Yo! Well, then you will know what that means: Hamburg - Heidelberg,
> 630 km, one stop for gas, 3:50h! And Munich - Heidelberg, 315 km,
> 1:55. Both *averages* at ~160 km/h including all those 120 km Zones
> etc. I couldn't do that no more and I'm sure such drives cost you a
> grey hair or two. Every respect for people doing that each night.
Yup.
> >The new engines are better than the old ones. You bet they will. Just
> >ask your friendly neighbourhood cabbie.
> Well then there's hope. I just decided my 318 (120.000 km) has to go
> another 5 years (another 120.000). What else except oil service any
> 10.000 and an inspection all 20.000 can I do?
In my experience, two things make the difference. The first being clean
combustion. A fuel filter, if not already installed, is a good idea (and
cheap). Also, make sure the ignition system works properly. The second, keep
the cooling system at peak performance all the time! That it should be filled
up to recommended level goes without saying. One thing that's often
neglected, though, is ensuring that there is no sediment inside the engine
block, which impedes on heat transfer to the cooling fluid. The wise motorist
checks the coolant temperature every few weeks or so. If it's up more than
10K from normal, it's a good idea to have it cleaned. I had colleagues who
installed filters in their cooling systems to reduce sedimentation. How
important this is, I experienced with my first long-distance car, a Citröen
CX 25 TRD Turbo Break. The first set of tyres lasted 270 Mm (169 kmiles), the
first exhaust pipe a whopping 430 Mm (269 kmiles). The engine had to be
replaced after 256 Mm (160 kmiles) due to a broken cylinder head, which,
going unnoticed, damaged two pistons and consequently the engine block. As I
was told, this was due to a combination of bad design and bad servicing. The
original engine was just a simple diesel with an output 65 hp (DIN), and not
designed to work as a 90 hp turbo. Obviously the engineering people at
Citröen told the sales people: "No problem, as long's the engine is regularly
serviced," and the sales people chose to ignore that "regular service" is a
pious wish instead of naked reality. In the end, this resulted in many sold
replacement cylinder heads. I wonder why? I might add, selfsame engine
outfitted with an intercooler and a beefed-up cooling system had no such
trouble while delivering 120 hp!
HTH Wolfram "You name it, I wreck it." 8-)#
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
Paul Lutus
I find it easy to poke fun at American urban cowboys, but in the breach, me
neither.
--
Paul Lutus
www.arachnoid.com
Lorenz [to_email_see_my_sig] Borsche wrote in message
<37072...@news.farside.net>...
Lorenz [to_email_see_my_sig] Borsche
wrote:
>In my experience, two things make the difference. The first being clean
>combustion. A fuel filter, if not already installed, is a good idea (and
>cheap).
Okay, I'll ask the mechanic.
>Also, make sure the ignition system works properly.
318i with accentuation on the 'i'
>The second, keep the cooling system at peak performance all the time!
>That it should be filled up to recommended level goes without saying.
No sweat. I had an air conditioning added last year. Since then it
doesn't heat as good as before and the thermometer never even shows
'normal', it's always a little below. The mechanic said it's because
of a bigger circulation system now.
Lorenz [to_email_see_my_sig] Borsche
><< And I'm not at all sure what to favor... >>
>
>I find it easy to poke fun at American urban cowboys,
.. as well as the typical german bureaucrat clinging to the rules as
stupid as they might be...
>but in the breach, me neither.
Good to know, as you have seen both sides (and lots more).
Jim Carr
"John Gilmer" <gil...@crosslink.net> writes:
>
>WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate Highways
>used as commuter roads. By optimum I mean, carries the greatest number of
>vehicles.
I think that there was actually a study that showed the answer is
something quite low, like 30 mph or less.
>How would one go about determining it?
You would define a function and maximize it.
>What data would it be necessary to obtain?
I think most of it is known. You need reaction times for the spectrum
of drivers and the stopping distances for the vehicles allowed on the
road. Limiting it to only cars will simplify matters somewhat.
>Would strict enforcement of "minimum speed" make a major difference.
I believe maximum capacity is only achieved if everyone is driving
the same exact speed, at least in a given lane. Anything else is
disruptive to the flow. It also has to assume that the drivers
are maximally attentive and alert at all times.
>From a NG in Virginia, a poster wrote me that to a first approximation,
>the speed limit doesn't make any difference. Each car would stay 2 seconds
>behind the car in front. The lane capacity becomes 2 seconds/car (ok, the
>car doesn't have zero lenght) but this is clearly a good first order guess.
Also wrong. The 2 second following distance is a good approximation
for minimum safe following distance at highway speeds under ideal
conditions, but underestimates what is needed at higher speeds and
overestimates what is needed at slow speeds.
The reason is that there are two factors. One is a constant (reaction
time) so the separation distance required for that grows only linearly
with speed, while the other is not (actual stopping distance, which
increases quadratically with speed because of the need to dissipate
kinetic energy in braking) and also depends on road conditions. The
latter favors lower speeds since the cars can be closer together.
You see, two seconds is 176 feet at 60 mph, which is in the vicinity
of braking distances for sedans on good pavement. You can find the
numbers for new cars in every sales brochure or car mag reviews. It
does not take 88 feet to panic stop from 30 mph.
>Thirty plus years ago a lot of simulation work was done in this area.
>Since then speed limits have gotten involved in politics and I don't think
>it is possible to get an objective (let alone honest) answered from studies
>paid for by the government.
Any study would show that the speed limit depends on conditions, but
there are no systems that alter the speed limit based on changing
conditions except on certain roads or bridges where experience has
shown that such things are needed.
Jim Carr
>
><< Each car would stay 2 seconds behind the car in front. >>
>
>to react to the sight of a car braking in front of you. It won't work if the
>car in front collides with something solid, as so often happens in fog. In
>this case, the two-second interval won't prevent your joining the pileup.
That is because two seconds is not enough time to evaluate a situation,
such as to determine that a car is now moving rapidly relative to you,
rather than just react to brake lights. It's also because you can't
see 2 seconds ahead in fog (or rain or snow) and because your braking
distance has increased by perhaps 20 or 30% because of the wet road.
>People generally don't know this, and that is one reason why fog (or heavy
>rain, darkness, curves) is so dangerous -- people falsely believe they are
>safe if they can see a two-second interval ahead.
I think most don't realize that they cannot see that far ahead.
They also don't realize that braking takes longer when it is wet.
Jim Carr
wsch...@mail.blinx.de (Wolfram Schmied) writes:
>
>On a well-constructed road system, it usually just depends on how fast
>you want to go. Example:
>Here in Germany, on a stretch of the A5 near Frankfurt I used to
>frequent a lot, you have the choice between four lanes for each
>direction. Rightmost, trucks and other slow vehicles go 50mph. Middle
>left, average speed 70, middle right 90-110. Leftmost, anything below
>130mph is a roadblock. So, except for rush hour (3-6pm), which slows
>speed down to 50mph on average, the optimum speed depends on the
>individual traveller.
Except it does not, which is why the speed drops when the road is
congested (i.e. when its capacity has to increase). The distance
you have to allow for reacting to possible 20 mph speed differentials
within a given lane or when a car needs to change lanes will increase
with speed, and will be even greater in the fast lane where larger
speed differences can be encountered.
One of the worst things in the US is how _low_ the minimum freeway
speed is. It is 40 mph on a 70 mph freeway in Florida, and a really
bad accident near here was caused by a vehicle traveling below that
minimum as it merged. If a 55 mph secondary road is available, I
think the minimum speed should be 55 mph or even 60 mph as long as
weather permits.
>You say 'accidents?' I reply, Germany is and has been for decades in
>the international average.
Is that per mile driven? My recollection is that the average in
Europe is quite a bit above the US average.
Etherman
Joe Fischer wrote in message <36fd2...@news.iglou.com>...
>John Gilmer (gil...@crosslink.net) wrote:
>: WHAT is the OPTIMUM SPEED LIMIT (actually enforced) for Interstate
Highways
>: used as commuter roads. By optimum I mean, carries the greatest number
of
>: necessary to obtain? Would strict enforcement of "minimum speed" make a
>: major difference.
>
> You have to consider the extra lives lost and
>the time lost to extra accidents at higher speeds.
> I drive 55, and keep a good distance behind
>other cars, and I get there about as fast as anybody.
I had to drive from a little north of Boston to Arlington,
VA a couple weeks ago. I estimated that at 60 I
could make it in 9 hours. I was doing between
70 and 80 all the way and made it in 8 hours.
Had it not been for construction in New York I
would have made it in 7 1/2. Excluding tolls
I could have made it in 7. So shaving off 2
hours is no small thing when you're driving long
distance. It also seems to be that accidents
aren't caused by speed, but by bad driving.
Etherman
Wolfram Schmied
>In article <36fe4937...@news.blinx.de>
>wsch...@mail.blinx.de (Wolfram Schmied) writes:
>>You say 'accidents?' I reply, Germany is and has been for decades in
>>the international average.
> Is that per mile driven? My recollection is that the average in
> Europe is quite a bit above the US average.
might think so. (I'm not implying Mr. Carr is a Europhobe.)
From what I heard, France is much worse off in that respect.
BTW, I can play this game, too. Combining México and the U.S. would
tend to badify the record, wouldn't it?
Wolfram 8-)#
Steve O'Hara Smith
: Is that per mile driven? My recollection is that the average in
: Europe is quite a bit above the US average.
I think that a contributing factor to this is that roads in the USA are
generally wider and straighter than those in Europe.
Lorenz [to_email_see_my_sig] Borsche
>
> I think that a contributing factor to this is that roads in the USA
>are generally wider and straighter than those in Europe.
Exactly. And you have that speed limit too. No wonder everyone falls
asleep...
(I *do* drive as fast as I can at night: it keeps me awake and my
adrenalin level high...)
Jim Carr
|
| In article <36fe4937...@news.blinx.de>
| wsch...@mail.blinx.de (Wolfram Schmied) writes:
| >You say 'accidents?' I reply, Germany is and has been for decades in
| >the international average.
|
| Europe is quite a bit above the US average.
In article <370a0de0...@news.blinx.de>
wsch...@mail.blinx.de (Wolfram Schmied) writes:
>
>Germany is not exactly the same as Europe, though some Europhobes
>might think so. (I'm not implying Mr. Carr is a Europhobe.)
Maybe I was not clear about what you meant by "in the international
average". I foreign-english parsed that as "close to" rather than
"included in" the average.
The latest numbers I could find from NHTSA say the US death rate is
1.7 per 100 million miles driven (in 1997). That would be about 1.1
deaths per 100 million km (or 11 per billion km) for metric comparisons.
>From what I heard, France is much worse off in that respect.
Any idea what the corresponding European (or German) rate is?
Tracking from the FIA crash testing site, I did find a graph
for 1994 that looks like it says the EU average is about 17 per
billion km, well above the US. I'm guessing D is Germany, which
is about that average, and that GR is Greece at almost 65 !!
The US always looks bad on total numbers killed (due to the large
population) or numbers of cars (we drive a lot) compared to some
other countries. Per mile is more realistic for the risk of being
on the road.
>BTW, I can play this game, too. Combining México and the U.S. would
>tend to badify the record, wouldn't it?
Ah, but as a point of comparison it would probably make the US
look very safe with a below-average risk. Similarly, combining
Germany with some other countries might make Europe look worse
or Germany better.
Lorenz [to_email_see_my_sig] Borsche
Carr) wrote:
> The latest numbers I could find from NHTSA say the US death rate is
> 1.7 per 100 million miles driven (in 1997). That would be about 1.1
> deaths per 100 million km (or 11 per billion km) for metric comparisons.
> Any idea what the corresponding European (or German) rate is?
Ok, let's see: 42 Million cars driving an average of 12.500 km/a,
seated with 1.7 people gives: 892 billion personkilometers. Death toll
is 7800/a. That is 1 death per 114 million km or 0.87 deaths per 100
million km (or ~9 per billion km)
> Tracking from the FIA crash testing site, I did find a graph
> for 1994 that looks like it says the EU average is about 17 per
> billion km, well above the US. I'm guessing D is Germany, which
> is about that average, and that GR is Greece at almost 65 !!
If it is from '94 the numbers were much worse here (because of bad
roads in the east and drivers not being used to fast cars). The number
I remember is well above 10.000/a. As there were less cars, less
kilometers driven but 35%-40% more deaths, an average of 15 per
billion km does not sound too far off the mark.
Jim Carr
In article <7ds8s2$1n...@r02n01.cac.psu.edu>
"Thomas Jaworowski" <no...@no.spam.edu> writes:
>
>Cars are not really all that aerodynamic. At around 200 MPH drag becomes an
>issue. Most production cars can't even surpass 130 MPH.
That is because power becomes an issue long before 200 mph.
It takes quite a bit of horsepower just to push a car through the
air at 200 mph, which is how NASCAR limits speeds by limiting power.
>If cars drove at 130 MPH, then they would be burning lots of fuel and since
>they are redlining their engines, their engines would blow.
Hardly. There are production cars in the US whose top speed of
160 mph is set by a speed limiter. They reach that speed well
below red line in top gear, and below red line in the next lower
gear as well, in one case.
>One day, perhaps, driving might be computer assisted and your car may one
>day have an auto pilot.
Boring. Might make the folks who are already reading while driving
to work in their Sport Futility Vehicles (not my invention) happy.
Jim Carr
"Ray Vanlandingham" <ray...@javanet.com> wrote:
}
} I seem to recall some EPA studies back in the eighties that said that 45 mph
} was the optimum speed, due to internal combustion engines burning fuel most
} efficiently at around that speed.
In article <37047...@news.farside.net>
pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) writes:
>
>LOL :-)
I don't know if that speed is correct, and it would certainly vary
from car to car (and over time, as designs change) and with weather
conditions, but there is a reason for that sort of result because
an internal combustion engine will have a peak efficiency at some
rpm and load under the constraint of a constant speed.
jmfb...@aol.com
joe...@iglou.com (Joe Fischer) wrote:
>Lorenz [to_email_see_my_sig] Borsche (pub...@usa.net) wrote:
>: (Jim Carr) wrote:
<snip>
> And I haven't seen anything on the news
>about brownouts for several years, although
>there has been a lot of people without power
>for up to two weeks or more because of storms
>and the large number of trees which tear down
>power lines and poles, a lot of this country
>has too many trees, and other parts don't
>have enough.
We had brownout _and_ blackout warnings last summer and it
wasn't really ever very hot. I didn't hear about a rolling
brownout last year but then, things with that importance rarely
make the news casts.
/BAH
Subtract a hundred and four for e-mail.
jmfb...@aol.com
j...@ibms48.scri.fsu.edu (Jim Carr) wrote:
>In article <3705d...@news.farside.net>>>The US a 3rd world country where on first floor you can see by the
>>flickering lights that the washing machine starts the spin cycle? I'm
>>not buying that.
>
> It is a free-market economy where minimal regulation can result
> in people buying exactly that sort of wiring system.
>
Are you telling me this PITA can be fixed? If so, please give
me the magic incantation that will cause the electrician (or
power company) to do just that.
jmfb...@aol.com
>
>>>What? I cannot believe that. We have a guarantee for not less than
>>>something (methinks 5%).
>
>
>[brown out]
>>It's what happens when the nuclear plants are shut down and can't
>>provide the power requested.
>
>And there's no backup? Over here, there the obligation to have that
>(20% for the whole countrywide net actually, thus ~12 NPP (out of ~25)
>could go down before anything would happen. Not even then. Old coal
>plants are being kept serviced and the market hasn't gown all to
>much. In real we could put up with 45% failures...
>
Those coal plants got into trouble because they were polluting.
The nuclear plants (that were going to be built) had trouble
because, if they ever got out of court with their designs, people
blocked the aisles to the building site to cause difficulty and
budget over-runs. I always wanted to ask those people if they
would be willing to stop using electricity so we could have theirs.
jmfb...@aol.com
pub...@usa.net (Lorenz [to_email_see_my_sig] Borsche) wrote:
>
>>What I'm trying to determine is if
>>a large draw from the public grid can cause power fluctuations
>>in his private grid,
>
>It sure could, but it could never draw more solar than there is. As I
>said: the solar is fed directly into the public grid before I get to
>see any single electron. It could be done on my neighbours house and
>wouldn't be any different to my washing machine.
So then, if there were a blackout, you still wouldn't be powered up.
I can't use that design. I need an energy source that guarantees
I will have power no matter what happens to public grid.
>
>
>>Think about a washing machine that first starts up. It
>>momentarily pulls quite a bit of power, causing the lights
>>to dim.
>
>What? You are making fun of me?
Nope. My washing machine and the circulator on the boiler both
draw quite a bit on startup. So does my printer; I'm thinking
of putting that on it's own separate breaker.
>
>>The same thing can happen with the public grid. It
>>happens here quite often now.
>
>The US a 3rd world country where on first floor you can see by the
>flickering lights that the washing machine starts the spin cycle? I'm
>not buying that.
I'll demonstrate. [emoticon starts washing socks and turns up
the thermostat] See? QED.
Tom Hardy
j...@ibms48.scri.fsu.edu (Jim Carr) wrote:
:
: The reason is that there are two factors. [Applicable to safe following
: distance] One is a constant (reaction
: with speed, while the other is not (actual stopping distance, which
: increases quadratically with speed because of the need to dissipate
: kinetic energy in braking) and also depends on road conditions. The
: latter favors lower speeds since the cars can be closer together.
Shouldn't the second factor be due to a constant closing rate while
both cars are under maximum deceleration? The required following
distance would then increase linearly with speed, no matter the actual
stopping distance.
Come to think of it, shouldn't reaction time following distance (the
first factor) be a constant distance? Ie, the distance closed (in the
smoothly traveling rest frame) while the first car is decelerating and
the second car is reacting, and then again while the first car is
stopped and the second is decelerating. Again, the actual road
distance is irrelevant.
And while I'm at it, in my experience my reaction time is more often
than not a negative value because I am reacting to events further down
the road than the car in front of me.
Sorry, someone had to argue the other side in this debate. :-) But
it makes the two second rule into an even better yardstick than you
give it credit for.
--
Tom Hardy <*>
rth...@email.msn.com
robert...@blake.pvt.k12.mn.us
Tom Hardy
j...@ibms48.scri.fsu.edu (Jim Carr) wrote:
:
:In article <7e1roo$jjh$1...@autumn.news.rcn.net>,
:}
:} I seem to recall some EPA studies back in the eighties that said that 45 mph
:} was the optimum speed, due to internal combustion engines burning fuel most
:} efficiently at around that speed.
:
:In article <37047...@news.farside.net>
:>
:>LOL :-)
:
: I don't know if that speed is correct, and it would certainly vary
: from car to car (and over time, as designs change) and with weather
: conditions, but there is a reason for that sort of result because
: an internal combustion engine will have a peak efficiency at some
: rpm and load under the constraint of a constant speed.
I recall that was some kind of tradeoff between convenience and drag;
below 45 mph, drag was no longer very signifigant. I don't imagine
it's changed too much. Cars have less drag these days; due to changes
in gearing and induction dynamics, they also operate more efficiently
at low power settings.
Mark Folsom
Tom Hardy <rth...@email.msn.com> wrote in message
news:3711d8b2....@news.uswest.net...
> In article <7ebfo9$71h$1...@news.fsu.edu>,
> j...@ibms48.scri.fsu.edu (Jim Carr) wrote:
> :
> : The reason is that there are two factors. [Applicable to safe following
> : distance] One is a constant (reaction
> : time) so the separation distance required for that grows only linearly
> : with speed, while the other is not (actual stopping distance, which
> : increases quadratically with speed because of the need to dissipate
> : kinetic energy in braking) and also depends on road conditions. The
> : latter favors lower speeds since the cars can be closer together.
>
> Shouldn't the second factor be due to a constant closing rate while
> both cars are under maximum deceleration? The required following
> distance would then increase linearly with speed, no matter the actual
> stopping distance.
Picture yourself cruising down the left lane of a freeway with a Lincoln
Navigator in front of you and a semi beside you. Suddenly the L.N. veers to
the right to reveal a stalled car sitting stationary in the lane ahead of
you. How far will it take you to stop? What's the distance you should
allow?
>
> Come to think of it, shouldn't reaction time following distance (the
> first factor) be a constant distance? Ie, the distance closed (in the
> smoothly traveling rest frame) while the first car is decelerating and
> the second car is reacting, and then again while the first car is
> stopped and the second is decelerating. Again, the actual road
> distance is irrelevant.
No. Look at the kinematics: if you start decelerating at the same place as
the driver in front of you did and decelerate at the same rate, you will
stop in the same location as she does. In order to start braking behind the
point where the driver in front of you did, you must react in less time than
it takes for you to reach that location. Since your reaction time
presumably doesn't get shorter with increasing speed, you have to increase
your following distance.
>
> And while I'm at it, in my experience my reaction time is more often
> than not a negative value because I am reacting to events further down
> the road than the car in front of me.
Keep telling yourself that.
>
> Sorry, someone had to argue the other side in this debate. :-) But
> it makes the two second rule into an even better yardstick than you
> give it credit for.
If you want to avoid a vehicle that stops in a collision or one that is
suddenly revealed to be stopped in your lane, you need a three-second rule
at 70 mph. But really, Xs=V*Tr+V^2/(2A), so Tf=Xs/V=Tr+V/(2A) which for .8
g and a one second reaction time would be
Tf=1+V*22/15/52=1+.028V
--
Mark Folsom, P.E.
Consulting Mechanical Engineer
http://www.redshift.com/~folsom
Jim Carr
j...@ibms48.scri.fsu.edu (Jim Carr) wrote:
|
| The reason is that there are two factors. [Applicable to safe following
| distance] One is a constant (reaction
| time) so the separation distance required for that grows only linearly
| with speed, while the other is not (actual stopping distance, which
| increases quadratically with speed because of the need to dissipate
| kinetic energy in braking) and also depends on road conditions. The
| latter favors lower speeds since the cars can be closer together.
In article <3711d8b2....@news.uswest.net>
rth...@email.msn.com (Tom Hardy) writes:
>
>Shouldn't the second factor be due to a constant closing rate while
>both cars are under maximum deceleration? The required following
>distance would then increase linearly with speed, no matter the actual
>stopping distance.
I think that is the case *if* you could assume that you only have to
worry about cars in front of you braking, but there is probably a
correction factor because it takes time to figure out that the car
is maximally braking rather than just adjusting speed and because
cars have different braking performance. In fact, that is precisely
the assumption people make when traveling on packed freeways at
high speed. They are trusting everyone else.
The problem is that other things can happen. You drive into a
rain shower, there turns out to be a truck going the minimum
speed or below pulling onto the highway that someone hits, fog
rolls in ... the usual thing that then results in 10 to 80 cars
forming a massive pileup every once in a while.
>And while I'm at it, in my experience my reaction time is more often
>than not a negative value because I am reacting to events further down
>the road than the car in front of me.
That is what can terminate a multi-car pileup, if the person behind
you is doing the same thing.
Lorenz [to_email_see_my_sig] Borsche
Carr) wrote:
>>LOL :-)
>
> I don't know if that speed is correct, and it would certainly vary
> from car to car (and over time, as designs change) and with weather
> conditions, but there is a reason for that sort of result because
> an internal combustion engine will have a peak efficiency at some
> rpm and load
That is correct..
>under the constraint of a constant speed.
.and that also. But it doesn't follow any given speed from it. If you
take a suburban equipped with a 1100cc honda sqeaky, the speed of
optimum load vs. rpm would probably around 30 mph, whereas the same
motor would drive a lightweight monocoque at 100 mph with the same
efficiency (given the right gearbox). Speed is just the wrong unit as
the 'right' speed depends on other factors like airdrag which again
depends on size and shape etc.... So my LOL was just saying: wrong
unit. The right unit for motor efficiency as you correctly named it is
a combination of revs and load.
Wolfram Schmied
[to_email_see_my_sig] Borsche) wrote:
>In article <7elr24$qia$1...@news.fsu.edu>, j...@ibms48.scri.fsu.edu (Jim
>Carr) wrote:
>.and that also. But it doesn't follow any given speed from it. If you
>take a suburban equipped with a 1100cc honda sqeaky, the speed of
>optimum load vs. rpm would probably around 30 mph, whereas the same
>motor would drive a lightweight monocoque at 100 mph with the same
>efficiency (given the right gearbox).
You're a pessimist. In the 30's they used 50cc engines (yes, that's
fifty cm^3) to propel those magnificent men through the 200km/h (125
mph) barrier. Those were the days...
Wolfram "Just Mach it" 8-)#
Lorenz [to_email_see_my_sig] Borsche
(Wolfram Schmied) wrote:
>You're a pessimist. In the 30's they used 50cc engines (yes, that's
>fifty cm^3) to propel those magnificent men through the 200km/h (125
>mph) barrier. Those were the days...
. my friend. But AFAIR it have not been monocoques, but small
motorbikes with full aerodynamical eggshape. Didn't they do it in the
sixties with a Kreidler Florett?
Lorenz [to_email_see_my_sig] Borsche
engineer. He said they're cruising on 1° AoA and Bernoulli is doing
90% of the work.
Cheers
jmfb...@aol.com
>(Wolfram Schmied) wrote:
>
>>You're a pessimist. In the 30's they used 50cc engines (yes, that's
>>fifty cm^3) to propel those magnificent men through the 200km/h (125
>>mph) barrier. Those were the days...
>
>sixties with a Kreidler Florett?
>
Kevin A. Scaldeferri
Lorenz [to_email_see_my_sig] Borsche <pub...@usa.net> wrote:
>Last info: Friday I had the chance to talk to a 'real' flight
>engineer. He said they're cruising on 1° AoA and Bernoulli is doing
>90% of the work.
Last semi-rant: As I've tried to say several times, Bernoulli is doing
100% of the work. Also, Newton is doing 100% of the work and
circulation is doing 100% of the work. They're all the same.
--
======================================================================
Kevin Scaldeferri Calif. Institute of Technology
The INTJ's Prayer:
Lord keep me open to others' ideas, WRONG though they may be.
Mark Folsom
> In article <92388850...@news.remarQ.com>,
> "Mark Folsom" <fols...@redshift.com> wrote:
> :
> :[....] Suddenly the L.N. veers to
> :the right to reveal a stalled car sitting stationary....
>
> Isn't this a separate matter though? Obviously important, but you are
> reacting to something other than the Lincoln.
Separate from what? It's something that can happen to you that would make
you unsafe if following closely. In such a situation, you could need to
stop at about the place where you saw the Lincoln move over. The reason why
I used a Lincoln Navigator is that you would be unlikely to see the car
ahead until the LN moved over. I once talked to someone who had just such
an accident---idiot stopped in fast lane, driver following closely sees car
ahead veer quickly to the right, then helplessly rams into stopped car.
> :
> :No. Look at the kinematics: <snip>
>
> Uhh. I should have said "constant time." I must've slipped.
>
> <snip>
>
> :If you want to avoid a vehicle that stops in a collision or one that is
> :suddenly revealed to be stopped in your lane, you need a three-second
rule
> :at 70 mph. But really, Xs=V*Tr+V^2/(2A), so Tf=Xs/V=Tr+V/(2A) which for
..8
> :g and a one second reaction time would be
> :
> :Tf=1+V*22/15/52=1+.028V
>
> I see Xs is total distance, Tf is total time, but I don't know how you
> named them. Also, you pulled a bunch of numbers out of a hat where I
> have a bunch of mixed units; could you explain the shortcut?
I meant Xs to be stopping distance, including operator response time. Tf is
safe following time for the case of a leading vehicle which suddenly stops
(as in an impact with a pileup) or moves aside to reveal a stationary
obstacle. It isn't the time it takes for anything to happen in the actual
braking situation. 22/15 is a conversion from miles per hour to feet per
second. 52 is ~2A where A is .8*32.2 or .8*g, where g is the acceleration
due to gravity at the surface of the earth. So, if I use V in miles per
hour and want the stopping distance in feet for .8g's deceleration, I use
the equation above. This NG is just so chock full of brilliant suckers, I
thought it would be obvious to everybody. ;-)
>
> (I am interested. I've seen it done before--just not lately.)
> --
Tom Hardy
j...@ibms48.scri.fsu.edu (Jim Carr) wrote:
:
:In article <3711d8b2....@news.uswest.net>
:>
:>Shouldn't the second factor be due to a constant closing rate while
:>both cars are under maximum deceleration? The required following
:>distance would then increase linearly with speed, no matter the actual
:>stopping distance.
:
: I think that is the case *if* you could assume that you only have to
: worry about cars in front of you braking, but there is probably a
: correction factor because it takes time to figure out that the car
: is maximally braking rather than just adjusting speed and because
: cars have different braking performance. In fact, that is precisely
: the assumption people make when traveling on packed freeways at
: high speed. They are trusting everyone else.
Don't get me wrong, I don't think everyone should always drive to
their reaction time limit. That's called white knuckle driving and
most people don't like it, though perhaps some do. :-) But you can
react to the brick wall that is 8 seconds ahead while being a constant
two seconds behind the car in front of you. And two seconds gives
some reaction time. How should it be figured?
Also, zero following distance would make more efficient use of the
highways and should be looked into. After all, trains manage to use
that strategy.
:
: The problem is that other things can happen. You drive into a
: rain shower, there turns out to be a truck going the minimum
: speed or below pulling onto the highway that someone hits, fog
: rolls in ... the usual thing that then results in 10 to 80 cars
: forming a massive pileup every once in a while.
You forgot to mention oncoming cars in your lane. :-) Obviously, it
would be good to account for these things. I think speed limits
attempt to address it. But aren't we addressing two different matters
here? One is safe following distance from a car with known current
velocity, and the other is making assumptions about the unknowable
around the next corner. And yes, you have no choice but to trust
other drivers, but that is a third issue (every time you pass an
oncoming car there is the potential for a collision that you can do
nothing to avoid.)
:
:>And while I'm at it, in my experience my reaction time is more often
:>than not a negative value because I am reacting to events further down
:>the road than the car in front of me.
:
: That is what can terminate a multi-car pileup, if the person behind
: you is doing the same thing.
I think most people leave themselves a comfortable amount of reaction
time most of the time (or think they do,) but they will react to
events as far ahead as possible, not just the nearest car. The only
way to prevent it is to deny them knowledge of the road ahead. But
yeah, I think you should allow for some net positive reaction time, on
the average, anyway. :-)
Tom Hardy
"Mark Folsom" <fols...@redshift.com> wrote:
:
:[....] Suddenly the L.N. veers to
:the right to reveal a stalled car sitting stationary....
Isn't this a separate matter though? Obviously important, but you are
reacting to something other than the Lincoln.
:
:No. Look at the kinematics: <snip>
Uhh. I should have said "constant time." I must've slipped.
<snip>
:If you want to avoid a vehicle that stops in a collision or one that is
:suddenly revealed to be stopped in your lane, you need a three-second rule
:at 70 mph. But really, Xs=V*Tr+V^2/(2A), so Tf=Xs/V=Tr+V/(2A) which for .8
:g and a one second reaction time would be
:
:Tf=1+V*22/15/52=1+.028V
I see Xs is total distance, Tf is total time, but I don't know how you
named them. Also, you pulled a bunch of numbers out of a hat where I
have a bunch of mixed units; could you explain the shortcut?
(I am interested. I've seen it done before--just not lately.)
John Feiereisen
[to_email_see_my_sig] Borsche) wrote:
>Last info: Friday I had the chance to talk to a 'real' flight
>engineer. He said they're cruising on 1° AoA and Bernoulli is doing
>90% of the work.
Correction: Bernoulli is *always* "doing 100% of the work". You
simply can't separate the effects of AOA and Bernoulli. You may,
however, separate the effects of AOA and camber.
Whether you develop lift with AOA, camber, or a combination of both,
the Bernoulli equation (Conservation of Momentum along a streamline)
*always* determines the pressure distribution and therefore the lift.
Perhaps this flight engineer meant that an uncambered, but otherwise
identical, wing would only produce 10% of the lift at that 1 deg AOA??
--
John
Note: Email address munged in an attempt (probably futile) to
foil spammers. There are no digits in the real address.
jmfb...@aol.com
Yesterday, I was followed by a female in one of those health
hazards called minivan or whatever. I couldn't see her
lights in my rearview mirror. In one hand she was holding
a cell phone, in the other the steering wheel....but only
half the time since she had to use it to talk. Her eye
contact with my car (this doesn't include the road ahead)
occurred maybe 20% of the time. Whenever her steering hand
was being used to emphasize her conversation, she looked
sideways. I was afraid to slow down or brake. How do
you counteract that flavor of non-driving?
jnew...@my-dejanews.com
feie...@utrc1.utc.com (John Feiereisen) wrote:
> In <37127...@news.farside.net>, pub...@usa.net (Lorenz
> [to_email_see_my_sig] Borsche) wrote:
>
> >Last info: Friday I had the chance to talk to a 'real' flight
> >engineer. He said they're cruising on 1° AoA and Bernoulli is doing
> >90% of the work.
>
> Correction: Bernoulli is *always* "doing 100% of the work". You
> simply can't separate the effects of AOA and Bernoulli. You may,
> however, separate the effects of AOA and camber.
>
> Whether you develop lift with AOA, camber, or a combination of both,
> the Bernoulli equation (Conservation of Momentum along a streamline)
> *always* determines the pressure distribution and therefore the lift.
>
> Perhaps this flight engineer meant that an uncambered, but otherwise
> identical, wing would only produce 10% of the lift at that 1 deg AOA??
How does "Bernoulli" create the velocity field?
Jan-Olov Newborg
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
Wolfram Schmied
>Yesterday, I was followed by a female in one of those health
>hazards called minivan or whatever. I couldn't see her
>lights in my rearview mirror. In one hand she was holding
>a cell phone, in the other the steering wheel....but only
>half the time since she had to use it to talk. Her eye
>contact with my car (this doesn't include the road ahead)
>occurred maybe 20% of the time. Whenever her steering hand
>was being used to emphasize her conversation, she looked
>sideways. I was afraid to slow down or brake. How do
>you counteract that flavor of non-driving?
The question bugging me is, how did you arrive at your estimate of her
attention deficit? Do have camera installed in your car and evaluated
the tape at home, or .....?
Wolfram "used to read while at the helm of a car going 100 mph" 8-)#