On 2022-02-17 09:04:57 +0000, Roland Perry said:

> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
> 2022, Muttley@dastardlyhq.com remarked:
>> On Wed, 16 Feb 2022 17:35:00 +0000
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>> 2022, Muttley@dastardlyhq.com remarked:
>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>> Bob <email@domain.com> wrote:
>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>> Intuitively, any driver will know that if they push their right foot
>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>> but if they are driving on the motorway, they can push their right foot
>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>> Anna may have different experiences, as each of them have made
>>>>> references to owning or having owned "atypical" cars).
>>>>
>>>> Well I know thats not true because some wheel driven land speed record cars
>>>> started to have wheelsip at very high speed which limited their record
>>>> run max V
>>>
>>> How many of us are driving land-speed-record cars on the streets?
>>
>> Not the point as you well know.
>
> The point, dear boy, is discussing the verascity of the assertion:
>
> "any driver will know that if they push their right foot all the way
> down at low speed, they will spin the wheels on their car"
>
> Notwithstanding I don't even think that's true of road-going cars, your
> record-breaking cars aren't even, by your own admission, travelling at
> "low speed".

And also not on a motorway.

Robin

On Thu, 17 Feb 2022 09:04:17 +0000
Graeme Wall <rail@greywall.demon.co.uk> wrote:
>On 17/02/2022 08:56, Muttley@dastardlyhq.com wrote:
>> On Wed, 16 Feb 2022 21:10:09 +0100
>> Bob <email@domain.com> wrote:
>>> On 2022-02-16 17:20:33 +0000, Muttley@dastardlyhq.com said:
>>>
>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>> Bob <email@domain.com> wrote:
>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>> Intuitively, any driver will know that if they push their right foot
>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>> but if they are driving on the motorway, they can push their right foot
>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>> Anna may have different experiences, as each of them have made
>>>>> references to owning or having owned "atypical" cars).
>>>>
>>>> Well I know thats not true because some wheel driven land speed record cars
>
>>>> started to have wheelsip at very high speed which limited their record
>>>> run max V
>>>
>>> Land speed record cars are in a somewhat unusual situation because
>>> first, they can't use pneumatic tyres, as they would disintigrate under
>>> the centrifugal loading, and second, they are driving on salt flats
>>> rather than paved road, which has a tendency to crumble under the
>>> extreme forces involved. As they go faster, the limiting friction for
>>> the wheels reduces as the interaction of the wheel with the ground
>>> causes the ground conditions to deteriorate.
>>
>> Quite possibly. But it demonstrates that you can get wheel slip due to wind
>> resistance at high speed.
>>
>
>What's wind got to do with it?

Wind, air, that stuff cars have to move through.

On Thu, 17 Feb 2022 09:04:57 +0000
Roland Perry <roland@perry.co.uk> wrote:
>In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>2022, Muttley@dastardlyhq.com remarked:
>>On Wed, 16 Feb 2022 17:35:00 +0000
>>Roland Perry <roland@perry.co.uk> wrote:
>>>In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>2022, Muttley@dastardlyhq.com remarked:
>>>>On Wed, 16 Feb 2022 11:26:39 +0100
>>>>Bob <email@domain.com> wrote:
>>>>>On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>Intuitively, any driver will know that if they push their right foot
>>>>>all the way down at low speed, they will spin the wheels on their car,
>>>>>but if they are driving on the motorway, they can push their right foot
>>>>>all the way to the floor and the wheels won't lose grip (Roland and
>>>>>Anna may have different experiences, as each of them have made
>>>>>references to owning or having owned "atypical" cars).
>>>>
>>>>Well I know thats not true because some wheel driven land speed record cars
>>>>started to have wheelsip at very high speed which limited their record
>>>>run max V
>>>
>>>How many of us are driving land-speed-record cars on the streets?
>>
>>Not the point as you well know.
>
>The point, dear boy, is discussing the verascity of the assertion:
>
> "any driver will know that if they push their right foot all the way
> down at low speed, they will spin the wheels on their car"
>
>Notwithstanding I don't even think that's true of road-going cars, your
>record-breaking cars aren't even, by your own admission, travelling at
>"low speed".

The point was Robin stated its impossible to get wheelspin due to air
resistance at all, never mind with a train. I pointed out he was wrong.

<Muttley@dastardlyhq.com> wrote:
> On Thu, 17 Feb 2022 09:04:57 +0000
> Roland Perry <roland@perry.co.uk> wrote:
>> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>> 2022, Muttley@dastardlyhq.com remarked:
>>> On Wed, 16 Feb 2022 17:35:00 +0000
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>> 2022, Muttley@dastardlyhq.com remarked:
>>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>>> Bob <email@domain.com> wrote:
>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>> Intuitively, any driver will know that if they push their right foot
>>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>>> but if they are driving on the motorway, they can push their right foot
>>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>>> Anna may have different experiences, as each of them have made
>>>>>> references to owning or having owned "atypical" cars).
>>>>>
>>>>> Well I know thats not true because some wheel driven land speed record cars
>>>>> started to have wheelsip at very high speed which limited their record
>>>>> run max V
>>>>
>>>> How many of us are driving land-speed-record cars on the streets?
>>>
>>> Not the point as you well know.
>>
>> The point, dear boy, is discussing the verascity of the assertion:
>>
>> "any driver will know that if they push their right foot all the way
>> down at low speed, they will spin the wheels on their car"
>>
>> Notwithstanding I don't even think that's true of road-going cars, your
>> record-breaking cars aren't even, by your own admission, travelling at
>> "low speed".
>
> The point was Robin stated its impossible to get wheelspin due to air
> resistance at all, never mind with a train. I pointed out he was wrong.
>
>

The wheelspin in a world speed record breaking car is more likely to come
from the attempt to accelerate. If running at a steady speed, there's
probably no wheel spin.

On 17/02/2022 09:04, Roland Perry wrote:
> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
> 2022, Muttley@dastardlyhq.com remarked:
>> On Wed, 16 Feb 2022 17:35:00 +0000
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>> 2022, Muttley@dastardlyhq.com remarked:
>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>> Bob <email@domain.com> wrote:
>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>> Intuitively, any driver will know that if they push their right foot
>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>> but if they are driving on the motorway, they can push their right
>>>>> foot
>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>> Anna may have different experiences, as each of them have made
>>>>> references to owning or having owned "atypical" cars).
>>>>
>>>> Well I know thats not true because some wheel driven land speed
>>>> record cars
>>>> started to have wheelsip at very high speed which limited their record
>>>> run max V
>>>
>>> How many of us are driving land-speed-record cars on the streets?
>>
>> Not the point as you well know.
>
> The point, dear boy, is discussing the verascity of the assertion:
>
>    "any driver will know that if they push their right foot all the way
>     down at low speed, they will spin the wheels on their car"
>
> Notwithstanding I don't even think that's true of road-going cars, your
> record-breaking cars aren't even, by your own admission, travelling at
> "low speed".

Modern land speed record cars don't rely on adhesion, being basically
jet aircraft with the wings removed.

--
Graeme Wall
This account not read.

On 17/02/2022 09:36, Marland wrote:
> Charles Ellson <charlesellson@btinternet.com> wrote:
>> On Mon, 14 Feb 2022 16:45:55 +0000, Roland Perry <roland@perry.co.uk>
>> wrote:
>>
>>> In message <suduvm$16ab$3@gioia.aioe.org>, at 16:11:33 on Mon, 14 Feb
>>> 2022, "hounslow3@yahoo.co.uk" <hounslow3@yahoo.co.uk> remarked:
>>>> On 14/02/2022 15:30, Anna Noyd-Dryver wrote:
>>>>> hounslow3@yahoo.co.uk <hounslow3@yahoo.co.uk> wrote:
>>>>>> On 11/02/2022 20:32, Charles Ellson wrote:
>
>>>
>>> When I was going to school on a bus, there was a sort of cattle pen
>>> enclosed bus shelter in the High Street with a barrier down most of the
>>> centre for the queue to weave round, and quite small [always open] entry
>>> and exit doorways. Big enough for maybe 30 pax.
>>>
>>> I've done some Google image searches, and can't find anything even
>>> remotely similar.
>>>
>> No barrier down the middle but I have seen old photographs of some
>> towns/cities where you used to get some fairly long (up to a couple of
>> bus lengths or so) bus/tram shelters, fully enclosed except for the
>> entrance and exit.
>>
>
> One of those was still in use well into the 1980’s at Cosham ,a suburb of
> Portsmouth from where it was originally located in city centre.
>
> Cosham was where the Tram and later Trolleybus routes terminated but had
> huge council estates constructed in the interwar period so a lot of people
> would head for the stop.
> At one time it was also the interchange for the Portsmouth and Horndean
> light Railway but I think that had closed by the time the shelter was moved
> there replacing the original arrangements which were a couple of old horse
> tram bodies.
>
> It has since been relocated again and used as a catering outlet in the
> Gunwharf shopping development.
>
> <https://goo.gl/maps/q5p4Dq7uW1LVSy369>
>

And serves very good cakes!

--
Graeme Wall
This account not read.

On 17/02/2022 10:01, Bob wrote:
> On 2022-02-17 09:04:17 +0000, Graeme Wall said:
>
>> On 17/02/2022 08:56, Muttley@dastardlyhq.com wrote:
>>> On Wed, 16 Feb 2022 21:10:09 +0100
>>> Bob <email@domain.com> wrote:
>>>> On 2022-02-16 17:20:33 +0000, Muttley@dastardlyhq.com said:
>>>>
>>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>>> Bob <email@domain.com> wrote:
>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>> Intuitively, any driver will know that if they push their right foot
>>>>>> all the way down at low speed, they will spin the wheels on their
>>>>>> car,
>>>>>> but if they are driving on the motorway, they can push their right
>>>>>> foot
>>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>>> Anna may have different experiences, as each of them have made
>>>>>> references to owning or having owned "atypical" cars).
>>>>>
>>>>> Well I know thats not true because some wheel driven land speed
>>>>> record cars
>>>>> started to have wheelsip at very high speed which limited their record
>>>>> run max V
>>>>
>>>> Land speed record cars are in a somewhat unusual situation because
>>>> first, they can't use pneumatic tyres, as they would disintigrate under
>>>> the centrifugal loading, and second, they are driving on salt flats
>>>> rather than paved road, which has a tendency to crumble under the
>>>> extreme forces involved.  As they go faster, the limiting friction for
>>>> the wheels reduces as the interaction of the wheel with the ground
>>>> causes the ground conditions to deteriorate.
>>>
>>> Quite possibly. But it demonstrates that you can get wheel slip due
>>> to wind
>>> resistance at high speed.
>>>
>>
>> What's wind got to do with it?
>>
>> Incidentally, someone said land speed record cars don't have pneumatic
>> tyres:
>>
>> <https://upload.wikimedia.org/wikipedia/common/1/19/Thrust2_chassis.jpg>
>>
>> But then again they don't have transmissions either. So the argument
>> is moot.
>
> The comment was specifically about wheel-driven speed records, so jet
> and rocket powered cars don't count for that.
>

When was the last attempt on the Land Speed Record attempted by a wheel
driven vehicle?

--
Graeme Wall
This account not read.

On 2022-02-17 10:06:43 +0000, Muttley@dastardlyhq.com said:

> On Thu, 17 Feb 2022 09:04:57 +0000
> Roland Perry <roland@perry.co.uk> wrote:
>> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>> 2022, Muttley@dastardlyhq.com remarked:
>>> On Wed, 16 Feb 2022 17:35:00 +0000
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>> 2022, Muttley@dastardlyhq.com remarked:
>>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>>> Bob <email@domain.com> wrote:
>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>> Intuitively, any driver will know that if they push their right foot
>>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>>> but if they are driving on the motorway, they can push their right foot
>>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>>> Anna may have different experiences, as each of them have made
>>>>>> references to owning or having owned "atypical" cars).
>>>>>
>>>>> Well I know thats not true because some wheel driven land speed record cars
>>>>> started to have wheelsip at very high speed which limited their record
>>>>> run max V
>>>>
>>>> How many of us are driving land-speed-record cars on the streets?
>>>
>>> Not the point as you well know.
>>
>> The point, dear boy, is discussing the verascity of the assertion:
>>
>> "any driver will know that if they push their right foot all the way
>> down at low speed, they will spin the wheels on their car"
>>
>> Notwithstanding I don't even think that's true of road-going cars, your
>> record-breaking cars aren't even, by your own admission, travelling at
>> "low speed".
>
> The point was Robin stated its impossible to get wheelspin due to air
> resistance at all, never mind with a train. I pointed out he was wrong.

No. In response to the question as to whether a train at high speed
could experienc wheelslip due to wind resistance, I pointed out that,
at high speed, a train will not have enough power installed to overcome
the friction that prevents wheelslip, and gave a bit of discussion on
how to establish what the cutoff speed is above which a train, with
good railhead conditions, is unable to spin its wheels.

Land speed record cars do not drive on solid surfaces, they drive on
things like sand or salt flats. The interaction between a steel wheel
and steel rail on a train, or a pneumatic tyre on a paved road, is
nothing like the interaction between a solid metal wheel and either
sand or salt, which I explianed elsewhere, hence the ability to achieve
good traction on those surfaces is a radically different situation. A
land speed record car exerts forces on the surface in such a way that,
at speed, the surface it is driving on breaks up, an it is essentially
driving on a powder, not a solid surface. Powders under those
conditions behave more like fluids than solids, so as a reference, it
is more like a boat being able to spin its propeller in water, rather
than a train trying to cause its wheels to spin.

Robin

On 2022-02-17 10:35:32 +0000, Graeme Wall said:

> On 17/02/2022 10:01, Bob wrote:
>> On 2022-02-17 09:04:17 +0000, Graeme Wall said:
>>
>>> On 17/02/2022 08:56, Muttley@dastardlyhq.com wrote:
>>>> On Wed, 16 Feb 2022 21:10:09 +0100
>>>> Bob <email@domain.com> wrote:
>>>>> On 2022-02-16 17:20:33 +0000, Muttley@dastardlyhq.com said:
>>>>>
>>>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>>>> Bob <email@domain.com> wrote:
>>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>> Intuitively, any driver will know that if they push their right foot
>>>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>>>> but if they are driving on the motorway, they can push their right foot
>>>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>>>> Anna may have different experiences, as each of them have made
>>>>>>> references to owning or having owned "atypical" cars).
>>>>>>
>>>>>> Well I know thats not true because some wheel driven land speed record cars
>>>>>> started to have wheelsip at very high speed which limited their record
>>>>>> run max V
>>>>>
>>>>> Land speed record cars are in a somewhat unusual situation because
>>>>> first, they can't use pneumatic tyres, as they would disintigrate under
>>>>> the centrifugal loading, and second, they are driving on salt flats
>>>>> rather than paved road, which has a tendency to crumble under the
>>>>> extreme forces involved.  As they go faster, the limiting friction for
>>>>> the wheels reduces as the interaction of the wheel with the ground
>>>>> causes the ground conditions to deteriorate.
>>>>
>>>> Quite possibly. But it demonstrates that you can get wheel slip due to wind
>>>> resistance at high speed.
>>>>
>>>
>>> What's wind got to do with it?
>>>
>>> Incidentally, someone said land speed record cars don't have pneumatic tyres:
>>>
>>> <https://upload.wikimedia.org/wikipedia/common/1/19/Thrust2_chassis.jpg>
>>>
>>> But then again they don't have transmissions either. So the argument is moot.
>>
>> The comment was specifically about wheel-driven speed records, so jet
>> and rocket powered cars don't count for that.
>>
>
> When was the last attempt on the Land Speed Record attempted by a wheel
> driven vehicle?

It depends on what you count. The "official" land speed record has
certain constraints on what the vehicle should be like, not just that
it be on land. For example the vehicle must run on four wheels
(tricycles are not counted). There are separate categories for driven
wheel and non-driven-wheel vehicles, with the most recent record in the
driven-wheel cateogry being set in 2018. If those rules didn't exist,
then things like rocket sleds would be counted, and unmanned rocket
sleds have run at over 6,000 mph on a test track. It would be possible
to make a manned rocket sled, of the sort used by John Stapp in the
1950s, but nobody bothers, because reasons.

Robin

On Thu, 17 Feb 2022 10:06:43 +0000, Muttley wrote:

> On Thu, 17 Feb 2022 09:04:57 +0000 Roland Perry <roland@perry.co.uk>
> wrote:
>>In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>>2022, Muttley@dastardlyhq.com remarked:
>>>On Wed, 16 Feb 2022 17:35:00 +0000 Roland Perry <roland@perry.co.uk>
>>>wrote:
>>>>In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>>2022, Muttley@dastardlyhq.com remarked:
>>>>>On Wed, 16 Feb 2022 11:26:39 +0100 Bob <email@domain.com> wrote:
>>>>>>On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>Intuitively, any driver will know that if they push their right foot
>>>>>>all the way down at low speed, they will spin the wheels on their
>>>>>>car, but if they are driving on the motorway, they can push their
>>>>>>right foot all the way to the floor and the wheels won't lose grip
>>>>>>(Roland and Anna may have different experiences, as each of them
>>>>>>have made references to owning or having owned "atypical" cars).
>>>>>
>>>>>Well I know thats not true because some wheel driven land speed
>>>>>record cars started to have wheelsip at very high speed which limited
>>>>>their record run max V
>>>>
>>>>How many of us are driving land-speed-record cars on the streets?
>>>
>>>Not the point as you well know.
>>
>>The point, dear boy, is discussing the verascity of the assertion:
>>
>> "any driver will know that if they push their right foot all the way
>> down at low speed, they will spin the wheels on their car"
>>
>>Notwithstanding I don't even think that's true of road-going cars, your
>>record-breaking cars aren't even, by your own admission, travelling at
>>"low speed".
>
> The point was Robin stated its impossible to get wheelspin due to air
> resistance at all, never mind with a train. I pointed out he was wrong.

Another back-of-envelope doodle: The limiting speed at which wheel slip
can occur for a given power input, for the case for a car-like thing with
a grip capable of acceleration of around 1 g, is close to R/6 where R is
the power to weight ratio in HP per ton and the answer is in miles per
hour.

For my car 135 HP and 1.5 ton, about 15 mi/h.

For a "go-kart" with 300 HP in half a ton it's be 100 mi/h.

And of course higher still if lower grip, then limit = R/(6*coeff of
friction).

It doesn't if the traction force is going into wind resistance or
acceleration, the limit is the same.

And this is the power limit, actual engine torques and gear ratios could
make the limit speed lower.

nib

In message <sulagg$4gu$1@dont-email.me>, at 11:11:12 on Thu, 17 Feb
2022, nib <news@ingram-bromley.co.uk> remarked:
>On Thu, 17 Feb 2022 10:06:43 +0000, Muttley wrote:
>
>> On Thu, 17 Feb 2022 09:04:57 +0000 Roland Perry <roland@perry.co.uk>
>> wrote:
>>>In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>>>2022, Muttley@dastardlyhq.com remarked:
>>>>On Wed, 16 Feb 2022 17:35:00 +0000 Roland Perry <roland@perry.co.uk>
>>>>wrote:
>>>>>In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>>>2022, Muttley@dastardlyhq.com remarked:
>>>>>>On Wed, 16 Feb 2022 11:26:39 +0100 Bob <email@domain.com> wrote:
>>>>>>>On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>>Intuitively, any driver will know that if they push their right foot
>>>>>>>all the way down at low speed, they will spin the wheels on their
>>>>>>>car, but if they are driving on the motorway, they can push their
>>>>>>>right foot all the way to the floor and the wheels won't lose grip
>>>>>>>(Roland and Anna may have different experiences, as each of them
>>>>>>>have made references to owning or having owned "atypical" cars).
>>>>>>
>>>>>>Well I know thats not true because some wheel driven land speed
>>>>>>record cars started to have wheelsip at very high speed which limited
>>>>>>their record run max V
>>>>>
>>>>>How many of us are driving land-speed-record cars on the streets?
>>>>
>>>>Not the point as you well know.
>>>
>>>The point, dear boy, is discussing the verascity of the assertion:
>>>
>>> "any driver will know that if they push their right foot all the way
>>> down at low speed, they will spin the wheels on their car"
>>>
>>>Notwithstanding I don't even think that's true of road-going cars, your
>>>record-breaking cars aren't even, by your own admission, travelling at
>>>"low speed".
>>
>> The point was Robin stated its impossible to get wheelspin due to air
>> resistance at all, never mind with a train. I pointed out he was wrong.
>
>Another back-of-envelope doodle: The limiting speed at which wheel slip
>can occur for a given power input, for the case for a car-like thing with
>a grip capable of acceleration of around 1 g, is close to R/6 where R is
>the power to weight ratio in HP per ton and the answer is in miles per
>hour.
>
>For my car 135 HP and 1.5 ton, about 15 mi/h.
>
>For a "go-kart" with 300 HP in half a ton it's be 100 mi/h.
>
>And of course higher still if lower grip, then limit = R/(6*coeff of
>friction).
>
>It doesn't if the traction force is going into wind resistance or
>acceleration, the limit is the same.
>
>And this is the power limit, actual engine torques and gear ratios could
>make the limit speed lower.

And I'm still fairly sure that my 160HP, 2.5ton 4x4 will refuse to spin
the wheels at all.
--
Roland Perry

On Thu, 17 Feb 2022 12:43:32 +0000, Roland Perry wrote:

> In message <sulagg$4gu$1@dont-email.me>, at 11:11:12 on Thu, 17 Feb
> 2022, nib <news@ingram-bromley.co.uk> remarked:
>>On Thu, 17 Feb 2022 10:06:43 +0000, Muttley wrote:
>>
>>> On Thu, 17 Feb 2022 09:04:57 +0000 Roland Perry <roland@perry.co.uk>
>>> wrote:
>>>>In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>>>>2022, Muttley@dastardlyhq.com remarked:
>>>>>On Wed, 16 Feb 2022 17:35:00 +0000 Roland Perry <roland@perry.co.uk>
>>>>>wrote:
>>>>>>In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16
>>>>>>Feb 2022, Muttley@dastardlyhq.com remarked:
>>>>>>>On Wed, 16 Feb 2022 11:26:39 +0100 Bob <email@domain.com> wrote:
>>>>>>>>On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>>>Intuitively, any driver will know that if they push their right
>>>>>>>>foot all the way down at low speed, they will spin the wheels on
>>>>>>>>their car, but if they are driving on the motorway, they can push
>>>>>>>>their right foot all the way to the floor and the wheels won't
>>>>>>>>lose grip (Roland and Anna may have different experiences, as each
>>>>>>>>of them have made references to owning or having owned "atypical"
>>>>>>>>cars).
>>>>>>>
>>>>>>>Well I know thats not true because some wheel driven land speed
>>>>>>>record cars started to have wheelsip at very high speed which
>>>>>>>limited their record run max V
>>>>>>
>>>>>>How many of us are driving land-speed-record cars on the streets?
>>>>>
>>>>>Not the point as you well know.
>>>>
>>>>The point, dear boy, is discussing the verascity of the assertion:
>>>>
>>>> "any driver will know that if they push their right foot all the
>>>> way
>>>> down at low speed, they will spin the wheels on their car"
>>>>
>>>>Notwithstanding I don't even think that's true of road-going cars,
>>>>your record-breaking cars aren't even, by your own admission,
>>>>travelling at "low speed".
>>>
>>> The point was Robin stated its impossible to get wheelspin due to air
>>> resistance at all, never mind with a train. I pointed out he was
>>> wrong.
>>
>>Another back-of-envelope doodle: The limiting speed at which wheel slip
>>can occur for a given power input, for the case for a car-like thing
>>with a grip capable of acceleration of around 1 g, is close to R/6 where
>>R is the power to weight ratio in HP per ton and the answer is in miles
>>per hour.
>>
>>For my car 135 HP and 1.5 ton, about 15 mi/h.
>>
>>For a "go-kart" with 300 HP in half a ton it's be 100 mi/h.
>>
>>And of course higher still if lower grip, then limit = R/(6*coeff of
>>friction).
>>
>>It doesn't if the traction force is going into wind resistance or
>>acceleration, the limit is the same.
>>
>>And this is the power limit, actual engine torques and gear ratios could
>>make the limit speed lower.
>
> And I'm still fairly sure that my 160HP, 2.5ton 4x4 will refuse to spin
> the wheels at all.

It may well not, depending on other things. It's only a maximum limit!

My 100kW 1.5 tonne electric will spin on take off from standing far too
easily; that's a different speed/torque curve and no gears.

nib

In message <sulhoe$4gu$2@dont-email.me>, at 13:14:54 on Thu, 17 Feb
2022, nib <news@ingram-bromley.co.uk> remarked:
>On Thu, 17 Feb 2022 12:43:32 +0000, Roland Perry wrote:
>
>> In message <sulagg$4gu$1@dont-email.me>, at 11:11:12 on Thu, 17 Feb
>> 2022, nib <news@ingram-bromley.co.uk> remarked:
>>>On Thu, 17 Feb 2022 10:06:43 +0000, Muttley wrote:
>>>
>>>> On Thu, 17 Feb 2022 09:04:57 +0000 Roland Perry <roland@perry.co.uk>
>>>> wrote:
>>>>>In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>>>>>2022, Muttley@dastardlyhq.com remarked:
>>>>>>On Wed, 16 Feb 2022 17:35:00 +0000 Roland Perry <roland@perry.co.uk>
>>>>>>wrote:
>>>>>>>In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16
>>>>>>>Feb 2022, Muttley@dastardlyhq.com remarked:
>>>>>>>>On Wed, 16 Feb 2022 11:26:39 +0100 Bob <email@domain.com> wrote:
>>>>>>>>>On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>>>>Intuitively, any driver will know that if they push their right
>>>>>>>>>foot all the way down at low speed, they will spin the wheels on
>>>>>>>>>their car, but if they are driving on the motorway, they can push
>>>>>>>>>their right foot all the way to the floor and the wheels won't
>>>>>>>>>lose grip (Roland and Anna may have different experiences, as each
>>>>>>>>>of them have made references to owning or having owned "atypical"
>>>>>>>>>cars).
>>>>>>>>
>>>>>>>>Well I know thats not true because some wheel driven land speed
>>>>>>>>record cars started to have wheelsip at very high speed which
>>>>>>>>limited their record run max V
>>>>>>>
>>>>>>>How many of us are driving land-speed-record cars on the streets?
>>>>>>
>>>>>>Not the point as you well know.
>>>>>
>>>>>The point, dear boy, is discussing the verascity of the assertion:
>>>>>
>>>>> "any driver will know that if they push their right foot all the
>>>>> way
>>>>> down at low speed, they will spin the wheels on their car"
>>>>>
>>>>>Notwithstanding I don't even think that's true of road-going cars,
>>>>>your record-breaking cars aren't even, by your own admission,
>>>>>travelling at "low speed".
>>>>
>>>> The point was Robin stated its impossible to get wheelspin due to air
>>>> resistance at all, never mind with a train. I pointed out he was
>>>> wrong.
>>>
>>>Another back-of-envelope doodle: The limiting speed at which wheel slip
>>>can occur for a given power input, for the case for a car-like thing
>>>with a grip capable of acceleration of around 1 g, is close to R/6 where
>>>R is the power to weight ratio in HP per ton and the answer is in miles
>>>per hour.
>>>
>>>For my car 135 HP and 1.5 ton, about 15 mi/h.
>>>
>>>For a "go-kart" with 300 HP in half a ton it's be 100 mi/h.
>>>
>>>And of course higher still if lower grip, then limit = R/(6*coeff of
>>>friction).
>>>
>>>It doesn't if the traction force is going into wind resistance or
>>>acceleration, the limit is the same.
>>>
>>>And this is the power limit, actual engine torques and gear ratios could
>>>make the limit speed lower.
>>
>> And I'm still fairly sure that my 160HP, 2.5ton 4x4 will refuse to spin
>> the wheels at all.
>
>It may well not, depending on other things. It's only a maximum limit!
>
>My 100kW 1.5 tonne electric will spin on take off from standing far too
>easily; that's a different speed/torque curve and no gears.

Can we at least keep to using the same units! 100kW = 134HP, it seems.
--
Roland Perry

Am 17.02.2022 um 13:43 schrieb Roland Perry:
> In message <sulagg$4gu$1@dont-email.me>, at 11:11:12 on Thu, 17 Feb
> 2022, nib <news@ingram-bromley.co.uk> remarked:
>> On Thu, 17 Feb 2022 10:06:43 +0000, Muttley wrote:
>>
>>> On Thu, 17 Feb 2022 09:04:57 +0000 Roland Perry <roland@perry.co.uk>
>>> wrote:
>>>> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>>>> 2022, Muttley@dastardlyhq.com remarked:
>>>>> On Wed, 16 Feb 2022 17:35:00 +0000 Roland Perry <roland@perry.co.uk>
>>>>> wrote:
>>>>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>>>> 2022, Muttley@dastardlyhq.com remarked:
>>>>>>> On Wed, 16 Feb 2022 11:26:39 +0100 Bob <email@domain.com> wrote:
>>>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>>> Intuitively, any driver will know that if they push their right
>>>>>>>> foot
>>>>>>>> all the way down at low speed, they will spin the wheels on their
>>>>>>>> car, but if they are driving on the motorway, they can push their
>>>>>>>> right foot all the way to the floor and the wheels won't lose grip
>>>>>>>> (Roland and Anna may have different experiences, as each of them
>>>>>>>> have made references to owning or having owned "atypical" cars).
>>>>>>>
>>>>>>> Well I know thats not true because some wheel driven land speed
>>>>>>> record cars started to have wheelsip at very high speed which
>>>>>>> limited
>>>>>>> their record run max V
>>>>>>
>>>>>> How many of us are driving land-speed-record cars on the streets?
>>>>>
>>>>> Not the point as you well know.
>>>>
>>>> The point, dear boy, is discussing the verascity of the assertion:
>>>>
>>>>    "any driver will know that if they push their right foot all the way
>>>>     down at low speed, they will spin the wheels on their car"
>>>>
>>>> Notwithstanding I don't even think that's true of road-going cars, your
>>>> record-breaking cars aren't even, by your own admission, travelling at
>>>> "low speed".
>>>
>>> The point was Robin stated its impossible to get wheelspin due to air
>>> resistance at all, never mind with a train. I pointed out he was wrong.
>>
>> Another back-of-envelope doodle: The limiting speed at which wheel slip
>> can occur for a given power input, for the case for a car-like thing with
>> a grip capable of acceleration of around 1 g, is close to R/6 where R is
>> the power to weight ratio in HP per ton and the answer is in miles per
>> hour.
>>
>> For my car 135 HP and 1.5 ton, about 15 mi/h.
>>
>> For a "go-kart" with 300 HP in half a ton it's be 100 mi/h.
>>
>> And of course higher still if lower grip, then limit = R/(6*coeff of
>> friction).
>>
>> It doesn't if the traction force is going into wind resistance or
>> acceleration, the limit is the same.
>>
>> And this is the power limit, actual engine torques and gear ratios could
>> make the limit speed lower.
>
> And I'm still fairly sure that my 160HP, 2.5ton 4x4 will refuse to spin
> the wheels at all.

On a 4x4 you might need to halve the speed from the formula above,
giving you a theoretical max slipping speed between 5 and 10 mph.

Modern cars have traction control.

On an old 2CV, the calculation would look like as follows:
27HP, half a ton gives a theoretic ability for wheel spin up to 10 mph.

With the engine speed necessary for 27HP, 1st gear would provide a speed
of 20 mph.
Gut feeling is that at half the max engine speed, the engine might
provide 60-70% of the max power, which would imply that under normal dry
conditions it's impossible to have wheel slip.

From memory, wheel slip was a possibility when starting uphill on a 1:5
hill when the front wheels were signifitly unloaded.

On Thu, 17 Feb 2022 11:54:06 +0100
Bob <email@domain.com> wrote:
>On 2022-02-17 10:06:43 +0000, Muttley@dastardlyhq.com said:
>> The point was Robin stated its impossible to get wheelspin due to air
>> resistance at all, never mind with a train. I pointed out he was wrong.
>
>No. In response to the question as to whether a train at high speed
>could experienc wheelslip due to wind resistance, I pointed out that,
>at high speed, a train will not have enough power installed to overcome
>the friction that prevents wheelslip, and gave a bit of discussion on
>how to establish what the cutoff speed is above which a train, with
>good railhead conditions, is unable to spin its wheels.

What about bad railhead conditions? It does tend to rain here quite a lot
not to mention the leaves.

>land speed record car exerts forces on the surface in such a way that,
>at speed, the surface it is driving on breaks up, an it is essentially
>driving on a powder, not a solid surface. Powders under those
>conditions behave more like fluids than solids, so as a reference, it
>is more like a boat being able to spin its propeller in water, rather
>than a train trying to cause its wheels to spin.

I see goalposts being subtley moved.

On Thu, 17 Feb 2022 17:06:30 +0100
Rolf Mantel <news@hartig-mantel.de> wrote:
>Am 17.02.2022 um 13:43 schrieb Roland Perry:
> From memory, wheel slip was a possibility when starting uphill on a 1:5
>hill when the front wheels were signifitly unloaded.

Front wheel drive cars and steep hills are not a good pairing, particularly
if there are any corners on the hill as the shifting camber tends to upset
them even more.

On 2022-02-17 16:15:13 +0000, Muttley@dastardlyhq.com said:

> On Thu, 17 Feb 2022 11:54:06 +0100
> Bob <email@domain.com> wrote:
>> On 2022-02-17 10:06:43 +0000, Muttley@dastardlyhq.com said:
>>> The point was Robin stated its impossible to get wheelspin due to air
>>> resistance at all, never mind with a train. I pointed out he was wrong.
>>
>> No. In response to the question as to whether a train at high speed
>> could experienc wheelslip due to wind resistance, I pointed out that,
>> at high speed, a train will not have enough power installed to overcome
>> the friction that prevents wheelslip, and gave a bit of discussion on
>> how to establish what the cutoff speed is above which a train, with
>> good railhead conditions, is unable to spin its wheels.
>
> What about bad railhead conditions? It does tend to rain here quite a lot
> not to mention the leaves.

Anna gave a driver's-eye-view of exactly that issue elsewhere in the
discussion. But last time I checked, leaves are not "wind resistance".

>> land speed record car exerts forces on the surface in such a way that,
>> at speed, the surface it is driving on breaks up, an it is essentially
>> driving on a powder, not a solid surface. Powders under those
>> conditions behave more like fluids than solids, so as a reference, it
>> is more like a boat being able to spin its propeller in water, rather
>> than a train trying to cause its wheels to spin.
>
> I see goalposts being subtley moved.

The goal posts were yanked up from the topic of fast passenger railway
trains, transported half a contry away and plonked down on the topic of
record-setting cars driving on dry salt lake beds. I didn't do that
shifting.

Robin

On Thu, 17 Feb 2022 17:51:24 +0100
Bob <email@domain.com> wrote:
>On 2022-02-17 16:15:13 +0000, Muttley@dastardlyhq.com said:
>> What about bad railhead conditions? It does tend to rain here quite a lot
>> not to mention the leaves.
>
>Anna gave a driver's-eye-view of exactly that issue elsewhere in the
>discussion. But last time I checked, leaves are not "wind resistance".

[Face -> palm]

No, but they do make the rail very slippy.

>> I see goalposts being subtley moved.
>
>The goal posts were yanked up from the topic of fast passenger railway
>trains, transported half a contry away and plonked down on the topic of
>record-setting cars driving on dry salt lake beds. I didn't do that
>shifting.

You're the one who stated it was impossible to get wheelslip due to air
resistence. Too late to backpedal now.

nib <news@ingram-bromley.co.uk> wrote:
> On Thu, 17 Feb 2022 12:43:32 +0000, Roland Perry wrote:
>
>> In message <sulagg$4gu$1@dont-email.me>, at 11:11:12 on Thu, 17 Feb
>> 2022, nib <news@ingram-bromley.co.uk> remarked:
>>> On Thu, 17 Feb 2022 10:06:43 +0000, Muttley wrote:
>>>
>>>> On Thu, 17 Feb 2022 09:04:57 +0000 Roland Perry <roland@perry.co.uk>
>>>> wrote:
>>>>> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>>>>> 2022, Muttley@dastardlyhq.com remarked:
>>>>>> On Wed, 16 Feb 2022 17:35:00 +0000 Roland Perry <roland@perry.co.uk>
>>>>>> wrote:
>>>>>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16
>>>>>>> Feb 2022, Muttley@dastardlyhq.com remarked:
>>>>>>>> On Wed, 16 Feb 2022 11:26:39 +0100 Bob <email@domain.com> wrote:
>>>>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>>>> Intuitively, any driver will know that if they push their right
>>>>>>>>> foot all the way down at low speed, they will spin the wheels on
>>>>>>>>> their car, but if they are driving on the motorway, they can push
>>>>>>>>> their right foot all the way to the floor and the wheels won't
>>>>>>>>> lose grip (Roland and Anna may have different experiences, as each
>>>>>>>>> of them have made references to owning or having owned "atypical"
>>>>>>>>> cars).
>>>>>>>>
>>>>>>>> Well I know thats not true because some wheel driven land speed
>>>>>>>> record cars started to have wheelsip at very high speed which
>>>>>>>> limited their record run max V
>>>>>>>
>>>>>>> How many of us are driving land-speed-record cars on the streets?
>>>>>>
>>>>>> Not the point as you well know.
>>>>>
>>>>> The point, dear boy, is discussing the verascity of the assertion:
>>>>>
>>>>> "any driver will know that if they push their right foot all the
>>>>> way
>>>>> down at low speed, they will spin the wheels on their car"
>>>>>
>>>>> Notwithstanding I don't even think that's true of road-going cars,
>>>>> your record-breaking cars aren't even, by your own admission,
>>>>> travelling at "low speed".
>>>>
>>>> The point was Robin stated its impossible to get wheelspin due to air
>>>> resistance at all, never mind with a train. I pointed out he was
>>>> wrong.
>>>
>>> Another back-of-envelope doodle: The limiting speed at which wheel slip
>>> can occur for a given power input, for the case for a car-like thing
>>> with a grip capable of acceleration of around 1 g, is close to R/6 where
>>> R is the power to weight ratio in HP per ton and the answer is in miles
>>> per hour.
>>>
>>> For my car 135 HP and 1.5 ton, about 15 mi/h.
>>>
>>> For a "go-kart" with 300 HP in half a ton it's be 100 mi/h.
>>>
>>> And of course higher still if lower grip, then limit = R/(6*coeff of
>>> friction).
>>>
>>> It doesn't if the traction force is going into wind resistance or
>>> acceleration, the limit is the same.
>>>
>>> And this is the power limit, actual engine torques and gear ratios could
>>> make the limit speed lower.
>>
>> And I'm still fairly sure that my 160HP, 2.5ton 4x4 will refuse to spin
>> the wheels at all.
>
> It may well not, depending on other things. It's only a maximum limit!
>
> My 100kW 1.5 tonne electric will spin on take off from standing far too
> easily; that's a different speed/torque curve and no gears.
>
> nib
>

Don’t electric cars have traction control?

On Thu, 17 Feb 2022 18:13:48 +0000, Tweed wrote:

> nib <news@ingram-bromley.co.uk> wrote:
>> On Thu, 17 Feb 2022 12:43:32 +0000, Roland Perry wrote:
>>
>>> In message <sulagg$4gu$1@dont-email.me>, at 11:11:12 on Thu, 17 Feb
>>> 2022, nib <news@ingram-bromley.co.uk> remarked:
>>>> On Thu, 17 Feb 2022 10:06:43 +0000, Muttley wrote:
>>>>
>>>>> On Thu, 17 Feb 2022 09:04:57 +0000 Roland Perry <roland@perry.co.uk>
>>>>> wrote:
>>>>>> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17
>>>>>> Feb 2022, Muttley@dastardlyhq.com remarked:
>>>>>>> On Wed, 16 Feb 2022 17:35:00 +0000 Roland Perry
>>>>>>> <roland@perry.co.uk>
>>>>>>> wrote:
>>>>>>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16
>>>>>>>> Feb 2022, Muttley@dastardlyhq.com remarked:
>>>>>>>>> On Wed, 16 Feb 2022 11:26:39 +0100 Bob <email@domain.com> wrote:
>>>>>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>>>>>> Intuitively, any driver will know that if they push their right
>>>>>>>>>> foot all the way down at low speed, they will spin the wheels
>>>>>>>>>> on their car, but if they are driving on the motorway, they can
>>>>>>>>>> push their right foot all the way to the floor and the wheels
>>>>>>>>>> won't lose grip (Roland and Anna may have different
>>>>>>>>>> experiences, as each of them have made references to owning or
>>>>>>>>>> having owned "atypical" cars).
>>>>>>>>>
>>>>>>>>> Well I know thats not true because some wheel driven land speed
>>>>>>>>> record cars started to have wheelsip at very high speed which
>>>>>>>>> limited their record run max V
>>>>>>>>
>>>>>>>> How many of us are driving land-speed-record cars on the streets?
>>>>>>>
>>>>>>> Not the point as you well know.
>>>>>>
>>>>>> The point, dear boy, is discussing the verascity of the assertion:
>>>>>>
>>>>>> "any driver will know that if they push their right foot all the
>>>>>> way down at low speed, they will spin the wheels on their car"
>>>>>>
>>>>>> Notwithstanding I don't even think that's true of road-going cars,
>>>>>> your record-breaking cars aren't even, by your own admission,
>>>>>> travelling at "low speed".
>>>>>
>>>>> The point was Robin stated its impossible to get wheelspin due to
>>>>> air resistance at all, never mind with a train. I pointed out he was
>>>>> wrong.
>>>>
>>>> Another back-of-envelope doodle: The limiting speed at which wheel
>>>> slip can occur for a given power input, for the case for a car-like
>>>> thing with a grip capable of acceleration of around 1 g, is close to
>>>> R/6 where R is the power to weight ratio in HP per ton and the answer
>>>> is in miles per hour.
>>>>
>>>> For my car 135 HP and 1.5 ton, about 15 mi/h.
>>>>
>>>> For a "go-kart" with 300 HP in half a ton it's be 100 mi/h.
>>>>
>>>> And of course higher still if lower grip, then limit = R/(6*coeff of
>>>> friction).
>>>>
>>>> It doesn't if the traction force is going into wind resistance or
>>>> acceleration, the limit is the same.
>>>>
>>>> And this is the power limit, actual engine torques and gear ratios
>>>> could make the limit speed lower.
>>>
>>> And I'm still fairly sure that my 160HP, 2.5ton 4x4 will refuse to
>>> spin the wheels at all.
>>
>> It may well not, depending on other things. It's only a maximum limit!
>>
>> My 100kW 1.5 tonne electric will spin on take off from standing far too
>> easily; that's a different speed/torque curve and no gears.
>>
>> nib
>>
>>
> Don’t electric cars have traction control?

It claims "electronic stability programme (ESP) with anti-slip regulation
(ASR) and understeer control (UCL)".

And I suppose it does, because the the wheels don't go on slipping and
the car keeps going the right way, even when cornering, but they
certainly slip a bit if you pull away sharpish, you can feel it.

Presumably, like ABS the other way, the wheels have to slip a bit for the
control system to detect it and take action.

nib

On Thu, 17 Feb 2022 08:58:50 -0000 (UTC), Muttley@dastardlyhq.com
wrote:

>On Thu, 17 Feb 2022 01:32:15 +0000
>Charles Ellson <charlesellson@btinternet.com> wrote:
>>On Mon, 14 Feb 2022 09:55:16 -0000 (UTC), Muttley@dastardlyhq.com
>>wrote:
>>
>>>On 14 Feb 2022 09:28:29 GMT
>>>Marland <gemehabal@btinternet.co.uk> wrote:
>>>>Charles Ellson <charlesellson@btinternet.com> wrote:
>>>>> On 13 Feb 2022 23:28:17 GMT, Marland <gemehabal@btinternet.co.uk>
>>>>>>
>>>>>> Thats all very well but please explain how S stock would make its way
>>along
>>>>>> a rebuilt Croxley branch
>>>>>> if permission to install conductor rails is not forthcoming.
>>>>>>
>>>>> It is an extension to an existing system (or two if you are looking
>>>>> from the DC line end).
>>>>>
>>>>
>>>>Extension to existing systems usually involve electrifying an existing
>>>>working railway.
>>>>Croxley having been closed for some time would not fall into that category
>>>
>>>However the watford end is still a working railway. Though its all rather moot
>>
>>>since I suspect that project is deader than the proverbial parrot now. Not
>>>that it ever really made much sense anyway. No one would use it to get to
>>>watford from london with much quicker options so its only purpose would be
>>>as a local railway which I doubt would have many pax.
>>>
>>Several origins other than London are available. The Met. doesn't just
>>have stations at the end of the line.
>
>With the best will in the world, I doubt the number of commuters from amersham o
>r
>rickmansworth to watford or vice verca would come even close to making rebuildin
>g
>the line economically viable.
>
I doubt if the projected passenger figures were based only on
commuters. OTOH there does seem to have been a bit of a presumption
that the county next door was going to pay for a lot of it.

On Thu, 17 Feb 2022 09:04:57 +0000, Roland Perry <roland@perry.co.uk>
wrote:

>In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>2022, Muttley@dastardlyhq.com remarked:
>>On Wed, 16 Feb 2022 17:35:00 +0000
>>Roland Perry <roland@perry.co.uk> wrote:
>>>In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>2022, Muttley@dastardlyhq.com remarked:
>>>>On Wed, 16 Feb 2022 11:26:39 +0100
>>>>Bob <email@domain.com> wrote:
>>>>>On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>Intuitively, any driver will know that if they push their right foot
>>>>>all the way down at low speed, they will spin the wheels on their car,
>>>>>but if they are driving on the motorway, they can push their right foot
>>>>>all the way to the floor and the wheels won't lose grip (Roland and
>>>>>Anna may have different experiences, as each of them have made
>>>>>references to owning or having owned "atypical" cars).
>>>>
>>>>Well I know thats not true because some wheel driven land speed record cars
>>>>started to have wheelsip at very high speed which limited their record
>>>>run max V
>>>
>>>How many of us are driving land-speed-record cars on the streets?
>>
>>Not the point as you well know.
>
>The point, dear boy, is discussing the verascity of the assertion:
>
> "any driver will know that if they push their right foot all the way
> down at low speed, they will spin the wheels on their car"
>
>Notwithstanding I don't even think that's true of road-going cars, your
>record-breaking cars aren't even, by your own admission, travelling at
>"low speed".
>
I can spin the wheels on my humble Dacia Logan despite dry conditions,
a decent set of Michelins and being in ECO mode. ITYF most front wheel
drive cars will manage that when turning if not going dead ahead.

On Thu, 17 Feb 2022 10:31:38 +0000, Graeme Wall
<rail@greywall.demon.co.uk> wrote:

>On 17/02/2022 09:04, Roland Perry wrote:
>> In message <sul2h7$1dfu$1@gioia.aioe.org>, at 08:55:03 on Thu, 17 Feb
>> 2022, Muttley@dastardlyhq.com remarked:
>>> On Wed, 16 Feb 2022 17:35:00 +0000
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sujbp1$1dl4$1@gioia.aioe.org>, at 17:20:33 on Wed, 16 Feb
>>>> 2022, Muttley@dastardlyhq.com remarked:
>>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>>> Bob <email@domain.com> wrote:
>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>> Intuitively, any driver will know that if they push their right foot
>>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>>> but if they are driving on the motorway, they can push their right
>>>>>> foot
>>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>>> Anna may have different experiences, as each of them have made
>>>>>> references to owning or having owned "atypical" cars).
>>>>>
>>>>> Well I know thats not true because some wheel driven land speed
>>>>> record cars
>>>>> started to have wheelsip at very high speed which limited their record
>>>>> run max V
>>>>
>>>> How many of us are driving land-speed-record cars on the streets?
>>>
>>> Not the point as you well know.
>>
>> The point, dear boy, is discussing the verascity of the assertion:
>>
>>    "any driver will know that if they push their right foot all the way
>>     down at low speed, they will spin the wheels on their car"
>>
>> Notwithstanding I don't even think that's true of road-going cars, your
>> record-breaking cars aren't even, by your own admission, travelling at
>> "low speed".
>
>Modern land speed record cars don't rely on adhesion, being basically
>jet aircraft with the wings removed.
>
... unless they are wheel-driven (436/451 mph in 2018?) which puts them
in a different record class.

On Thu, 17 Feb 2022 10:05:42 -0000 (UTC), Muttley@dastardlyhq.com
wrote:

>On Thu, 17 Feb 2022 09:04:17 +0000
>Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>On 17/02/2022 08:56, Muttley@dastardlyhq.com wrote:
>>> On Wed, 16 Feb 2022 21:10:09 +0100
>>> Bob <email@domain.com> wrote:
>>>> On 2022-02-16 17:20:33 +0000, Muttley@dastardlyhq.com said:
>>>>
>>>>> On Wed, 16 Feb 2022 11:26:39 +0100
>>>>> Bob <email@domain.com> wrote:
>>>>>> On 2022-02-16 08:54:49 +0000, Muttley@dastardlyhq.com said:
>>>>>> Intuitively, any driver will know that if they push their right foot
>>>>>> all the way down at low speed, they will spin the wheels on their car,
>>>>>> but if they are driving on the motorway, they can push their right foot
>>>>>> all the way to the floor and the wheels won't lose grip (Roland and
>>>>>> Anna may have different experiences, as each of them have made
>>>>>> references to owning or having owned "atypical" cars).
>>>>>
>>>>> Well I know thats not true because some wheel driven land speed record cars
>>
>>>>> started to have wheelsip at very high speed which limited their record
>>>>> run max V
>>>>
>>>> Land speed record cars are in a somewhat unusual situation because
>>>> first, they can't use pneumatic tyres, as they would disintigrate under
>>>> the centrifugal loading, and second, they are driving on salt flats
>>>> rather than paved road, which has a tendency to crumble under the
>>>> extreme forces involved. As they go faster, the limiting friction for
>>>> the wheels reduces as the interaction of the wheel with the ground
>>>> causes the ground conditions to deteriorate.
>>>
>>> Quite possibly. But it demonstrates that you can get wheel slip due to wind
>>> resistance at high speed.
>>>
>>
>>What's wind got to do with it?
>
>Wind, air, that stuff cars have to move through.
>
Enough of it in the last few days to be fairly noticeable on the more
open bits of the M25.

In message <sum4an$4gu$3@dont-email.me>, at 18:31:51 on Thu, 17 Feb
2022, nib <news@ingram-bromley.co.uk> remarked:

>>>>>>> "any driver will know that if they push their right foot all the
>>>>>>> way down at low speed, they will spin the wheels on their car"
....
>>> My 100kW 1.5 tonne electric will spin on take off from standing far too
>>> easily; that's a different speed/torque curve and no gears.
>>>
>> Don’t electric cars have traction control?
>
>It claims "electronic stability programme (ESP) with anti-slip regulation
>(ASR) and understeer control (UCL)".
>
>And I suppose it does, because the the wheels don't go on slipping and
>the car keeps going the right way, even when cornering, but they
>certainly slip a bit if you pull away sharpish, you can feel it.

There's a difference between pulling away from stationary, and being at
a low speed. (I'm not sure anyone gave a figure for that, but let's fly
a kite at 15mph)

--
Roland Perry