Theo <theom+news@chiark.greenend.org.uk> wrote:
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> Add in 5/10 minutes allowance to
>> connect/disconnect shore supply (perhaps allowing time to dress in
>> appropriate PPE and clean yourself afterwards before eating; though I guess
>> that at least effluent all over the underframe isn't a problem now, but
>> dead animals, grease and brake dust still is); suddenly your driver can't
>> work the same train back out, and you need either another driver at the
>> station (ie long layovers, plus re-writing many of the driver diagrams and
>> hence the roster) or another set laying over at the station (another £?? of
>> expenditure, perhaps; plus see also point 2c).
>
> Not to disagree with your other points, but it could be provided by points a
> bit like EV chargers under manhole-style flaps on the platform surface. The
> charge point is on the loco/coaches above platform level (perhaps one point
> per coach to reduce alignment issues). Driver gets out of cab, bends down,
> unlocks flap that's in the platform surface near the edge, grabs cable and
> plugs into side of loco. Maybe there is some kind of RFID style lock so
> they just press the flap with their foot and the cable pops out. Takes
> about as much time and hassle as plugging in an EV (could even use the same
> connectors/etc).
>
> Then the cable is interlocked with the traction so you can't drive away with
> it plugged in.
>
> You might want to wear gloves/wash your hands afterwards, but it would be
> about as dirty as a roadside EV charger might be, and you wouldn't need to
> leave platform level.
>

Until now, all shore supply provision in the UK has used trackside
equipment and connected to the existing connections for supply within the
train, located on the buffer beam; a dirty and potentially dangerous
environment.

Using an additional connector above platform level is actually a great
idea, is it used anywhere already?

It adds two extra potential points of failure per vehicle (or per
loco/Driving Trailer, if not all carriages need to be fitted) because the
covers are interlocked with the supply, but that's a comparatively minor
consideration.

Anna Noyd-Dryver

Theo <theom+news@chiark.greenend.org.uk> wrote:
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> Add in 5/10 minutes allowance to
>> connect/disconnect shore supply (perhaps allowing time to dress in
>> appropriate PPE and clean yourself afterwards before eating; though I guess
>> that at least effluent all over the underframe isn't a problem now, but
>> dead animals, grease and brake dust still is); suddenly your driver can't
>> work the same train back out, and you need either another driver at the
>> station (ie long layovers, plus re-writing many of the driver diagrams and
>> hence the roster) or another set laying over at the station (another £?? of
>> expenditure, perhaps; plus see also point 2c).
>
> Not to disagree with your other points, but it could be provided by points a
> bit like EV chargers under manhole-style flaps on the platform surface. The
> charge point is on the loco/coaches above platform level (perhaps one point
> per coach to reduce alignment issues). Driver gets out of cab, bends down,
> unlocks flap that's in the platform surface near the edge, grabs cable and
> plugs into side of loco. Maybe there is some kind of RFID style lock so
> they just press the flap with their foot and the cable pops out. Takes
> about as much time and hassle as plugging in an EV (could even use the same
> connectors/etc).
>
> Then the cable is interlocked with the traction so you can't drive away with
> it plugged in.
>
> You might want to wear gloves/wash your hands afterwards, but it would be
> about as dirty as a roadside EV charger might be, and you wouldn't need to
> leave platform level.
>
> Theo
>

I was about to make a similar point. Having seen trains in termini hooked
up to water hoses with not to be moved signs hung on the train, plugging in
a power cable at platform level doesn’t seem to be a big leap.

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
> Until now, all shore supply provision in the UK has used trackside
> equipment and connected to the existing connections for supply within the
> train, located on the buffer beam; a dirty and potentially dangerous
> environment.
>
> Using an additional connector above platform level is actually a great
> idea, is it used anywhere already?

I don't know. What do sleepers do for powering the coaches at the
origin/destination? Presumably they must be plugged in, rather than running
the loco? (A lot of European sleepers will be under the wires, but I
suppose some won't)

> It adds two extra potential points of failure per vehicle (or per
> loco/Driving Trailer, if not all carriages need to be fitted) because the
> covers are interlocked with the supply, but that's a comparatively minor
> consideration.

You might decide not to interlock the covers, only interlock the
communication. You could arrange that the covers were not out of gauge (eg
sliding covers) so that you could drive away with the cover open without
problems. It would only immobilise the train if a cable was plugged in and
some basic communication happening (even simply reading a resistor on the
cable).

Your mention of 800V DC makes me wonder whether you could reuse EV DC rapid
chargers for the shore supply part of this. The new generation of EVs are
based on an 800V platform, so chargers exist that can deliver 500kW at 800V.
All the train has to do is present as an 800V EV with an empty battery and
let the charger deliver the current - it just never announces that it's
approaching 'full' and so the current is delivered continuously. I don't
know what those chargers cost to install, but I imagine a lot less than any
custom DC train supply unit.
https://electrek.co/2021/08/30/gac-aion-unveils-480-kw-fast-charger-well-below-previously-rumored-600-kw/

Theo

On 2022-03-15 10:49:20 +0000, Theo said:

> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> Until now, all shore supply provision in the UK has used trackside
>> equipment and connected to the existing connections for supply within the
>> train, located on the buffer beam; a dirty and potentially dangerous
>> environment.
>>
>> Using an additional connector above platform level is actually a great
>> idea, is it used anywhere already?
>
> I don't know. What do sleepers do for powering the coaches at the
> origin/destination? Presumably they must be plugged in, rather than running
> the loco? (A lot of European sleepers will be under the wires, but I
> suppose some won't)

I'm hard pressed to think of a night train route in Western Europe
other than the Highland and Night Riviera in the UK that use diesel
traction. What are the provisions made for hotel power on carriages on
the Straits of Messina train ferry?

Robin

On 15/03/2022 10:59, Bob wrote:
> On 2022-03-15 10:49:20 +0000, Theo said:
>
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> Until now, all shore supply provision in the UK has used trackside
>>> equipment and connected to the existing connections for supply within
>>> the
>>> train, located on the buffer beam; a dirty and potentially dangerous
>>> environment.
>>>
>>> Using an additional connector above platform level is actually a great
>>> idea, is it used anywhere already?
>>
>> I don't know.  What do sleepers do for powering the coaches at the
>> origin/destination?  Presumably they must be plugged in, rather than
>> running
>> the loco?  (A lot of European sleepers will be under the wires, but I
>> suppose some won't)
>
> I'm hard pressed to think of a night train route in Western Europe other
> than the Highland and Night Riviera in the UK that use diesel traction.
> What are the provisions made for hotel power on carriages on the Straits
> of Messina train ferry?
>

IIRC an inappropriately named "shore supply".

--
Graeme Wall
This account not read.

On Mon, 14 Mar 2022 11:41:45 -0000 (UTC)
Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>> On Mon, 14 Mar 2022 10:48:04 -0000 (UTC)
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> Theo <theom+news@chiark.greenend.org.uk> wrote:
>>>> Alan <alan@darkroom.+.com> wrote:
>>>>> The engine noise/running problem is explained. The alternators cannot
>>>>> supply the train power, even in the terminus, at idle speed, so they have
>
>>>>> to run at 'Notch 3' to keep the coaches 'live'. At notch 3, the engine ,
>>>>> apparently, throbs like mad. And uses 60 litres of diesel a hour when in
>>>>> that state.
>>>>
>>>> I wonder if that's because the hotel load is more than expected, or the
>>>> power output less?
>>>>
>>>
>>> Neither, I suspect, I think it's very likely to be as designed.
>>
>> Given this was specifically built to be a passenger locomotive it doesn't
>> seem to me like a particularly smart design. Didn't they think of hotel loads
>
>> during the design phase or is running the engine at higher than idle rpm
>> in stations normal in europe?
>>
>>
>
>As I said, it's normal for every UK passenger locomotive built since the
>1970s. I don't know enough about the ones built in the 1960s.

Seems like in some respects the railways are still in the 50s. If a bus
couldn't run its aircon/heating and lighting with the engine at idle no one
would buy it. Ok, not entirely electrically powered but its a design
consideration that these things work at all times regardless.

>I also don't know enough about non-UK diesel passenger locomotives to say
>how they run.

Well I doubt they need to worry about engine rpm!

<Muttley@dastardlyhq.com> wrote:
> On Mon, 14 Mar 2022 11:41:45 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On Mon, 14 Mar 2022 10:48:04 -0000 (UTC)
>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>> Theo <theom+news@chiark.greenend.org.uk> wrote:
>>>>> Alan <alan@darkroom.+.com> wrote:
>>>>>> The engine noise/running problem is explained. The alternators cannot
>>>>>> supply the train power, even in the terminus, at idle speed, so they have
>>
>>>>>> to run at 'Notch 3' to keep the coaches 'live'. At notch 3, the engine ,
>>>>>> apparently, throbs like mad. And uses 60 litres of diesel a hour when in
>>>>>> that state.
>>>>>
>>>>> I wonder if that's because the hotel load is more than expected, or the
>>>>> power output less?
>>>>>
>>>>
>>>> Neither, I suspect, I think it's very likely to be as designed.
>>>
>>> Given this was specifically built to be a passenger locomotive it doesn't
>>> seem to me like a particularly smart design. Didn't they think of hotel loads
>>
>>> during the design phase or is running the engine at higher than idle rpm
>>> in stations normal in europe?
>>>
>>>
>>
>> As I said, it's normal for every UK passenger locomotive built since the
>> 1970s. I don't know enough about the ones built in the 1960s.
>
> Seems like in some respects the railways are still in the 50s. If a bus
> couldn't run its aircon/heating and lighting with the engine at idle no one
> would buy it. Ok, not entirely electrically powered but its a design
> consideration that these things work at all times regardless.
>

My car idles faster when the aircon is cooling than when it's not.

I can't ask my bus contact about bus/coach aircon right now as he's busy
delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
not joking!), but perhaps coach engines always idle at a speed suitable to
provide aircon power, when without that requirement they could idle slower?

>> I also don't know enough about non-UK diesel passenger locomotives to say
>> how they run.
>
> Well I doubt they need to worry about engine rpm!
>

Why would diesel locomotives in other countries not worry about engine
speed?

Anna Noyd-Dryver

On 15/03/2022 10:59, Bob wrote:
> On 2022-03-15 10:49:20 +0000, Theo said:
>
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> Until now, all shore supply provision in the UK has used trackside
>>> equipment and connected to the existing connections for supply within
>>> the
>>> train, located on the buffer beam; a dirty and potentially dangerous
>>> environment.
>>>
>>> Using an additional connector above platform level is actually a great
>>> idea, is it used anywhere already?
>>
>> I don't know.  What do sleepers do for powering the coaches at the
>> origin/destination?  Presumably they must be plugged in, rather than
>> running
>> the loco?  (A lot of European sleepers will be under the wires, but I
>> suppose some won't)
>
> I'm hard pressed to think of a night train route in Western Europe other
> than the Highland and Night Riviera in the UK that use diesel traction.
> What are the provisions made for hotel power on carriages on the Straits
> of Messina train ferry?
>
> Robin
>

SNCF use diesel haulage on the Paris (Austerlitz) - Briançon night train
between Valence and Briançon. Usually a pair of BB75000 diesels, but in
the past it was a single CC72000.

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
> <Muttley@dastardlyhq.com> wrote:
>> On Mon, 14 Mar 2022 11:41:45 -0000 (UTC)
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> <Muttley@dastardlyhq.com> wrote:
>>>> On Mon, 14 Mar 2022 10:48:04 -0000 (UTC)
>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>> Theo <theom+news@chiark.greenend.org.uk> wrote:
>>>>>> Alan <alan@darkroom.+.com> wrote:
>>>>>>> The engine noise/running problem is explained. The alternators cannot
>>>>>>> supply the train power, even in the terminus, at idle speed, so they have
>>>
>>>>>>> to run at 'Notch 3' to keep the coaches 'live'. At notch 3, the engine ,
>>>>>>> apparently, throbs like mad. And uses 60 litres of diesel a hour when in
>>>>>>> that state.
>>>>>>
>>>>>> I wonder if that's because the hotel load is more than expected, or the
>>>>>> power output less?
>>>>>>
>>>>>
>>>>> Neither, I suspect, I think it's very likely to be as designed.
>>>>
>>>> Given this was specifically built to be a passenger locomotive it doesn't
>>>> seem to me like a particularly smart design. Didn't they think of hotel loads
>>>
>>>> during the design phase or is running the engine at higher than idle rpm
>>>> in stations normal in europe?
>>>>
>>>>
>>>
>>> As I said, it's normal for every UK passenger locomotive built since the
>>> 1970s. I don't know enough about the ones built in the 1960s.
>>
>> Seems like in some respects the railways are still in the 50s. If a bus
>> couldn't run its aircon/heating and lighting with the engine at idle no one
>> would buy it. Ok, not entirely electrically powered but its a design
>> consideration that these things work at all times regardless.
>>
>
> My car idles faster when the aircon is cooling than when it's not.

That’s been true of two cars that I’ve had.

> I can't ask my bus contact about bus/coach aircon right now as he's busy
> delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
> not joking!), but perhaps coach engines always idle at a speed suitable to
> provide aircon power, when without that requirement they could idle slower?

See my previous comment about donkey engines on N.American coaches.

>>> I also don't know enough about non-UK diesel passenger locomotives to say
>>> how they run.
>>
>> Well I doubt they need to worry about engine rpm!
>>
>
> Why would diesel locomotives in other countries not worry about engine
> speed?

Because they’re foreign! Do keep up.

Sam

--
The entity formerly known as Sam.Wilson@ed.ac.uk
Spit the dummy to reply

Dazzler <dazusenet@gmail.com> wrote:
> On 15/03/2022 10:59, Bob wrote:
>> On 2022-03-15 10:49:20 +0000, Theo said:
>>
>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>> Until now, all shore supply provision in the UK has used trackside
>>>> equipment and connected to the existing connections for supply within
>>>> the
>>>> train, located on the buffer beam; a dirty and potentially dangerous
>>>> environment.
>>>>
>>>> Using an additional connector above platform level is actually a great
>>>> idea, is it used anywhere already?
>>>
>>> I don't know.  What do sleepers do for powering the coaches at the
>>> origin/destination?  Presumably they must be plugged in, rather than
>>> running
>>> the loco?  (A lot of European sleepers will be under the wires, but I
>>> suppose some won't)
>>
>> I'm hard pressed to think of a night train route in Western Europe other
>> than the Highland and Night Riviera in the UK that use diesel traction.
>> What are the provisions made for hotel power on carriages on the Straits
>> of Messina train ferry?
>>
>> Robin
>>
>
> SNCF use diesel haulage on the Paris (Austerlitz) - Briançon night train
> between Valence and Briançon. Usually a pair of BB75000 diesels, but in
> the past it was a single CC72000.

The one time I was on a French motorail sleeper train (Calais - ?Toulouse;
we got off at Brive-la-Gaillarde in a weirdly warm early morning fog) it
had a pair of BB diesels on the front, possibly BB67000s, but it was quite
a while ago. The Paris-Nice and return sleepers had a single electric BB,
I think, but I can’t find a record of them at the moment.

Sam

--
The entity formerly known as Sam.Wilson@ed.ac.uk
Spit the dummy to reply

On 15/3/22 21:59, Bob wrote:

> I'm hard pressed to think of a night train route in Western Europe other
> than the Highland and Night Riviera in the UK that use diesel traction. 
> What are the provisions made for hotel power on carriages on the Straits
> of Messina train ferry?

I did a day crossing a few years ago - the coaches are coupled to a
coupler equipped buffer at the end of the deck and were connected to
main and 'train' air pipes. A brake valve was provided on the buffer to
control the brakes. I assume they do this to have the brake system fully
charged and to hold the coach brakes on during the crossing instead of
winding all the hand brakes on.

The coaches were powered via a shore power connector on the side, not
via the railway standard hotel power connector at the end. The photo I
have looks like the coach was plugged in via a standard 380v 3 phase lead.

On Tue, 15 Mar 2022 14:23:45 -0000 (UTC)
Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>> Seems like in some respects the railways are still in the 50s. If a bus
>> couldn't run its aircon/heating and lighting with the engine at idle no one
>> would buy it. Ok, not entirely electrically powered but its a design
>> consideration that these things work at all times regardless.
>>
>
>My car idles faster when the aircon is cooling than when it's not.

You must have an old car. Modern cars keep the idle rpm constant regardless,
they simply use a bit more fuel in the process if there's a load on it.

>I can't ask my bus contact about bus/coach aircon right now as he's busy
>delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
>not joking!), but perhaps coach engines always idle at a speed suitable to
>provide aircon power, when without that requirement they could idle slower?

Possibly, but I never noticed any difference.

>>> I also don't know enough about non-UK diesel passenger locomotives to say
>>> how they run.
>>
>> Well I doubt they need to worry about engine rpm!
>>
>
>Why would diesel locomotives in other countries not worry about engine
>speed?

Ignore that comment, I misread your line as non diesel. I shouldn't skim read.

<Muttley@dastardlyhq.com> wrote:
> On Tue, 15 Mar 2022 14:23:45 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> Seems like in some respects the railways are still in the 50s. If a bus
>>> couldn't run its aircon/heating and lighting with the engine at idle no one
>>> would buy it. Ok, not entirely electrically powered but its a design
>>> consideration that these things work at all times regardless.
>>>
>>
>> My car idles faster when the aircon is cooling than when it's not.
>
> You must have an old car. Modern cars keep the idle rpm constant regardless,
> they simply use a bit more fuel in the process if there's a load on it.
>

Yes, it's a 54 plate but I kinda love it (it's time to get rid of it now
that I only ever use it to make sure it still works, though). Idles at
400rpm, or 6-800rpm when the aircon is cooling.

My other car of similar age doesn't have aircon and idles at 1,200rpm!

>> I can't ask my bus contact about bus/coach aircon right now as he's busy
>> delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
>> not joking!), but perhaps coach engines always idle at a speed suitable to
>> provide aircon power, when without that requirement they could idle slower?
>
> Possibly, but I never noticed any difference.
>

You wouldn't, if they're set to always idle at that speed regardless.

Anna Noyd-Dryver

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
> <Muttley@dastardlyhq.com> wrote:
>> On Mon, 14 Mar 2022 11:41:45 -0000 (UTC)
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> <Muttley@dastardlyhq.com> wrote:
>>>> On Mon, 14 Mar 2022 10:48:04 -0000 (UTC)
>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>> Theo <theom+news@chiark.greenend.org.uk> wrote:
>>>>>> Alan <alan@darkroom.+.com> wrote:
>>>>>>> The engine noise/running problem is explained. The alternators cannot
>>>>>>> supply the train power, even in the terminus, at idle speed, so they have
>>>
>>>>>>> to run at 'Notch 3' to keep the coaches 'live'. At notch 3, the engine ,
>>>>>>> apparently, throbs like mad. And uses 60 litres of diesel a hour when in
>>>>>>> that state.
>>>>>>
>>>>>> I wonder if that's because the hotel load is more than expected, or the
>>>>>> power output less?
>>>>>>
>>>>>
>>>>> Neither, I suspect, I think it's very likely to be as designed.
>>>>
>>>> Given this was specifically built to be a passenger locomotive it doesn't
>>>> seem to me like a particularly smart design. Didn't they think of hotel loads
>>>
>>>> during the design phase or is running the engine at higher than idle rpm
>>>> in stations normal in europe?
>>>>
>>>>
>>>
>>> As I said, it's normal for every UK passenger locomotive built since the
>>> 1970s. I don't know enough about the ones built in the 1960s.
>>
>> Seems like in some respects the railways are still in the 50s. If a bus
>> couldn't run its aircon/heating and lighting with the engine at idle no one
>> would buy it. Ok, not entirely electrically powered but its a design
>> consideration that these things work at all times regardless.
>>
>
> My car idles faster when the aircon is cooling than when it's not.
>
> I can't ask my bus contact about bus/coach aircon right now as he's busy
> delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
> not joking!), but perhaps coach engines always idle at a speed suitable to
> provide aircon power, when without that requirement they could idle slower?

Bus engines also have to drive a compressor for the brakes ,suspension
systems etc so may be set at a sensible minimum to cope with anticipated
demand from those.

GH

On Wed, 16 Mar 2022 12:02:35 -0000 (UTC)
Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>> On Tue, 15 Mar 2022 14:23:45 -0000 (UTC)
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> <Muttley@dastardlyhq.com> wrote:
>>>> Seems like in some respects the railways are still in the 50s. If a bus
>>>> couldn't run its aircon/heating and lighting with the engine at idle no one
>
>>>> would buy it. Ok, not entirely electrically powered but its a design
>>>> consideration that these things work at all times regardless.
>>>>
>>>
>>> My car idles faster when the aircon is cooling than when it's not.
>>
>> You must have an old car. Modern cars keep the idle rpm constant regardless,
>> they simply use a bit more fuel in the process if there's a load on it.
>>
>
>Yes, it's a 54 plate but I kinda love it (it's time to get rid of it now
>that I only ever use it to make sure it still works, though). Idles at
>400rpm, or 6-800rpm when the aircon is cooling.

If I switch the aircon on in mine at idle the revs drop momentarily then
go back to idle rpm.

>My other car of similar age doesn't have aircon and idles at 1,200rpm!

You need to get that looked at as thats a higher idle speed than a lot of
motorbikes and clearly not right.

>>> delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
>>> not joking!), but perhaps coach engines always idle at a speed suitable to
>>> provide aircon power, when without that requirement they could idle slower?
>>
>> Possibly, but I never noticed any difference.
>>
>
>You wouldn't, if they're set to always idle at that speed regardless.

You don't want a large vehicle with a needlessly high idle speed. Fuel economy
really matters.

On 16 Mar 2022 16:45:54 GMT
Marland <gemehabal@btinternet.co.uk> wrote:
>Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> I can't ask my bus contact about bus/coach aircon right now as he's busy
>> delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
>> not joking!), but perhaps coach engines always idle at a speed suitable to
>> provide aircon power, when without that requirement they could idle slower?
>
>
>Bus engines also have to drive a compressor for the brakes ,suspension
>systems etc so may be set at a sensible minimum to cope with anticipated
>demand from those.

I've often wondered about the logic of which vehicles use hydraulic brakes
and which use air brakes. For semi trailer tractors its a no brainer - you
couldn't have a flexible hydraulic brake link to a trailer that gets detached
possibly a number of times a day. Yet a bus which may never pull any trailer
still has air brakes. Arguments about size don't wash because a 500 ton A380
- and every other airliner - use hydraulic braking. Strange.

<Muttley@dastardlyhq.com> wrote:
> On Wed, 16 Mar 2022 12:02:35 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On Tue, 15 Mar 2022 14:23:45 -0000 (UTC)
>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>> <Muttley@dastardlyhq.com> wrote:
>>>>> Seems like in some respects the railways are still in the 50s. If a bus
>>>>> couldn't run its aircon/heating and lighting with the engine at idle no one
>>
>>>>> would buy it. Ok, not entirely electrically powered but its a design
>>>>> consideration that these things work at all times regardless.
>>>>>
>>>>
>>>> My car idles faster when the aircon is cooling than when it's not.
>>>
>>> You must have an old car. Modern cars keep the idle rpm constant regardless,
>>> they simply use a bit more fuel in the process if there's a load on it.
>>>
>>
>> Yes, it's a 54 plate but I kinda love it (it's time to get rid of it now
>> that I only ever use it to make sure it still works, though). Idles at
>> 400rpm, or 6-800rpm when the aircon is cooling.
>
> If I switch the aircon on in mine at idle the revs drop momentarily then
> go back to idle rpm.
>

So it … count be made to idle slower, then, if it didn't have to provide
this extra output? ;)

>> My other car of similar age doesn't have aircon and idles at 1,200rpm!
>
> You need to get that looked at as thats a higher idle speed than a lot of
> motorbikes and clearly not right.
>

It's not exactly a normal car. Made by a small manufacturer in England,
using a Honda Civic Type S engine and a non-reprogrammable ECU from an
independent component manufacturer. The idle speed is unchanged from when I
bought the car at 1 year old and the factory have never expressed concern
about it on any of the occasions I've visited there for service or repair.

Anna Noyd-Dryver

<Muttley@dastardlyhq.com> wrote:
> On 16 Mar 2022 16:45:54 GMT
> Marland <gemehabal@btinternet.co.uk> wrote:
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> I can't ask my bus contact about bus/coach aircon right now as he's busy
>>> delivering a coach full of teddy bears to the Hungary/Ukraine border (I'm
>>> not joking!), but perhaps coach engines always idle at a speed suitable to
>>> provide aircon power, when without that requirement they could idle slower?
>>
>>
>> Bus engines also have to drive a compressor for the brakes ,suspension
>> systems etc so may be set at a sensible minimum to cope with anticipated
>> demand from those.
>
> I've often wondered about the logic of which vehicles use hydraulic brakes
> and which use air brakes. For semi trailer tractors its a no brainer - you
> couldn't have a flexible hydraulic brake link to a trailer that gets detached
> possibly a number of times a day. Yet a bus which may never pull any trailer
> still has air brakes. Arguments about size don't wash because a 500 ton A380
> - and every other airliner - use hydraulic braking. Strange.
>
>

I suspect that airliner hydraulic brakes work rather differently than those
on your car. Some modern trams use hydraulic brakes, for example (because
that means they don't need an air system), but they're hydraulic only for
the very last section - from the electrically-operated actuator, to the
brake cylinder. Control of the system is electrical from the driver's
controls. Actually thinking about it that's not so different to the
arrangement on a modern EV.

Conventional hydraulic brakes need assistance. I've driven a few cars
without a servo and they need a very heavy right foot!! The van-based
minibuses of the 1980s/90s used hydraulic brakes because they didn't have
an air system. Air brakes on the other hand 'provide their own assistance'
you might say - the pressure at the cylinders is proportional to the amount
of air admitted, rather than the force applied to the pedal.

Once the vehicle has an air system for one component you might as well use
it for other components where it makes life easier - on a bus that's
parking brake, doors, brakes, wipers and suspension. On a coach you can add
luggage lockers, driver's seat and potentially the toilet module?

Actually one late addition to that list is probably the most significant. I
bet there's a high correlation between a vehicle having air suspension and
then using that air supply for other purposes eg brakes.

Anna Noyd-Dryver

Mark Goodge wrote:

>On Thu, 17 Mar 2022 12:10:57 -0000 (UTC), Anna Noyd-Dryver
><anna@noyd-dryver.com> wrote:
>>
>>Conventional hydraulic brakes need assistance. I've driven a few cars
>>without a servo and they need a very heavy right foot!!

>Back in my early days after leaving school, I did a short stint as a
>delivery driver before going over to the dark side and getting involved
>in computers. One of the things I noted when moving up from a
>Transit-sized vehicle with hydraulic brakes to an air-braked 7.5 tonner
>is how little force it took to operate the brakes on the latter. Until I
>got the hang of it, I was forever ending up with my nose practically
>against the windscreen and anything I'd put on the passenger seat (eg,
>my sandwiches!) splattered against the dash when I needed to slow down.

When I inherited my Dad's Austin 1800, not in its first spring of
youth, it was very different from my even more aged Beetle, and
there was a short period when I drove both of them.

The Beetle had manual brakes, and the 1800 the delights of a
servo, so I had to be a bit more gentle on the pedal. Back in the
Beetle, by the time I noticed that I wasn't slowing quite as much
as might be prudent, it could get quite close to revealing the
car's handling limitations.

If you fancy an upper-body workout, try taking an 1800 - FWD and
manual steering - around a multi-storey car park. Not much fun.

Chris
--
Chris J Dixon Nottingham UK
chris@cdixon.me.uk @ChrisJDixon1

Plant amazing Acers.

On Thu, 17 Mar 2022 12:10:56 -0000 (UTC)
Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>> On Wed, 16 Mar 2022 12:02:35 -0000 (UTC)
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> Yes, it's a 54 plate but I kinda love it (it's time to get rid of it now
>>> that I only ever use it to make sure it still works, though). Idles at
>>> 400rpm, or 6-800rpm when the aircon is cooling.
>>
>> If I switch the aircon on in mine at idle the revs drop momentarily then
>> go back to idle rpm.
>>
>
>So it … count be made to idle slower, then, if it didn't have to provide
>this extra output? ;)

I suspect if it idled slower than its current 600rpm things might get a bit
rough and given its a diesel it probably needs a minimum piston speed to
compress the air fast enough for it to get hot enough before the heat is
sucked away but the cylinder walls. But who knows. Its all controlled by the
ECU anyway.

>> You need to get that looked at as thats a higher idle speed than a lot of
>> motorbikes and clearly not right.
>>
>
>It's not exactly a normal car. Made by a small manufacturer in England,
>using a Honda Civic Type S engine and a non-reprogrammable ECU from an
>independent component manufacturer. The idle speed is unchanged from when I
>bought the car at 1 year old and the factory have never expressed concern
>about it on any of the occasions I've visited there for service or repair.

Perhaps they've set the idle high due to limited clutch movement and hence
to prevent stalling. Either way, that high idle speed won't do the engine any
favours particularly when stone cold or your fuel economy.

<Muttley@dastardlyhq.com> wrote:
> On Thu, 17 Mar 2022 12:10:56 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On Wed, 16 Mar 2022 12:02:35 -0000 (UTC)
>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>> Yes, it's a 54 plate but I kinda love it (it's time to get rid of it now
>>>> that I only ever use it to make sure it still works, though). Idles at
>>>> 400rpm, or 6-800rpm when the aircon is cooling.
>>>
>>> If I switch the aircon on in mine at idle the revs drop momentarily then
>>> go back to idle rpm.
>>>
>>
>> So it … count be made to idle slower, then, if it didn't have to provide
>> this extra output? ;)
>
> I suspect if it idled slower than its current 600rpm things might get a bit
> rough and given its a diesel it probably needs a minimum piston speed to
> compress the air fast enough for it to get hot enough before the heat is
> sucked away but the cylinder walls. But who knows. Its all controlled by the
> ECU anyway.
>
>>> You need to get that looked at as thats a higher idle speed than a lot of
>>> motorbikes and clearly not right.
>>>
>>
>> It's not exactly a normal car. Made by a small manufacturer in England,
>> using a Honda Civic Type S engine and a non-reprogrammable ECU from an
>> independent component manufacturer. The idle speed is unchanged from when I
>> bought the car at 1 year old and the factory have never expressed concern
>> about it on any of the occasions I've visited there for service or repair.
>
> Perhaps they've set the idle high due to limited clutch movement and hence
> to prevent stalling. Either way, that high idle speed won't do the engine any
> favours particularly when stone cold or your fuel economy.
>
>

Considering it's done about 500 miles in the last two years, neither of
those is much of a concern.

Anna Noyd-Dryver

On Thu, 17 Mar 2022 12:10:57 -0000 (UTC)
Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>> On 16 Mar 2022 16:45:54 GMT
>> possibly a number of times a day. Yet a bus which may never pull any trailer
>> still has air brakes. Arguments about size don't wash because a 500 ton A380
>> - and every other airliner - use hydraulic braking. Strange.
>>
>>
>
>I suspect that airliner hydraulic brakes work rather differently than those

I'm sure Recliner can fill us in on that.

>on your car. Some modern trams use hydraulic brakes, for example (because
>that means they don't need an air system), but they're hydraulic only for
>the very last section - from the electrically-operated actuator, to the
>brake cylinder. Control of the system is electrical from the driver's
>controls. Actually thinking about it that's not so different to the
>arrangement on a modern EV.

Electric vehicles can always use regen braking too.

>Conventional hydraulic brakes need assistance. I've driven a few cars
>without a servo and they need a very heavy right foot!! The van-based

I used to spend a lot of time in a traffic jam going down a hill and would
always switch the engine off to save fuel. After a few brake applications my
right leg certainly started getting some good exercise :)

>minibuses of the 1980s/90s used hydraulic brakes because they didn't have
>an air system. Air brakes on the other hand 'provide their own assistance'

I imagine transit based minibuses still use hydraulic brakes.

>you might say - the pressure at the cylinders is proportional to the amount
>of air admitted, rather than the force applied to the pedal.

I'm guessing its more subtle than that because even if they pedal only
opened the pipe to the brakes a small amount it would still end up at max
pressure on the brake after a while and you'd have a lock up.

>Once the vehicle has an air system for one component you might as well use
>it for other components where it makes life easier - on a bus that's
>parking brake, doors, brakes, wipers and suspension. On a coach you can add
>luggage lockers, driver's seat and potentially the toilet module?

Lockers?

>Actually one late addition to that list is probably the most significant. I
>bet there's a high correlation between a vehicle having air suspension and
>then using that air supply for other purposes eg brakes.

Never been on a bus yet where the air suspension improved the ride.

On 17/03/2022 16:18, Muttley@dastardlyhq.com wrote:
> On Thu, 17 Mar 2022 12:10:57 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On 16 Mar 2022 16:45:54 GMT
>>> possibly a number of times a day. Yet a bus which may never pull any trailer
>>> still has air brakes. Arguments about size don't wash because a 500 ton A380
>>> - and every other airliner - use hydraulic braking. Strange.
>>>
>>>
>>
>> I suspect that airliner hydraulic brakes work rather differently than those
>
> I'm sure Recliner can fill us in on that.
>
>> on your car. Some modern trams use hydraulic brakes, for example (because
>> that means they don't need an air system), but they're hydraulic only for
>> the very last section - from the electrically-operated actuator, to the
>> brake cylinder. Control of the system is electrical from the driver's
>> controls. Actually thinking about it that's not so different to the
>> arrangement on a modern EV.
>
> Electric vehicles can always use regen braking too.
>
>> Conventional hydraulic brakes need assistance. I've driven a few cars
>> without a servo and they need a very heavy right foot!! The van-based
>
> I used to spend a lot of time in a traffic jam going down a hill and would
> always switch the engine off to save fuel. After a few brake applications my
> right leg certainly started getting some good exercise :)
>
>> minibuses of the 1980s/90s used hydraulic brakes because they didn't have
>> an air system. Air brakes on the other hand 'provide their own assistance'
>
> I imagine transit based minibuses still use hydraulic brakes.
>
>> you might say - the pressure at the cylinders is proportional to the amount
>> of air admitted, rather than the force applied to the pedal.
>
> I'm guessing its more subtle than that because even if they pedal only
> opened the pipe to the brakes a small amount it would still end up at max
> pressure on the brake after a while and you'd have a lock up.
>
>> Once the vehicle has an air system for one component you might as well use
>> it for other components where it makes life easier - on a bus that's
>> parking brake, doors, brakes, wipers and suspension. On a coach you can add
>> luggage lockers, driver's seat and potentially the toilet module?
>
> Lockers?

Modern coaches have remotely operated luggage doors.

--
Graeme Wall
This account not read.

On Thu, 17 Mar 2022 16:07:06 +0000
Chris J Dixon <chris@cdixon.me.uk> wrote:
>Mark Goodge wrote:
>
>>On Thu, 17 Mar 2022 12:10:57 -0000 (UTC), Anna Noyd-Dryver
>><anna@noyd-dryver.com> wrote:
>>>
>>>Conventional hydraulic brakes need assistance. I've driven a few cars
>>>without a servo and they need a very heavy right foot!!
>
>>Back in my early days after leaving school, I did a short stint as a
>>delivery driver before going over to the dark side and getting involved
>>in computers. One of the things I noted when moving up from a
>>Transit-sized vehicle with hydraulic brakes to an air-braked 7.5 tonner
>>is how little force it took to operate the brakes on the latter. Until I
>>got the hang of it, I was forever ending up with my nose practically
>>against the windscreen and anything I'd put on the passenger seat (eg,
>>my sandwiches!) splattered against the dash when I needed to slow down.

Lorry brakes are set up for a full load so if you're driving an unloaded
wagon the brakes can be pretty sharp :) When I started HGV lessons for the
first times I often ended up doing an unintentional emergency stop at
junctions.

>If you fancy an upper-body workout, try taking an 1800 - FWD and
>manual steering - around a multi-storey car park. Not much fun.

The steeing on most modern cars when stationary with the engine off is almost
impossible to turn for a lot of people particularly women as you're not just
fighting the tyre friction but the power steering pump too.

On Thu, 17 Mar 2022 16:24:29 +0000
Graeme Wall <rail@greywall.demon.co.uk> wrote:
>On 17/03/2022 16:18, Muttley@dastardlyhq.com wrote:
>>> Once the vehicle has an air system for one component you might as well use
>>> it for other components where it makes life easier - on a bus that's
>>> parking brake, doors, brakes, wipers and suspension. On a coach you can add
>>> luggage lockers, driver's seat and potentially the toilet module?
>>
>> Lockers?
>
>Modern coaches have remotely operated luggage doors.

They do? News to me. Anyway, I thought he meant lockers inside the cabin.