On Thu, 17 Mar 2022 16:18:29 +0000, Muttley 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.

Usually a clever valve that uses some of the pressure let through to push
back against the pedal tending to close the valve again, so that pressure
in the brake pipe is proportional to pressure on the pedal.

(My ancient Citroen BX had something like that on its power brake system,
running from the same hydraulic system as the suspension and steering.
Almost no movement on the brake pedal. And of course, no engine, no
brakes at all eventually, however hard you pressed, apart from the
handbrake working the front disks.)

nib

>>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.

<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.

Airliners have multiple (usually three or even four) hydraulic circuits,
and the brakes will be powered by at least two independent systems, each
powered by a different engine.

>
>> 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.

In fact, they're expected to shed most of te kinetic energy that way.

>
>> 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.
>

It's a way of keeping constant ride height with varying load, and also
lowering the bus at stops. It's those reasons, rather than comfort, that
justify its use. Similarly, in my car, the air suspension lowers the car at
speed, as well as levelling the car, regardless of boot or rear seat
loading.

On 17/03/2022 16:28, Muttley@dastardlyhq.com wrote:
> 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.
>

You don't strike me as the sort of person who travels by coach much :-)
The National Express coaches for London from Portsmouth stop near my
local Tescos and I've seen them boarding passengers. The driver presses
a button and the luggage doors open automagically.

--
Graeme Wall
This account not read.

In message <t0vs9g$f0e$1@dont-email.me>, at 17:48:32 on Thu, 17 Mar
2022, Recliner <recliner.usenet@gmail.com> remarked:

>> Never been on a bus yet where the air suspension improved the ride.
>
>It's a way of keeping constant ride height with varying load, and also
>lowering the bus at stops. It's those reasons, rather than comfort, that
>justify its use. Similarly, in my car, the air suspension lowers the car at
>speed, as well as levelling the car, regardless of boot or rear seat
>loading.

That must be really handy if you encounter one of those speed "bump"
pillows. My last car used to tend to ground on them if straddled,
without the car also having lowered itself.
--
Roland Perry

Roland Perry <roland@perry.co.uk> wrote:
> In message <t0vs9g$f0e$1@dont-email.me>, at 17:48:32 on Thu, 17 Mar
> 2022, Recliner <recliner.usenet@gmail.com> remarked:
>
>>> Never been on a bus yet where the air suspension improved the ride.
>>
>> It's a way of keeping constant ride height with varying load, and also
>> lowering the bus at stops. It's those reasons, rather than comfort, that
>> justify its use. Similarly, in my car, the air suspension lowers the car at
>> speed, as well as levelling the car, regardless of boot or rear seat
>> loading.
>
> That must be really handy if you encounter one of those speed "bump"
> pillows. My last car used to tend to ground on them if straddled,
> without the car also having lowered itself.

Some low riding cars automatically raise themselves at very low speeds (eg,
under 30 km/h), but mine doesn't do that. So they may have three different
ride heights (eg, up to 30, 30-80, 80+ km/h). Mine only has two, but at
least it never sinks on its springs, as the air pump automatically adjusts
the pressure in the rear springs as needed. This is all automatic, with no
user controls.

In message <t0vvfa$as4$1@dont-email.me>, at 18:42:50 on Thu, 17 Mar
2022, Recliner <recliner.usenet@gmail.com> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <t0vs9g$f0e$1@dont-email.me>, at 17:48:32 on Thu, 17 Mar
>> 2022, Recliner <recliner.usenet@gmail.com> remarked:
>>
>>>> Never been on a bus yet where the air suspension improved the ride.
>>>
>>> It's a way of keeping constant ride height with varying load, and also
>>> lowering the bus at stops. It's those reasons, rather than comfort, that
>>> justify its use. Similarly, in my car, the air suspension lowers the car at
>>> speed, as well as levelling the car, regardless of boot or rear seat
>>> loading.
>>
>> That must be really handy if you encounter one of those speed "bump"
>> pillows. My last car used to tend to ground on them if straddled,
>> without the car also having lowered itself.
>
>Some low riding cars automatically raise themselves at very low speeds (eg,
>under 30 km/h), but mine doesn't do that. So they may have three different
>ride heights (eg, up to 30, 30-80, 80+ km/h). Mine only has two, but at
>least it never sinks on its springs, as the air pump automatically adjusts
>the pressure in the rear springs as needed. This is all automatic, with no
>user controls.

Luckily I can nowadays straddle such pillows at 30mph as if they weren't
there (and obviously one wouldn't want to exceed the speed limit). My
previous car scraped its sump-guard on them at anything over walking
pace.
--
Roland Perry

nib <news@ingram-bromley.co.uk> wrote:
> On Thu, 17 Mar 2022 16:18:29 +0000, Muttley 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.
>
> Usually a clever valve that uses some of the pressure let through to push
> back against the pedal tending to close the valve again, so that pressure
> in the brake pipe is proportional to pressure on the pedal.
>
> (My ancient Citroen BX had something like that on its power brake system,
> running from the same hydraulic system as the suspension and steering.
> Almost no movement on the brake pedal. And of course, no engine, no
> brakes at all eventually, however hard you pressed, apart from the
> handbrake working the front disks.)

My brother’s GS had a very similar, probably identical, system - you
pressed harder on the pedal and got more braking even though the pedal felt
as though it didn’t move at all after taking up the slack.

We did have a Ford Fiesta courtesy car whose brakes were almost the inverse
of that: the pedal moved pretty freely but there was almost no modulation -
about half way down the brakes came on hard and it was really difficult to
brake progressively. My current car, a Skoda, has a little of that about
it - the brakes are much sharper than my old Xsara Picasso, whose brakes
were very conventional, not at all like earlier Citroens.

Sam

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

<Muttley@dastardlyhq.com> wrote:
> On 16 Mar 2022 16:45:54 GMT

>
> 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.

You can , most of those large agricultural trailers hauled by agricultural
tractors use such connections as tractors don’t usually have air
compressors but have hydraulic systems.
At times such as shuttling trailers between fields and yard where one
tractor will be shuttling different trailers left for others to load the
detachment will probably be occurring more frequently than a semi trailer
and cab units.
The couplings are nothing exceptional being just another variety of self
sealing probe and socket bayonet connection types used in applications from
air tools to in flight refuelling , many people have something similar in
their kitchen if they have a gas cooker so they can easily exchange for a
new one or just move it out of the way for cleaning or decorating without
having to bring in a gas fitter.

I think at least one miniature railway uses hydraulic brakes with said
couplings between coaches but ICBW.

GH

Marland <gemehabal@btinternet.co.uk> wrote:
> <Muttley@dastardlyhq.com> wrote:
>> On 16 Mar 2022 16:45:54 GMT
>
>>
>> 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.
>
> You can , most of those large agricultural trailers hauled by agricultural
> tractors use such connections as tractors don’t usually have air
> compressors but have hydraulic systems.
> At times such as shuttling trailers between fields and yard where one
> tractor will be shuttling different trailers left for others to load the
> detachment will probably be occurring more frequently than a semi trailer
> and cab units.
> The couplings are nothing exceptional being just another variety of self
> sealing probe and socket bayonet connection types used in applications from
> air tools to in flight refuelling , many people have something similar in
> their kitchen if they have a gas cooker so they can easily exchange for a
> new one or just move it out of the way for cleaning or decorating without
> having to bring in a gas fitter.
>
> I think at least one miniature railway uses hydraulic brakes with said
> couplings between coaches but ICBW.

Interesting. Do the circuits have to be bled after connecting or are they
somehow self-bleeding?

Sam

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

On Thu, 17 Mar 2022 17:48:32 -0000 (UTC)
Recliner <recliner.usenet@gmail.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>>> I suspect that airliner hydraulic brakes work rather differently than those
>>
>> I'm sure Recliner can fill us in on that.
>
>Airliners have multiple (usually three or even four) hydraulic circuits,
>and the brakes will be powered by at least two independent systems, each
>powered by a different engine.

Explains a lot.

>> Never been on a bus yet where the air suspension improved the ride.
>>
>
>It's a way of keeping constant ride height with varying load, and also
>lowering the bus at stops. It's those reasons, rather than comfort, that

Yes, I imagine the kneeling bus routine would be tricky with steel springs.

On Thu, 17 Mar 2022 17:54:51 +0000
Graeme Wall <rail@greywall.demon.co.uk> wrote:
>On 17/03/2022 16:28, Muttley@dastardlyhq.com wrote:
>> 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.
>>
>
>You don't strike me as the sort of person who travels by coach much :-)

Coach , damn right. If I need to go long distance its either train or car.
NE is strictly for skint students and cabbage pickers IMO.

>The National Express coaches for London from Portsmouth stop near my
>local Tescos and I've seen them boarding passengers. The driver presses
>a button and the luggage doors open automagically.

That could just be like a car boot though - it simply unlocks them and the
struts push it up. I'd be surprised if they close automatically too.

On 17 Mar 2022 23:34:52 GMT
Marland <gemehabal@btinternet.co.uk> wrote:
><Muttley@dastardlyhq.com> wrote:
>> On 16 Mar 2022 16:45:54 GMT
>
>>
>> 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.
>
>You can , most of those large agricultural trailers hauled by agricultural
>tractors use such connections as tractors don’t usually have air
>compressors but have hydraulic systems.
>At times such as shuttling trailers between fields and yard where one
>tractor will be shuttling different trailers left for others to load the
>detachment will probably be occurring more frequently than a semi trailer
>and cab units.
>The couplings are nothing exceptional being just another variety of self
>sealing probe and socket bayonet connection types used in applications from
>air tools to in flight refuelling , many people have something similar in
>their kitchen if they have a gas cooker so they can easily exchange for a
>new one or just move it out of the way for cleaning or decorating without
>having to bring in a gas fitter.

Yes , but in those instances it doesn't matter if some air gets in the system
or a bit of fuel spills. But you really don't want air bubbles in a brake
system and hydraulic fluid is somewhat toxic AFAIK.

On 18/03/2022 10:05, Muttley@dastardlyhq.com wrote:
> On Thu, 17 Mar 2022 17:54:51 +0000
> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>> On 17/03/2022 16:28, Muttley@dastardlyhq.com wrote:
>>> 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.
>>>
>>
>> You don't strike me as the sort of person who travels by coach much :-)
>
> Coach , damn right. If I need to go long distance its either train or car.
> NE is strictly for skint students and cabbage pickers IMO.
>
>> The National Express coaches for London from Portsmouth stop near my
>> local Tescos and I've seen them boarding passengers. The driver presses
>> a button and the luggage doors open automagically.
>
> That could just be like a car boot though - it simply unlocks them and the
> struts push it up. I'd be surprised if they close automatically too.
>

They do, driver presses the other button.

--
Graeme Wall
This account not read.

On Fri, 18 Mar 2022 10:15:07 +0000
Graeme Wall <rail@greywall.demon.co.uk> wrote:
>On 18/03/2022 10:05, Muttley@dastardlyhq.com wrote:
>> On Thu, 17 Mar 2022 17:54:51 +0000
>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>> On 17/03/2022 16:28, Muttley@dastardlyhq.com wrote:
>>>> 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.
>>>>
>>>
>>> You don't strike me as the sort of person who travels by coach much :-)
>>
>> Coach , damn right. If I need to go long distance its either train or car.
>> NE is strictly for skint students and cabbage pickers IMO.
>>
>>> The National Express coaches for London from Portsmouth stop near my
>>> local Tescos and I've seen them boarding passengers. The driver presses
>>> a button and the luggage doors open automagically.
>>
>> That could just be like a car boot though - it simply unlocks them and the
>> struts push it up. I'd be surprised if they close automatically too.
>>
>
>They do, driver presses the other button.

Fair enough. Just sounds like something else to go wrong and delay the service
though.

<Muttley@dastardlyhq.com> wrote:
> On Thu, 17 Mar 2022 17:54:51 +0000
> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>> On 17/03/2022 16:28, Muttley@dastardlyhq.com wrote:
>>> 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.
>>>
>>
>> You don't strike me as the sort of person who travels by coach much :-)
>
> Coach , damn right. If I need to go long distance its either train or car.
> NE is strictly for skint students and cabbage pickers IMO.
>

I trace by coach mostly on holiday.

>> The National Express coaches for London from Portsmouth stop near my
>> local Tescos and I've seen them boarding passengers. The driver presses
>> a button and the luggage doors open automagically.
>
> That could just be like a car boot though - it simply unlocks them and the
> struts push it up. I'd be surprised if they close automatically too.
>
>

They're on air struts, opened and closed by switches in the cab.

Anna Noyd-Dryver

<Muttley@dastardlyhq.com> wrote:
> On Fri, 18 Mar 2022 10:15:07 +0000
> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>> On 18/03/2022 10:05, Muttley@dastardlyhq.com wrote:
>>> On Thu, 17 Mar 2022 17:54:51 +0000
>>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>> On 17/03/2022 16:28, Muttley@dastardlyhq.com wrote:
>>>>> 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.
>>>>>
>>>>
>>>> You don't strike me as the sort of person who travels by coach much :-)
>>>
>>> Coach , damn right. If I need to go long distance its either train or car.
>>> NE is strictly for skint students and cabbage pickers IMO.
>>>
>>>> The National Express coaches for London from Portsmouth stop near my
>>>> local Tescos and I've seen them boarding passengers. The driver presses
>>>> a button and the luggage doors open automagically.
>>>
>>> That could just be like a car boot though - it simply unlocks them and the
>>> struts push it up. I'd be surprised if they close automatically too.
>>>
>>
>> They do, driver presses the other button.
>
> Fair enough. Just sounds like something else to go wrong and delay the service
> though.
>
>
>

I'd hazard a guess that only a minority of coaches are used on 'service';
most will be on contracts or excursions.

Anna Noyd-Dryver

On Fri, 18 Mar 2022 06:18:16 -0700
Nobody <jock@soccer.com> wrote:
>On Fri, 18 Mar 2022 10:05:38 -0000 (UTC), Muttley@dastardlyhq.com
>wrote:
>
>>On Thu, 17 Mar 2022 17:54:51 +0000
>>Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>On 17/03/2022 16:28, Muttley@dastardlyhq.com wrote:
>>>> 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.
>>>>
>>>
>>>You don't strike me as the sort of person who travels by coach much :-)
>>
>>Coach , damn right. If I need to go long distance its either train or car.
>>NE is strictly for skint students and cabbage pickers IMO.
>
>Ouch...
>
>As an occasional international visitor to the Ewe Kay, and at times
>requiring single-stage transfers between airports (e.g.LGW-MAN and
>reverse).... and direct door-to-door airport-to-hotel out-of-town (LHR
>to Premier in Southampton) with luggage. NE has been a breeze.

Thats up to you. For me they'd be the absolute last resort since they're
considerably slower than a train and far less comfortable. Who TF wants to
sit in a narrow seat in a traffic jam on the motorway where you can't even
get up and walk around?

<Muttley@dastardlyhq.com> wrote:
.. Who TF wants to
> sit in a narrow seat in a traffic jam on the motorway where you can't even
> get up and walk around?
>
>

Motorcyclists.

GH

On 18 Mar 2022 14:56:00 GMT
Marland <gemehabal@btinternet.co.uk> wrote:
><Muttley@dastardlyhq.com> wrote:
>.. Who TF wants to
>> sit in a narrow seat in a traffic jam on the motorway where you can't even
>> get up and walk around?
>>
>>
>
>Motorcyclists.

Surely one of the few (only?) advantages of a motorbike is you can filter
through traffic jams.

On 18/03/2022 15:45, Muttley@dastardlyhq.com wrote:
> On 18 Mar 2022 14:56:00 GMT
> Marland <gemehabal@btinternet.co.uk> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>> .. Who TF wants to
>>> sit in a narrow seat in a traffic jam on the motorway where you can't even
>>> get up and walk around?
>>>
>>>
>>
>> Motorcyclists.
>
> Surely one of the few (only?) advantages of a motorbike is you can filter
> through traffic jams.
>
>

That was the idea, but modern bikes are so wide and unweildy that this
is often impossible. I recall riding bikes when they were much neater
and could weave well!

--
Colin

<Muttley@dastardlyhq.com> wrote:
> On 17 Mar 2022 23:34:52 GMT
> Marland <gemehabal@btinternet.co.uk> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On 16 Mar 2022 16:45:54 GMT
>>
you
>>> couldn't have a flexible hydraulic brake link to a trailer that gets detached
>>
>>> possibly a number of times a day.
>>
>> You can , most of those large agricultural trailers hauled by agricultural
>> tractors use such connections as tractors don’t usually have air
>> compressors but have hydraulic systems.

>> The couplings are nothing exceptional being just another variety of self
>> sealing probe and socket bayonet connection types used in applications from
>> air tools to in flight refuelling , many people have something similar in
>> their kitchen if they have a gas cooker so they can easily exchange for a
>> new one or just move it out of the way for cleaning or decorating without
>> having to bring in a gas fitter.
>
> Yes , but in those instances it doesn't matter if some air gets in the system
> or a bit of fuel spills. But you really don't want air bubbles in a brake
> system and hydraulic fluid is somewhat toxic AFAIK.
>
>
>

The agricultural equipment ones have been coming under the scrutiny of the
HSE for a while now.
While the single pipe hydraulic trailer brake system was a great
improvement on having no or just overrun brakes *when it was introduced
around 30 to 40 years ago tractors and trailers were smaller and a lot
slower then and loads were lighter.
As we can all see on the roads tractors and trailers have got a lot larger
,heavier and faster and a study by the HSE found 80% of such set ups were
probably performing inadequately and that was before the lack of
maintenance that farmers are renowned for.
Consequently more and more tractors and hauled equipment are coming
equipped with compressors and air brake system as used on trucks.

* One of the kickstarters for the hydraulic versions was the introduction
of safety cabs on tractors, before some braked trailers were manually
operated by the driver reaching back and moving a long lever poking
forward in a manner not dissimilar to the application of brakes on non
fitted railway wagons before descending an incline. Enclosed cabs made
that operation difficult.

GH

<Muttley@dastardlyhq.com> wrote:
> On 18 Mar 2022 14:56:00 GMT
> Marland <gemehabal@btinternet.co.uk> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>> .. Who TF wants to
>>> sit in a narrow seat in a traffic jam on the motorway where you can't even
>>> get up and walk around?
>>>
>>>
>>
>> Motorcyclists.
>
> Surely one of the few (only?) advantages of a motorbike is you can filter
> through traffic jams.
>
>
>

True, but it was just a throwaway remark really and sometimes even
Motorcyclists find the jam is caused by a blocked carriageway either by
accident or closed while debris is removed with a Police vehicle whose
occupants would not view filtering past them favourably.

GH

In message <t129f7$ldv$1@gioia.aioe.org>, at 15:45:43 on Fri, 18 Mar
2022, Muttley@dastardlyhq.com remarked:
>On 18 Mar 2022 14:56:00 GMT
>Marland <gemehabal@btinternet.co.uk> wrote:
>><Muttley@dastardlyhq.com> wrote:
>>.. Who TF wants to
>>> sit in a narrow seat in a traffic jam on the motorway where you can't even
>>> get up and walk around?
>>
>>Motorcyclists.
>
>Surely one of the few (only?) advantages of a motorbike is you can filter
>through traffic jams.

Indeed, and the organ donor programme is very grateful.
--
Roland Perry

Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> wrote:
> Marland <gemehabal@btinternet.co.uk> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On 16 Mar 2022 16:45:54 GMT
>>

>>
>> You can , most of those large agricultural trailers hauled by agricultural
>> tractors use such connections as tractors don’t usually have air
>> compressors but have hydraulic systems.

>
> Interesting. Do the circuits have to be bled after connecting or are they
> somehow self-bleeding?
>
> Sam
>

Honest answer is I don’t know. The couplings are fairly well engineered,
the size of modern agricultural equipment means there are a lot of
hydraulics involved to set positions, raise or lower
parts and with some power axles which have hydraulic “motors” so hauled
equipment is not totally being dragged by the hitch. There can be up to 8
hoses (4 circuits )to be connected with some machinery so robust couplings
are well established.

GH

On Fri, 18 Mar 2022 17:32:20 +0000, Marland wrote:

> Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> wrote:
>> Marland <gemehabal@btinternet.co.uk> wrote:
>>> <Muttley@dastardlyhq.com> wrote:
>>>> On 16 Mar 2022 16:45:54 GMT
>>>
>>>
>
>>> You can , most of those large agricultural trailers hauled by
>>> agricultural tractors use such connections as tractors don’t usually
>>> have air compressors but have hydraulic systems.
>
>
>> Interesting. Do the circuits have to be bled after connecting or are
>> they somehow self-bleeding?
>>
>> Sam
>>
>>
> Honest answer is I don’t know. The couplings are fairly well engineered,
> the size of modern agricultural equipment means there are a lot of
> hydraulics involved to set positions, raise or lower parts and with some
> power axles which have hydraulic “motors” so hauled equipment is not
> totally being dragged by the hitch. There can be up to 8 hoses (4
> circuits )to be connected with some machinery so robust couplings are
> well established.
>
> GH

Not hydraulics, but in industrial inkjet we use self-sealing connectors
to disconnect ink circuits, which can get very messy, and they drop an
amazingly small amount on disconnection. The valves shut to flush flat
faces on both sides. As they engage, the flat faces touch first, then the
outer ring of one side pushes the outer ring of the other side while the
centre pin of the other side pushes the pin on the first side to open the
connection.

nib

nib