do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?

"Jim GM4DHJ ..." wrote in message
...
do you think the merrycan way of switching with down off is more
sensibubble that what we do in the uk ?

I know it is harder to accidentally knock things up than down ......or is
there another reason?

Jim GM4DHJ ... has brought this to us :
do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?

We have several opposing conventions. MCB's and CU main switches are up
for on. Only (1w) wall switches a down for on.

On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power
to the electronics was off! Guess how much damage was caused to plug in
boards that didn't like to be hot plugged?


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Tuesday, 22 January 2019 09:08:10 UTC, Jim GM4DHJ ... wrote:
"Jim GM4DHJ ..." wrote in message
...
do you think the merrycan way of switching with down off is more
sensibubble that what we do in the uk ?

I know it is harder to accidentally knock things up than down ......or is
there another reason?

There was an old expression of getting a girl knocked up which meant getting her pregnant.

On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I see that as the same action, the latter having a modified toggle.

Someone told me that strictly speaking American three pin sockets
should be mounted with the earth pin down, but this is universally
ignored to make them look like a face.

I think they also mount them sideways in architraves.

We never (well hardly ever) mount our sockets otherwise than earth pin
up, but I have more than one Chinese wall-wart with labeling affixed
in an orientation that suggests some people in China think our sockets
are earth pin down.

--
Graham.

%Profound_observation%

On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power
to the electronics was off! Guess how much damage was caused to plug in
boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies. Most
have wanted a green light for say a pump running ok and red for stopped
or failed, but some wanted the reverse, as they reasoned red for
energised and green for deenergised and therefore safer. A few even
wanted a mix, with green being for fail-closed valves that were in the
open position and for fail-open valves in the closed position, thus
showing their energisation rather than their positions.

SteveW

Steve Walker wrote:

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power
to the electronics was off!

Plessey ISDX is similar, a white bulb which is barely visible through
the slits in the case means power has failed ...

On 22/01/2019 12:43, Steve Walker wrote:
On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power
to the electronics was off! Guess how much damage was caused to plug
in boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies. Most
have wanted a green light for say a pump running ok and red for stopped
or failed, but some wanted the reverse, as they reasoned red for
energised and green for deenergised and therefore safer. A few even
wanted a mix, with green being for fail-closed valves that were in the
open position and for fail-open valves in the closed position, thus
showing their energisation rather than their positions.

SteveW

I worked on a (nuclear) project with a lot of C&I in the noughties, the
designers initial design followed the green for good, red for bad
convention. However, when the mandatory Human Factors specialist came in
she insisted that only white lights were used.

In article ,
alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

At one time, Crabtree sockets had their rocker switch flush when off.
Raised on. Which meant bashing it with a chair leg or whatever meant it
could only be switched off. Seemed quite sensible to me.

--
*Experience is something you don't get until just after you need it.*

Dave Plowman London SW
To e-mail, change noise into sound.

"Tim Streater" wrote in message
.. .
In article ,
newshound wrote:

I worked on a (nuclear) project with a lot of C&I in the noughties, the
designers initial design followed the green for good, red for bad
convention. However, when the mandatory Human Factors specialist came in
she insisted that only white lights were used.

Why?

Maybe because people with red/green colour-blindness wouldn't be able to
distinguish between the two. If so, it's a classic case of dragging everyone
down to their level: make everyone suffer from "can't distinguish" between
two white lights for the deficiencies of the minority.

By all means have "ON" and "OFF" on the lights, or different shapes of
light, but don't throw away colour just because some people can't use it.

On 22/01/2019 14:23, NY wrote:
"Tim Streater" wrote in message
.. .
In article ,
newshound wrote:

I worked on a (nuclear) project with a lot of C&I in the noughties,
the designers initial design followed the green for good, red for bad
convention. However, when the mandatory Human Factors specialist came
in she insisted that only white lights were used.

Why?

Maybe because people with red/green colour-blindness wouldn't be able to
distinguish between the two. If so, it's a classic case of dragging
everyone down to their level: make everyone suffer from "can't
distinguish" between two white lights for the deficiencies of the minority.

I think that is one of the reasons, IIRC another is that, as with the
valve example quoted earlier, the reality is that people can sometimes
interpret the colours differently. For example, for a valve is green
"open" and red "closed"? Or is green "normal" and red "fault condition"?

It is some while since I had the discussion, but in fact the expert made
a very sound case, including some clever but real life examples. The
argument is that it is better for people to pause to think about an
indicator, and to read its markup before taking action.

This is not to say that colours are not acceptable for separate things
like fire, gas, or other emergency alarms. In the civil nuclear
industry, the primary alarms are audible rather than visible: continuous
for "Fire" and intermittent or warbling for "Nuclear". Visual beacons
are needed for areas with high noise levels, though. The lights are
positioned in a stack, always in the same order, so that the colourblind
can always interpret them correctly.


By all means have "ON" and "OFF" on the lights, or different shapes of
light, but don't throw away colour just because some people can't use it.

See above.

On 22/01/2019 12:43, Steve Walker wrote:
On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power
to the electronics was off! Guess how much damage was caused to plug
in boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies. Most
have wanted a green light for say a pump running ok and red for stopped
or failed, but some wanted the reverse, as they reasoned red for
energised and green for deenergised and therefore safer. A few even
wanted a mix, with green being for fail-closed valves that were in the
open position and for fail-open valves in the closed position, thus
showing their energisation rather than their positions.

A green traffic signal should mean stop as green is a calm colour. Red
is fierce and should mean go.

Green chillies tend to be hotter than red ones, so the hot tap should be
green and the cold one red.

--
Max Demian

"Jim GM4DHJ ..." wrote in message
...

"Jim GM4DHJ ..." wrote in message
...
do you think the merrycan way of switching with down off is more
sensibubble that what we do in the uk ?

I know it is harder to accidentally knock things up than down ......or is
there another reason?

Not convinced that there ever was a rational reason.

When something can be done two ways, you can be sure
some will choose to do it one way and some the other
way. Same with the side of the road you drive on and
dave the sot's story about swords is just plain troll****.

On 22/01/2019 15:03, Max Demian wrote:
On 22/01/2019 12:43, Steve Walker wrote:
On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the
power to the electronics was off! Guess how much damage was caused to
plug in boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies.
Most have wanted a green light for say a pump running ok and red for
stopped or failed, but some wanted the reverse, as they reasoned red
for energised and green for deenergised and therefore safer. A few
even wanted a mix, with green being for fail-closed valves that were
in the open position and for fail-open valves in the closed position,
thus showing their energisation rather than their positions.

A green traffic signal should mean stop as green is a calm colour. Red
is fierce and should mean go.

Green chillies tend to be hotter than red ones, so the hot tap should be
green and the cold one red.


Cold makes you turn blue, and hot makes you turn red.

But...

The Earth is blue, while earth is usually brown or black, live things
are often green and a green/yellow thing would probably be poisonous,
white or grey is neutral.

Cheers
--
Clive

On Tuesday, 22 January 2019 14:09:15 UTC, Dave Plowman (News) wrote:
In article ,
alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

At one time, Crabtree sockets had their rocker switch flush when off.
Raised on. Which meant bashing it with a chair leg or whatever meant it
could only be switched off. Seemed quite sensible to me.

Is this why hospitals tend to have sockets without a switch so they can't accidently be switched off ?

"Rod Speed" wrote in message
...


"Jim GM4DHJ ..." wrote in message
...

"Jim GM4DHJ ..." wrote in message
...
do you think the merrycan way of switching with down off is more
sensibubble that what we do in the uk ?

I know it is harder to accidentally knock things up than down ......or is
there another reason?

Not convinced that there ever was a rational reason.

When something can be done two ways, you can be sure
some will choose to do it one way and some the other
way. Same with the side of the road you drive on and
dave the sot's story about swords is just plain troll****.
it was just those merrycans being bolshie and trying to annoy the English ,

"Harry Bloomfield" wrote in message
...
Jim GM4DHJ ... has brought this to us :
do you think the merrycan way of switching with down off is more
sensibubble that what we do in the uk ?

We have several opposing conventions. MCB's and CU main switches are up
for on. Only (1w) wall switches a down for on.

do you think that was to help the rcds with a bit of gravity ? ...

On 1/22/2019 10:03 AM, Max Demian wrote:

A green traffic signal should mean stop as green is a calm colour. Red
is fierce and should mean go.

Green chillies tend to be hotter than red ones, so the hot tap should be
green and the cold one red.


In the UK signs for emergency exits tend to be green - in the US,
they're red...

"Graham." wrote in message
...
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I see that as the same action, the latter having a modified toggle.

Someone told me that strictly speaking American three pin sockets
should be mounted with the earth pin down, but this is universally
ignored to make them look like a face.

There is nothing universal about that. There has in fact just
recently been a thread discussing that in alt.home.repair
and that makes it clear that there is no universal approach
to that in the USA.

I think they also mount them sideways in architraves.

We never (well hardly ever) mount our sockets otherwise than earth pin
up, but I have more than one Chinese wall-wart with labeling affixed
in an orientation that suggests some people in China think our sockets
are earth pin down.

Depends, we have done both over here. If you extended a toggle from the flat
of a rocker light switch up would be on, but on the other hand are you
really likely to be falling past a switch with the presence of mind to
switch it off which ever way it was?

Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Jim GM4DHJ ..." wrote in message
...
do you think the merrycan way of switching with down off is more
sensibubble that what we do in the uk ?

Well I mean, what is it in other countries, sideways?

Some old TVs used to have a toggle switch on the back some were up for on
some were down for on, it seemed to be dependent on whether the switch was
one way up or the other!
Some of the old metal mains power switches wer up for on but many others the
other way around. I never did understand why they could not have simply said
we want it this way and then everyone might be the same.
I bet the French have a unique take on this one.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Jim GM4DHJ ..." wrote in message
...

"Jim GM4DHJ ..." wrote in message
...
do you think the merrycan way of switching with down off is more
sensibubble that what we do in the uk ?

I know it is harder to accidentally knock things up than down ......or is
there another reason?

In article ,
NY wrote:
Maybe because people with red/green colour-blindness wouldn't be able to
distinguish between the two. If so, it's a classic case of dragging
everyone down to their level: make everyone suffer from "can't
distinguish" between two white lights for the deficiencies of the
minority.

By all means have "ON" and "OFF" on the lights, or different shapes of
light, but don't throw away colour just because some people can't use
it.

It's red and green which are the problem. A quite high percentage of the
male population have problems distinguishing between them under some
circumstances. It's just convention they are used for on and off. Other
colours would be more suitable.

--
*Time is the best teacher; unfortunately it kills all its students.

Dave Plowman London SW
To e-mail, change noise into sound.

On 22/01/2019 15:56, Jethro_uk wrote:
On Tue, 22 Jan 2019 10:31:32 -0500, S Viemeister wrote:

On 1/22/2019 10:03 AM, Max Demian wrote:

A green traffic signal should mean stop as green is a calm colour. Red
is fierce and should mean go.

Green chillies tend to be hotter than red ones, so the hot tap should
be green and the cold one red.


In the UK signs for emergency exits tend to be green - in the US,
they're red...

I think they're green in the EU generally ? Presumably there's a reg
somewhere ?

Is the Pope Catholic?

Isn't there something about which one is easier to see in a fire/smoke ?


also many people are drivers where green=go, red=no go

--
Robin
reply-to address is (intended to be) valid

On 22/01/2019 15:20, Jethro_uk wrote:

I think railway signalmen were onto that over a century previously, no ?
Railway signals using a colour *and* position to indicate status.


Didn't they have to change the meaning of mechanical signals? Signal
lever flag down initially meant that it was safe to proceed but the
signals had a tenancy to freeze in that position in winter weather.??

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On Tuesday, 22 January 2019 16:26:38 UTC, alan_m wrote:
On 22/01/2019 15:20, Jethro_uk wrote:

I think railway signalmen were onto that over a century previously, no ?
Railway signals using a colour *and* position to indicate status.


Didn't they have to change the meaning of mechanical signals? Signal
lever flag down initially meant that it was safe to proceed but the
signals had a tenancy to freeze in that position in winter weather.??

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

Is thre a convention for which (on mixer taps) that hot is on the left and cold on the right. I seemed to remmebr sweden being the oppersite way around.
A friend of mine just had their kitchen done and the fitter said I've just put yuor taps around the right way, and now after 20+ years of being around the 'wrong' way keeps turning the wrong tap on/off.

Jim GM4DHJ ... explained on 22/01/2019 :
do you think that was to help the rcds with a bit of gravity ? ...

Probably not, because it predates RCD's and even MCB's. Even the old
cast iron units were down/ off, to release the lids. Even the multi-
thousand amp isolators were down for off - though some of them took
quite an effort to operate, perhaps that was the idea? Easier to turn
off by swinging on a long bar with gravity to help, than trying to push
up to off.

"Max Demian" wrote in message news:-

Green chillies tend to be hotter than red ones,

I stand to be correctyed but I think you'll find that all the capsicums of which chillie
peppers
are one, ripen from green to red, to yellow, or to brown.

And get hotter, or sweeter in the case of sweet peppers, as they ripen


michael adams

....

"Harry Bloomfield" wrote in message
...
Jim GM4DHJ ... explained on 22/01/2019 :
do you think that was to help the rcds with a bit of gravity ? ...

Probably not, because it predates RCD's and even MCB's. Even the old cast
iron units were down/ off, to release the lids. Even the multi- thousand
amp isolators were down for off - though some of them took quite an effort
to operate, perhaps that was the idea? Easier to turn off by swinging on a
long bar with gravity to help, than trying to push up to off.

interesting

On Tuesday, 22 January 2019 08:55:14 UTC, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?

Down was always on in the UK But now it seems to be up for on.
Blasted EUSSR I 'spect.

Maybe to do with the mechanism of MCBs .The toggle doesn't have to be lifted to trip?

"harry" wrote in message
...
On Tuesday, 22 January 2019 08:55:14 UTC, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?

Down was always on in the UK But now it seems to be up for on.
Blasted EUSSR I 'spect.

Maybe to do with the mechanism of MCBs .The toggle doesn't have to be
lifted to trip?

Does gravity play any part in tripping an MCB or RCD? I thought you
tensioned a spring when you turned the switch on, and when the circuit
breaker tripped, a solenoid that was holding the switch on (counteracting
the spring) was released. The weight of the switch toggle would make a very
small difference, but much less than the tension of the spring.

On 22/01/2019 15:55, Brian Gaff wrote:
Well I mean, what is it in other countries, sideways?

Sideways in Japan.

--
Max Demian

On 22/01/2019 15:19, whisky-dave wrote:
On Tuesday, 22 January 2019 14:09:15 UTC, Dave Plowman (News) wrote:
In article ,
alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

At one time, Crabtree sockets had their rocker switch flush when off.
Raised on. Which meant bashing it with a chair leg or whatever meant it
could only be switched off. Seemed quite sensible to me.

Is this why hospitals tend to have sockets without a switch so they can't accidently be switched off ?

The cleaner just unplugs the life support to plug in the vac.

--
Max Demian

"michael adams" wrote in message
...

"Max Demian" wrote in message news:-

Green chillies tend to be hotter than red ones,

That’s bull****.
https://pepperhead.com/top-10-worlds-hottest-peppers/

I stand to be correctyed

You do indeed.

but I think you'll find that all the capsicums of which chillie peppers
are one, ripen from green to red, to yellow, or to brown.

Fraid not. And he isnt talking about capsicums anyway.

And get hotter, or sweeter in the case of sweet peppers, as they ripen

"Steve Walker" wrote in message
...
On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power to
the electronics was off! Guess how much damage was caused to plug in
boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies. Most
have wanted a green light for say a pump running ok and red for stopped or
failed, but some wanted the reverse, as they reasoned red for energised
and green for deenergised and therefore safer. A few even wanted a mix,
with green being for fail-closed valves that were in the open position and
for fail-open valves in the closed position, thus showing their
energisation rather than their positions.

SteveW

would they not have been better with black buttons on a black background
that light up black

On 22/01/2019 20:08, Jim GM4DHJ ... wrote:
"Steve Walker" wrote in message
...
On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the power to
the electronics was off! Guess how much damage was caused to plug in
boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies. Most
have wanted a green light for say a pump running ok and red for stopped or
failed, but some wanted the reverse, as they reasoned red for energised
and green for deenergised and therefore safer. A few even wanted a mix,
with green being for fail-closed valves that were in the open position and
for fail-open valves in the closed position, thus showing their
energisation rather than their positions.

SteveW

would they not have been better with black buttons on a black background
that light up black



"€˜Its the wild colour scheme that freaks me out, said Zaphod, whose
love affair with the ship had lasted almost three minutes into the
flight. 'Every time you try and operate these weird black controls that
are labeled in black on a black background, a little black light lights
up in black to let you know youve done it."

Zaphod Beeblebrox, The Restaurant At The End Of The Universe


--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 22/01/2019 13:14, newshound wrote:
On 22/01/2019 12:43, Steve Walker wrote:
On 22/01/2019 10:41, alan_m wrote:
On 22/01/2019 08:55, Jim GM4DHJ ... wrote:
do you think the merrycan way of switching with down off is more
sensibubble
that what we do in the uk ?




Two way switching uses both conventions.

Up/down os probably only really seen with older tooggle knobs on
switches. Most of us probably use sockets/switches where pressing the
lower part is on and pressing the upper part is off.

I once worked on a rack of equipment where the (military) customer
specified that a big red illuminated front panel light meant the
power to the electronics was off! Guess how much damage was caused to
plug in boards that didn't like to be hot plugged?

I have worked on designs for many oil and gas/chemicals companies.
Most have wanted a green light for say a pump running ok and red for
stopped or failed, but some wanted the reverse, as they reasoned red
for energised and green for deenergised and therefore safer. A few
even wanted a mix, with green being for fail-closed valves that were
in the open position and for fail-open valves in the closed position,
thus showing their energisation rather than their positions.

SteveW

I worked on a (nuclear) project with a lot of C&I in the noughties, the
designers initial design followed the green for good, red for bad
convention. However, when the mandatory Human Factors specialist came in
she insisted that only white lights were used.

It is a lot easier in the nuclear that I have seen and worked on, as
they have used a clear, standard document and so no-one is in doubt.
Still has to be run past Human Factors for confirmation though.

SteveW

On 22/01/2019 13:19, Tim Streater wrote:
In article ,
newshound wrote:

I worked on a (nuclear) project with a lot of C&I in the noughties,
the designers initial design followed the green for good, red for bad
convention. However, when the mandatory Human Factors specialist came
in she insisted that only white lights were used.

Why?

Because they have a clear standard - green is healthy, red is fault,
amber is a warning and white is a status (running for instance). All of
which means you cannot mistake a running indication for a healthy one or
vice-versa.

SteveW

On 22/01/2019 16:26, alan_m wrote:
On 22/01/2019 15:20, Jethro_uk wrote:

I think railway signalmen were onto that over a century previously, no ?
Railway signals using a colour *and* position to indicate status.


Didn't they have to change the meaning of mechanical signals? Signal
lever flag down initially meant that it was safe to proceed but the
signals had a tenancy to freeze in that position in winter weather.??

Nearly. Early on, they had to change from slotted post types where the
signal arm could freeze into the slot and they also had to mandate that
semaphore signals are kept at danger until a train approaches and were
then cleared for it.

Colour light signals, on the other hand, go green when the way ahead is
clear, regardless of how long it may be until the next train arrives.

Only later (BR days?) did upper quadrant semaphores become the standard
and even then, many of the former Great Western lines remained lower
quadrant.

SteveW

On 22/01/2019 15:56, Jethro_uk wrote:
On Tue, 22 Jan 2019 10:31:32 -0500, S Viemeister wrote:

On 1/22/2019 10:03 AM, Max Demian wrote:

A green traffic signal should mean stop as green is a calm colour. Red
is fierce and should mean go.

Green chillies tend to be hotter than red ones, so the hot tap should
be green and the cold one red.


In the UK signs for emergency exits tend to be green - in the US,
they're red...

I think they're green in the EU generally ? Presumably there's a reg
somewhere ?

Isn't there something about which one is easier to see in a fire/smoke ?

Probably more to do with Red being conventionally for warnings and
prohibitions, while Green is for informative items.

SteveW