In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
Recliner <recliner.usenet@gmail.com> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3 Feb 2022,
>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3 Feb 2022,
>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>
>>>>>>>>>> If you watch a stream of water cutting a channel, it’s usually the
>>>>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>>>>
>>>>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>>>>> more droop?
>>>>>>>>
>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>before the other side of the track. So the track is unsupported
>>>>>>>>under one side only; has non-zero weight and is not a rigid
>>>>>>>>structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>It's not Hornby "long straight" rigid track which can be used
>>>>>>>>as a bridge without any further support!
>>>>>>>
>>>>>>> Slewing requires a horizontal force perpendicular to the track, and what
>>>>>>> is providing that force. Drooping requires gravity acting downwards, and
>>>>>>> that's in plentiful supply.
>>>>>>
>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>> predominantly under one side only of the track.
>>>>>
>>>>> If you put a marble on a slope the only force according to Roland is just
>>>>> downwards gravity. Yet as the marble rolls down the hill it moves both
>>>>> vertically and horizontally.
>>>>>
>>>>> The eroded track length is effectively rolling down hill (well not rolling
>>>>> but you know what I mean).
>>>>
>>>> If the ground under the track has eroded by more than about six inches,
>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>> mid air.
>>>
>>> But at that point it had only eroded under *one side of the track*.
>>
>> Sure about that?
>>
>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>> 23_1643568862268.jpg>
>
>That was taken later.

What we need (and there won't be one, unless GA released some cab
footage) is a picture of the tracks before the train arrived.

The one linked above doesn't show anything like as much of a kink as
<https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
which suggests it was moving left and right quite a bit.

I still think the ianhardie kink is a result of the track buckling from
the braking force of the train, not sliding sideways downhill.
--
Roland Perry

ColinR <rail@greystane.shetland.co.uk> wrote:
> On 06/02/2022 09:27, Roland Perry wrote:
>> In message <sthl4p$dtg$1@dont-email.me>, at 22:31:53 on Thu, 3 Feb 2022,
>> Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>
>>>> Good grief, has logic silenced the Perry??
>>>
>>> Unlikely.  He saves up his responses to reply in a batch.  Expect a
>>> flurry
>>> in the morning.
>>
>> A flurry some morning. I'm afraid I don't have the time or energy to
>> reply in real time.
>
> Oops, the box has opened.....
>

Roland seems to think replying is quicker and easier if it's done later.
I'm not quite sure why that is.

But it certainly gives his RP™ arguments a staccato quality.

Roland Perry <roland@perry.co.uk> wrote:
> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
> Recliner <recliner.usenet@gmail.com> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3 Feb 2022,
>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3 Feb 2022,
>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>
>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s usually the
>>>>>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>>>>>
>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>>>>>> more droop?
>>>>>>>>>
>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>> as a bridge without any further support!
>>>>>>>>
>>>>>>>> Slewing requires a horizontal force perpendicular to the track, and what
>>>>>>>> is providing that force. Drooping requires gravity acting downwards, and
>>>>>>>> that's in plentiful supply.
>>>>>>>
>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>> predominantly under one side only of the track.
>>>>>>
>>>>>> If you put a marble on a slope the only force according to Roland is just
>>>>>> downwards gravity. Yet as the marble rolls down the hill it moves both
>>>>>> vertically and horizontally.
>>>>>>
>>>>>> The eroded track length is effectively rolling down hill (well not rolling
>>>>>> but you know what I mean).
>>>>>
>>>>> If the ground under the track has eroded by more than about six inches,
>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>> mid air.
>>>>
>>>> But at that point it had only eroded under *one side of the track*.
>>>
>>> Sure about that?
>>>
>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>> 23_1643568862268.jpg>
>>
>> That was taken later.
>
> What we need (and there won't be one, unless GA released some cab
> footage) is a picture of the tracks before the train arrived.
>
> The one linked above doesn't show anything like as much of a kink as
> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
> which suggests it was moving left and right quite a bit.
>
> I still think the ianhardie kink is a result of the track buckling from
> the braking force of the train, not sliding sideways downhill.

Why would braking cause a track to buckle sideways? CWR is under tension.

In message <stoe6i$du1$1@dont-email.me>, at 12:16:18 on Sun, 6 Feb 2022,
Recliner <recliner.usenet@gmail.com> remarked:
>ColinR <rail@greystane.shetland.co.uk> wrote:
>> On 06/02/2022 09:27, Roland Perry wrote:
>>> In message <sthl4p$dtg$1@dont-email.me>, at 22:31:53 on Thu, 3 Feb 2022,
>>> Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>
>>>>> Good grief, has logic silenced the Perry??
>>>>
>>>> Unlikely.  He saves up his responses to reply in a batch.  Expect a
>>>> flurry
>>>> in the morning.
>>>
>>> A flurry some morning. I'm afraid I don't have the time or energy to
>>> reply in real time.
>>
>> Oops, the box has opened.....
>>
>
>Roland seems to think replying is quicker and easier if it's done later.
>I'm not quite sure why that is.

Because after being dog-piled by several correspondents, it's quicker
and easier to answer them all at one sitting, which won't necessarily be
on that very same day.

Currently I'm posting in three or four threads here (and maybe a dozen
elsewhere), and would prefer to only have to think about a few themes on
any particular day. There's no particular reason the ones on ukr deserve
special priority.
--
Roland Perry

In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
Recliner <recliner.usenet@gmail.com> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>> Recliner <recliner.usenet@gmail.com> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3 Feb 2022,
>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>Feb 2022,
>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>
>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>
>>>>>>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>>>>>>
>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>>>>>>> more droop?
>>>>>>>>>>
>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>
>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>track, and what
>>>>>>>>> is providing that force. Drooping requires gravity acting
>>>>>>>>>downwards, and
>>>>>>>>> that's in plentiful supply.
>>>>>>>>
>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>> predominantly under one side only of the track.
>>>>>>>
>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>the hill it moves both vertically and horizontally.
>>>>>>>
>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>not rolling but you know what I mean).
>>>>>>
>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>> mid air.
>>>>>
>>>>> But at that point it had only eroded under *one side of the track*.
>>>>
>>>> Sure about that?
>>>>
>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>> 23_1643568862268.jpg>
>>>
>>> That was taken later.
>>
>> What we need (and there won't be one, unless GA released some cab
>> footage) is a picture of the tracks before the train arrived.
>>
>> The one linked above doesn't show anything like as much of a kink as
>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>> which suggests it was moving left and right quite a bit.
>>
>> I still think the ianhardie kink is a result of the track buckling from
>> the braking force of the train, not sliding sideways downhill.
>
>Why would braking cause a track to buckle sideways? CWR is under tension.

If it's under tension [and yes, I agree it is, and underpins my own
theory], how can it do a crazy zig-zag buckle in the way that's being
claimed, when the only force on it is gravity downwards - and what that
would cause is just a small droop.
--
Roland Perry

On Sun, 6 Feb 2022 13:42:18 +0000, Roland Perry <roland@perry.co.uk> wrote:

>In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>Recliner <recliner.usenet@gmail.com> remarked:
>>Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3 Feb 2022,
>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>Feb 2022,
>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>
>>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>>
>>>>>>>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>>>>>>>
>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>>>>>>>> more droop?
>>>>>>>>>>>
>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>
>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>track, and what
>>>>>>>>>> is providing that force. Drooping requires gravity acting
>>>>>>>>>>downwards, and
>>>>>>>>>> that's in plentiful supply.
>>>>>>>>>
>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>
>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>the hill it moves both vertically and horizontally.
>>>>>>>>
>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>not rolling but you know what I mean).
>>>>>>>
>>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>>> mid air.
>>>>>>
>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>
>>>>> Sure about that?
>>>>>
>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>> 23_1643568862268.jpg>
>>>>
>>>> That was taken later.
>>>
>>> What we need (and there won't be one, unless GA released some cab
>>> footage) is a picture of the tracks before the train arrived.
>>>
>>> The one linked above doesn't show anything like as much of a kink as
>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>> which suggests it was moving left and right quite a bit.
>>>
>>> I still think the ianhardie kink is a result of the track buckling from
>>> the braking force of the train, not sliding sideways downhill.
>>
>>Why would braking cause a track to buckle sideways? CWR is under tension.
>
>If it's under tension [and yes, I agree it is, and underpins my own
>theory], how can it do a crazy zig-zag buckle in the way that's being
>claimed, when the only force on it is gravity downwards - and what that
>would cause is just a small droop.

The force was the sideways slippage of the earth in which the sleepers were embedded. You seem to be obsessed with the
notion that the ground simply descended downwards in a sheer vertical plane, but that clearly isn't what happened. It
was eroded from one side, and gradually slipped down in that direction. That's when the train arrived.

Ultimately, all the earth under the track washed away, removing the lateral force, so the horizontal displacement of the
track would cease, and instead, the track sagged into the void beneath (similar to the end state at Dawlish).

Roland Perry <roland@perry.co.uk> wrote:
> In message <sth6b9$35c$1@dont-email.me>, at 18:19:21 on Thu, 3 Feb 2022,
> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <stg84j$cr0$2@dont-email.me>, at 09:43:47 on Thu, 3 Feb 2022,
>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>
>>>>>> If you watch a stream of water cutting a channel, it’s usually the
>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>
>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>> more droop?
>>>>
>>>> The collapsing embankment would first have slid sideways into the water,
>>>> rather than descending vertically. There wasn't a through flow of water at
>>>> that stage, so no upstream or downstream.
>>>
>>> As soon as the embankment has crumbled below the level of the sleepers,
>>> which isn't much, then the only force on the track is gravity -
>>> downwards.
>>
>> The crumbling of the embankment will have been a gradual process, not
>> immediate across the entire width; for part of that time, one side of the
>> track was supported and the other side was unsupported. The unsupported
>> side gets affected by gravity, the track tilts and gravity once again
>> affects it and it slides sideways a certain extent.
>>
>> You can see that clearly in this photo
>> <https://twitter.com/greatnorthroad2/status/1487801794327728129?s=21>
>
> All we can see there is what happened as a result of the train arriving,
> not what it looked like *before* the train arrived.

You can also see missing ballast on the river side of the line, but ballast
remaining across the rest of the formation, suggesting that that side of
the line would have lost support before and/or more than other side.

Consider also a pair of rails in tension across a gap which is wider on one
side, next to the river, than on the other. They’d be pretty much
straight. Now add the weight of the train. Which of the rails will sag
more? What will be the overall resulting movement?

Sam

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

In message <qrkvvgpbhdegch0llbm05vpdtoq366vme0@4ax.com>, at 14:02:09 on
Sun, 6 Feb 2022, Recliner <recliner.usenet@gmail.com> remarked:
>On Sun, 6 Feb 2022 13:42:18 +0000, Roland Perry <roland@perry.co.uk> wrote:
>
>>In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>>Recliner <recliner.usenet@gmail.com> remarked:
>>>Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3
>>>>>>>>Feb 2022,
>>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>>Feb 2022,
>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>>
>>>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> upstream end of the channel that gets the most energetic
>>>>>>>>>>>>>>erosion.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream),
>>>>>>>>>>>>>
>>>>>>>>>>>>> more droop?
>>>>>>>>>>>>
>>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>>
>>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>>track, and what is providing that force. Drooping requires
>>>>>>>>>>> downwards, and that's in plentiful supply.
>>>>>>>>>>
>>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>>
>>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>>Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>>the hill it moves both vertically and horizontally.
>>>>>>>>>
>>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>>not rolling but you know what I mean).
>>>>>>>>
>>>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>>>> mid air.
>>>>>>>
>>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>>
>>>>>> Sure about that?
>>>>>>
>>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>>> 23_1643568862268.jpg>
>>>>>
>>>>> That was taken later.
>>>>
>>>> What we need (and there won't be one, unless GA released some cab
>>>> footage) is a picture of the tracks before the train arrived.
>>>>
>>>> The one linked above doesn't show anything like as much of a kink as
>>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>>> which suggests it was moving left and right quite a bit.
>>>>
>>>> I still think the ianhardie kink is a result of the track buckling from
>>>> the braking force of the train, not sliding sideways downhill.
>>>
>>>Why would braking cause a track to buckle sideways? CWR is under tension.
>>
>>If it's under tension [and yes, I agree it is, and underpins my own
>>theory], how can it do a crazy zig-zag buckle in the way that's being
>>claimed, when the only force on it is gravity downwards - and what that
>>would cause is just a small droop.
>
>The force was the sideways slippage of the earth in which the sleepers
>were embedded.

Why didn't the ballast and sleepers simply skid over the sideways moving
earth, which was very soon below the level it was capable of exerting a
force on them anyway.

>You seem to be obsessed

No, just sticking with the soil mechanics and structural engineering
training I have received.
--
Roland Perry

In message <stos6e$klt$1@dont-email.me>, at 16:15:10 on Sun, 6 Feb 2022,
Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <sth6b9$35c$1@dont-email.me>, at 18:19:21 on Thu, 3 Feb 2022,
>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <stg84j$cr0$2@dont-email.me>, at 09:43:47 on Thu, 3 Feb 2022,
>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>
>>>>>>> If you watch a stream of water cutting a channel, it’s usually the
>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>
>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>> more droop?
>>>>>
>>>>> The collapsing embankment would first have slid sideways into the water,
>>>>> rather than descending vertically. There wasn't a through flow of water at
>>>>> that stage, so no upstream or downstream.
>>>>
>>>> As soon as the embankment has crumbled below the level of the sleepers,
>>>> which isn't much, then the only force on the track is gravity -
>>>> downwards.
>>>
>>> The crumbling of the embankment will have been a gradual process, not
>>> immediate across the entire width; for part of that time, one side of the
>>> track was supported and the other side was unsupported. The unsupported
>>> side gets affected by gravity, the track tilts and gravity once again
>>> affects it and it slides sideways a certain extent.
>>>
>>> You can see that clearly in this photo
>>> <https://twitter.com/greatnorthroad2/status/1487801794327728129?s=21>
>>
>> All we can see there is what happened as a result of the train arriving,
>> not what it looked like *before* the train arrived.
>
>You can also see missing ballast on the river side of the line, but ballast
>remaining across the rest of the formation, suggesting that that side of
>the line would have lost support before and/or more than other side.
>
>Consider also a pair of rails in tension across a gap which is wider on one
>side, next to the river, than on the other. They’d be pretty much
>straight.

Exactly.

>Now add the weight of the train.

The suggestion was that the driver saw the sideways zig-zag, and that
was (before the arrived) the trigger to stop. I think he saw a dip, not
a sideways displacement.

> Which of the rails will sag more? What will be the overall resulting
>movement?

Not into a sideways zig-zag because of the weight alone, my proposition
is the *braking* force of the train pushed the track slightly forwards,
hence causing the sideways buckling (the track beyond the breach being
held longitudinally in place buy its undisturbed ballast).
--
Roland Perry

Roland Perry <roland@perry.co.uk> wrote:
> In message <qrkvvgpbhdegch0llbm05vpdtoq366vme0@4ax.com>, at 14:02:09 on
> Sun, 6 Feb 2022, Recliner <recliner.usenet@gmail.com> remarked:
>> On Sun, 6 Feb 2022 13:42:18 +0000, Roland Perry <roland@perry.co.uk> wrote:
>>
>>> In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3
>>>>>>>>> Feb 2022,
>>>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>>> Feb 2022,
>>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>>>
>>>>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> upstream end of the channel that gets the most energetic
>>>>>>>>>>>>>>> erosion.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream),
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> more droop?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>>>
>>>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>>> track, and what is providing that force. Drooping requires
>>>>>>>>>>>> downwards, and that's in plentiful supply.
>>>>>>>>>>>
>>>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>>>
>>>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>>> Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>>> the hill it moves both vertically and horizontally.
>>>>>>>>>>
>>>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>>> not rolling but you know what I mean).
>>>>>>>>>
>>>>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>>>>> mid air.
>>>>>>>>
>>>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>>>
>>>>>>> Sure about that?
>>>>>>>
>>>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>>>> 23_1643568862268.jpg>
>>>>>>
>>>>>> That was taken later.
>>>>>
>>>>> What we need (and there won't be one, unless GA released some cab
>>>>> footage) is a picture of the tracks before the train arrived.
>>>>>
>>>>> The one linked above doesn't show anything like as much of a kink as
>>>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>>>> which suggests it was moving left and right quite a bit.
>>>>>
>>>>> I still think the ianhardie kink is a result of the track buckling from
>>>>> the braking force of the train, not sliding sideways downhill.
>>>>
>>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>>
>>> If it's under tension [and yes, I agree it is, and underpins my own
>>> theory], how can it do a crazy zig-zag buckle in the way that's being
>>> claimed, when the only force on it is gravity downwards - and what that
>>> would cause is just a small droop.
>>
>> The force was the sideways slippage of the earth in which the sleepers
>> were embedded.
>
> Why didn't the ballast and sleepers simply skid over the sideways moving
> earth,

The ballast and track don't sit lightly on top of a separate slippery block
of earth.

> which was very soon below the level it was capable of exerting a
> force on them anyway.

How soon is 'soon'? The train clearly arrived early in the transition.

>
>> You seem to be obsessed
>
> No, just sticking with the soil mechanics and structural engineering
> training I have received.

Ah, another of your many areas of expertise!

Recliner <recliner.usenet@gmail.com> wrote:

>
> CWR is under tension.
>

That depends on the ambient temperature. So at the moment, very likely yes,
it's in tension.

When the ambient temperature is higher, though, CWR will likely be under
compression; that's why it's (a) clamped very tightly to the sleepers (b)
the ballast shoulders at the ends of the sleepers are a lot higher than in
years past (c) certain areas of trackwork have yellow things ("Lateral
Resistance Plates
<https://twitter.com/garethdennis/status/1014886371775995904?s=21>) bolted
to the sleepers which project downward into the ballast to prevent sideways
movement.

If the CWR isn't correctly pre-tensioned after engineering work, then if
rail temperature gets too high, the compression in the rail becomes too
high for the measures to contain it, and the rail risks buckling. Hence the
various speed restrictions in high temperatures.

Anna Noyd-Dryver

Roland Perry <roland@perry.co.uk> wrote:
> In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
> Recliner <recliner.usenet@gmail.com> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3 Feb 2022,
>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>> Feb 2022,
>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>
>>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>>
>>>>>>>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>>>>>>>
>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>>>>>>>> more droop?
>>>>>>>>>>>
>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>
>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>> track, and what
>>>>>>>>>> is providing that force. Drooping requires gravity acting
>>>>>>>>>> downwards, and
>>>>>>>>>> that's in plentiful supply.
>>>>>>>>>
>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>
>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>> Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>> the hill it moves both vertically and horizontally.
>>>>>>>>
>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>> not rolling but you know what I mean).
>>>>>>>
>>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>>> mid air.
>>>>>>
>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>
>>>>> Sure about that?
>>>>>
>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>> 23_1643568862268.jpg>
>>>>
>>>> That was taken later.
>>>
>>> What we need (and there won't be one, unless GA released some cab
>>> footage) is a picture of the tracks before the train arrived.
>>>
>>> The one linked above doesn't show anything like as much of a kink as
>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>> which suggests it was moving left and right quite a bit.
>>>
>>> I still think the ianhardie kink is a result of the track buckling from
>>> the braking force of the train, not sliding sideways downhill.
>>
>> Why would braking cause a track to buckle sideways? CWR is under tension.
>
> If it's under tension [and yes, I agree it is, and underpins my own
> theory], how can it do a crazy zig-zag buckle in the way that's being
> claimed, when the only force on it is gravity downwards - and what that
> would cause is just a small droop.

Because it's quite heavy, and not designed to support its own weight
unsupported over such a long distance.

Anna Noyd-Dryver

Roland Perry <roland@perry.co.uk> wrote:
> In message <stos6e$klt$1@dont-email.me>, at 16:15:10 on Sun, 6 Feb 2022,
> Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sth6b9$35c$1@dont-email.me>, at 18:19:21 on Thu, 3 Feb 2022,
>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <stg84j$cr0$2@dont-email.me>, at 09:43:47 on Thu, 3 Feb 2022,
>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>
>>>>>>>> If you watch a stream of water cutting a channel, it’s usually the
>>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>>
>>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>>> more droop?
>>>>>>
>>>>>> The collapsing embankment would first have slid sideways into the water,
>>>>>> rather than descending vertically. There wasn't a through flow of water at
>>>>>> that stage, so no upstream or downstream.
>>>>>
>>>>> As soon as the embankment has crumbled below the level of the sleepers,
>>>>> which isn't much, then the only force on the track is gravity -
>>>>> downwards.
>>>>
>>>> The crumbling of the embankment will have been a gradual process, not
>>>> immediate across the entire width; for part of that time, one side of the
>>>> track was supported and the other side was unsupported. The unsupported
>>>> side gets affected by gravity, the track tilts and gravity once again
>>>> affects it and it slides sideways a certain extent.
>>>>
>>>> You can see that clearly in this photo
>>>> <https://twitter.com/greatnorthroad2/status/1487801794327728129?s=21>
>>>
>>> All we can see there is what happened as a result of the train arriving,
>>> not what it looked like *before* the train arrived.
>>
>> You can also see missing ballast on the river side of the line, but ballast
>> remaining across the rest of the formation, suggesting that that side of
>> the line would have lost support before and/or more than other side.
>>
>> Consider also a pair of rails in tension across a gap which is wider on one
>> side, next to the river, than on the other. They’d be pretty much
>> straight.
>
> Exactly.
>
>> Now add the weight of the train.
>
> The suggestion was that the driver saw the sideways zig-zag, and that
> was (before the arrived) the trigger to stop. I think he saw a dip, not
> a sideways displacement.
>

Where was that suggested? I don't recall reading it here.

>> Which of the rails will sag more? What will be the overall resulting
>> movement?
>

In message <stpem1$93h$4@dont-email.me>, at 21:30:41 on Sun, 6 Feb 2022,
Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <stos6e$klt$1@dont-email.me>, at 16:15:10 on Sun, 6 Feb 2022,
>> Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sth6b9$35c$1@dont-email.me>, at 18:19:21 on Thu, 3 Feb 2022,
>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <stg84j$cr0$2@dont-email.me>, at 09:43:47 on Thu, 3 Feb 2022,
>>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>>
>>>>>>>>> If you watch a stream of water cutting a channel, it’s usually the
>>>>>>>>> upstream end of the channel that gets the most energetic erosion.
>>>>>>>>
>>>>>>>> Yes, but why does that cause lateral slewing (upstream), rather than
>>>>>>>> more droop?
>>>>>>>
>>>>>>> The collapsing embankment would first have slid sideways into the water,
>>>>>>> rather than descending vertically. There wasn't a through flow
>>>>>>>of water at
>>>>>>> that stage, so no upstream or downstream.
>>>>>>
>>>>>> As soon as the embankment has crumbled below the level of the sleepers,
>>>>>> which isn't much, then the only force on the track is gravity -
>>>>>> downwards.
>>>>>
>>>>> The crumbling of the embankment will have been a gradual process, not
>>>>> immediate across the entire width; for part of that time, one side of the
>>>>> track was supported and the other side was unsupported. The unsupported
>>>>> side gets affected by gravity, the track tilts and gravity once again
>>>>> affects it and it slides sideways a certain extent.
>>>>>
>>>>> You can see that clearly in this photo
>>>>> <https://twitter.com/greatnorthroad2/status/1487801794327728129?s=21>
>>>>
>>>> All we can see there is what happened as a result of the train arriving,
>>>> not what it looked like *before* the train arrived.
>>>
>>> You can also see missing ballast on the river side of the line, but ballast
>>> remaining across the rest of the formation, suggesting that that side of
>>> the line would have lost support before and/or more than other side.
>>>
>>> Consider also a pair of rails in tension across a gap which is wider on one
>>> side, next to the river, than on the other. They’d be pretty much
>>> straight.
>>
>> Exactly.
>>
>>> Now add the weight of the train.
>>
>> The suggestion was that the driver saw the sideways zig-zag, and that
>> was (before the arrived) the trigger to stop. I think he saw a dip, not
>> a sideways displacement.
>
>Where was that suggested? I don't recall reading it here.

It's the coverage which says in effect "train narrowly avoids derailing
on zig-zag track". I'm not suggesting it wouldn't have come to grief on
sagging track, but it looks to me as if the zig-zag was caused by the
braking of the train.

>>> Which of the rails will sag more? What will be the overall resulting
>>> movement?

--
Roland Perry

In message <stpem1$93h$3@dont-email.me>, at 21:30:41 on Sun, 6 Feb 2022,
Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>> Recliner <recliner.usenet@gmail.com> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3
>>>>>>>>Feb 2022,
>>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>> Feb 2022,
>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>>
>>>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> upstream end of the channel that gets the most energetic
>>>>>>>>>>>>>>erosion.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream),
>>>>>>>>>>>>>
>>>>>>>>>>>>> more droop?
>>>>>>>>>>>>
>>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>>
>>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>> track, and what
>>>>>>>>>>> is providing that force. Drooping requires gravity acting
>>>>>>>>>>> downwards, and
>>>>>>>>>>> that's in plentiful supply.
>>>>>>>>>>
>>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>>
>>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>> Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>> the hill it moves both vertically and horizontally.
>>>>>>>>>
>>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>> not rolling but you know what I mean).
>>>>>>>>
>>>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>>>> mid air.
>>>>>>>
>>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>>
>>>>>> Sure about that?
>>>>>>
>>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>>> 23_1643568862268.jpg>
>>>>>
>>>>> That was taken later.
>>>>
>>>> What we need (and there won't be one, unless GA released some cab
>>>> footage) is a picture of the tracks before the train arrived.
>>>>
>>>> The one linked above doesn't show anything like as much of a kink as
>>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>>> which suggests it was moving left and right quite a bit.
>>>>
>>>> I still think the ianhardie kink is a result of the track buckling from
>>>> the braking force of the train, not sliding sideways downhill.
>>>
>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>
>> If it's under tension [and yes, I agree it is, and underpins my own
>> theory], how can it do a crazy zig-zag buckle in the way that's being
>> claimed, when the only force on it is gravity downwards - and what that
>> would cause is just a small droop.
>
>Because it's quite heavy, and not designed to support its own weight
>unsupported over such a long distance.

So it droops (incidentally increasing the tension in the rails), it
doesn't head off sideways against the tension of the rails holding
it in a straight line.
--
Roland Perry

Roland Perry <roland@perry.co.uk> wrote:
> In message <stpem1$93h$3@dont-email.me>, at 21:30:41 on Sun, 6 Feb 2022,
> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3
>>>>>>>>> Feb 2022,
>>>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>>> Feb 2022,
>>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>>>
>>>>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> upstream end of the channel that gets the most energetic
>>>>>>>>>>>>>>> erosion.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream),
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> more droop?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>>>
>>>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>>> track, and what
>>>>>>>>>>>> is providing that force. Drooping requires gravity acting
>>>>>>>>>>>> downwards, and
>>>>>>>>>>>> that's in plentiful supply.
>>>>>>>>>>>
>>>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>>>
>>>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>>> Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>>> the hill it moves both vertically and horizontally.
>>>>>>>>>>
>>>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>>> not rolling but you know what I mean).
>>>>>>>>>
>>>>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>>>>> mid air.
>>>>>>>>
>>>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>>>
>>>>>>> Sure about that?
>>>>>>>
>>>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>>>> 23_1643568862268.jpg>
>>>>>>
>>>>>> That was taken later.
>>>>>
>>>>> What we need (and there won't be one, unless GA released some cab
>>>>> footage) is a picture of the tracks before the train arrived.
>>>>>
>>>>> The one linked above doesn't show anything like as much of a kink as
>>>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>>>> which suggests it was moving left and right quite a bit.
>>>>>
>>>>> I still think the ianhardie kink is a result of the track buckling from
>>>>> the braking force of the train, not sliding sideways downhill.
>>>>
>>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>>
>>> If it's under tension [and yes, I agree it is, and underpins my own
>>> theory], how can it do a crazy zig-zag buckle in the way that's being
>>> claimed, when the only force on it is gravity downwards - and what that
>>> would cause is just a small droop.
>>
>> Because it's quite heavy, and not designed to support its own weight
>> unsupported over such a long distance.
>
> So it droops (incidentally increasing the tension in the rails), it
> doesn't head off sideways against the tension of the rails holding
> it in a straight line.

The slewing was caused by the ground shifting sideways as it slipped down
the temporary slope.

Several of us have told you this multiple times, and the early pictures
make this mechanism clear. I think we have to conclude that you are
demonstrating yet another failure to comprehend, simply because you cannot
admit to ever being wrong. It seems really pointless trying to explain
something so basic to someone as stubbornly ignorant as you.

On 07/02/2022 10:33, Recliner wrote:
> Roland Perry <roland@perry.co.uk> wrote:
>> In message <stpem1$93h$3@dont-email.me>, at 21:30:41 on Sun, 6 Feb 2022,
>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6 Feb 2022,
>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3
>>>>>>>>>> Feb 2022,
>>>>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>>>> Feb 2022,
>>>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> If you watch a stream of water cutting a channel, it’s
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> upstream end of the channel that gets the most energetic
>>>>>>>>>>>>>>>> erosion.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream),
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> more droop?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>>>>
>>>>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>>>> track, and what
>>>>>>>>>>>>> is providing that force. Drooping requires gravity acting
>>>>>>>>>>>>> downwards, and
>>>>>>>>>>>>> that's in plentiful supply.
>>>>>>>>>>>>
>>>>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>>>>
>>>>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>>>> Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>>>> the hill it moves both vertically and horizontally.
>>>>>>>>>>>
>>>>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>>>> not rolling but you know what I mean).
>>>>>>>>>>
>>>>>>>>>> If the ground under the track has eroded by more than about six inches,
>>>>>>>>>> there isn't a slope for the track to slide down. It's just hanging in
>>>>>>>>>> mid air.
>>>>>>>>>
>>>>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>>>>
>>>>>>>> Sure about that?
>>>>>>>>
>>>>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>>>>> 23_1643568862268.jpg>
>>>>>>>
>>>>>>> That was taken later.
>>>>>>
>>>>>> What we need (and there won't be one, unless GA released some cab
>>>>>> footage) is a picture of the tracks before the train arrived.
>>>>>>
>>>>>> The one linked above doesn't show anything like as much of a kink as
>>>>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>>>>> which suggests it was moving left and right quite a bit.
>>>>>>
>>>>>> I still think the ianhardie kink is a result of the track buckling from
>>>>>> the braking force of the train, not sliding sideways downhill.
>>>>>
>>>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>>>
>>>> If it's under tension [and yes, I agree it is, and underpins my own
>>>> theory], how can it do a crazy zig-zag buckle in the way that's being
>>>> claimed, when the only force on it is gravity downwards - and what that
>>>> would cause is just a small droop.
>>>
>>> Because it's quite heavy, and not designed to support its own weight
>>> unsupported over such a long distance.
>>
>> So it droops (incidentally increasing the tension in the rails), it
>> doesn't head off sideways against the tension of the rails holding
>> it in a straight line.
>
> The slewing was caused by the ground shifting sideways as it slipped down
> the temporary slope.
>
> Several of us have told you this multiple times, and the early pictures
> make this mechanism clear. I think we have to conclude that you are
> demonstrating yet another failure to comprehend, simply because you cannot
> admit to ever being wrong. It seems really pointless trying to explain
> something so basic to someone as stubbornly ignorant as you.
>
Yes it does seem he has reverted to his previous troll persona of
'Meldrew of Melbourn'

ian

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On 07/02/2022 11:27, ianb wrote:
> On 07/02/2022 10:33, Recliner wrote:
>> The slewing was caused by the ground shifting sideways as it slipped down
>> the temporary slope.
>>
>> Several of us have told you this multiple times, and the early pictures
>> make this mechanism clear. I think we have to conclude that you are
>> demonstrating yet another failure to comprehend, simply because you
>> cannot
>> admit to ever being wrong. It seems really pointless trying to explain
>> something so basic to someone as stubbornly ignorant as you.
>>
> Yes it does seem he has reverted to his previous troll persona of
> 'Meldrew of Melbourn'

We've told him, but he doesn't believe it?

In message <stpc4b$kme$1@dont-email.me>, at 20:47:07 on Sun, 6 Feb 2022,
Recliner <recliner.usenet@gmail.com> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <qrkvvgpbhdegch0llbm05vpdtoq366vme0@4ax.com>, at 14:02:09 on
>> Sun, 6 Feb 2022, Recliner <recliner.usenet@gmail.com> remarked:
>>> On Sun, 6 Feb 2022 13:42:18 +0000, Roland Perry <roland@perry.co.uk> wrote:
>>>
>>>> In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6
>>>>>>>>Feb 2022,
>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3
>>>>>>>>>> Feb 2022,
>>>>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>>>> Feb 2022,
>>>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> If you watch a stream of water cutting a channel,
>>>>>>>>>>>>>>>> upstream end of the channel that gets the most
>>>>>>>>>>>>>>>> erosion.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream),
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> more droop?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>>>>
>>>>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>>>> track, and what is providing that force. Drooping requires
>>>>>>>>>>>>> downwards, and that's in plentiful supply.
>>>>>>>>>>>>
>>>>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>>>>
>>>>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>>>> Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>>>> the hill it moves both vertically and horizontally.
>>>>>>>>>>>
>>>>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>>>> not rolling but you know what I mean).
>>>>>>>>>>
>>>>>>>>>> If the ground under the track has eroded by more than about
>>>>>>>>>>six inches, there isn't a slope for the track to slide down.
>>>>>>>>>>It's just hanging in mid air.
>>>>>>>>>
>>>>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>>>>
>>>>>>>> Sure about that?
>>>>>>>>
>>>>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>>>>> 23_1643568862268.jpg>
>>>>>>>
>>>>>>> That was taken later.
>>>>>>
>>>>>> What we need (and there won't be one, unless GA released some cab
>>>>>> footage) is a picture of the tracks before the train arrived.
>>>>>>
>>>>>> The one linked above doesn't show anything like as much of a kink as
>>>>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>>>>> which suggests it was moving left and right quite a bit.
>>>>>>
>>>>>> I still think the ianhardie kink is a result of the track buckling from
>>>>>> the braking force of the train, not sliding sideways downhill.
>>>>>
>>>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>>>
>>>> If it's under tension [and yes, I agree it is, and underpins my own
>>>> theory], how can it do a crazy zig-zag buckle in the way that's being
>>>> claimed, when the only force on it is gravity downwards - and what that
>>>> would cause is just a small droop.
>>>
>>> The force was the sideways slippage of the earth in which the sleepers
>>> were embedded.
>>
>> Why didn't the ballast and sleepers simply skid over the sideways moving
>> earth,
>
>The ballast and track don't sit lightly on top of a separate slippery block
>of earth.

Indeed, that earth has been eroded away.

>> which was very soon below the level it was capable of exerting a
>> force on them anyway.
>
>How soon is 'soon'? The train clearly arrived early in the transition.

Why is that clear?

>>> You seem to be obsessed
>>
>> No, just sticking with the soil mechanics and structural engineering
>> training I have received.
>
>Ah, another of your many areas of expertise!

Yes, it is! Quite a long time ago now, but I don't think any of the
basic principles have hanged.
--
Roland Perry

In message <stqsh5$76e$1@dont-email.me>, at 10:33:09 on Mon, 7 Feb 2022,
Recliner <recliner.usenet@gmail.com> remarked:
>>>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>>>
>>>> If it's under tension [and yes, I agree it is, and underpins my own
>>>> theory], how can it do a crazy zig-zag buckle in the way that's being
>>>> claimed, when the only force on it is gravity downwards - and what that
>>>> would cause is just a small droop.
>>>
>>> Because it's quite heavy, and not designed to support its own weight
>>> unsupported over such a long distance.
>>
>> So it droops (incidentally increasing the tension in the rails), it
>> doesn't head off sideways against the tension of the rails holding
>> it in a straight line.
>
>The slewing was caused by the ground shifting sideways as it slipped down
>the temporary slope.

So now we do have a slippery slope. Make you mind up!

>Several of us have told you this multiple times, and the early pictures
>make this mechanism clear.

Can you show me an early picture without the train present. That would
help me change my mind.

>I think we have to conclude that you are demonstrating yet another
>failure to comprehend, simply because you cannot admit to ever being
>wrong. It seems really pointless trying to explain something so basic
>to someone as stubbornly ignorant as you.

As I said days ago (and nevertheless you don't appear to want to let go)
I'm simply disagreeing with your analysis of the engineering of the
situation. Find that picture without the train, and we can have another
go at reaching a consensus.
--
Roland Perry

In message <stqvnh$uad$1@dont-email.me>, at 11:27:45 on Mon, 7 Feb 2022,
ianb <i.bidwell@ntlworld.com> remarked:

>Yes it does seem he has reverted to his previous troll persona of
>'Meldrew of Melbourn'

Meldrew of Meldreth, actually.

But no-one here has yet managed to explain how two tensioned rails
strung across a gap would start moving sideways (with no force on them
from the landslide) hence increasing that tension in the rails (further
distance to cover due to the pair of curves in the zig-zag. Surely they
would snap back to being straight across.
--
Roland Perry

On Mon, 7 Feb 2022 13:16:08 +0000, Roland Perry <roland@perry.co.uk> wrote:

>In message <stpc4b$kme$1@dont-email.me>, at 20:47:07 on Sun, 6 Feb 2022,
>Recliner <recliner.usenet@gmail.com> remarked:
>>Roland Perry <roland@perry.co.uk> wrote:
>>> In message <qrkvvgpbhdegch0llbm05vpdtoq366vme0@4ax.com>, at 14:02:09 on
>>> Sun, 6 Feb 2022, Recliner <recliner.usenet@gmail.com> remarked:
>>>> On Sun, 6 Feb 2022 13:42:18 +0000, Roland Perry <roland@perry.co.uk> wrote:
>>>>
>>>>> In message <stoe9d$fkg$1@dont-email.me>, at 12:17:49 on Sun, 6 Feb 2022,
>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sto9hd$g9t$1@dont-email.me>, at 10:56:45 on Sun, 6 Feb 2022,
>>>>>>> Recliner <recliner.usenet@gmail.com> remarked:
>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>> In message <sto7bj$5cb$2@dont-email.me>, at 10:19:31 on Sun, 6
>>>>>>>>>Feb 2022,
>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>> In message <sth7uq$f0i$1@dont-email.me>, at 18:46:50 on Thu, 3
>>>>>>>>>>> Feb 2022,
>>>>>>>>>>> Tweed <usenet.tweed@gmail.com> remarked:
>>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>>>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>>>> In message <stgal4$t5h$1@dont-email.me>, at 10:26:45 on Thu, 3
>>>>>>>>>>>>>> Feb 2022,
>>>>>>>>>>>>>> Anna Noyd-Dryver <anna@noyd-dryver.com> remarked:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> If you watch a stream of water cutting a channel,
>>>>>>>>>>>>>>>>> upstream end of the channel that gets the most
>>>>>>>>>>>>>>>>> erosion.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Yes, but why does that cause lateral slewing (upstream),
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> more droop?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Because the upstream side of the track gets eroded-under first,
>>>>>>>>>>>>>>> before the other side of the track. So the track is unsupported
>>>>>>>>>>>>>>> under one side only; has non-zero weight and is not a rigid
>>>>>>>>>>>>>>> structure. Why do you think it *wouldn't* slew to one side?
>>>>>>>>>>>>>>> It's not Hornby "long straight" rigid track which can be used
>>>>>>>>>>>>>>> as a bridge without any further support!
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Slewing requires a horizontal force perpendicular to the
>>>>>>>>>>>>>> track, and what is providing that force. Drooping requires
>>>>>>>>>>>>>> downwards, and that's in plentiful supply.
>>>>>>>>>>>>>
>>>>>>>>>>>>> The imbalance of force is provided by the erosion being initially
>>>>>>>>>>>>> predominantly under one side only of the track.
>>>>>>>>>>>>
>>>>>>>>>>>> If you put a marble on a slope the only force according to
>>>>>>>>>>>> Roland is just downwards gravity. Yet as the marble rolls down
>>>>>>>>>>>> the hill it moves both vertically and horizontally.
>>>>>>>>>>>>
>>>>>>>>>>>> The eroded track length is effectively rolling down hill (well
>>>>>>>>>>>> not rolling but you know what I mean).
>>>>>>>>>>>
>>>>>>>>>>> If the ground under the track has eroded by more than about
>>>>>>>>>>>six inches, there isn't a slope for the track to slide down.
>>>>>>>>>>>It's just hanging in mid air.
>>>>>>>>>>
>>>>>>>>>> But at that point it had only eroded under *one side of the track*.
>>>>>>>>>
>>>>>>>>> Sure about that?
>>>>>>>>>
>>>>>>>>> <https://i.dailymail.co.uk/1s/2022/01/30/18/53556263-10457643-image-m-
>>>>>>>>> 23_1643568862268.jpg>
>>>>>>>>
>>>>>>>> That was taken later.
>>>>>>>
>>>>>>> What we need (and there won't be one, unless GA released some cab
>>>>>>> footage) is a picture of the tracks before the train arrived.
>>>>>>>
>>>>>>> The one linked above doesn't show anything like as much of a kink as
>>>>>>> <https://twitter.com/ianhardie9018/status/1487783395660869633?s=21>
>>>>>>> which suggests it was moving left and right quite a bit.
>>>>>>>
>>>>>>> I still think the ianhardie kink is a result of the track buckling from
>>>>>>> the braking force of the train, not sliding sideways downhill.
>>>>>>
>>>>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>>>>
>>>>> If it's under tension [and yes, I agree it is, and underpins my own
>>>>> theory], how can it do a crazy zig-zag buckle in the way that's being
>>>>> claimed, when the only force on it is gravity downwards - and what that
>>>>> would cause is just a small droop.
>>>>
>>>> The force was the sideways slippage of the earth in which the sleepers
>>>> were embedded.
>>>
>>> Why didn't the ballast and sleepers simply skid over the sideways moving
>>> earth,
>>
>>The ballast and track don't sit lightly on top of a separate slippery block
>>of earth.
>
>Indeed, that earth has been eroded away.

But not in one single explosive action. It was gradually eroded over a period of time, starting from the right-hand
edge.

>
>>> which was very soon below the level it was capable of exerting a
>>> force on them anyway.
>>
>>How soon is 'soon'? The train clearly arrived early in the transition.
>
>Why is that clear?

From one of the photos AND posted.

>
>>>> You seem to be obsessed
>>>
>>> No, just sticking with the soil mechanics and structural engineering
>>> training I have received.
>>
>>Ah, another of your many areas of expertise!
>
>Yes, it is! Quite a long time ago now, but I don't think any of the
>basic principles have hanged.

So you were taught that the thick carpet of interlocked ballast slips easily off the earth it's embedded in?

Even if that were so, the temporarily sloping base under the track would have slipped sideways, not vertically, even
according to your understanding of soil mechanics.

On Mon, 7 Feb 2022 13:19:36 +0000, Roland Perry <roland@perry.co.uk> wrote:

>In message <stqsh5$76e$1@dont-email.me>, at 10:33:09 on Mon, 7 Feb 2022,
>Recliner <recliner.usenet@gmail.com> remarked:
>>>>>> Why would braking cause a track to buckle sideways? CWR is under tension.
>>>>>
>>>>> If it's under tension [and yes, I agree it is, and underpins my own
>>>>> theory], how can it do a crazy zig-zag buckle in the way that's being
>>>>> claimed, when the only force on it is gravity downwards - and what that
>>>>> would cause is just a small droop.
>>>>
>>>> Because it's quite heavy, and not designed to support its own weight
>>>> unsupported over such a long distance.
>>>
>>> So it droops (incidentally increasing the tension in the rails), it
>>> doesn't head off sideways against the tension of the rails holding
>>> it in a straight line.
>>
>>The slewing was caused by the ground shifting sideways as it slipped down
>>the temporary slope.
>
>So now we do have a slippery slope. Make you mind up!

It's been repeatedly mentioned, but you simply ignored it.

>
>>Several of us have told you this multiple times, and the early pictures
>>make this mechanism clear.
>
>Can you show me an early picture without the train present. That would
>help me change my mind.

No. Unlike theoreticians like you, engineers in the real world have to use the evidence available.

>
>>I think we have to conclude that you are demonstrating yet another
>>failure to comprehend, simply because you cannot admit to ever being
>>wrong. It seems really pointless trying to explain something so basic
>>to someone as stubbornly ignorant as you.
>
>As I said days ago (and nevertheless you don't appear to want to let go)
>I'm simply disagreeing with your analysis of the engineering of the
>situation. Find that picture without the train, and we can have another
>go at reaching a consensus.

We reached a consensus very early, minus the usual argumentative objector. Everyone but you understands how it happened.
But you obstinately won't accept that your pet theory was wrong. The earth would have to reverse its direction of spin
before you'd ever accept that you were wrong, yet again.

On Mon, 7 Feb 2022 13:24:07 +0000, Roland Perry <roland@perry.co.uk> wrote:

>In message <stqvnh$uad$1@dont-email.me>, at 11:27:45 on Mon, 7 Feb 2022,
>ianb <i.bidwell@ntlworld.com> remarked:
>
>>Yes it does seem he has reverted to his previous troll persona of
>>'Meldrew of Melbourn'
>
>Meldrew of Meldreth, actually.
>
>But no-one here has yet managed to explain how two tensioned rails
>strung across a gap would start moving sideways (with no force on them
>from the landslide) hence increasing that tension in the rails (further
>distance to cover due to the pair of curves in the zig-zag. Surely they
>would snap back to being straight across.

Nobody has explained that, because that's obviously not what happened, and nobody suggested it did. What we have
explained is what actually happened.

Why don't you actually read the explanations you have already decided you don't agree with? Please, just for once?

In message <i8920htgi5mvn37ailcg3re771qv2c1o7s@4ax.com>, at 13:58:44 on
Mon, 7 Feb 2022, Recliner <recliner.usenet@gmail.com> remarked:
>On Mon, 7 Feb 2022 13:24:07 +0000, Roland Perry <roland@perry.co.uk> wrote:
>
>>In message <stqvnh$uad$1@dont-email.me>, at 11:27:45 on Mon, 7 Feb 2022,
>>ianb <i.bidwell@ntlworld.com> remarked:
>>
>>>Yes it does seem he has reverted to his previous troll persona of
>>>'Meldrew of Melbourn'
>>
>>Meldrew of Meldreth, actually.
>>
>>But no-one here has yet managed to explain how two tensioned rails
>>strung across a gap would start moving sideways (with no force on them
>>from the landslide) hence increasing that tension in the rails (further
>>distance to cover due to the pair of curves in the zig-zag. Surely they
>>would snap back to being straight across.
>
>Nobody has explained that, because that's obviously not what happened,
>and nobody suggested it did. What we have
>explained is what actually happened.
>
>Why don't you actually read the explanations you have already decided
>you don't agree with? Please, just for once?

I have read them all, and they defy physics.

--
Roland Perry