Roland Perry <roland@perry.co.uk> wrote:
> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>
>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>> proposition that there's now a mythical train that can do end-to-end
>>>>>>>>> on one charge?
>>>>>>>>
>>>>>>>> There isn't.
>>>>>>>
>>>>>>> So it seems, despite claims early in the thread, that were based on
>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>> operational issues.
>>>>>>
>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>> short of the Inverness-Wick distance. There was an initial typo
>>>>>> suggesting that the record was 25% longer, but that was corrected.
>>>>>
>>>>> Given that the consensus is now that charging stations only at the ends
>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>
>>>> It always was. I don’t know how you got the idea that it was anything
>>>> other. Perhaps you could go back and check the beginning of the thread
>>>> again?
>>>
>>> Original posting:
>>>
>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>> Inverness to Wick becomes possible."
>>
>> You need to read just a little further. In the very next message Recliner
>> wrote:
>>
>> “That record-breaking distance is 25% higher [later corrected to lower]
>> than Inverness-Wick. The reliable, operational range will be much less, of
>> course.
>>
>> I suppose the solution would be to have 2-3 top-up stations en route, …”
>>
>> And the conversation proceeded on that basis.
>
> Indeed so. This subthread has been lagging the general discussion
> somewhat.

Is that the closest we’re going to get to “ah, sorry, I missed that”?

Sam

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

In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>
>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>> proposition that there's now a mythical train that can do end-to-end
>>>>>>>>>> on one charge?
>>>>>>>>>
>>>>>>>>> There isn't.
>>>>>>>>
>>>>>>>> So it seems, despite claims early in the thread, that were based on
>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>> operational issues.
>>>>>>>
>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>> short of the Inverness-Wick distance. There was an initial typo
>>>>>>> suggesting that the record was 25% longer, but that was corrected.
>>>>>>
>>>>>> Given that the consensus is now that charging stations only at the ends
>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>
>>>>> It always was. I don’t know how you got the idea that it was anything
>>>>> other. Perhaps you could go back and check the beginning of the thread
>>>>> again?
>>>>
>>>> Original posting:
>>>>
>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>> Inverness to Wick becomes possible."
>>>
>>> You need to read just a little further. In the very next message Recliner
>>> wrote:
>>>
>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>> than Inverness-Wick. The reliable, operational range will be much less, of
>>> course.
>>>
>>> I suppose the solution would be to have 2-3 top-up stations en route, …”
>>>
>>> And the conversation proceeded on that basis.
>>
>> Indeed so. This subthread has been lagging the general discussion
>> somewhat.
>
>Is that the closest we’re going to get to “ah, sorry, I missed that”?

Obviously I hadn't missed the fact the discussion had proceeded on. Did
you not see my several mentions of Thurso (rather than Wick) being the
best place for the northern charging station, and Brora being the best
places to add an intermediate charging station?
--
Roland Perry

Bob <email@domain.com> wrote:
> On 2022-02-14 19:51:57 +0000, Anna Noyd-Dryver said:
>
>> Tweed <usenet.tweed@gmail.com> wrote:
>>> Bob <email@domain.com> wrote:
>>>> On 2022-02-13 19:07:22 +0000, nib said:
>>>>
>>>>> On Sun, 13 Feb 2022 18:34:02 +0000, Anna Noyd-Dryver wrote:
>>>>>
>>>>>> nib <news@ingram-bromley.co.uk> wrote:
>>>>>>> On Sun, 13 Feb 2022 15:58:12 +0000, Marland wrote:
>>>>> ...
>>>>>>> Have we decided that some form of shielded bottom-contact 3rd-rail is
>>>>>>> also not possible?
>>>>>>>
>>>>>>> If it were, then surely just changing shoe-gear at the ends of the new
>>>>>>> bit of line would be better than dual-voltage?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> It is permitted, but it's not compatible with the existing 3rd rail
>>>>>> equipment.
>>>>>>
>>>>>
>>>>> Do you mean that it wouldn't be possible to design some automated gadget
>>>>> to retract one set of shoes and enable another - or is there some
>>>>> fundamental reason that you can't combine both on one train?
>>>>
>>>> There are both under-running and over-running 3rd rail systems in New
>>>> York, and I believe there are trains that can run on both systems, so
>>>> it is technically possible. With the general maturity of dual voltage
>>>> technology, though, there really isn't a good reason for not using 25
>>>> kV OHLE, even in traditionally 3rd rail territory.
>>>>
>>>
>>> I’d be genuinely interested in figures that compared electrocution
>>> (electric shock not necessarily involving death before we start the
>>> argument about the definition of electrocution again) per installed km of
>>> track of 3rd rail vs 25kV OHLE.
>>>
>>
>> For 25kV, I'm only aware of one such incident involving staff, in the last
>> decade or so:
>> <https://assets.publishing.service.gov.uk/media/558803de40f0b615b600001a/R072015_150624_Sutton_Weaver.pdf>.
>>
>>
>> The various injuries to/deaths of trespassers (usually children) must be
>> listed somewhere, presumably? Two or perhaps three come to mind.
>
> Another safety issue is that due to the low voltage, 3rd rail systems
> need to be able to provide a truely huge current as part of normal
> operations, while 25 kV lines do not. A short to ground on a 25 kV
> line will pretty easily trigger the circuit breakers. On a 3rd rail
> line, if a fault is not a very highly conductive short, the current
> flowing may well be insufficient to trigger the circuit breakers as it
> may be less than the starting current of a couple of longer trains.
>
> Robin
>
>

But that’s more of a fire risk mitigation. No amount of current limiting is
going to protect a human in the circuit.

It’s been mentioned that it’s not a good idea having 3rd rail at ankle
level in the working environment. Are there any requirements for rail
workers, including train staff, to wear appropriate safety footwear? It’s
relatively easy to insulate footwear to withstand 1000V, especially as it’s
DC and therefore no capacitive coupling.

On 15/02/2022 16:09, Roland Perry wrote:
> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>
>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>> end-to-end
>>>>>>>>>>> on one charge?
>>>>>>>>>>
>>>>>>>>>> There isn't.
>>>>>>>>>
>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>> based on
>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>> operational issues.
>>>>>>>>
>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>> suggesting that the  record was 25% longer, but that was corrected.
>>>>>>>
>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>> the ends
>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>
>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>> anything
>>>>>> other.  Perhaps you could go back and check the beginning of the
>>>>>> thread
>>>>>> again?
>>>>>
>>>>> Original posting:
>>>>>
>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>> Inverness to Wick becomes possible."
>>>>
>>>> You need to read just a little further.  In the very next message
>>>> Recliner
>>>> wrote:
>>>>
>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>> than Inverness-Wick. The reliable, operational range will be much
>>>> less, of
>>>> course.
>>>>
>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>> route, …”
>>>>
>>>> And the conversation proceeded on that basis.
>>>
>>> Indeed so. This subthread has been lagging the general discussion
>>> somewhat.
>>
>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>
> Obviously I hadn't missed the fact the discussion had proceeded on. Did
> you not see my several mentions of Thurso (rather than Wick) being the
> best place for the northern charging station, and Brora being the best
> places to add an intermediate charging station?

I'm not convinced that anywhere other then the end points makes a good
place for a charging station, as the train won't be there long enough.

Certes <none@nowhere.net> wrote:
> On 15/02/2022 16:09, Roland Perry wrote:
>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>
>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>> end-to-end
>>>>>>>>>>>> on one charge?
>>>>>>>>>>>
>>>>>>>>>>> There isn't.
>>>>>>>>>>
>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>> based on
>>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>>> operational issues.
>>>>>>>>>
>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>>> suggesting that the  record was 25% longer, but that was corrected.
>>>>>>>>
>>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>>> the ends
>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>
>>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>>> anything
>>>>>>> other.  Perhaps you could go back and check the beginning of the
>>>>>>> thread
>>>>>>> again?
>>>>>>
>>>>>> Original posting:
>>>>>>
>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>> Inverness to Wick becomes possible."
>>>>>
>>>>> You need to read just a little further.  In the very next message
>>>>> Recliner
>>>>> wrote:
>>>>>
>>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>>> than Inverness-Wick. The reliable, operational range will be much
>>>>> less, of
>>>>> course.
>>>>>
>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>> route, …”
>>>>>
>>>>> And the conversation proceeded on that basis.
>>>>
>>>> Indeed so. This subthread has been lagging the general discussion
>>>> somewhat.
>>>
>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>>
>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>> you not see my several mentions of Thurso (rather than Wick) being the
>> best place for the northern charging station, and Brora being the best
>> places to add an intermediate charging station?
>
> I'm not convinced that anywhere other then the end points makes a good
> place for a charging station, as the train won't be there long enough.
>

Intermediate stations get you out of trouble if the train has to be turned
back early, or if the far end charging station is not working. Otherwise
you really need enough range to get you there and back.

On 15/02/2022 19:35, Tweed wrote:
> Certes <none@nowhere.net> wrote:
>> On 15/02/2022 16:09, Roland Perry wrote:
>>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>
>>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>> end-to-end
>>>>>>>>>>>>> on one charge?
>>>>>>>>>>>>
>>>>>>>>>>>> There isn't.
>>>>>>>>>>>
>>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>> based on
>>>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>>>> operational issues.
>>>>>>>>>>
>>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>>>> suggesting that the  record was 25% longer, but that was corrected.
>>>>>>>>>
>>>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>>>> the ends
>>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>>
>>>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>>>> anything
>>>>>>>> other.  Perhaps you could go back and check the beginning of the
>>>>>>>> thread
>>>>>>>> again?
>>>>>>>
>>>>>>> Original posting:
>>>>>>>
>>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>>> Inverness to Wick becomes possible."
>>>>>>
>>>>>> You need to read just a little further.  In the very next message
>>>>>> Recliner
>>>>>> wrote:
>>>>>>
>>>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>>>> than Inverness-Wick. The reliable, operational range will be much
>>>>>> less, of
>>>>>> course.
>>>>>>
>>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>> route, …”
>>>>>>
>>>>>> And the conversation proceeded on that basis.
>>>>>
>>>>> Indeed so. This subthread has been lagging the general discussion
>>>>> somewhat.
>>>>
>>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>>>
>>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>>> you not see my several mentions of Thurso (rather than Wick) being the
>>> best place for the northern charging station, and Brora being the best
>>> places to add an intermediate charging station?
>>
>> I'm not convinced that anywhere other then the end points makes a good
>> place for a charging station, as the train won't be there long enough.
>>
>
> Intermediate stations get you out of trouble if the train has to be turned
> back early, or if the far end charging station is not working. Otherwise
> you really need enough range to get you there and back.
>
True but I don't see intermediate chargers getting in normal service,
except maybe before the morning peak short run into Inverness.

> You could say the same about unfenced drops, but oddly enough they're not
> permitted either.

More likely that you are required to wear a harness attached to a safety
line.

On 15/02/2022 20:49, Certes wrote:
> On 15/02/2022 19:35, Tweed wrote:
>> Certes <none@nowhere.net> wrote:
>>> On 15/02/2022 16:09, Roland Perry wrote:
>>>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun,
>>>>>>>>>> 13 Feb
>>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>
>>>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to
>>>>>>>>>>>>>> the
>>>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>>> end-to-end
>>>>>>>>>>>>>> on one charge?
>>>>>>>>>>>>>
>>>>>>>>>>>>> There isn't.
>>>>>>>>>>>>
>>>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>>> based on
>>>>>>>>>>>> mileage myths, as much as airbrushing out
>>>>>>>>>>>> only-charge-at-the-ends
>>>>>>>>>>>> operational issues.
>>>>>>>>>>>
>>>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial
>>>>>>>>>>> typo
>>>>>>>>>>> suggesting that the  record was 25% longer, but that was
>>>>>>>>>>> corrected.
>>>>>>>>>>
>>>>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>>>>> the ends
>>>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>>>
>>>>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>>>>> anything
>>>>>>>>> other.  Perhaps you could go back and check the beginning of the
>>>>>>>>> thread
>>>>>>>>> again?
>>>>>>>>
>>>>>>>> Original posting:
>>>>>>>>
>>>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>>>> Inverness to Wick becomes possible."
>>>>>>>
>>>>>>> You need to read just a little further.  In the very next message
>>>>>>> Recliner
>>>>>>> wrote:
>>>>>>>
>>>>>>> “That record-breaking distance is 25% higher [later corrected to
>>>>>>> lower]
>>>>>>> than Inverness-Wick. The reliable, operational range will be much
>>>>>>> less, of
>>>>>>> course.
>>>>>>>
>>>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>>> route, …”
>>>>>>>
>>>>>>> And the conversation proceeded on that basis.
>>>>>>
>>>>>> Indeed so. This subthread has been lagging the general discussion
>>>>>> somewhat.
>>>>>
>>>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>>>>
>>>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>>>> you not see my several mentions of Thurso (rather than Wick) being the
>>>> best place for the northern charging station, and Brora being the best
>>>> places to add an intermediate charging station?
>>>
>>> I'm not convinced that anywhere other then the end points makes a good
>>> place for a charging station, as the train won't be there long enough.
>>>
>>
>> Intermediate stations get you out of trouble if the train has to be
>> turned
>> back early, or if the far end charging station is not working. Otherwise
>> you really need enough range to get you there and back.
>>
> True but I don't see intermediate chargers getting in normal service,
> except maybe before the morning peak short run into Inverness.
I agree but consideration has to be made for when things go wrong.

Roland Perry <roland@perry.co.uk> wrote:
> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>> Roland Perry <roland@perry.co.uk> wrote:
>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>
>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>> proposition that there's now a mythical train that can do end-to-end
>>>>>>>>>>> on one charge?
>>>>>>>>>>
>>>>>>>>>> There isn't.
>>>>>>>>>
>>>>>>>>> So it seems, despite claims early in the thread, that were based on
>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>> operational issues.
>>>>>>>>
>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>> short of the Inverness-Wick distance. There was an initial typo
>>>>>>>> suggesting that the record was 25% longer, but that was corrected.
>>>>>>>
>>>>>>> Given that the consensus is now that charging stations only at the ends
>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>
>>>>>> It always was. I don’t know how you got the idea that it was anything
>>>>>> other. Perhaps you could go back and check the beginning of the thread
>>>>>> again?
>>>>>
>>>>> Original posting:
>>>>>
>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>> Inverness to Wick becomes possible."
>>>>
>>>> You need to read just a little further. In the very next message Recliner
>>>> wrote:
>>>>
>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>> than Inverness-Wick. The reliable, operational range will be much less, of
>>>> course.
>>>>
>>>> I suppose the solution would be to have 2-3 top-up stations en route, …”
>>>>
>>>> And the conversation proceeded on that basis.
>>>
>>> Indeed so. This subthread has been lagging the general discussion
>>> somewhat.
>>
>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>
> Obviously I hadn't missed the fact the discussion had proceeded on. Did
> you not see my several mentions of Thurso (rather than Wick) being the
> best place for the northern charging station, and Brora being the best
> places to add an intermediate charging station?

Well I’ve lost the posting where “the proposition that there's now a
mythical train that can do end-to-end on one charge” came up except where
your wrote it above.

Sam

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

Certes <none@nowhere.net> wrote:
> On 15/02/2022 19:35, Tweed wrote:
>> Certes <none@nowhere.net> wrote:
>>> On 15/02/2022 16:09, Roland Perry wrote:
>>>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>
>>>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>>> end-to-end
>>>>>>>>>>>>>> on one charge?
>>>>>>>>>>>>>
>>>>>>>>>>>>> There isn't.
>>>>>>>>>>>>
>>>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>>> based on
>>>>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>>>>> operational issues.
>>>>>>>>>>>
>>>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>>>>> suggesting that the  record was 25% longer, but that was corrected.
>>>>>>>>>>
>>>>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>>>>> the ends
>>>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>>>
>>>>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>>>>> anything
>>>>>>>>> other.  Perhaps you could go back and check the beginning of the
>>>>>>>>> thread
>>>>>>>>> again?
>>>>>>>>
>>>>>>>> Original posting:
>>>>>>>>
>>>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>>>> Inverness to Wick becomes possible."
>>>>>>>
>>>>>>> You need to read just a little further.  In the very next message
>>>>>>> Recliner
>>>>>>> wrote:
>>>>>>>
>>>>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>>>>> than Inverness-Wick. The reliable, operational range will be much
>>>>>>> less, of
>>>>>>> course.
>>>>>>>
>>>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>>> route, …”
>>>>>>>
>>>>>>> And the conversation proceeded on that basis.
>>>>>>
>>>>>> Indeed so. This subthread has been lagging the general discussion
>>>>>> somewhat.
>>>>>
>>>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>>>>
>>>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>>>> you not see my several mentions of Thurso (rather than Wick) being the
>>>> best place for the northern charging station, and Brora being the best
>>>> places to add an intermediate charging station?
>>>
>>> I'm not convinced that anywhere other then the end points makes a good
>>> place for a charging station, as the train won't be there long enough.
>>>
>>
>> Intermediate stations get you out of trouble if the train has to be turned
>> back early, or if the far end charging station is not working. Otherwise
>> you really need enough range to get you there and back.
>>
> True but I don't see intermediate chargers getting in normal service,
> except maybe before the morning peak short run into Inverness.
>

Presumably they'd be fitted at one or two crossover stations, where trains
stop for several minutes anyway, plus Thurso.

Tweed <usenet.tweed@gmail.com> wrote:
:

> It’s been mentioned that it’s not a good idea having 3rd rail at ankle
> level in the working environment. Are there any requirements for rail
> workers, including train staff, to wear appropriate safety footwear? It’s
> relatively easy to insulate footwear to withstand 1000V, especially as it’s
> DC and therefore no capacitive coupling.
>
>

This LT safety film shows how things used to be , footwear wasn’t much help
with the working practices of the time depicted about 8 mins in . Clothing
is mentioned about about 4 mins in but basically is making sure your coat
is done up tightly.

<https://youtu.be/Uia2jH9nRb8>

I do have a clear recollection circa 1968 of two workers working on the
positive rail at Turnham Green
in between trains. They were both wearing thick gloves which I assumed were
rubber and using spanners to tighten something either a feed or cable
around a joint.
I would be surprised if such a task is done in those conditions now.

GH

<martin.coffee@round-midnight.org.uk> wrote:
> On 15/02/2022 20:49, Certes wrote:
>> On 15/02/2022 19:35, Tweed wrote:
>>> Certes <none@nowhere.net> wrote:
>>>> On 15/02/2022 16:09, Roland Perry wrote:
>>>>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun,
>>>>>>>>>>> 13 Feb
>>>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>
>>>>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to
>>>>>>>>>>>>>>> the
>>>>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>>>> end-to-end
>>>>>>>>>>>>>>> on one charge?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> There isn't.
>>>>>>>>>>>>>
>>>>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>>>> based on
>>>>>>>>>>>>> mileage myths, as much as airbrushing out
>>>>>>>>>>>>> only-charge-at-the-ends
>>>>>>>>>>>>> operational issues.
>>>>>>>>>>>>
>>>>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial
>>>>>>>>>>>> typo
>>>>>>>>>>>> suggesting that the  record was 25% longer, but that was
>>>>>>>>>>>> corrected.
>>>>>>>>>>>
>>>>>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>>>>>> the ends
>>>>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>>>>
>>>>>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>>>>>> anything
>>>>>>>>>> other.  Perhaps you could go back and check the beginning of the
>>>>>>>>>> thread
>>>>>>>>>> again?
>>>>>>>>>
>>>>>>>>> Original posting:
>>>>>>>>>
>>>>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>>>>> Inverness to Wick becomes possible."
>>>>>>>>
>>>>>>>> You need to read just a little further.  In the very next message
>>>>>>>> Recliner
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>> “That record-breaking distance is 25% higher [later corrected to
>>>>>>>> lower]
>>>>>>>> than Inverness-Wick. The reliable, operational range will be much
>>>>>>>> less, of
>>>>>>>> course.
>>>>>>>>
>>>>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>>>> route, …”
>>>>>>>>
>>>>>>>> And the conversation proceeded on that basis.
>>>>>>>
>>>>>>> Indeed so. This subthread has been lagging the general discussion
>>>>>>> somewhat.
>>>>>>
>>>>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>>>>>
>>>>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>>>>> you not see my several mentions of Thurso (rather than Wick) being the
>>>>> best place for the northern charging station, and Brora being the best
>>>>> places to add an intermediate charging station?
>>>>
>>>> I'm not convinced that anywhere other then the end points makes a good
>>>> place for a charging station, as the train won't be there long enough.
>>>>
>>>
>>> Intermediate stations get you out of trouble if the train has to be
>>> turned
>>> back early, or if the far end charging station is not working. Otherwise
>>> you really need enough range to get you there and back.
>>>
>> True but I don't see intermediate chargers getting in normal service,
>> except maybe before the morning peak short run into Inverness.
> I agree but consideration has to be made for when things go wrong.
>

Yes, one could imagine a scenario where the intermediate chargers normally
just deliver a quick 2-3 min top-up during a routine stop, but can provide
a 10-15 min full charge if needed (eg, if there's a fault on another
charger).

Certes <none@nowhere.net> wrote:
> On 15/02/2022 19:35, Tweed wrote:
>> Certes <none@nowhere.net> wrote:
>>> On 15/02/2022 16:09, Roland Perry wrote:
>>>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>
>>>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>>> end-to-end
>>>>>>>>>>>>>> on one charge?
>>>>>>>>>>>>>
>>>>>>>>>>>>> There isn't.
>>>>>>>>>>>>
>>>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>>> based on
>>>>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>>>>> operational issues.
>>>>>>>>>>>
>>>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>>>>> suggesting that the  record was 25% longer, but that was corrected.
>>>>>>>>>>
>>>>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>>>>> the ends
>>>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>>>
>>>>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>>>>> anything
>>>>>>>>> other.  Perhaps you could go back and check the beginning of the
>>>>>>>>> thread
>>>>>>>>> again?
>>>>>>>>
>>>>>>>> Original posting:
>>>>>>>>
>>>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>>>> Inverness to Wick becomes possible."
>>>>>>>
>>>>>>> You need to read just a little further.  In the very next message
>>>>>>> Recliner
>>>>>>> wrote:
>>>>>>>
>>>>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>>>>> than Inverness-Wick. The reliable, operational range will be much
>>>>>>> less, of
>>>>>>> course.
>>>>>>>
>>>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>>> route, …”
>>>>>>>
>>>>>>> And the conversation proceeded on that basis.
>>>>>>
>>>>>> Indeed so. This subthread has been lagging the general discussion
>>>>>> somewhat.
>>>>>
>>>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>>>>
>>>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>>>> you not see my several mentions of Thurso (rather than Wick) being the
>>>> best place for the northern charging station, and Brora being the best
>>>> places to add an intermediate charging station?
>>>
>>> I'm not convinced that anywhere other then the end points makes a good
>>> place for a charging station, as the train won't be there long enough.
>>>
>>
>> Intermediate stations get you out of trouble if the train has to be turned
>> back early, or if the far end charging station is not working. Otherwise
>> you really need enough range to get you there and back.
>>
> True but I don't see intermediate chargers getting in normal service,
> except maybe before the morning peak short run into Inverness.
>

For people who missed my post in the other (Chiltern) thread:

From
<https://www.modernrailways.com/article/vivarails-battery-230-greenford-branch>

Vivarail’s battery-powered Class 230 unit which debuted at the COP26
climate change conference in 2021 is to be tested on the West
Ealing-Greenford branch later this year.

Following the conclusion of a deal between Great Western Railway and
Vivarail, rapid charging equipment will be installed at West Ealing station
for the train to run on the two-mile, 40-chain line. The trial is being
supported by £2.15 million in funding from the Department for Transport’s
Rail Network Enhancement Pipeline while Innovate UK helped to fund
development of the fast charge technology.

Using a variant of the London Underground four-rail system, the train will
automatically connect to the fast charging system, which in off-network
tests has filled the batteries within 10 minutes.

Train No 23001 Viva Venturer is powered by six Hoppecke batteries, with
three under each driving vehicle although the third is not normally used
except to provide resilience. Its range is estimated at around 62 miles – a
cautious estimate intended to maximise battery life.

While the converted London Underground ‘D’ stock train will run on the
branch, Vivarail’s long-term aim is to sell its battery and fast charging
technology, with 50 routes identified where a hybrid electric/battery train
could run away from the wires for up to 40 miles and replace DMUs.

GWR Managing Director Mark Hopwood said: ‘This is a really exciting
development and underlines our commitment to reduce the carbon emissions of
our train fleet with a view to removing all diesel-only traction from the
network by 2040, in line with the Government’s Transport Decarbonisation
Plan.

‘We’re looking forward to working with our rail industry colleagues over
the coming months to be able to rigorously test this battery train and
charger on the Greenford branch line.’

Vivarail Managing Director Steve McBride said the support from GWR, Network
Rail and the DfT to get the project under way was ‘phenomenal’

<Muttley@dastardlyhq.com> wrote:
> On Mon, 14 Feb 2022 17:56:50 +0100
> Bob <email@domain.com> wrote:
>> On 2022-02-14 16:45:46 +0000, Muttley@dastardlyhq.com said:
>>
>>> On Mon, 14 Feb 2022 11:02:20 +0100
>>> Bob <email@domain.com> wrote:
>>>> On 2022-02-14 08:55:32 +0000, Muttley@dastardlyhq.com said:
>>>>>> With the resignalling to ETCS2 on the ECML (as discussed in another
>>>>>> thread recently), the issues preventing >125 mph running on the ECML
>>>>>> will be resolved, and it will be possible to run trains at higher
>>>>>> speeds. Too late for the 91s, though.
>>>>>
>>>>> Its *possible* to run the Javelins at 140mph on HS1 but apparently they're
>>>>> still limited to 125 for [reasons]. So wrt the ECML I'll believe it when I
>>>>> see it.
>>>>
>>>> They are permitted to run at 140. They are timetabled at 125, with the
>>>> intention that higher speeds can be used to recover from delays and
>>>> ensure reliability of the service.
>>>
>>> Which completely defeats the point. You wouldn't get the French saying
>>> "We can run our TGVs at 186 but we'll limit them to 170 so we can recover
>>> the timetable if they're running late". Its a utter farce and it'll be
>>> exactly the same nonsense on the ECML I can guarantee it.
>>
>> Given the length of HS1, the difference between 125 mph timings and 140
>> mph timings is going to be something like 2 minutes. Two minutes of
>> recovery time seems a reasonable ammount of padding to include on
>> routes like these.
>
> Problem is you can use that argument reducto as absurdum. The timing
> difference between 120 and 100mph would also be slight over that distance
> so why not reduce it down to 100? Ditto 100 and 70 etc etc. In the end
> you'd be down to the speed of horse drawn carraiges.
>
>
>

Pre-electrification timetable, GWML HSTs could maintain time but not regain
lost time if limited to 100mph (eg broken outer skin of double-glazed
window, one tone of horn not working). At 70mph you'd lose acres of time!

One clue is that acceleration gets much slower as speed gets higher, so
100->125 takes more distance than 0->100.

Anna Noyd-Dryver

Certes <none@nowhere.net> wrote:
> On 15/02/2022 11:28, ColinR wrote:
>> On 15/02/2022 09:53, Graeme Wall wrote:
>>> On 15/02/2022 09:03, Muttley@dastardlyhq.com wrote:
>>>> I would say its entirely reasonable to lay 3rd rail to Uckfield and
>>>> Reading via Dorking given both lines are fimrly in 3rd rail territory
>>>> and already have 3rd rail at one end.
>>>
>>> Reading - Dorking even more so as it has the Guildford third-rail
>>> island in the middle. Someone has posted the correct mileages in the
>>> past but I think it adds up to less than 10 route miles to be
>>> converted in two bits. If the 769s ever get into service that will
>>> partially solve the problem in the relatively short term. The longer
>>> term solution is probably battery-electric hybrid units. Also
>>> discussed on here in the past. That will probably work out cheaper
>>> than either electrification system.
>>>
>> Maybe battery would be cheaper than electrification, but at what
>> environmental cost? The manufacture of current battery technology relies
>> on rare metals which have a significant environmental legacy with
>> extraction. Maybe recycling of batteries will help this in the future
>> but...
>
> I hope that worn-out vehicle batteries will find a second home as
> static backup, either on premises or at grid level, where the lower
> power to weight ratio matters less. However, they'll still need to
> be scrapped eventually.
>

Almost every part can be recycled into new batteries.

Anna Noyd-Dryver

Tweed <usenet.tweed@gmail.com> wrote:
> Bob <email@domain.com> wrote:
>> On 2022-02-14 19:51:57 +0000, Anna Noyd-Dryver said:
>>
>>> Tweed <usenet.tweed@gmail.com> wrote:
>>>> Bob <email@domain.com> wrote:
>>>>> On 2022-02-13 19:07:22 +0000, nib said:
>>>>>
>>>>>> On Sun, 13 Feb 2022 18:34:02 +0000, Anna Noyd-Dryver wrote:
>>>>>>
>>>>>>> nib <news@ingram-bromley.co.uk> wrote:
>>>>>>>> On Sun, 13 Feb 2022 15:58:12 +0000, Marland wrote:
>>>>>> ...
>>>>>>>> Have we decided that some form of shielded bottom-contact 3rd-rail is
>>>>>>>> also not possible?
>>>>>>>>
>>>>>>>> If it were, then surely just changing shoe-gear at the ends of the new
>>>>>>>> bit of line would be better than dual-voltage?
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>> It is permitted, but it's not compatible with the existing 3rd rail
>>>>>>> equipment.
>>>>>>>
>>>>>>
>>>>>> Do you mean that it wouldn't be possible to design some automated gadget
>>>>>> to retract one set of shoes and enable another - or is there some
>>>>>> fundamental reason that you can't combine both on one train?
>>>>>
>>>>> There are both under-running and over-running 3rd rail systems in New
>>>>> York, and I believe there are trains that can run on both systems, so
>>>>> it is technically possible. With the general maturity of dual voltage
>>>>> technology, though, there really isn't a good reason for not using 25
>>>>> kV OHLE, even in traditionally 3rd rail territory.
>>>>>
>>>>
>>>> I’d be genuinely interested in figures that compared electrocution
>>>> (electric shock not necessarily involving death before we start the
>>>> argument about the definition of electrocution again) per installed km of
>>>> track of 3rd rail vs 25kV OHLE.
>>>>
>>>
>>> For 25kV, I'm only aware of one such incident involving staff, in the last
>>> decade or so:
>>> <https://assets.publishing.service.gov.uk/media/558803de40f0b615b600001a/R072015_150624_Sutton_Weaver.pdf>.
>>>
>>>
>>> The various injuries to/deaths of trespassers (usually children) must be
>>> listed somewhere, presumably? Two or perhaps three come to mind.
>>
>> Another safety issue is that due to the low voltage, 3rd rail systems
>> need to be able to provide a truely huge current as part of normal
>> operations, while 25 kV lines do not. A short to ground on a 25 kV
>> line will pretty easily trigger the circuit breakers. On a 3rd rail
>> line, if a fault is not a very highly conductive short, the current
>> flowing may well be insufficient to trigger the circuit breakers as it
>> may be less than the starting current of a couple of longer trains.
>>
>> Robin
>>
>>
>
> But that’s more of a fire risk mitigation. No amount of current limiting is
> going to protect a human in the circuit.
>
> It’s been mentioned that it’s not a good idea having 3rd rail at ankle
> level in the working environment. Are there any requirements for rail
> workers, including train staff, to wear appropriate safety footwear? It’s
> relatively easy to insulate footwear to withstand 1000V, especially as it’s
> DC and therefore no capacitive coupling.
>
>

Safety footwear of a number of varieties is required for traincrew (shoes
are permitted which wouldn't protect against eg. accidental sideways
contact with 3rd rail). I would expect safety boots to be mandated for
track workers but I still wouldn't want to stand on 3rd rail whatever the
leaflet which came with my shoes said.

Anna Noyd-Dryver

MB <MB@nospam.net> wrote:
>
>> You could say the same about unfenced drops, but oddly enough they're not
>> permitted either.
>
> More likely that you are required to wear a harness attached to a safety
> line.
>
>

In the example I quoted, a fence should have been attached to the
scaffolding, but the boss couldn't be bothered, and his dad died after
falling off.

Anna Noyd-Dryver

In message <sugu8k$8ki$1@dont-email.me>, at 19:17:40 on Tue, 15 Feb
2022, Certes <none@nowhere.net> remarked:
>On 15/02/2022 16:09, Roland Perry wrote:
>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>
>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>
>>>>>>>>>>>> on one charge?
>>>>>>>>>>>
>>>>>>>>>>> There isn't.
>>>>>>>>>>
>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>
>>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>>> operational issues.
>>>>>>>>>
>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>>> suggesting that the  record was 25% longer, but that was corrected.
>>>>>>>>
>>>>>>>> Given that the consensus is now that charging stations only at
>>>>>>>>the ends
>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>
>>>>>>> It always was.  I don’t know how you got the idea that it was
>>>>>>>anything
>>>>>>> other.  Perhaps you could go back and check the beginning of
>>>>>>>thread
>>>>>>> again?
>>>>>>
>>>>>> Original posting:
>>>>>>
>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>> Inverness to Wick becomes possible."
>>>>>
>>>>> You need to read just a little further.  In the very next message
>>>>>Recliner
>>>>> wrote:
>>>>>
>>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>>> than Inverness-Wick. The reliable, operational range will be much
>>>>>less, of
>>>>> course.
>>>>>
>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>route, …”
>>>>>
>>>>> And the conversation proceeded on that basis.
>>>>
>>>> Indeed so. This subthread has been lagging the general discussion
>>>> somewhat.
>>>
>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>> Obviously I hadn't missed the fact the discussion had proceeded on.
>>Did you not see my several mentions of Thurso (rather than Wick)
>>being the best place for the northern charging station, and Brora
>>being the best places to add an intermediate charging station?
>
>I'm not convinced that anywhere other then the end points makes a good
>place for a charging station, as the train won't be there long enough.

As I pointed out earlier, the train already only stops for a few minutes
at Inverness.

"Ah, but you can change the timetable" was the reply.

Well, you can also change the timetable to dwell at somewhere like Brora
for ten minutes.

If it's really that important to remove the final 1% of 0.4% of *gross*
carbon emissions by doing that, the passengers will surely understand.

Alternatively they might prefer a slightly higher fare so someone can
plant a few carbon-offset trees.

Although in practice, what with it being a 4.5hr journey, maybe the
electric train could run just a few mph faster to make up the time (the
current average speed is only 40mph)
--
Roland Perry

In message <suh96h$hht$1@dont-email.me>, at 22:24:17 on Tue, 15 Feb
2022, Recliner <recliner.usenet@gmail.com> remarked:
>Certes <none@nowhere.net> wrote:
>> On 15/02/2022 19:35, Tweed wrote:
>>> Certes <none@nowhere.net> wrote:
>>>> On 15/02/2022 16:09, Roland Perry wrote:
>>>>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>
>>>>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>>>> end-to-end
>>>>>>>>>>>>>>> on one charge?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> There isn't.
>>>>>>>>>>>>>
>>>>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>>>>based on mileage myths, as much as airbrushing out
>>>>>>>>>>>>>only-charge-at-the-ends operational issues.
>>>>>>>>>>>>
>>>>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>>>>>> suggesting that the  record was 25% longer, but that was
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Given that the consensus is now that charging stations only
>>>>>>>>>>> the ends is a non-starter, the relevance of the "world
>>>>>>>>>>>record" is bleak.
>>>>>>>>>>
>>>>>>>>>> It always was.  I don’t know how you got the idea that it
>>>>>>>>>> anything other.  Perhaps you could go back and check the
>>>>>>>>>>beginning of the thread again?
>>>>>>>>>
>>>>>>>>> Original posting:
>>>>>>>>>
>>>>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>>>>> Inverness to Wick becomes possible."
>>>>>>>>
>>>>>>>> You need to read just a little further.  In the very next
>>>>>>>> Recliner wrote:
>>>>>>>>
>>>>>>>> “That record-breaking distance is 25% higher [later corrected
>>>>>>>>to lower] than Inverness-Wick. The reliable, operational range
>>>>>>>> less, of course.
>>>>>>>>
>>>>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>>>> route, …”
>>>>>>>>
>>>>>>>> And the conversation proceeded on that basis.
>>>>>>>
>>>>>>> Indeed so. This subthread has been lagging the general discussion
>>>>>>> somewhat.
>>>>>>
>>>>>> Is that the closest we’re going to get to “ah, sorry, I
>>>>>>missed that”?
>>>>>
>>>>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>>>>> you not see my several mentions of Thurso (rather than Wick) being the
>>>>> best place for the northern charging station, and Brora being the best
>>>>> places to add an intermediate charging station?
>>>>
>>>> I'm not convinced that anywhere other then the end points makes a good
>>>> place for a charging station, as the train won't be there long enough.
>>>
>>> Intermediate stations get you out of trouble if the train has to be turned
>>> back early, or if the far end charging station is not working. Otherwise
>>> you really need enough range to get you there and back.
>>>
>> True but I don't see intermediate chargers getting in normal service,
>> except maybe before the morning peak short run into Inverness.
>
>Presumably they'd be fitted at one or two crossover stations, where trains
>stop for several minutes anyway,

A quick look at RTT shows 3 mins at Muir of Ord and Fornisard, but no
obvious other candidates. I'm not sufficiently familiar with the line to
know where the loops in fact are.

>plus Thurso.
>

--
Roland Perry

In message <suh93m$gvm$1@dont-email.me>, at 22:22:46 on Tue, 15 Feb
2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>> Roland Perry <roland@perry.co.uk> wrote:
>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>
>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>
>>>>>>>>>>>> on one charge?
>>>>>>>>>>>
>>>>>>>>>>> There isn't.
>>>>>>>>>>
>>>>>>>>>> So it seems, despite claims early in the thread, that were based on
>>>>>>>>>> mileage myths, as much as airbrushing out only-charge-at-the-ends
>>>>>>>>>> operational issues.
>>>>>>>>>
>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>> short of the Inverness-Wick distance. There was an initial typo
>>>>>>>>> suggesting that the record was 25% longer, but that was corrected.
>>>>>>>>
>>>>>>>> Given that the consensus is now that charging stations only at the ends
>>>>>>>> is a non-starter, the relevance of the "world record" is bleak.
>>>>>>>
>>>>>>> It always was. I don’t know how you got the idea that it was anything
>>>>>>> other. Perhaps you could go back and check the beginning of the thread
>>>>>>> again?
>>>>>>
>>>>>> Original posting:
>>>>>>
>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>> Inverness to Wick becomes possible."
>>>>>
>>>>> You need to read just a little further. In the very next message Recliner
>>>>> wrote:
>>>>>
>>>>> “That record-breaking distance is 25% higher [later corrected to lower]
>>>>> than Inverness-Wick. The reliable, operational range will be much less, of
>>>>> course.
>>>>>
>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>route, …”
>>>>>
>>>>> And the conversation proceeded on that basis.
>>>>
>>>> Indeed so. This subthread has been lagging the general discussion
>>>> somewhat.
>>>
>>> Is that the closest we’re going to get to “ah, sorry, I missed that”?
>>
>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>> you not see my several mentions of Thurso (rather than Wick) being the
>> best place for the northern charging station, and Brora being the best
>> places to add an intermediate charging station?
>
>Well I’ve lost the posting where “the proposition that there's now a
>mythical train that can do end-to-end on one charge” came up except where
>your wrote it above.

That was a week ago, and less than eight hours into the discussion.

There are 345 postings in the thread (according to my newsreader, today
at 7am) so it's not impossible for some fog to be developing.
--
Roland Perry

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
> Tweed <usenet.tweed@gmail.com> wrote:
>> Bob <email@domain.com> wrote:
>>> On 2022-02-14 19:51:57 +0000, Anna Noyd-Dryver said:
>>>
>>>> Tweed <usenet.tweed@gmail.com> wrote:
>>>>> Bob <email@domain.com> wrote:
>>>>>> On 2022-02-13 19:07:22 +0000, nib said:
>>>>>>
>>>>>>> On Sun, 13 Feb 2022 18:34:02 +0000, Anna Noyd-Dryver wrote:
>>>>>>>
>>>>>>>> nib <news@ingram-bromley.co.uk> wrote:
>>>>>>>>> On Sun, 13 Feb 2022 15:58:12 +0000, Marland wrote:
>>>>>>> ...
>>>>>>>>> Have we decided that some form of shielded bottom-contact 3rd-rail is
>>>>>>>>> also not possible?
>>>>>>>>>
>>>>>>>>> If it were, then surely just changing shoe-gear at the ends of the new
>>>>>>>>> bit of line would be better than dual-voltage?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>> It is permitted, but it's not compatible with the existing 3rd rail
>>>>>>>> equipment.
>>>>>>>>
>>>>>>>
>>>>>>> Do you mean that it wouldn't be possible to design some automated gadget
>>>>>>> to retract one set of shoes and enable another - or is there some
>>>>>>> fundamental reason that you can't combine both on one train?
>>>>>>
>>>>>> There are both under-running and over-running 3rd rail systems in New
>>>>>> York, and I believe there are trains that can run on both systems, so
>>>>>> it is technically possible. With the general maturity of dual voltage
>>>>>> technology, though, there really isn't a good reason for not using 25
>>>>>> kV OHLE, even in traditionally 3rd rail territory.
>>>>>>
>>>>>
>>>>> I’d be genuinely interested in figures that compared electrocution
>>>>> (electric shock not necessarily involving death before we start the
>>>>> argument about the definition of electrocution again) per installed km of
>>>>> track of 3rd rail vs 25kV OHLE.
>>>>>
>>>>
>>>> For 25kV, I'm only aware of one such incident involving staff, in the last
>>>> decade or so:
>>>> <https://assets.publishing.service.gov.uk/media/558803de40f0b615b600001a/R072015_150624_Sutton_Weaver.pdf>.
>>>>
>>>>
>>>> The various injuries to/deaths of trespassers (usually children) must be
>>>> listed somewhere, presumably? Two or perhaps three come to mind.
>>>
>>> Another safety issue is that due to the low voltage, 3rd rail systems
>>> need to be able to provide a truely huge current as part of normal
>>> operations, while 25 kV lines do not. A short to ground on a 25 kV
>>> line will pretty easily trigger the circuit breakers. On a 3rd rail
>>> line, if a fault is not a very highly conductive short, the current
>>> flowing may well be insufficient to trigger the circuit breakers as it
>>> may be less than the starting current of a couple of longer trains.
>>>
>>> Robin
>>>
>>>
>>
>> But that’s more of a fire risk mitigation. No amount of current limiting is
>> going to protect a human in the circuit.
>>
>> It’s been mentioned that it’s not a good idea having 3rd rail at ankle
>> level in the working environment. Are there any requirements for rail
>> workers, including train staff, to wear appropriate safety footwear? It’s
>> relatively easy to insulate footwear to withstand 1000V, especially as it’s
>> DC and therefore no capacitive coupling.
>>
>>
>
> Safety footwear of a number of varieties is required for traincrew (shoes
> are permitted which wouldn't protect against eg. accidental sideways
> contact with 3rd rail). I would expect safety boots to be mandated for
> track workers but I still wouldn't want to stand on 3rd rail whatever the
> leaflet which came with my shoes said.
>
>
> Anna Noyd-Dryver
>
>

I wouldn’t purposely stand on a third rail with appropriate safety shoes,
but neither would I drop a brick on my head when wearing a hard hat. I’m
surprised any member of staff that may be required to walk on the track
with a live third rail isn’t required to wear suitable protective boots.
Even some sort of plastic over trousers or gaiters would help. I can see
wearing such stuff would be unpleasant whilst working in the train. But
it’s not beyond possible to have stored PPE to put on when having to walk
the track. Many other industries require PPE.

Roland Perry <roland@perry.co.uk> wrote:
> In message <suh96h$hht$1@dont-email.me>, at 22:24:17 on Tue, 15 Feb
> 2022, Recliner <recliner.usenet@gmail.com> remarked:
>> Certes <none@nowhere.net> wrote:
>>> On 15/02/2022 19:35, Tweed wrote:
>>>> Certes <none@nowhere.net> wrote:
>>>>> On 15/02/2022 16:09, Roland Perry wrote:
>>>>>> In message <sugdmh$m84$2@dont-email.me>, at 14:34:57 on Tue, 15 Feb
>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>> In message <sufuvg$ogc$1@dont-email.me>, at 10:23:44 on Tue, 15 Feb
>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>> In message <sub73d$kkl$1@dont-email.me>, at 15:11:41 on Sun, 13 Feb
>>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>>>>>>> In message <sub2h3$kpq$1@dont-email.me>, at 13:53:39 on Sun, 13 Feb
>>>>>>>>>>>> 2022, Sam Wilson <ukr@dummy.wislons.fastmail.co.uk> remarked:
>>>>>>>>
>>>>>>>>>>>>>>>> Aren't multiple charging stations diametrically opposed to the
>>>>>>>>>>>>>>>> proposition that there's now a mythical train that can do
>>>>>>>>>>>>>>>> end-to-end
>>>>>>>>>>>>>>>> on one charge?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> There isn't.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> So it seems, despite claims early in the thread, that were
>>>>>>>>>>>>>> based on mileage myths, as much as airbrushing out
>>>>>>>>>>>>>> only-charge-at-the-ends operational issues.
>>>>>>>>>>>>>
>>>>>>>>>>>>> The claims were that the current record distance is 15% or 25%
>>>>>>>>>>>>> short of the  Inverness-Wick distance.  There was an initial typo
>>>>>>>>>>>>> suggesting that the  record was 25% longer, but that was
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> Given that the consensus is now that charging stations only
>>>>>>>>>>>> the ends is a non-starter, the relevance of the "world
>>>>>>>>>>>> record" is bleak.
>>>>>>>>>>>
>>>>>>>>>>> It always was.  I don’t know how you got the idea that it
>>>>>>>>>>> anything other.  Perhaps you could go back and check the
>>>>>>>>>>> beginning of the thread again?
>>>>>>>>>>
>>>>>>>>>> Original posting:
>>>>>>>>>>
>>>>>>>>>> "Add 10-15% to that [invisible words alert: "World Record"] and
>>>>>>>>>> Inverness to Wick becomes possible."
>>>>>>>>>
>>>>>>>>> You need to read just a little further.  In the very next
>>>>>>>>> Recliner wrote:
>>>>>>>>>
>>>>>>>>> “That record-breaking distance is 25% higher [later corrected
>>>>>>>>> to lower] than Inverness-Wick. The reliable, operational range
>>>>>>>>> less, of course.
>>>>>>>>>
>>>>>>>>> I suppose the solution would be to have 2-3 top-up stations en
>>>>>>>>> route, …”
>>>>>>>>>
>>>>>>>>> And the conversation proceeded on that basis.
>>>>>>>>
>>>>>>>> Indeed so. This subthread has been lagging the general discussion
>>>>>>>> somewhat.
>>>>>>>
>>>>>>> Is that the closest we’re going to get to “ah, sorry, I
>>>>>>> missed that”?
>>>>>>
>>>>>> Obviously I hadn't missed the fact the discussion had proceeded on. Did
>>>>>> you not see my several mentions of Thurso (rather than Wick) being the
>>>>>> best place for the northern charging station, and Brora being the best
>>>>>> places to add an intermediate charging station?
>>>>>
>>>>> I'm not convinced that anywhere other then the end points makes a good
>>>>> place for a charging station, as the train won't be there long enough.
>>>>
>>>> Intermediate stations get you out of trouble if the train has to be turned
>>>> back early, or if the far end charging station is not working. Otherwise
>>>> you really need enough range to get you there and back.
>>>>
>>> True but I don't see intermediate chargers getting in normal service,
>>> except maybe before the morning peak short run into Inverness.
>>
>> Presumably they'd be fitted at one or two crossover stations, where trains
>> stop for several minutes anyway,
>
> A quick look at RTT shows 3 mins at Muir of Ord and Fornisard, but no
> obvious other candidates. I'm not sufficiently familiar with the line to
> know where the loops in fact are.
>
>> plus Thurso.
>>
>

Well I’ll still come back to stating that something like the
Birmingham-Leicester-Stansted service would be better suited to such a
battery train. Once Leicester is electrified there will be sufficient
opportunities to keep the battery topped up. I’m surprised that enclosed
stations such as Birmingham New Street don’t fall foul of legislation about
the quality of air that station staff have to inhale.

On 2022-02-16 00:33:15 +0000, Anna Noyd-Dryver said:

> <Muttley@dastardlyhq.com> wrote:
>> On Mon, 14 Feb 2022 17:56:50 +0100
>> Bob <email@domain.com> wrote:
>>> On 2022-02-14 16:45:46 +0000, Muttley@dastardlyhq.com said:
>>>
>>>> On Mon, 14 Feb 2022 11:02:20 +0100
>>>> Bob <email@domain.com> wrote:
>>>>> On 2022-02-14 08:55:32 +0000, Muttley@dastardlyhq.com said:
>>>>>>> With the resignalling to ETCS2 on the ECML (as discussed in another
>>>>>>> thread recently), the issues preventing >125 mph running on the ECML
>>>>>>> will be resolved, and it will be possible to run trains at higher
>>>>>>> speeds. Too late for the 91s, though.
>>>>>>
>>>>>> Its *possible* to run the Javelins at 140mph on HS1 but apparently they're
>>>>>> still limited to 125 for [reasons]. So wrt the ECML I'll believe it when I
>>>>>> see it.
>>>>>
>>>>> They are permitted to run at 140. They are timetabled at 125, with the
>>>>> intention that higher speeds can be used to recover from delays and
>>>>> ensure reliability of the service.
>>>>
>>>> Which completely defeats the point. You wouldn't get the French saying
>>>> "We can run our TGVs at 186 but we'll limit them to 170 so we can recover
>>>> the timetable if they're running late". Its a utter farce and it'll be
>>>> exactly the same nonsense on the ECML I can guarantee it.
>>>
>>> Given the length of HS1, the difference between 125 mph timings and 140
>>> mph timings is going to be something like 2 minutes. Two minutes of
>>> recovery time seems a reasonable ammount of padding to include on
>>> routes like these.
>>
>> Problem is you can use that argument reducto as absurdum. The timing
>> difference between 120 and 100mph would also be slight over that distance
>> so why not reduce it down to 100? Ditto 100 and 70 etc etc. In the end
>> you'd be down to the speed of horse drawn carraiges.

> Pre-electrification timetable, GWML HSTs could maintain time but not regain
> lost time if limited to 100mph (eg broken outer skin of double-glazed
> window, one tone of horn not working). At 70mph you'd lose acres of time!

That would suggest that timings are based on 100 mph maximum speed for
the 125 mph HST (with higher speeds used to allow for delays), in the
same way that on HS1 the Kent timings are based on 125 mph for 140 mph
395s. Useful data point, thanks. Out of curiosity, what situations
might lead to an HST being restricted to 70 mph? Or is that just an
arbitrary example speed.

> One clue is that acceleration gets much slower as speed gets higher, so
> 100->125 takes more distance than 0->100.

Even at constant acceleration (ie speed gain per time), the distance
covered would be greater for higher speeds. (going back to A-Level,
s=ut+1/2at^2). At higher speeds, accelerating trains are going to be
running at full power, so can be treated as having a fixed power
output. P=F*v so as v increases, F (the force accelerating the train)
decreases. Even in the absence of any resistance to motion, the
acceleration would decrease, but at high speeds aerodynamic drag is
going to dominate the resistance to motion, and that to a first
approximation goes as the square of velocity, so the excess tractive
force able to accelerate the train will reduce significantly as speed
increases, hence that last bit up to top speed takes quite a long time.

Electric trains generally have much more installed power than diesel
ones, hence they accelerate better at higher speeds. That's why a
91+MK4s, although slower from a standing start than an HST (4 powered
axles against 8), once they get past the point where the number of
powered axles makes a difference, can significantly out-accelerate an
HST at higher speeds. Obviously an IEP on electric has the advantage
of both more powered axles to get a fast off-the-line acceleration at
low speeds and also a high power output for better acceleration at
higher speeds.

For locomotives with DC traction motors there are other effects related
to the characteristics of the traction motor itself, with things like
field weakening needed to achieve higher speeds as the back-EMF becomes
large, but that's a more advanced topic, and with AC traction motors
that are now largely standard, things work differently anyway.

Robin

On Wed, 16 Feb 2022 09:07:49 +0100
Bob <email@domain.com> wrote:
>On 2022-02-16 00:33:15 +0000, Anna Noyd-Dryver said:
>Electric trains generally have much more installed power than diesel
>ones, hence they accelerate better at higher speeds. That's why a
>91+MK4s, although slower from a standing start than an HST (4 powered
>axles against 8), once they get past the point where the number of
>powered axles makes a difference, can significantly out-accelerate an

Wouldn't the number of axles matter at any speed because at high speed you
have a lot of wind and rolling resistence and in theory could get wheelslip
because of it?

Tweed <usenet.tweed@gmail.com> wrote:
>
>>>
>>> But that’s more of a fire risk mitigation. No amount of current limiting is
>>> going to protect a human in the circuit.
>>>
>>> It’s been mentioned that it’s not a good idea having 3rd rail at ankle
>>> level in the working environment. Are there any requirements for rail
>>> workers, including train staff, to wear appropriate safety footwear? It’s
>>> relatively easy to insulate footwear to withstand 1000V, especially as it’s
>>> DC and therefore no capacitive coupling.
>>>
>>>
>>
>> Safety footwear of a number of varieties is required for traincrew (shoes
>> are permitted which wouldn't protect against eg. accidental sideways
>> contact with 3rd rail). I would expect safety boots to be mandated for
>> track workers but I still wouldn't want to stand on 3rd rail whatever the
>> leaflet which came with my shoes said.
>>
>>
>> Anna Noyd-Dryver
>>
>>
>
> I wouldn’t purposely stand on a third rail with appropriate safety shoes,
> but neither would I drop a brick on my head when wearing a hard hat. I’m
> surprised any member of staff that may be required to walk on the track
> with a live third rail isn’t required to wear suitable protective boots.
> Even some sort of plastic over trousers or gaiters would help. I can see
> wearing such stuff would be unpleasant whilst working in the train. But
> it’s not beyond possible to have stored PPE to put on when having to walk
> the track. Many other industries require PPE.
>
>

One thing that is essential to check with electrically protective footwear
is that the sole hasn’t been penetrated by an object like a nail or screw
or even a bit of sharp metal debri .

There have been cases where such a nail has penetrated just far enough to
not cause the wearer
discomfort but is inserted far enough to be in contact with the damp and
conductive environment inside the boot caused by perspiration and general
muck inside, subsequently when the wearer should have been protected the
current did what it does and found a path through the wearers leg and foot.

GH