On Thu, 14 Apr 2022 17:39:39 +0100, "hounslow3@yahoo.co.uk"
<hounslow3@yahoo.co.uk> wrote:

>On 13/04/2022 21:59, Charles Ellson wrote:
>> On Wed, 13 Apr 2022 02:30:20 +0100, "hounslow3@yahoo.co.uk"
>> <hounslow3@yahoo.co.uk> wrote:
>>
>>> On 13/04/2022 00:22, Certes wrote:
>>>> On 12/04/2022 22:47, hounslow3@yahoo.co.uk wrote:
>>>>> On 12/04/2022 18:48, Bevan Price wrote:
>>>>>> On 12/04/2022 13:24, Recliner wrote:
>>>>>>> On Tue, 12 Apr 2022 12:47:46 +0100, Scott
>>>>>>> <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>>
>>>>>>>> On Tue, 12 Apr 2022 12:18:36 +0100, Certes <none@nowhere.net> wrote:
>>>>>>>>
>>>>>>>>> On 12/04/2022 12:11, Recliner wrote:
>>>>>>>>>> On Tue, 12 Apr 2022 09:23:03 +0100, Scott
>>>>>>>>>> <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>>>>>
>>>>>>>>>>> On Mon, 11 Apr 2022 22:08:35 +0100, Charles Ellson
>>>>>>>>>>> <charlesellson@btinternet.com> wrote:
>>>>>>>>>>> [snip]
>>>>>>>>>>>
>>>>>>>>>>> I think OP needs to rephrase the question.
>>>>>>>>>>
>>>>>>>>>> I suppose the distilled question is, "Why are passengers allowed
>>>>>>>>>> to walk across tram tracks, but not light railway
>>>>>>>>>> tracks?".
>>>>>>>>>
>>>>>>>>> Because trams usually run on roads, and pedestrians are allowed to
>>>>>>>>> walk
>>>>>>>>> across roads (and along them, even at level crossings).  Light
>>>>>>>>> railways
>>>>>>>>> generally seem to be fenced, perhaps because they used to be heavy
>>>>>>>>> rail.
>>>>>>>>
>>>>>>>> This is a circular argument.  Pedestrians are allowed because trams
>>>>>>>> run on roads.  But on what basis are the trams allowed to run on a
>>>>>>>> road?  The question seems to be: what are the defining criteria?
>>>>>>>
>>>>>>> Trams in the UK usually run much more on segregated track than
>>>>>>> roads, and they usually run faster on such sections. But
>>>>>>> passengers can still walk across the tracks, particularly at stops.
>>>>>>
>>>>>> On unsegregated track, trams in UK have to obey the locally
>>>>>> applicable road regulations, including speed limits, traffic lights,
>>>>>> etc.
>>>>>
>> Your first trouble is that trams work in kph (maybe an exception for
>> Blackpool as it has been there for years?) so road speed limit signs
>> would need translation.
>>
>>>>> Really? I thought that unsgregated trams in the UK were subject to
>>>>> their own signal signs and signals, which can differ from road
>>>>> regulations.
>>>>>
>>>>> That is the case in Germany, AFAIK.
>>>>
>>>> That's the case in Edinburgh.  For examples, see
>>>> <https://commons.wikimedia.org/wiki/Edinburgh_Trams:_signals#Street
>>>> running signalling>
>>>
>>> Where is there a website that contains information on signals and signal
>>> signs on UK tram networks, BTW?
>>>
>> Some in :-
>> https://uktram.com/wp-content/uploads/2018/07/TGN32-Signing_of_Tramways_2.pdf
>
>I saw that, thanks.
>
>I notice that there are a couple of signals and signal signs that are
>not listed in the attachment.
>
>At Dundonald Road, for example, the middle LED in the signal is dark. It
>then lights up before the entire signal clears.
>
>You can see that aspect here:
>
>https://upload.wikimedia.org/wikipedia/commons/0/08/Dundonald_Road_tramstop_look_east.JPG
>
I am tempted to suggest it is faulty.
Ah, hang on - "Special Tram Traffic Signals" about 1/3 down
https://citytransport.info/Tramlink.htm
it looks like a tram equivalent to red+amber on road ATS.
"and the tram signals operate in a way designed to minimise delays /
maximise junction throughput."

>I don't know if, when the LED lights up, it means CD, put your
>controller into station holding or if it is just means prepare to depart.
>
>Perhaps the signal is an 'Approach Restricted' aspect, however? IIRC,
>there is another signal just like that on the line between stops and
>closer to East Croydon. IIRC, the signal goes through those aspects as a
>tram approaches.
>
>I have also seen the diamond signal sign with the letter 'C'. Does that
>mean coast?
>
Pass. The only non-numeric diamond sign I can find is with a black
horizontal bar in Dublin and Edinburgh, described in Irish legislation
as "Stop". It also appears along with signals so in full appears to be
Stop then Proceed (unless otherwise indicated) like a road junction
Stop sign. Perhaps the "C" sign is Croydon-specific or otherwise has
infrequent use?

On Thu, 14 Apr 2022 12:21:37 +0100, Mark Goodge
<usenet@listmail.good-stuff.co.uk> wrote:

>On Wed, 13 Apr 2022 22:02:16 +0100, Charles Ellson
><charlesellson@btinternet.com> wrote:
>
>>On Wed, 13 Apr 2022 13:31:46 +0100, Mark Goodge
>><usenet@listmail.good-stuff.co.uk> wrote:
>>
>>>On Wed, 13 Apr 2022 11:43:33 +0200, Rolf Mantel <news@hartig-mantel.de>
>>>wrote:
>>>
>>>>Am 12.04.2022 um 23:47 schrieb hounslow3@yahoo.co.uk:
>>>>> On 12/04/2022 18:48, Bevan Price wrote:
>>>>
>>>>>> On unsegregated track, trams in UK have to obey the locally applicable
>>>>>> road regulations, including speed limits, traffic lights, etc.
>>>>>>
>>>>>
>>>>> Really? I thought that unsgregated trams in the UK were subject to their
>>>>> own signal signs and signals, which can differ from road regulations.
>>>>>
>>>>> That is the case in Germany, AFAIK.
>>>>
>>>>Let's be very precise: In Germany, trams on the road have to obey the
>>>>same road traffic rules as busses with the exception of not being able
>>>>to chose which lane to drive in; I would strongly speculate this is the
>>>>same in UK (and is one reason not to build any "trams on the road").
>>>
>>>It's not quite the same. For example, traffic lights don't apply to
>>>trams - at light-controlled junctions, trams will always have their own
>>>signals which will be the same as on off-road sections. Obviously, these
>>>will change in sync with the traffic lights on shared sections, but both
>>>will always be present.
>>>
>>>Signs giving instructions for mandatory or prohibited turns also don't
>>>apply to trams, but other signs do, unless explicitly overridden by
>>>tram-specific signs. That includes speed limits.
>>>
>>Trams are excluded from the general definition of
>>"mechanically-propelled vehicles" to which road traffic signs apply.
>
>Do you have a cite for that? Because the Traffic Signs Regulations and
>General Directions 2002 explicitly exempts trams from obeying traffic
>lights and mandatory turn signs, something which would not be necessary
>if they were not otherwise generally subject to signage.
>
I think we had something similar a few years back with trams being
subject to multiple specific examptions rather than more general ones.

There is also case law that a tram is not a "motor vehicle" or
"mechanically propelled vehicle" (in the context of road traffic
legislation) as it cannot travel on a road surface if it leaves the
rails:-
https://www.linkedin.com/pulse/tram-motor-vehicle-daniel-rothel

The Road Traffic Act 1988 also has multiple but varying optional
exceptions** (including ss.34-48 wherein traffic signs lie) for trams,
trolley vehicles and guided vehicles. The 1988 Act is possibly just
the tip of an iceberg of applicable legislation.

** including -
" s.193A Tramcars and Trolley Vehicles
(1) The Secretary of State may by regulations provide that such of the
provisions mentioned in subsection (2) below as are specified in the
regulations shall not apply, or shall apply with modifications --"

On Thu, 14 Apr 2022 13:14:45 +0200, Rolf Mantel
<news@hartig-mantel.de> wrote:

>Am 13.04.2022 um 22:40 schrieb Charles Ellson:
>> The standard round signs also thus do not apply to e.g. pedal cycles
>> or horse/horse-drawn traffic.
>
>That's interesting. In Germany, generic speed limits are only relevant
>for motorized traffic but signposted speed limits are relevant for all
>traffic.
>As a bicyclist, I may go faster than 50 km/h in town but I have to stick
>to the 30 km/h speed limits in residential areas.
>
Cyclists and horse-riders in England and Wales aren't entirely free to
thrash through town as they are subject to the 1861 and 1847 offences
of "wanton and furious driving" (if any injury is caused) or "riding
furiously" (if no injury is caused). Prosecutions generally occur if
they kill or injure someone else not themselves

In Scotland there is the catch-all Common Law offence of Culpable and
Reckless Conduct with a maximum [in theory] penalty of life
imprisonment but you would have to really annoy the prosecutors to get
the case sent to the High Court for that sentence.

Scott <newsgroups@gefion.myzen.co.uk> wrote:
> On Thu, 14 Apr 2022 14:50:22 -0000 (UTC), Anna Noyd-Dryver
> <anna@noyd-dryver.com> wrote:
>
>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>> On Wed, 13 Apr 2022 21:59:28 -0000 (UTC), Sam Wilson
>>> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>>>
>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>> In message <t34dlg$89a$1@gioia.aioe.org>, at 17:42:08 on Tue, 12 Apr
>>>>> 2022, muttley@dastardlyhq.com remarked:
>>>>>> On Tue, 12 Apr 2022 06:24:22 +0100
>>>>>> Roland Perry <roland@perry.co.uk> wrote:
>>>>>>> In message <t3258p$4t6$1@dont-email.me>, at 21:06:33 on Mon, 11 Apr
>>>>>>> 2022, Recliner <recliner.usenet@gmail.com> remarked:
>>>>>>>> I thought 'light railways' (like preserved railways) were limited to 25mph,
>>>>>>>> whereas trams go up to 50mph (or more?). Yet tram stops, even in
>>>>>>>> segregated sections, allow passengers to freely walk across the tracks,
>>>>>>>> with no fences or barriers.
>>>>>>>
>>>>>>> Trams have many safety features to deflect pedestrians rather than crush
>>>>>>
>>>>>> I wouldn't want to put them to the test.
>>>>>>
>>>>>>> them, and when street-running ding their bell frequently.
>>>>>>>
>>>>>>> Wasn't the OP really asking about *miniature* railways like the one at
>>>>>>> Longleat?
>>>>>>
>>>>>> No. I was asking about where the dividing line is between railways where
>>>>>> people can meander along and across and ones where there is strict segregation.
>>>>>
>>>>> Even the ECML still has a couple of level crossings one can wander
>>>>> across.
>>>>
>>>> I don?t know if they?re still there, but there certainly used to be
>>>> pedestrian crossings on the ECML near Belford in Northumberland with no
>>>> protection, just a stile. I?ve moaned before about one of them crossing a
>>>> siding with a rake of wagons parked on it. I don?t think that particular
>>>> siding exists any more, but there must be other places like that.
>>>>
>>> Que? Why would you moan about that?
>>>
>> Because the wagons parked in the siding (loop?) block the footpath.
>>
> I didn't appreciate that they were causing a blockage. I thought he
> meant the wagons were parked in the siding.
>

They are. And the footpath crosses the siding ;)

Anna Noyd-Dryver

<Muttley@dastardlyhq.com> wrote:
> On Thu, 14 Apr 2022 14:50:22 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> True. Though I think battery powered trams are an absurd idea. Their only
>>> raison d'etre is to stop nimbies complaining about overhead wires yet there
>>> already are a number of discrete embedded 3rd rail systems for trams which
>>> could be used instead. The most obvious one has been used since electric
>> trams
>>> were invented.
>>>
>>>
>>
>> Conduit? So trouble-free that Blackpool abandoned it as soon as a reliable
>> system of overhead contact was available!
>
> Used in London for decades. In fact until a lot of the routes were closed.
>

Used because it was good or used because they had no choice?

On the grounds that it was used only in the central area where wires
weren't allowed, and many routes changed to overhead wires part way, I
suspect the latter.

> Anyway, the French system seems to work well enough:
>
> https://goo.gl/maps/u6Pc4kX5VVomA2an7
>

Hasn't 'been used since electric trams were invented', though, unless you
mean the oh-so-successful stud system.

I'm sure the APS system is usually derided when mentioned here as being
excessively complicated, how does it cope in floods, etc. I'd love to see
it in action though.

I note that most systems (Dubai and Istanbul being the exceptions) use it
either 'in the historic city centre' with wires elsewhere, or to charge
battery (or capacitor) trams at stops only, which implies that wires, in
general, are preferable; the Wikipedia page on one Chinese system includes
"The power supply was especially vulnerable to rainwater, causing short
circuits and electricity leakage.[4]", while the page about Bordeaux says
"This was the source of many difficulties and breakdowns when first
introduced.". Hmmm.

Anna Noyd-Dryver

Graeme Wall <rail@greywall.demon.co.uk> wrote:
> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>> On Thu, 14 Apr 2022 10:03:17 -0000 (UTC)
>> Recliner <recliner.usenet@gmail.com> wrote:
>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>> On Thu, 14 Apr 2022 09:17:38 -0000 (UTC), Recliner
>>>> <recliner.usenet@gmail.com> wrote:
>>>>> The whole idea of this system is to have lightweight, shallow track that's
>>>>> much cheaper and quicker to install than normal tramways in this country.
>>>>> Most underground services won't need to be disturbed and no OHLE will be
>>>>> required. That takes away most of the objections to normal trams.
>>>>
>>>> Surely it is the weight of the tram not the track that is the main
>>>> issue? I assume battery powered trams will be heavier.
>>>>
>>>
>>> The whole point of these new trams is that they're very light. That's why
>>> they're called Coventry Very Light Rail (CVLR).
>>
>> Get back to us when they've actually built one. "Light" is a relative term
>> when it comes to rail vehicles. Even the PPM weighs 12 tons and thats with
>> a flywheel, not heavy batteries.
>>
>
> Flywheels are heavy, that is the point of them.
>

I was going to post that, but the only reference I could easily find to a
Parry flywheel says it's 500kg, which isn't as much as I'd expected.

Anna Noyd-Dryver

<Muttley@dastardlyhq.com> wrote:
> On Thu, 14 Apr 2022 10:44:27 -0000 (UTC)
> Recliner <recliner.usenet@gmail.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> There's a system used in france that has the 3rd rail flush with the ground
>>> and is only energised when a tram is over it. They use it in Angier in the
>>> historic centre. Probably costs a fair amount over OHLE but then I imagine
>> so
>>> do batteries.
>>
>> Why would the batteries be very expensive? Lots of conventional trams are
>
> Because LiOn traction batteries are expensive.
>
>> now fitted with batteries, including in Birmingham, to allow discontinuous
>> electrification. These light trams will need relatively small batteries, as
>> they don't need a long range.
>
> Since there will be no electrification whatsoever presumably the batteries
> will have to be charged in the morning and last all day unless they have some
> sort of 3rd rail or overhead charge point at the termini.
>

The usual arrangement is to have charging at stops (for example the
supercapacitor-powered line I travelled on in Taiwan) or for the battery
section to be only a short length between wired parts (eg Birmingham).

Anna Noyd-Dryver

hounslow3@yahoo.co.uk <hounslow3@yahoo.co.uk> wrote:
> On 14/04/2022 11:44, Recliner wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On Thu, 14 Apr 2022 09:53:47 +0100
>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>> On Thu, 14 Apr 2022 08:11:40 -0000 (UTC), Muttley@dastardlyhq.com
>>>> wrote:
>>>>>> But that's the same issue whether you use battery-powered busses or a
>>>>>> battery-powered tram.
>>>>>
>>>>> True. Though I think battery powered trams are an absurd idea. Their only
>>>>> raison d'etre is to stop nimbies complaining about overhead wires yet there
>>>>> already are a number of discrete embedded 3rd rail systems for trams which
>>>>> could be used instead. The most obvious one has been used since electric trams
>>>>
>>>>> were invented.
>>>>
>>>> Conduit in the LCC area.
>>>>
>>>> I thought it was far more heavy maintenance than overhead wires and
>>>> less reliable.
>>>
>>> There's a system used in france that has the 3rd rail flush with the ground
>>> and is only energised when a tram is over it. They use it in Angier in the
>>> historic centre. Probably costs a fair amount over OHLE but then I imagine so
>>> do batteries.
>>
>> Why would the batteries be very expensive? Lots of conventional trams are
>> now fitted with batteries, including in Birmingham, to allow discontinuous
>> electrification.
>
> They have same on the main square in Padova, I think in that case not to
> spoil the view. IIRC, there is also discontinuous electrification on the
> Mestre-Venice tram, at least on the Venice side.
>

The Mestre-Venice 'tram' is actually one of the single-rail-guided, rubber
tyre systems, and has OLE throughout. It doesn't enter any historic areas
of Venice, it terminates next to the bus station, near the railway station,
as soon as it's crossed the causeway from the mainland.

Anna Noyd-Dryver

nib <news@ingram-bromley.co.uk> wrote:
> On Thu, 14 Apr 2022 13:45:47 +0100, Recliner wrote:
>
>> On Thu, 14 Apr 2022 12:02:03 -0000 (UTC), Sam Wilson
>> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>>
>>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>>>> On Thu, 14 Apr 2022 10:03:17 -0000 (UTC)
>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>> On Thu, 14 Apr 2022 09:17:38 -0000 (UTC), Recliner
>>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>>> The whole idea of this system is to have lightweight, shallow
>>>>>>>> track that's much cheaper and quicker to install than normal
>>>>>>>> tramways in this country. Most underground services won't need to
>>>>>>>> be disturbed and no OHLE will be required. That takes away most of
>>>>>>>> the objections to normal trams.
>>>>>>>
>>>>>>> Surely it is the weight of the tram not the track that is the main
>>>>>>> issue? I assume battery powered trams will be heavier.
>>>>>>>
>>>>>>>
>>>>>> The whole point of these new trams is that they're very light.
>>>>>> That's why they're called Coventry Very Light Rail (CVLR).
>>>>>
>>>>> Get back to us when they've actually built one. "Light" is a relative
>>>>> term when it comes to rail vehicles. Even the PPM weighs 12 tons and
>>>>> thats with a flywheel, not heavy batteries.
>>>>>
>>>>>
>>>> Flywheels are heavy, that is the point of them.
>>>
>>> Or fast, or both.
>>
>> The PPM flywheel is 1m diameter, rotates at 2500 rpm, and weighs 0.5
>> tonnes. It also needs some sort of small engine,
>> generator, fuel store, etc.
>
> If all that 500 kg is at the periphery with only very light spokes then
> the moment of inertia is mr^2 = 500 * 0.5^2 = 125 kg.m^2.
>
> 2500 rpm is 260 radians/sec. Energy stored = 0.5 * I * w^2 = 0.5 * 125 *
> 260 * 260 = 4.2 MJ, or 1.2 kWh. OK, it's more than 3 times the size of
> the battery on my bike but it's only about 1/40 of a 300 kg EV battery.
>
> So good for storing regen and power from a small motor and putting it
> back into acceleration but not going to take a tram (or even a PPM) very
> far on a non-electrified section.
>
>

Thanks for doing the maths; it's the only easily-obtainable figure for the
Parry flywheel, but without further clarification, I suspect it might
relate to some earlier experimental vehicles, rather than the 'production'
pair.

Anna Noyd-Dryver

On 15/04/2022 02:36, Anna Noyd-Dryver wrote:
> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>> On Thu, 14 Apr 2022 10:03:17 -0000 (UTC)
>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>> On Thu, 14 Apr 2022 09:17:38 -0000 (UTC), Recliner
>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>> The whole idea of this system is to have lightweight, shallow track that's
>>>>>> much cheaper and quicker to install than normal tramways in this country.
>>>>>> Most underground services won't need to be disturbed and no OHLE will be
>>>>>> required. That takes away most of the objections to normal trams.
>>>>>
>>>>> Surely it is the weight of the tram not the track that is the main
>>>>> issue? I assume battery powered trams will be heavier.
>>>>>
>>>>
>>>> The whole point of these new trams is that they're very light. That's why
>>>> they're called Coventry Very Light Rail (CVLR).
>>>
>>> Get back to us when they've actually built one. "Light" is a relative term
>>> when it comes to rail vehicles. Even the PPM weighs 12 tons and thats with
>>> a flywheel, not heavy batteries.
>>>
>>
>> Flywheels are heavy, that is the point of them.
>>
>
> I was going to post that, but the only reference I could easily find to a
> Parry flywheel says it's 500kg, which isn't as much as I'd expected.
>
>

The weight distribution is probably more important than the weight. If
most of the weight is on the outside of the flywheel it will store far
more energy than if it is evenly distributed.

In message <t3a580$7o0$1@dont-email.me>, at 21:55:12 on Thu, 14 Apr
2022, Recliner <recliner.usenet@gmail.com> remarked:
>Roland Perry <roland@perry.co.uk> wrote:
>> In message <ai6g5hpvbqljqikjek6bro4e4it6fgmlh2@4ax.com>, at 13:58:54 on
>> Thu, 14 Apr 2022, Recliner <recliner.usenet@gmail.com> remarked:
>>> On Thu, 14 Apr 2022 11:25:40 +0100, Roland Perry <roland@perry.co.uk> wrote:
>>>
>>>> In message <tvqf5h9m93i1vfad5osiqsvq7fi5tm22uf@4ax.com>, at 10:41:33 on
>>>> Thu, 14 Apr 2022, Scott <newsgroups@gefion.myzen.co.uk> remarked:
>>>>
>>>>>> The former 80 km/h limit was on segregated, former BR track, and
>>>>>>nothing to
>>>>>> do with road speed limits. The accident occurred as a tram was coming off
>>>>>> such a section, going round a tight right-angle bend to enter the
>>>>>>on-street
>>>>>> urban section. The Croydon trams have little on-street running, only on
>>>>>> town centre roads probably with a 30mph limit or lower.
>>>>>>
>>>>>> The speedo shows how 80 km/h was previously permitted:
>>>>>> <https://www.flickr.com/photos/recliner/31194316805/in/album-7215767697
>>>>>> 6959855/>
>>>>>
>>>>> I'm not sure it shows anything of the sort. My car speedo goes up to
>>>>> 140 mph but this does not show this speed was previously permitted.
>>>>
>>>> Or even possible. When I was in short trousers we'd peer at through the
>>>> window at the speedos on cars and assume the to speed was whatever the
>>>> speedo went up to. One of the reasons for tram speed limits being
>>>> reduced for 80 to 70 is reportedly that some networks have bought their
>>>> second generation stock, which is only capable of 70kph (possibly a
>>>> European thing).
>>>
>>> I don't think it would be a European thing. They may simply have
>>> decided to specify new trams with a lower top speed and
>>> better acceleration. Overall, that might produce faster journey times.
>>
>> What I mean is that the market for trams in Europe is allegedly for
>> 70kph max, while they might have made some "80kph specials" for the UK
>> 20yrs ago, maybe they are less inclined to now. [Not a Brexit thing]
>
>Is there a European 70 km/h upper speed?

In practice it looks like that's typically the fastest they operate with
modern stock. Athens for example, built for 80mph is nevertheless
introducing its 2nd generation using 70kph Alstom stock.
--
Roland Perry

On 14/04/2022 21:57, hounslow3@yahoo.co.uk wrote:
> On 14/04/2022 18:42, Marland wrote:
>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>> On Thu, 14 Apr 2022 10:44:27 -0000 (UTC), Recliner
>>> <recliner.usenet@gmail.com> wrote:
>>>
>>>> <Muttley@dastardlyhq.com> wrote:
>>>>> On Thu, 14 Apr 2022 09:53:47 +0100
>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>> On Thu, 14 Apr 2022 08:11:40 -0000 (UTC), Muttley@dastardlyhq.com
>>>>>> wrote:
>>>>>>>> But that's the same issue whether you use battery-powered busses
>>>>>>>> or a
>>>>>>>> battery-powered tram.
>>>>>>>
>>>>>>> True. Though I think battery powered trams are an absurd idea.
>>>>>>> Their only
>>>>>>> raison d'etre is to stop nimbies complaining about overhead wires
>>>>>>> yet there
>>>>>>> already are a number of discrete embedded 3rd rail systems for
>>>>>>> trams which
>>>>>>> could be used instead. The most obvious one has been used since
>>>>>>> electric trams
>>>>>>
>>>>>>> were invented.
>>>>>>
>>>>>> Conduit in the LCC area.
>>>>>>
>>>>>> I thought it was far more heavy maintenance than overhead wires and
>>>>>> less reliable.
>>>>>
>>>>> There's a system used in france that has the 3rd rail flush with
>>>>> the ground
>>>>> and is only energised when a tram is over it. They use it in Angier
>>>>> in the
>>>>> historic centre. Probably costs a fair amount over OHLE but then I
>>>>> imagine so
>>>>> do batteries.
>>>>
>>>> Why would the batteries be very expensive?  Lots of conventional
>>>> trams are
>>>> now fitted with batteries, including in Birmingham, to allow
>>>> discontinuous
>>>> electrification. These light trams will need relatively small
>>>> batteries, as
>>>> they don't need a long range.
>>>
>>> Because AIUI there is a shortage of lithium and chromium with Chinese
>>> companies buying up mines in Africa.
>>>
>>
>> Time to start digging up Cornwall again then.
>> That’ll piss off all those second home owners who move down to wax
>> lyrical
>> over the landscape without appreciating that a good part of the
>> ambience is
>> caused by remains of an Industrial revolution that was virtually over
>> before the main one got underway.
>>
>> GH
>>
>
> I've heard of tin mining in Cornwall, but not chromium.

Tin was the classic mining activity, going back to pre-Roman times, but
Cornwall has quite a lot of different ores which have been commercially
mined in the recent past.

--
Graeme Wall
This account not read.

On Thu, 14 Apr 2022 18:37:21 +0100
Graeme Wall <rail@greywall.demon.co.uk> wrote:
>On 14/04/2022 16:22, Muttley@dastardlyhq.com wrote:
>> On Thu, 14 Apr 2022 11:48:46 +0100
>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>>>> The whole point of these new trams is that they're very light. That's why
>>>>> they're called Coventry Very Light Rail (CVLR).
>>>>
>>>> Get back to us when they've actually built one. "Light" is a relative term
>>>> when it comes to rail vehicles. Even the PPM weighs 12 tons and thats with
>>>> a flywheel, not heavy batteries.
>>>>
>>>
>>> Flywheels are heavy, that is the point of them.
>>
>> https://www.focustransport.org/2016/01/double-deck-parry-people-mover.html
>>
>> "A typical PPM flywheel is made from steel laminates, 1m in diameter and
>500kg
>> mass"
>>
>> Thats the same as an EV car battery and it only lasts for the half mile or so
>
>> the PPM has to crawl along. The battery for a 10+ ton tram will need to
>> be somewhat larger especially due to all the stop start that'll occur along
>> city streets and the longer route.
>>
>
>Rather like the electric buses that are working all day, every day in a
>number of towns and cities.

Check out the kerb weight of those buses compared to their diesel counterparts.

On Fri, 15 Apr 2022 01:36:02 -0000 (UTC)
Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>> Used in London for decades. In fact until a lot of the routes were closed.
>>
>
>Used because it was good or used because they had no choice?

No idea.

>On the grounds that it was used only in the central area where wires
>weren't allowed, and many routes changed to overhead wires part way, I
>suspect the latter.
>
>> Anyway, the French system seems to work well enough:
>>
>> https://goo.gl/maps/u6Pc4kX5VVomA2an7
>>
>
>Hasn't 'been used since electric trams were invented', though, unless you

Where did I say it had? Its fairly new.

>I'm sure the APS system is usually derided when mentioned here as being
>excessively complicated, how does it cope in floods, etc. I'd love to see
>it in action though.

The power is only on when a tram is on the section and during floods I doubt
trams are running anyway.

Anyway, these sorts of 3rd rail systems or batteries are only required due to
nimbies and over zealous planning committees. No sane authority would choose
them if OHLE was an option.

Graeme Wall <rail@greywall.demon.co.uk> wrote:
> On 14/04/2022 21:57, hounslow3@yahoo.co.uk wrote:
>> On 14/04/2022 18:42, Marland wrote:
>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>> On Thu, 14 Apr 2022 10:44:27 -0000 (UTC), Recliner
>>>> <recliner.usenet@gmail.com> wrote:
>>>>
>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>> On Thu, 14 Apr 2022 09:53:47 +0100
>>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>> On Thu, 14 Apr 2022 08:11:40 -0000 (UTC), Muttley@dastardlyhq.com
>>>>>>> wrote:
>>>>>>>>> But that's the same issue whether you use battery-powered busses
>>>>>>>>> or a
>>>>>>>>> battery-powered tram.
>>>>>>>>
>>>>>>>> True. Though I think battery powered trams are an absurd idea.
>>>>>>>> Their only
>>>>>>>> raison d'etre is to stop nimbies complaining about overhead wires
>>>>>>>> yet there
>>>>>>>> already are a number of discrete embedded 3rd rail systems for
>>>>>>>> trams which
>>>>>>>> could be used instead. The most obvious one has been used since
>>>>>>>> electric trams
>>>>>>>
>>>>>>>> were invented.
>>>>>>>
>>>>>>> Conduit in the LCC area.
>>>>>>>
>>>>>>> I thought it was far more heavy maintenance than overhead wires and
>>>>>>> less reliable.
>>>>>>
>>>>>> There's a system used in france that has the 3rd rail flush with
>>>>>> the ground
>>>>>> and is only energised when a tram is over it. They use it in Angier
>>>>>> in the
>>>>>> historic centre. Probably costs a fair amount over OHLE but then I
>>>>>> imagine so
>>>>>> do batteries.
>>>>>
>>>>> Why would the batteries be very expensive?  Lots of conventional
>>>>> trams are
>>>>> now fitted with batteries, including in Birmingham, to allow
>>>>> discontinuous
>>>>> electrification. These light trams will need relatively small
>>>>> batteries, as
>>>>> they don't need a long range.
>>>>
>>>> Because AIUI there is a shortage of lithium and chromium with Chinese
>>>> companies buying up mines in Africa.
>>>>
>>>
>>> Time to start digging up Cornwall again then.
>>> That’ll piss off all those second home owners who move down to wax
>>> lyrical
>>> over the landscape without appreciating that a good part of the
>>> ambience is
>>> caused by remains of an Industrial revolution that was virtually over
>>> before the main one got underway.
>>>
>>> GH
>>>
>>
>> I've heard of tin mining in Cornwall, but not chromium.
>
> Tin was the classic mining activity, going back to pre-Roman times, but
> Cornwall has quite a lot of different ores which have been commercially
> mined in the recent past.
>

I don’t think the residents of Cornwall need be too concerned.

https://wits.worldbank.org/trade/comtrade/en/country/ALL/year/2018/tradeflow/Exports/partner/WLD/product/261000

In 2018, Top exporters of Chromium ores and concentrates are South Africa
($1,850,172.51K ), Turkey ($306,470.59K , 1,457,210,000 Kg), Kazakhstan
($156,636.70K , 956,342,000 Kg), Zimbabwe ($94,136.05K , 847,155,000 Kg),
Pakistan ($69,509.07K , 258,130,000 Kg).

https://www.statista.com/statistics/268789/countries-with-the-largest-production-output-of-lithium/

In 2021, Australia was the world leader in terms of lithium mine
production, with an estimated output of 55,000 metric tons. Chile and China
ranked second and third, with lithium production totaling 26,000 and 14,000
metric tons, respectively.

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
> nib <news@ingram-bromley.co.uk> wrote:
>> On Thu, 14 Apr 2022 13:45:47 +0100, Recliner wrote:
>>
>>> On Thu, 14 Apr 2022 12:02:03 -0000 (UTC), Sam Wilson
>>> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>>>
>>>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>>>>> On Thu, 14 Apr 2022 10:03:17 -0000 (UTC)
>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>>> On Thu, 14 Apr 2022 09:17:38 -0000 (UTC), Recliner
>>>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>>>> The whole idea of this system is to have lightweight, shallow
>>>>>>>>> track that's much cheaper and quicker to install than normal
>>>>>>>>> tramways in this country. Most underground services won't need to
>>>>>>>>> be disturbed and no OHLE will be required. That takes away most of
>>>>>>>>> the objections to normal trams.
>>>>>>>>
>>>>>>>> Surely it is the weight of the tram not the track that is the main
>>>>>>>> issue? I assume battery powered trams will be heavier.
>>>>>>>>
>>>>>>>>
>>>>>>> The whole point of these new trams is that they're very light.
>>>>>>> That's why they're called Coventry Very Light Rail (CVLR).
>>>>>>
>>>>>> Get back to us when they've actually built one. "Light" is a relative
>>>>>> term when it comes to rail vehicles. Even the PPM weighs 12 tons and
>>>>>> thats with a flywheel, not heavy batteries.
>>>>>>
>>>>>>
>>>>> Flywheels are heavy, that is the point of them.
>>>>
>>>> Or fast, or both.
>>>
>>> The PPM flywheel is 1m diameter, rotates at 2500 rpm, and weighs 0.5
>>> tonnes. It also needs some sort of small engine,
>>> generator, fuel store, etc.
>>
>> If all that 500 kg is at the periphery with only very light spokes then
>> the moment of inertia is mr^2 = 500 * 0.5^2 = 125 kg.m^2.
>>
>> 2500 rpm is 260 radians/sec. Energy stored = 0.5 * I * w^2 = 0.5 * 125 *
>> 260 * 260 = 4.2 MJ, or 1.2 kWh. OK, it's more than 3 times the size of
>> the battery on my bike but it's only about 1/40 of a 300 kg EV battery.
>>
>> So good for storing regen and power from a small motor and putting it
>> back into acceleration but not going to take a tram (or even a PPM) very
>> far on a non-electrified section.
>>
>>
>
> Thanks for doing the maths; it's the only easily-obtainable figure for the
> Parry flywheel, but without further clarification, I suspect it might
> relate to some earlier experimental vehicles, rather than the 'production'
> pair.
>

There are two propulsion versions, self-powered with a small on-board
engine and the 1m flywheel for regen brakes (the current class 139), and an
intermittent electric powered variant, with a larger, heavier flywheel that
gets spun up at the stops, which can be up to half a mile apart:

Self-powered vehicles: Engine Ford DSG423 (propane gas or diesel fuel)
Primary transmission via gearbox, freewheel clutch and Tandler bevel box
4 ‘V-belt’ belt transmission to flywheel

Intermittent electric supply: 70V DC motor (requires 20kW supply at
stopping points)
‘Charge’ time at stopping points 30s, distance between stops up to 800m

Flywheel energy storage:
Effective speed range 1,000-2,600rpm
Flywheel diameter/mass 1m/500kg (self-powered), 1.2m/750kg (intermittent
electric)

http://friendlycreatives.co.uk/ppm/two-axle-vehicles/

nib <news@ingram-bromley.co.uk> wrote:
> On Thu, 14 Apr 2022 13:45:47 +0100, Recliner wrote:
>
>> On Thu, 14 Apr 2022 12:02:03 -0000 (UTC), Sam Wilson
>> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>>
>>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>>>> On Thu, 14 Apr 2022 10:03:17 -0000 (UTC)
>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>> On Thu, 14 Apr 2022 09:17:38 -0000 (UTC), Recliner
>>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>>> The whole idea of this system is to have lightweight, shallow
>>>>>>>> track that's much cheaper and quicker to install than normal
>>>>>>>> tramways in this country. Most underground services won't need to
>>>>>>>> be disturbed and no OHLE will be required. That takes away most of
>>>>>>>> the objections to normal trams.
>>>>>>>
>>>>>>> Surely it is the weight of the tram not the track that is the main
>>>>>>> issue? I assume battery powered trams will be heavier.
>>>>>>>
>>>>>>>
>>>>>> The whole point of these new trams is that they're very light.
>>>>>> That's why they're called Coventry Very Light Rail (CVLR).
>>>>>
>>>>> Get back to us when they've actually built one. "Light" is a relative
>>>>> term when it comes to rail vehicles. Even the PPM weighs 12 tons and
>>>>> thats with a flywheel, not heavy batteries.
>>>>>
>>>>>
>>>> Flywheels are heavy, that is the point of them.
>>>
>>> Or fast, or both.
>>
>> The PPM flywheel is 1m diameter, rotates at 2500 rpm, and weighs 0.5
>> tonnes. It also needs some sort of small engine,
>> generator, fuel store, etc.
>
> If all that 500 kg is at the periphery with only very light spokes then
> the moment of inertia is mr^2 = 500 * 0.5^2 = 125 kg.m^2.
>
> 2500 rpm is 260 radians/sec. Energy stored = 0.5 * I * w^2 = 0.5 * 125 *
> 260 * 260 = 4.2 MJ, or 1.2 kWh. OK, it's more than 3 times the size of
> the battery on my bike but it's only about 1/40 of a 300 kg EV battery.
>
> So good for storing regen and power from a small motor and putting it
> back into acceleration but not going to take a tram (or even a PPM) very
> far on a non-electrified section.

Thank you for doing the maths. I started looking at it but needed too long
to refamiliarise myself with the calculations. I did come across a page on
Wikipedia showing examples of kWh/kg, and has startling note comparing it
with that for petrol. Your calculations above come out to 0.0024 kWh/kg;
petrol is 12.3 kWh/kg, so roughly 5000 times better.

<https://en.wikipedia.org/wiki/Flywheel#Table_of_energy_storage_traits>

Sam

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

Charles Ellson <charlesellson@btinternet.com> wrote:
> On Wed, 13 Apr 2022 22:03:31 -0000 (UTC), Sam Wilson
> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>
>> Charles Ellson <charlesellson@btinternet.com> wrote:
>>> On Tue, 12 Apr 2022 12:49:05 +0100, Scott
>>> <newsgroups@gefion.myzen.co.uk> wrote:
>>>
>>>> On Tue, 12 Apr 2022 11:30:24 -0000 (UTC), Sam Wilson
>>>> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>>>>
>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>> On Tue, 12 Apr 2022 09:23:03 +0100, Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>
>>>>>>> On Mon, 11 Apr 2022 22:08:35 +0100, Charles Ellson
>>>>>>> <charlesellson@btinternet.com> wrote:
>>>>>>> [snip]
>>>>>>>
>>>>>>> I think OP needs to rephrase the question.
>>>>>>
>>>>>> I suppose the distilled question is, "Why are passengers allowed to walk
>>>>>> across tram tracks, but not light railway
>>>>>> tracks?".
>>>>>>
>>>>>
>>>>> It?s probably slightly more complex than that. This place has a train:
>>>>>
>>>>> <http://www.eastlinks.co.uk/>
>>>>> <https://goo.gl/maps/hHmicsUZTCL9a2rj6>
>>>>>
>>>>> but the track is completely segregated and fenced except for two (or
>>>>> three?) places, either side of the single station, where footways cross the
>>>>> track. There is no protection for pedestrians except for the train
>>>>> announcing its presence, but there are partial fences and no entry signs
>>>>> for pedestrians at the crossings.
>>>>>
>>>>> So this is probably a light railway - it?s certainly not a tram - but
>>>>> pedestrians are allowed to walk across the tracks at certain, well
>>>>> specified points, with no gates and no warning other than the train?s
>>>>> whistle.
>>>>>
>>>> Are there any national rail stations where passengers can cross the
>>>> tracks? I certainly remember this from the past.
>>>>
>>> West Highland Line ?
>>
>> See the several previous answers to this posting!
>>
> I saw yours for Arisaig but I thought there were one or two other
> stations with island platforms and no footbridge.

I don’t remember any, but my memory is by no means exhaustive. There
certainly aren’t on the Mallaig extension nor on the section from Perth to
Inverness. Crianlarich has an island platform with a subway.

Sam

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

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>
>>> Get back to us when they've actually built one. "Light" is a relative term
>>> when it comes to rail vehicles. Even the PPM weighs 12 tons and thats with
>>> a flywheel, not heavy batteries.
>>>
>>
>> Flywheels are heavy, that is the point of them.
>>
>
> I was going to post that, but the only reference I could easily find to a
> Parry flywheel says it's 500kg, which isn't as much as I'd expected.
>
>
> Anna Noyd-Dryver
>
>

The Swiss developed but used in Belgium and one of their colonies Gyrobus
system was more substantial with a flywheel weighing 1.5T spinning at 3000
revs.
Interestingly to provide as little drag as possible the flywheel and
motor/generator enclosure was filled with Hydrogen which puts the worries
of carrying quantities in tanks to power fuel cells into perspective.

The gyroscopic effect was enough to affect the steering of the vehicles.
The system saw little use , a few years back you could still find one of
the charging poles still in place in what is now Kinsasha which seems
surprising when in Africa most things are recycled fairly quickly
when they are finished with or in many cases before.

<http://kosubaawate.blogspot.com/2011/10/leopoldville-1954-transports-en-commun.html>

Fairly comprehensive info on the gyrobus here.
<http://www.photo.proaktiva.eu/digest/2008_gyrobus.html>

GH

<Muttley@dastardlyhq.com> wrote:
> On Fri, 15 Apr 2022 01:36:02 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> Used in London for decades. In fact until a lot of the routes were closed.
>>>
>>
>> Used because it was good or used because they had no choice?
>
> No idea.
>
>> On the grounds that it was used only in the central area where wires
>> weren't allowed, and many routes changed to overhead wires part way, I
>> suspect the latter.
>>
>>> Anyway, the French system seems to work well enough:
>>>
>>> https://goo.gl/maps/u6Pc4kX5VVomA2an7
>>>
>>
>> Hasn't 'been used since electric trams were invented', though, unless you
>
> Where did I say it had? Its fairly new.
>

14 April 0911 "Their only raison d'etre is to stop nimbies complaining
about overhead wires yet there already are a number of discrete embedded
3rd rail systems for trams which could be used instead. The most obvious
one has been used since electric trams were invented."

So that comment must have been about conduit (or stud), not modern APS.

>> I'm sure the APS system is usually derided when mentioned here as being
>> excessively complicated, how does it cope in floods, etc. I'd love to see
>> it in action though.
>
> The power is only on when a tram is on the section and during floods I doubt
> trams are running anyway.
>

Try this <https://youtu.be/32CNuq3XNjQ>, this
<https://youtube.com/shorts/Lgk7G1iZzpc>, the last half of this
<https://youtu.be/zwOFRbkypt0> (none of which was the video I was looking
for, but hey ho).

> Anyway, these sorts of 3rd rail systems or batteries are only required due to
> nimbies and over zealous planning committees. No sane authority would choose
> them if OHLE was an option.
>

Isn't that where we came in?

Anna Noyd-Dryver

Graeme Wall <rail@greywall.demon.co.uk> wrote:
> On 14/04/2022 21:57, hounslow3@yahoo.co.uk wrote:
>> On 14/04/2022 18:42, Marland wrote:
>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>> On Thu, 14 Apr 2022 10:44:27 -0000 (UTC), Recliner
>>>> <recliner.usenet@gmail.com> wrote:
>>>>
>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>> On Thu, 14 Apr 2022 09:53:47 +0100
>>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>> On Thu, 14 Apr 2022 08:11:40 -0000 (UTC), Muttley@dastardlyhq.com
>>>>>>> wrote:
>>>>>>>>> But that's the same issue whether you use battery-powered busses
>>>>>>>>> or a
>>>>>>>>> battery-powered tram.
>>>>>>>>
>>>>>>>> True. Though I think battery powered trams are an absurd idea.
>>>>>>>> Their only
>>>>>>>> raison d'etre is to stop nimbies complaining about overhead wires
>>>>>>>> yet there
>>>>>>>> already are a number of discrete embedded 3rd rail systems for
>>>>>>>> trams which
>>>>>>>> could be used instead. The most obvious one has been used since
>>>>>>>> electric trams
>>>>>>>
>>>>>>>> were invented.
>>>>>>>
>>>>>>> Conduit in the LCC area.
>>>>>>>
>>>>>>> I thought it was far more heavy maintenance than overhead wires and
>>>>>>> less reliable.
>>>>>>
>>>>>> There's a system used in france that has the 3rd rail flush with
>>>>>> the ground
>>>>>> and is only energised when a tram is over it. They use it in Angier
>>>>>> in the
>>>>>> historic centre. Probably costs a fair amount over OHLE but then I
>>>>>> imagine so
>>>>>> do batteries.
>>>>>
>>>>> Why would the batteries be very expensive?  Lots of conventional
>>>>> trams are
>>>>> now fitted with batteries, including in Birmingham, to allow
>>>>> discontinuous
>>>>> electrification. These light trams will need relatively small
>>>>> batteries, as
>>>>> they don't need a long range.
>>>>
>>>> Because AIUI there is a shortage of lithium and chromium with Chinese
>>>> companies buying up mines in Africa.
>>>>
>>>
>>> Time to start digging up Cornwall again then.
>>> That’ll piss off all those second home owners who move down to wax
>>> lyrical
>>> over the landscape without appreciating that a good part of the
>>> ambience is
>>> caused by remains of an Industrial revolution that was virtually over
>>> before the main one got underway.
>>>
>>> GH
>>>
>>
>> I've heard of tin mining in Cornwall, but not chromium.
>
> Tin was the classic mining activity, going back to pre-Roman times, but
> Cornwall has quite a lot of different ores which have been commercially
> mined in the recent past.
>

Over the years Cornwall has actually produced more copper than tin.
The latter though was more valuable and became more well known,if
electrical equipment and distribution had developed a few decades earlier
it may have been a different story.

GH

Recliner <recliner.usenet@gmail.com> wrote:
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> nib <news@ingram-bromley.co.uk> wrote:
>>> On Thu, 14 Apr 2022 13:45:47 +0100, Recliner wrote:
>>>
>>>> On Thu, 14 Apr 2022 12:02:03 -0000 (UTC), Sam Wilson
>>>> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>>>>
>>>>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>>>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>>>>>> On Thu, 14 Apr 2022 10:03:17 -0000 (UTC)
>>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>>>> On Thu, 14 Apr 2022 09:17:38 -0000 (UTC), Recliner
>>>>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>>>>> The whole idea of this system is to have lightweight, shallow
>>>>>>>>>> track that's much cheaper and quicker to install than normal
>>>>>>>>>> tramways in this country. Most underground services won't need to
>>>>>>>>>> be disturbed and no OHLE will be required. That takes away most of
>>>>>>>>>> the objections to normal trams.
>>>>>>>>>
>>>>>>>>> Surely it is the weight of the tram not the track that is the main
>>>>>>>>> issue? I assume battery powered trams will be heavier.
>>>>>>>>>
>>>>>>>>>
>>>>>>>> The whole point of these new trams is that they're very light.
>>>>>>>> That's why they're called Coventry Very Light Rail (CVLR).
>>>>>>>
>>>>>>> Get back to us when they've actually built one. "Light" is a relative
>>>>>>> term when it comes to rail vehicles. Even the PPM weighs 12 tons and
>>>>>>> thats with a flywheel, not heavy batteries.
>>>>>>>
>>>>>>>
>>>>>> Flywheels are heavy, that is the point of them.
>>>>>
>>>>> Or fast, or both.
>>>>
>>>> The PPM flywheel is 1m diameter, rotates at 2500 rpm, and weighs 0.5
>>>> tonnes. It also needs some sort of small engine,
>>>> generator, fuel store, etc.
>>>
>>> If all that 500 kg is at the periphery with only very light spokes then
>>> the moment of inertia is mr^2 = 500 * 0.5^2 = 125 kg.m^2.
>>>
>>> 2500 rpm is 260 radians/sec. Energy stored = 0.5 * I * w^2 = 0.5 * 125 *
>>> 260 * 260 = 4.2 MJ, or 1.2 kWh. OK, it's more than 3 times the size of
>>> the battery on my bike but it's only about 1/40 of a 300 kg EV battery.
>>>
>>> So good for storing regen and power from a small motor and putting it
>>> back into acceleration but not going to take a tram (or even a PPM) very
>>> far on a non-electrified section.
>>>
>>>
>>
>> Thanks for doing the maths; it's the only easily-obtainable figure for the
>> Parry flywheel, but without further clarification, I suspect it might
>> relate to some earlier experimental vehicles, rather than the 'production'
>> pair.
>>
>
> There are two propulsion versions, self-powered with a small on-board
> engine and the 1m flywheel for regen brakes (the current class 139), and an
> intermittent electric powered variant, with a larger, heavier flywheel that
> gets spun up at the stops, which can be up to half a mile apart:
>
> Self-powered vehicles: Engine Ford DSG423 (propane gas or diesel fuel)
> Primary transmission via gearbox, freewheel clutch and Tandler bevel box
> 4 ‘V-belt’ belt transmission to flywheel
>
> Intermittent electric supply: 70V DC motor (requires 20kW supply at
> stopping points)
> ‘Charge’ time at stopping points 30s, distance between stops up to 800m
>
> Flywheel energy storage:
> Effective speed range 1,000-2,600rpm
> Flywheel diameter/mass 1m/500kg (self-powered), 1.2m/750kg (intermittent
> electric)
>
> http://friendlycreatives.co.uk/ppm/two-axle-vehicles/
>

The class 139 uses the engine to spin up the flywheel at the terminus
stations. The flywheel isn't only used for regen as you imply.

Anna Noyd-Dryver

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
> Recliner <recliner.usenet@gmail.com> wrote:
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> nib <news@ingram-bromley.co.uk> wrote:
>>>> On Thu, 14 Apr 2022 13:45:47 +0100, Recliner wrote:
>>>>
>>>>> On Thu, 14 Apr 2022 12:02:03 -0000 (UTC), Sam Wilson
>>>>> <ukr@dummy.wislons.fastmail.co.uk> wrote:
>>>>>
>>>>>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>>>>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>>>>>>> On Thu, 14 Apr 2022 10:03:17 -0000 (UTC)
>>>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>>>>> Scott <newsgroups@gefion.myzen.co.uk> wrote:
>>>>>>>>>> On Thu, 14 Apr 2022 09:17:38 -0000 (UTC), Recliner
>>>>>>>>>> <recliner.usenet@gmail.com> wrote:
>>>>>>>>>>> The whole idea of this system is to have lightweight, shallow
>>>>>>>>>>> track that's much cheaper and quicker to install than normal
>>>>>>>>>>> tramways in this country. Most underground services won't need to
>>>>>>>>>>> be disturbed and no OHLE will be required. That takes away most of
>>>>>>>>>>> the objections to normal trams.
>>>>>>>>>>
>>>>>>>>>> Surely it is the weight of the tram not the track that is the main
>>>>>>>>>> issue? I assume battery powered trams will be heavier.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>> The whole point of these new trams is that they're very light.
>>>>>>>>> That's why they're called Coventry Very Light Rail (CVLR).
>>>>>>>>
>>>>>>>> Get back to us when they've actually built one. "Light" is a relative
>>>>>>>> term when it comes to rail vehicles. Even the PPM weighs 12 tons and
>>>>>>>> thats with a flywheel, not heavy batteries.
>>>>>>>>
>>>>>>>>
>>>>>>> Flywheels are heavy, that is the point of them.
>>>>>>
>>>>>> Or fast, or both.
>>>>>
>>>>> The PPM flywheel is 1m diameter, rotates at 2500 rpm, and weighs 0.5
>>>>> tonnes. It also needs some sort of small engine,
>>>>> generator, fuel store, etc.
>>>>
>>>> If all that 500 kg is at the periphery with only very light spokes then
>>>> the moment of inertia is mr^2 = 500 * 0.5^2 = 125 kg.m^2.
>>>>
>>>> 2500 rpm is 260 radians/sec. Energy stored = 0.5 * I * w^2 = 0.5 * 125 *
>>>> 260 * 260 = 4.2 MJ, or 1.2 kWh. OK, it's more than 3 times the size of
>>>> the battery on my bike but it's only about 1/40 of a 300 kg EV battery.
>>>>
>>>> So good for storing regen and power from a small motor and putting it
>>>> back into acceleration but not going to take a tram (or even a PPM) very
>>>> far on a non-electrified section.
>>>>
>>>>
>>>
>>> Thanks for doing the maths; it's the only easily-obtainable figure for the
>>> Parry flywheel, but without further clarification, I suspect it might
>>> relate to some earlier experimental vehicles, rather than the 'production'
>>> pair.
>>>
>>
>> There are two propulsion versions, self-powered with a small on-board
>> engine and the 1m flywheel for regen brakes (the current class 139), and an
>> intermittent electric powered variant, with a larger, heavier flywheel that
>> gets spun up at the stops, which can be up to half a mile apart:
>>
>> Self-powered vehicles: Engine Ford DSG423 (propane gas or diesel fuel)
>> Primary transmission via gearbox, freewheel clutch and Tandler bevel box
>> 4 ‘V-belt’ belt transmission to flywheel
>>
>> Intermittent electric supply: 70V DC motor (requires 20kW supply at
>> stopping points)
>> ‘Charge’ time at stopping points 30s, distance between stops up to 800m
>>
>> Flywheel energy storage:
>> Effective speed range 1,000-2,600rpm
>> Flywheel diameter/mass 1m/500kg (self-powered), 1.2m/750kg (intermittent
>> electric)
>>
>> http://friendlycreatives.co.uk/ppm/two-axle-vehicles/
>>
>
> The class 139 uses the engine to spin up the flywheel at the terminus
> stations. The flywheel isn't only used for regen as you imply.
>

Isn't the engine running all the time?

<Muttley@dastardlyhq.com> wrote:
> On Fri, 15 Apr 2022 01:36:02 -0000 (UTC)
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> Used in London for decades. In fact until a lot of the routes were closed.
>>>
>>
>> Used because it was good or used because they had no choice?
>
> No idea.
>
>> On the grounds that it was used only in the central area where wires
>> weren't allowed, and many routes changed to overhead wires part way, I
>> suspect the latter.
>>
>>> Anyway, the French system seems to work well enough:
>>>
>>> https://goo.gl/maps/u6Pc4kX5VVomA2an7
>>>
>>
>> Hasn't 'been used since electric trams were invented', though, unless you
>
> Where did I say it had? Its fairly new.
>
>> I'm sure the APS system is usually derided when mentioned here as being
>> excessively complicated, how does it cope in floods, etc. I'd love to see
>> it in action though.
>
> The power is only on when a tram is on the section and during floods I doubt
> trams are running anyway.

Plenty of views of old style trams negotiating floods around the web,
wether damage to motors was worthwhile is another question but old style DC
traction equipment was fairly robust or easy to swap out.
Modern stuff is probably more delicate so its probably not wise but noone
seems to have told this Dublin driver.

<https://www.bbc.co.uk/news/av/world-europe-36543780>

GH

On 15/04/2022 08:55, Muttley@dastardlyhq.com wrote:
> On Thu, 14 Apr 2022 18:37:21 +0100
> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>> On 14/04/2022 16:22, Muttley@dastardlyhq.com wrote:
>>> On Thu, 14 Apr 2022 11:48:46 +0100
>>> Graeme Wall <rail@greywall.demon.co.uk> wrote:
>>>> On 14/04/2022 11:19, Muttley@dastardlyhq.com wrote:
>>>>>> The whole point of these new trams is that they're very light. That's why
>>>>>> they're called Coventry Very Light Rail (CVLR).
>>>>>
>>>>> Get back to us when they've actually built one. "Light" is a relative term
>>>>> when it comes to rail vehicles. Even the PPM weighs 12 tons and thats with
>>>>> a flywheel, not heavy batteries.
>>>>>
>>>>
>>>> Flywheels are heavy, that is the point of them.
>>>
>>> https://www.focustransport.org/2016/01/double-deck-parry-people-mover.html
>>>
>>> "A typical PPM flywheel is made from steel laminates, 1m in diameter and
>> 500kg
>>> mass"
>>>
>>> Thats the same as an EV car battery and it only lasts for the half mile or so
>>
>>> the PPM has to crawl along. The battery for a 10+ ton tram will need to
>>> be somewhat larger especially due to all the stop start that'll occur along
>>> city streets and the longer route.
>>>
>>
>> Rather like the electric buses that are working all day, every day in a
>> number of towns and cities.
>
> Check out the kerb weight of those buses compared to their diesel counterparts.
>

Kerb weight of the battery bus: 13-14.4 tonnes

Kerb weight of the diesel equivalent: 14.4-18 tonnes

--
Graeme Wall
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