On Jan 25, 10:59 am, Andy wrote:


The Class 350s can regenerate, but I don't know if it is being used at
the moment. The Pendolinos certainly do, as it is claimed to give a
17% reduction in energy use. The class 321s don't have regen, as far
as I know.

17%! Wow!

That's higher than I'd have guessed in ideal circumstances.

I've not taken a GPS onto a pendolino but the 125 and 225s spend a
couple of minutes accelerating, about 15-20 minutes at speed and then
a few minutes slowing down again typically (at least as far as
Newcastle)

Regenerative braking must be an even better deal on local services
that are stopping all the time. E.g. the 08:06 from Watford Junction
stops at Bushey and H&W. 12 carriage train. One day I'll have to take
the GPS on that and see how much of the time is actually accelerating/
braking and how much is cruising

Tim.

On Jan 25, 11:58*am, "
wrote:
On Jan 25, 10:59 am, Andy wrote:



The Class 350s can regenerate, but I don't know if it is being used at
the moment. The Pendolinos certainly do, as it is claimed to give a
17% reduction in energy use. The class 321s don't have regen, as far
as I know.

17%! Wow!

That's higher than I'd have guessed in ideal circumstances.


My figures came from the Informed Sources column back in July's Issue
of Modern Railways. There is a link to the archive here, look under
the technology section:

http://www.alycidon.com/ALYCIDON%20R...007%202007.htm


I've not taken a GPS onto a pendolino but the 125 and 225s spend a
couple of minutes accelerating, about 15-20 minutes at speed and then
a few minutes slowing down again typically (at least as far as
Newcastle)

Regenerative braking must be an even better deal on local services
that are stopping all the time. E.g. the 08:06 from Watford Junction
stops at Bushey and H&W. 12 carriage train. One day I'll have to take
the GPS on that and see how much of the time is actually accelerating/
braking and how much is cruising


Indeed the article suggests that the Electrostars on c2c services save
more like 21%.

wrote in message
...
On Jan 25, 9:45 am, Graeme Wall wrote:

Which can be affected by the length of the train, think side winds.

To a first approximation it shouldn't matter because the force will be
perpendicular to the trains movement.

It will have an effect but I'd expect it to be small relative to the
energy required to accelerate and the energy required to push the
train through the air.

I'm not sure if modern wheel profiles would make a difference, but there is
a record of the effect of side winds dating from 1962. A West Highland train
emerged from the shelter of the Horse Shoe into a full westerly gale, and
speed dropped from 35 mph to 15. At first the driver thought the cord had
been pulled, but a glance at the vacuum gauge refuted this. What had
happened was that the wind pushing on the side of the coaches was grinding
the wheel flanges against the rails.

Peter

On Jan 25, 12:21 pm, Andy wrote:
On Jan 25, 11:58 am, "
wrote:

On Jan 25, 10:59 am, Andy wrote:

The Class 350s can regenerate, but I don't know if it is being used at
the moment. The Pendolinos certainly do, as it is claimed to give a
17% reduction in energy use. The class 321s don't have regen, as far
as I know.

17%! Wow!

That's higher than I'd have guessed in ideal circumstances.

My figures came from the Informed Sources column back in July's Issue
of Modern Railways. There is a link to the archive here, look under
the technology section:

http://www.alycidon.com/ALYCIDON%20R...CES%20ARCHIVE/...


Thank you for that.

It makes me despair.

The only thing stopping us using regenerative braking everywhere is
that currently there isn't any technology that can store the amount of
energy being generated at the sorts of rates that it is generated.

Supercapacitors look like they might be an answer eventually but
they're not there yet.

But electric trains are nearly perfect for this technology. The
biggest headache being making sure you can maintain braking if the
circuit is broken.

If a few people rode bicycles a bit more often then they'd learn why
cyclists don't like stopping for red lights and why accelerating is
such bloody hard work.

I've read that a cyclist goes 20x as far at a constant 12mph as they
do accelerating from 0 to 12mph for the same energy use

Tim.

On Thu, 24 Jan 2008, Neil Williams wrote:

On Thu, 24 Jan 2008 03:16:17 -0800 (PST), "
wrote:

I wouldn't be surprised to see a timetable alteration that moves this
train earlier by 4 (or 5) minutes.

(Of course, moving all the trains later by 10 minutes would also help
because then there would be a 19:04 and a 19:14)

However, you've been lucky if you've never had to stand. Those trains
are always busy. It's quieter from about the 19:54 through to about
21:54 then it starts getting busy again.

As to the timetable, I can't remember what happens to the all-shacks
trains, but the fasts and slows will be offset by about 15 minutes
unlike the present situation where they leave at roughly the same time
(e.g. 1823 fast, 1824 slow).

Do these trains use the same tracks? If so, isn't that pattern of
departures necessary so the fasts have a clear run ahead of them behind
the preceding slow?

This will mean the slows will become more attractive to MKC passengers,
which might have an interesting and undesirable[1] effect.

[1] The slows can't be longer than 8 cars southbound due to Bletchley's
short platforms and the fact that none of the stock has SDO. They can
be 12-car northbound (like the 1754 is) but you'd have a big problem
arranging that without a lot of units building up at Northampton...

You could make 12-car trains, and lock the rear 4 cars OOU on the
southbound leg. You could even unlock them once you were past Bletchley
and into 12-car land (if that's possible, and if it is indeed all
12-car-clear south of there).

Alternatively, you run 50% more trains southbound than northbound, and
never have more than one 4-car set sitting at Northampton. This would be a
nightmare to do, though.

tom

--
I had no idea it was going to end in such tragedy

On Thu, 24 Jan 2008, Mizter T wrote:

On 24 Jan, 23:43, Arthur Figgis wrote:
Chris Tolley wrote:
Paul Scott wrote:

much as it might seem straightforward to have a London centred zonal
system spreading ever outwards, there will have to be a limit somewhere -
and it might as well be the Greater London boundary as anywhere.

Actually ... I rather like the idea of the zones spreading ever
outwards. With Zone 43 including the great arc of Wrexham, Chester,
Warrington, Manchester, Huddersfield, Leeds and Hull, it looks like a
one-zone ticket will be quite good value, though knowing the way that
such boundaries are set, I expect a Chester to Manchester via Knutsford
ticket would have to be a 2-zoner. ;-)

Some countries do have a national zone model, where you pay for the
zones you pass through. They use boxes or cells rather than concentric
rings as the zones.

This is how things are done in Tyne & Wear - see:

http://www.nexus.org.uk/ufs/shared/i...ne_Map_Col.pdf

The numbering logic behind the zones seems bizarre at first sight -
the zone numbers ascend in a sort of diagonal sweep from the south
west to the north east of the metropolitan county of T&W.

Surely north west to south east? Oh, you mean like a raster? Yes, i see -
the lines of the raster run SW-NE, and the raster progresses NW-SE.

The diagonal is basically the axis parallel to the Tyne, isn't it? At
least, the downstream reach. It's akin to Stanford's 'logical north'.

However I think it may be designed this was to make it easy to issue and
- crucially - verify the validity of tickets with zonal combinations
that are in a row or in a ring (think of a busy bus driver checking
tickets).

Yes, and each line in the raster has its own leading digit, with the
second digit increasing along it, so that the corresponding zones in each
line are adjacent. Although 58-60 are special cases: they should be 65, 66
and 75, respectively.

It'd be fun to do a version of that map coloured by the orthogonal
elements of the zone numbers; say, number 0x in red to 5x in violet, and
x3 in a pale shade to x9 in a dark one. Or with patterns of dots or
stripes instead of shade, so you can see at a glance how the coordinate
meanders across the map.

Note that the Tyne ferry has zone 38 all to itself.

39. I wonder which zones it counts as being adjacent to? Any which have
piers, i suppose.

The '4 zones in a ring' option is described as 'any 3 zones in a ring plus
one adjacent zone'; does that mean i could have three in a ring and one
touching just one of them? 56, 58, 59 and 60, say?

tom

--
I had no idea it was going to end in such tragedy

On Fri, 25 Jan 2008, wrote:

On Jan 25, 6:10 am, (Neil Williams)
wrote:
On Thu, 24 Jan 2008 17:03:56 -0800 (PST), Andy
wrote:

See above, this is one of the delights of having a mixed fleet of
incompatible units.

Not on a Sunday, when there are (I think) only 4 diagrams giving a
half-hourly service, and most of them tend to be 4-car. This is lunacy
given the actual demand.

Does anyone know what proportion of the running costs of a train are
power consumption and how that scales with length of train?

Presumably for trains with few stops the power consumption is
approximately constant regardless of the length of the train because
the main loss will be air drag.

As long as the train never wants to climb a hill, perhaps. If it does, the
old mgh term rears its head.

Do you think that drag is overwhelmingly greater than rolling resistance,
losses in the bearings, etc?

Drag does have a term from the sides of the train, i should point out.
Skin drag, or body drag, or something. I believe it's usually a lot less
than the wave drag at the front, though.

Hmm. Perhaps we should fit trains with aerospikes? Not sure what the
health and safety would make of that ...

tom

--
I had no idea it was going to end in such tragedy

On Fri, 25 Jan 2008, Andy wrote:

On Jan 25, 8:26*am, "
wrote:

I presume trains don't use regenerative braking at all (ISTR some of
the underground trains are now starting to use this)

The Class 350s can regenerate,

Oh god, that means it's only a matter of time before they come back as
Christopher Ecclestone, doesn't it?

tom

--
I had no idea it was going to end in such tragedy

In message
" wrote:

On Jan 25, 9:45 am, Graeme Wall wrote:
In message
" wrote:



On Jan 25, 6:10 am, (Neil Williams)
wrote:
On Thu, 24 Jan 2008 17:03:56 -0800 (PST), Andy
wrote:

See above, this is one of the delights of having a mixed fleet of
incompatible units.

Not on a Sunday, when there are (I think) only 4 diagrams giving a
half-hourly service, and most of them tend to be 4-car. This is
lunacy given the actual demand.

Does anyone know what proportion of the running costs of a train are
power consumption and how that scales with length of train?

Presumably for trains with few stops the power consumption is
approximately constant regardless of the length of the train because
the main loss will be air drag.

Which can be affected by the length of the train, think side winds.

To a first approximation it shouldn't matter because the force will be
perpendicular to the trains movement.

It will have an effect but I'd expect it to be small relative to the
energy required to accelerate and the energy required to push the
train through the air.

It will increase the frictional losses as the train bears against the leeward
rail, also it will create turbulence around the gaps between the coaches and
around the bogies.


If I'm wrong and it is a significant effect then I'd expect that to be
due to turbulence of the air passing under the train and where the
carriages join. But I'd assume that a train reasonably approximates a
long straight bar.


--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

Tom Anderson wrote:

On Thu, 24 Jan 2008, Mizter T wrote:

(snip)


This is how things are done in Tyne & Wear - see:

http://www.nexus.org.uk/ufs/shared/i...ne_Map_Col.pdf

The numbering logic behind the zones seems bizarre at first sight -
the zone numbers ascend in a sort of diagonal sweep from the south
west to the north east of the metropolitan county of T&W.

Surely north west to south east? Oh, you mean like a raster? Yes, i see -
the lines of the raster run SW-NE, and the raster progresses NW-SE.

The diagonal is basically the axis parallel to the Tyne, isn't it? At
least, the downstream reach. It's akin to Stanford's 'logical north'.

However I think it may be designed this was to make it easy to issue and
- crucially - verify the validity of tickets with zonal combinations
that are in a row or in a ring (think of a busy bus driver checking
tickets).

Yes, and each line in the raster has its own leading digit, with the
second digit increasing along it, so that the corresponding zones in each
line are adjacent. Although 58-60 are special cases: they should be 65, 66
and 75, respectively.


You describe it a lot more eloquently than I could - but yes, that was
what I was trying to express, each of the two digits have meaning.


It'd be fun to do a version of that map coloured by the orthogonal
elements of the zone numbers; say, number 0x in red to 5x in violet, and
x3 in a pale shade to x9 in a dark one. Or with patterns of dots or
stripes instead of shade, so you can see at a glance how the coordinate
meanders across the map.


Yes, indeed, though I'm not sure how useful that'd be to the average
punter! My alternative would involve massively simplifying the whole
system! But of course, that would need the agreement of all the bus
companies involved,


Note that the Tyne ferry has zone 38 all to itself.

39. I wonder which zones it counts as being adjacent to? Any which have
piers, i suppose.

38, 39, it's all the same to me - so it's probably just as well I'm
not a bus driver on Tyneside or Wearside, I'd be letting on people
with all sorts of wrong zonal Traveltickets! (Though dare I suggest
that I might get along ok in London, given the total disinterest that
some drivers seem to have when it comes to checking tickets!)

The Tyne ferry sails between North and South Shields, so the adjacent
zones would be 29 and 38.


The '4 zones in a ring' option is described as 'any 3 zones in a ring plus
one adjacent zone'; does that mean i could have three in a ring and one
touching just one of them? 56, 58, 59 and 60, say?


From my reading of things, yes that looks like a legit combination.

Incidentally you can buy Travelticket renewals online on the website
of Nexus (the T&W PTE) - select the first option, "Network
Travelticket", to be taken into the system...
https://www.nexus.org.uk/wps/wcm/con...ickets+online/

....and you will find something interesting - the online system is
incapable of selling the "4 zones in a ring" combination! It seems
that if you want such a ticket you'll have to go and deal with someone
face to face.

Casual travellers will be happy to note that the T&W Metro operates a
far simpler concentric zone system, zones A, B and C...
http://tinyurl.com/3acd76

....though of course valid Network Traveltickets (i.e. those with the
correct numbered zones) are accepted on the Me'ro.


And just to prove that things can change for the better, the
"Transfare" ticket scheme has recently been simplified - these are
tickets that allow for through journeys from bus to Metro or vice-
versa. However, perhaps just so as to ensure things don't get too
simple the new Transfare scheme has introduced the new idea of
concentric yellow, green, and grey zones - thankfully these do
actually correspond with the Metro's concentric A, B and C zones, and
they also share the same colours except for Metro zone C being a shade
of violet whilst the outer Transfare zone is grey. I suppose the logic
is that the Transfare grey zone covers much more ground than the Metro
C zone.

Anyhow, here is a page on the new Transfare ticket scheme...
http://www.nexus.org.uk/wps/wcm/conn...etro+Transfare

....and this leaflet shows the new Transfare yellow/green/grey zones
(PDF)...
http://www.nexus.org.uk/wps/wcm/reso...fare%20map.pdf

The world is complicated!