Pantographs (somewhat OT)

[bob]

I was considering the question of pantograph specifications recently
when a 4-system DB TRAXX on an intermodal passed through my local
station the other evening. Looking at Europe as a whole, the railways
have largely settled on four overhead electrification electrical
standards: 1500 V DC (Netherlands, some of France etc), 3000 V DC
(Belgium, Italy etc), 15 kV 16.7 Hz (Germany, Austria, Switzerland
etc) and 25 kV 50 Hz (UK, rest of France, Luxembourg, various high
speed lines in various places). Your average modern 4 system
locomotive has four pantographs on the roof, and that would lead one
to naively assume that this translates to one pantograph design per
electrical system. Clearly the situation is not as straightforward as
this. For a start, on 1500 V DC lines, it is common to require two
pantographs to handle the current under certain conditions, so at
least two of the pantographs must be compatible with the 1500 V
standard. Also, trains that work across the Belgian/Dutch border seem
to be content to use the same pantograph for both systems, and from
what I can tell ICEs that run in both Germany and France use the same
pantograph for 15 kV and 25 kV. On the other hand, observation
suggests that Swiss pantographs are significantly narrower than German
ones (I believe the difference between the Re 420 and Re 421 is that
the latter has one German pantograph, while the former is only able to
run in Switzerland). The older generation of Cisalpino Pendolini that
run over the Gotthard seem to have more pantographs than you can shake
a stick at, presumably that's related to not using a 3 kV bus in
Italy? Can anyone shed light on this subject?

Robin

[D7666]

On Jan 14, 11:04 am, bob <***@gmail.com> wrote:

I do not think this is OT at all ... it is directly relevant to
potential through working of locos and trainsets to UK from far flung
continental locations.

Post by bob
Your average modern 4 system
locomotive has four pantographs on the roof, and that would lead one
to naively assume that this translates to one pantograph design per
electrical system. Clearly the situation is not as straightforward as
this.

Correct.

It is more complex than that.

The only reason multi system multi land e-locos all have 4 pans is to
have less would artificially limit usefulness and 4 is the maximum
number that fits on top a machine like a Traxx / ES64 / Vectron /
Prima.

Even earlier multi-system locos like DB 184 had 4 pans but they were
not 1 pan per voltage.

Post by bob
Can anyone shed light on this subject?

The pan head differences are due to the width of the contact area and
its material (copper and/or carbon) and the restriction list is not as
obvious as it may seem.

There are 6 different pan contact strips you'd commonly find on the
1432 mm gauge continental mainlines that are connected by the various
25/15/3/1.5 kV traction systems i.e. where a single loco could
reasonably be expected to need to through work.

In German the list is :

Dänemark, Deutschland, Norwegen, Österreich, Schweden, Slowakei,
Tschechien ... Wechselstrom ... 15 kV/25 kV ... 1950 mm ... Kohle

Frankreich, Luxemburg, Schweiz ... Wechselstrom ... 15 kV/25 kV ...
1450 mm ... Kohle

Ungarn (durch Oberleitungsanpassungen obsolet) ... Wechselstrom ... 25
kV ... 2060 mm ... Kohle

Belgien, Frankreich, Luxemburg, Niederlande, Slowakei, Tschechien ...
Gleichstrom ... 1500 V/3000 V ... 1950 mm ... Kohle metallisiert

Italien ... Gleichstrom ... 3000 V ... 1450 mm ... Kupfer

Polen ... Gleichstrom ... 3000 V ... 1950 mm ... Kupfer

AFAIK Channel Tunnel and UK HS1 complies with the French AC pan *for*
*this* *purpose*.

I put the gauge in since none of the multi system loco types in
present operation or production are capable of variable gauge (they
can of course be regauged, but that is irrelevant) so there is no need
to consider Russian or Iberian gauges hence pantographs, nor for
example any of the narrow gauge with differing catenary in Swiss etc.

There are many other differences between national catenary but pan
contact heads can deal with them. Some main line within each lands
with restrictions e.g. south west SNCF in the DC area north of
Bordeaux / Toulouse a specfic pantogrpah type is used and not all
26000s and 27000s have them.

There are also small pools of non-standard e-locos that have special
mods to deal with certain cross border traffic without additional
arrays of pans e.g. CZ/PL and SK/PL DC 1950 mm but one s copper the
other carbon, DE/CH 15 kV at Lindau same material different width, and
so on.

There is a UIC project to unify pan heads ... I think it is called
EuroPAC (pac not pan) but not sure.

There of course other physical limits on multi system traction ... it
is not currently possible to install every lands safety systems in a
single BoBo loco without exceeding 22.5 tonne axle load. You don't
really run into the not enough pans for everything issue because you
hit the safety systems physical limit first. Hence Siemens and
Bombardier et al offer packages of certain sensible practical
combinations.

--
Nick

[82045]

A follow up discussion to this plethora of pantographs must include a
discussion on the possibility of converting to one system (25Kv?) as
the other systems come due for renewal: as seems to be the case for
ground rail in the UK.

[Matthew Geier]

Post by 82045
A follow up discussion to this plethora of pantographs must include a
discussion on the possibility of converting to one system (25Kv?) as
the other systems come due for renewal: as seems to be the case for
ground rail in the UK.

It's a rather complex job - especially where the geometry of the contact wire needs to be changed, but changed in such a way that in the transition the old trains can still run.

At one point the Dutch were planning to change to 25kvAC as that's effectively the 'standard' now and were doing all OHS renewals with that in mine. I gather that idea has died, but it could still be policy to do renewals with this in mind.
The main complaint about the Dutch plan is that they would still be an 'island' of incompatible system - with the 11kv 16 3/4Hz on one border and the 3kv DC on the other.

At the end of the day the different voltages are not the main issue any more - modern power electronics can cope with that - it's the different contact wire geometry - you can not solve that with clever electronics. The railway has to get out there and change the infrastructure.

I suspect the best we can hope for it get it down to something that can be handled by the 4 pantographs you can get on the top of a locomotive and possibly some acceptance than under the lowest voltage (1500DV) there may be operational restrictions on the available power due to current draw considerations - but even then for the areas were this high power output is required (say for a steep grade) it may be possible for the railway to do a relatively cheap 'quick fix' ,say to ensure that a wider or narrower pan head will not come to grief to allow the locomotive to raise another pan for a short while.

But as some one has already pointed out - at this point the limiting factor is that it's just not possible to fit all the various national safety systems into the one locomotive/train. Even if you could stuff in all the various sensors and supporting electronics - the drivers cab would not be able to have all the various 'DMI's installed - the console simply can big enough.

I have read of a sub project in the ERTMS group were they are attempting to design a Driver-Machine-Interface console that can be a 'standard' front end multiple 'country specific back ends'. Although I suspect the main push is not for interoperability but so the train manufacturers don't have to keep redesigning the control desk for each countries safety system's 'DMI'. The idea is to design and get approved in the various jurisdictions this common DMI, so even if there isn't enough space to fit all the back end electronics and the sensors, it becomes a relatively straight forward swap of electronics modules and pick up sensors if a locomotive or train gets re-assigned, instead of a semi major rebuild of the cab as well.

[bob]

Post by D7666
I do not think this is OT at all ... it is directly relevant to
potential through working of locos and trainsets to UK from far flung
continental locations.

Post by bob
Your average modern 4 system
locomotive has four pantographs on the roof, and that would lead one
to naively assume that this translates to one pantograph design per
electrical system. Clearly the situation is not as straightforward as
this.

Correct.
It is more complex than that.
The only reason multi system multi land e-locos all have 4 pans is to
have less would artificially limit usefulness and 4 is the maximum
number that fits on top a machine like a Traxx / ES64 / Vectron /
Prima.
Even earlier multi-system locos like DB 184 had 4 pans but they were
not 1 pan per voltage.

Post by bob
Can anyone shed light on this subject?

The pan head differences are due to the width of the contact area and
its material (copper and/or carbon) and the restriction list is not as
obvious as it may seem.
There are 6 different pan contact strips you'd commonly find on the
1432 mm gauge continental mainlines that are connected by the various
25/15/3/1.5 kV traction systems i.e. where a single loco could
reasonably be expected to need to through work.

[snip]

Thanks for the list, that explains a few oddities, like TGV sets
running in CH with the same pan they use in France while trains
running between CH and Germany (same electrical system) needing
different pans (Re 421). What is the British 25 kV pantograph width/
material? Is it the same as France on 25 kV (I assume so given the
NoL sets ran on the ECML without new pans)?

What are the implications of using carbon as opposed to copper?
Presumably carbon wears faster, but is there a technical reason why a
system intended for copper pantographs couldn't be used by a carbon
headed pantograph?

I assume the BOStrab standards for tramways includes a standard
pantograph definition (and further I assume that new build UK systems
conform to this).

Post by D7666
There is a UIC project to unify pan heads ... I think it is called
EuroPAC (pac not pan) but not sure.

Seems like a sensible idea, though I expect it will take time for
standardization to be achieved.

Post by D7666
There of course other physical limits on multi system traction ... it
is not currently possible to install every lands safety systems in a
single BoBo loco without exceeding 22.5 tonne axle load. You don't
really run into the not enough pans for everything issue because you
hit the safety systems physical limit first. Hence Siemens and
Bombardier et al offer packages of certain sensible practical
combinations.

And of course this is the idea behind ERTMS.

Robin

[Nick Leverton]

Post by bob

Post by D7666
There are 6 different pan contact strips you'd commonly find on the
1432 mm gauge continental mainlines that are connected by the various
25/15/3/1.5 kV traction systems i.e. where a single loco could
reasonably be expected to need to through work.

[snip]

Post by D7666
There is a UIC project to unify pan heads ... I think it is called
EuroPAC (pac not pan) but not sure.

Seems like a sensible idea, though I expect it will take time for
standardization to be achieved.

Post by D7666
There of course other physical limits on multi system traction ... it
is not currently possible to install every lands safety systems in a
single BoBo loco without exceeding 22.5 tonne axle load. You don't
really run into the not enough pans for everything issue because you
hit the safety systems physical limit first. Hence Siemens and
Bombardier et al offer packages of certain sensible practical
combinations.

And of course this is the idea behind ERTMS.

What we need is a standard for EUPANTS.

Nick

[D7666]

Post by bob

Post by D7666
is not currently possible to install every lands safety systems in a
single BoBo loco without exceeding 22.5 tonne axle load. You don't
really run into the not enough pans for everything issue because you
hit the safety systems physical limit first. Hence Siemens and
Bombardier et al offer packages of certain sensible practical
combinations.

And of course this is the idea behind ERTMS.

Well yes but that is a LONG way off.

At the moment, and for the forseeable future, to avoid loco changes
ERTMS kit is simply one extra system adding yet more weight. Its a
long way to go along the time before the local kit will be removable
(or not installed in new locos).

--
Nick

[Jan Henning]

Post by bob
What are the implications of using carbon as opposed to copper?
Presumably carbon wears faster, but is there a technical reason why a
system intended for copper pantographs couldn't be used by a carbon
headed pantograph?

Copper pans roughen the contact wire, which leads to increased wear on
carbon pans. The German Wikipedia also claims that there are negative
electrochemical implications in mixing carbon and copper pantographs.

Post by bob
I assume the BOStrab standards for tramways includes a standard
pantograph definition (and further I assume that new build UK systems
conform to this).

No, the BOStrab standards are relatively flexible as far technical
details are concerned, because they have to account for a very wide
range of operations, from possibly historically grown tramway networks
to newly built light railway systems.

[puffernutter]

Post by Jan Henning

Post by bob
What are the implications of using carbon as opposed to copper?
Presumably carbon wears faster, but is there a technical reason why a
system intended for copper pantographs couldn't be used by a carbon
headed pantograph?

Copper pans roughen the contact wire, which leads to increased wear on
carbon pans. The German Wikipedia also claims that there are negative
electrochemical implications in mixing carbon and copper pantographs.

Post by bob
I assume the BOStrab standards for tramways includes a standard
pantograph definition (and further I assume that new build UK systems
conform to this).

No, the BOStrab standards are relatively flexible as far technical
details are concerned, because they have to account for a very wide
range of operations, from possibly historically grown tramway networks
to newly built light railway systems.

Unless there is a derogation (agreed exception), then any new overhead
electrical systems on European defined interoperable routes (we have
the following in the UK - ECML, WCML, HS1/2 and Western Main Line)
shall meet the Technical Specifications for Interoperabilty (TSI) for
overhead systems, which is 25kV 50Hz.

Regards

Puffernutter

[Jan Henning]

Post by puffernutter

Post by Jan Henning
No, the BOStrab standards are relatively flexible as far technical
details are concerned, because they have to account for a very wide
range of operations, from possibly historically grown tramway networks
to newly built light railway systems.

Unless there is a derogation (agreed exception), then any new overhead
electrical systems on European defined interoperable routes (we have
the following in the UK - ECML, WCML, HS1/2 and Western Main Line)
shall meet the Technical Specifications for Interoperabilty (TSI) for
overhead systems, which is 25kV 50Hz.

You're right as far as heavy rail is concerned, but I don't think
tramway, or light railway lines would fall within the scope of the TSI
regulations.

[Jan Henning]

Post by D7666
Dänemark, Deutschland, Norwegen, Österreich, Schweden, Slowakei,
Tschechien ... Wechselstrom ... 15 kV/25 kV ... 1950 mm ... Kohle
Frankreich, Luxemburg, Schweiz ... Wechselstrom ... 15 kV/25 kV ...
1450 mm ... Kohle
Ungarn (durch Oberleitungsanpassungen obsolet) ... Wechselstrom ... 25
kV ... 2060 mm ... Kohle
Belgien, Frankreich, Luxemburg, Niederlande, Slowakei, Tschechien ...
Gleichstrom ... 1500 V/3000 V ... 1950 mm ... Kohle metallisiert
Italien ... Gleichstrom ... 3000 V ... 1450 mm ... Kupfer
Polen ... Gleichstrom ... 3000 V ... 1950 mm ... Kupfer

As indicated in the list, Hungary's system is already obsolete.
Presumably they've switched to the standard 1950 mm width.
Other than that, it seems that Poland and Italy have switched, or are in
the process of switching over to metallised carbon.
This means that we're down to four different pantograph standards,
which, if necessary, could all be fitted onto one locomotive:
1950 mm carbon, 1450 mm carbon, 1950 mm metallised carbon and 1450
metallised carbon

[D7666]

Post by Jan Henning

Post by D7666
Ungarn (durch Oberleitungsanpassungen obsolet) ... Wechselstrom ... 25
kV ... 2060 mm ... Kohle

As indicated in the list, Hungary's system is already obsolete.
Presumably they've switched to the standard 1950 mm width.

Obsolete does not mean it no longer exists. Well not in English
anyway, and I believe there is no subtle difference between the German
obsolet and the English obsolete.

AFAIK, only the main lines from the Budapest area towards the Wien
area have altered catenary - 25 kV lines elsewhere that were formerly
16 kV 50 Hz have yet to be altered.

I might be a bit out of date on this, but certainly as at last year
there pantograph restrictions on non-MAV non-HU locos operating in HU-
land.

--
Nick

[82045]

Post by D7666

Post by Jan Henning

Post by D7666
Ungarn (durch Oberleitungsanpassungen obsolet) ... Wechselstrom ... 25
kV ... 2060 mm ... Kohle

As indicated in the list, Hungary's system is already obsolete.
Presumably they've switched to the standard 1950 mm width.

Obsolete does not mean it no longer exists. Well not in English
anyway, and I believe there is no subtle difference between the German
obsolet and the English obsolete.
AFAIK, only the main lines from the Budapest area towards the Wien
area have altered catenary -  25 kV lines elsewhere that were formerly
16 kV 50 Hz have yet to be altered.
I might be a bit out of date on this, but certainly as at last year
there pantograph restrictions on non-MAV non-HU locos operating in HU-
land.
--
Nick

Perhaps obsolescent may be more appropriate.

[Johannes Picht]

Hi!

Post by D7666
There of course other physical limits on multi system traction ... it
is not currently possible to install every lands safety systems in a
single BoBo loco without exceeding 22.5 tonne axle load. You don't
really run into the not enough pans for everything issue because you
hit the safety systems physical limit first. Hence Siemens and
Bombardier et al offer packages of certain sensible practical
combinations.

It's not only weight, but also (rather?) finding the space for the
antennae (with sometimes incompatible positioning requirements and
electromagnetic interference issues).

Here is a presentation from 2005 (in German) describing some of the
issues (pantographs included):

http://www.schienenfahrzeugtagung.at/download/PDF2005/32%20-%20Graz%20Vitins_K%F6ck.pdf

Cheers,

Johannes.

[Johannes Picht]

Post by Johannes Picht
Hi!

Post by D7666
There of course other physical limits on multi system traction ... it
is not currently possible to install every lands safety systems in a
single BoBo loco without exceeding 22.5 tonne axle load. You don't
really run into the not enough pans for everything issue because you
hit the safety systems physical limit first. Hence Siemens and
Bombardier et al offer packages of certain sensible practical
combinations.

It's not only weight, but also (rather?) finding the space for the
antennae (with sometimes incompatible positioning requirements and
electromagnetic interference issues).
Here is a presentation from 2005 (in German) describing some of the
http://www.schienenfahrzeugtagung.at/download/PDF2005/32%20-%20Graz%20Vitins_K%F6ck.pdf

... plus fun requirements like front colour (white or yellow in NL, red
in Italy) or fire extinguishers (required in some countries, forbidden
in others ...

Johannes.

[Anna Noyd-Dryver]

Post by bob
On the other hand, observation
suggests that Swiss pantographs are significantly narrower than German
ones (I believe the difference between the Re 420 and Re 421 is that
the latter has one German pantograph, while the former is only able to
run in Switzerland).

The Austrian and Swiss pantographs are different; those RailJet sets which
can operate through to Switzerland have a second pantograph.


Anna Noyd-Dryver

[bob]

Post by Anna Noyd-Dryver

 On the other hand, observation
suggests that Swiss pantographs are significantly narrower than German
ones (I believe the difference between the Re 420 and Re 421 is that
the latter has one German pantograph, while the former is only able to
run in Switzerland).

The Austrian and Swiss pantographs are different; those RailJet sets which
can operate through to Switzerland have a second pantograph.

The having of a second pantograph in and of itself is not necessarily
indicative; the majority of Swiss domestic locomotives have two
pantographs[1] but they are both Swiss-domestic only. As Nick's
comprehensive list indicates, De and At both use 1950mm pantographs
while CH uses 1450mm ones, though all three use 15 kV 16.7 Hz.

[1] a subset of the Re460 seem to have a different design of
pantograph at each end, with one having a single contact strip and the
other having two, while most of the fleet seem to have the double-
contact-strip variety at both end. I have no idea why.

Robin

[Anna Noyd-Dryver]

Post by bob

Post by Anna Noyd-Dryver

Post by bob
On the other hand, observation
suggests that Swiss pantographs are significantly narrower than German
ones (I believe the difference between the Re 420 and Re 421 is that
the latter has one German pantograph, while the former is only able to
run in Switzerland).

The Austrian and Swiss pantographs are different; those RailJet sets which
can operate through to Switzerland have a second pantograph.

The having of a second pantograph in and of itself is not necessarily
indicative; the majority of Swiss domestic locomotives have two
pantographs[1] but they are both Swiss-domestic only. As Nick's
comprehensive list indicates, De and At both use 1950mm pantographs
while CH uses 1450mm ones, though all three use 15 kV 16.7 Hz.

Turns out I was wrong, anyway; according to the ever-reliable Wikipedia,
the first batch (which can operate into Switzerland) have *three*
pantographs, the remainder (which can operate in Austria and Germany) have
two.

Post by bob
[1] a subset of the Re460 seem to have a different design of
pantograph at each end, with one having a single contact strip and the
other having two, while most of the fleet seem to have the double-
contact-strip variety at both end. I have no idea why.

Curious. Is there any consistency within the 'different' locos? Are they
permitted to operate at a higher speed, maybe? Or perhaps it's just
'dual-sourcing' and the two types happen to look different....


Anna Noyd-Dryver

[D7666]

Post by bob
[1] a subset of the Re460 seem to have a different design of
pantograph at each end, with one having a single contact strip and the
other having two, while most of the fleet seem to have the double-
contact-strip variety at both end.  I have no idea why.

19 Re460s had new pans of a different type fitted around 2008/2009 -
these allow unrestricted 200 km/h operation of Re460s in multiple and/
or in push-pull in any position in the train. Before this there were
restrictions on certain 200 km/h operations - but I do not know what
those restrictions are or were. There may well now be more than 19
Re460s so equipped. I do not know if this is related to the question
of different pans at each end but maybe it is ???

--
Nick