[clive hayward]

Hello,
I'm going to ask this question because it has always fascinated me. What happens when you have a station with dual voltage lines i.e. at border stations when there are 2 networks which meet but both have different voltages. Example French/german border stations 25Kv to 15Kv, French/Italian stations 1500V/300V or even French/French stations 25Kv/1500V (eg Marseille st Charles, Albertville or Dôle). Does each track have it's own voltage, thereby necessitating use of diesel locos to transfer the train between the 2, or is there some way of switching voltage between the two? Most networks now have bi, tri or even quad voltage locos to alleviate the problem but what happenened in the 50s and 60s?

regards

Clive

 

[goedel]

An interesting question! On the Brennerbahn at the Austrian-Italian or 15000V AC / 3000V DC border I believe that the Austrian locomotives coast (downhill too) with their trains across the divide after lowering their pantographs and a diesel is on hand to shunt them back over the "electrical border" and an Italian DC locomotive is plugged on the train, and vice versa. Much better to use the momentum of the train to get it across than use diesels to pull the actual trains or start switching the voltages of different sections of catenary...and of course the swish new multi-voltage locomotives, assuming they've jumped through the many loopholes and are certified for INDUSI, ELEKTRA, ETCS level II, what ever the Italians use etc. just swap pantographs and thunder through, although this a much more recent innovation that you would think.

Non-compatible signalling and safety systems, even requiements for red paint patches on fronts of locomotives and approval from national railway bodies have held up multivoltage locomotives from actually crossing borders for a long time and it's only just now that Europe is starting to open up and apply common standards. And of course if the Italians has licensed the Austrians (with more modern locomotives) to run their trains into Italy then the Austrians would have taken some business of the Italians, and there is no way the existing Italian DC locomotives could get into AC Austria in return!

It must now be possible to traverse from the toe of Italy to the top of Denmark or further with certain four-system-locomotives if enough black boxes are crammed in. Electrical border stations must be more interesting that most stations for train movements I would think!

 

[John Webb]

I cannot answer for continental matters, but I occasionally use the 'Thameslink' line through Central London. At Farringdon station the system changes from the 750volt third-rail used on the former Southern Region railways to the 25kV overhead catenery.

The change-over is done while the train is stopped at the platforms, which are fitted with both power systems. There is usually just a brief flicker of the lights when the driver switches from one system to another.

Regards,
John Webb

 

[72C]

QUOTE Most networks now have bi, tri or even quad voltage locos to alleviate the problem but what happenened in the 50s and 60s?

Clive, do you refer to the train or operation in general?

If you refer only to the train, the loco was switched out and replaced by appropriate motive power- some coaches used dual electrical systems however most did not and the alternate system was switched over.

Hence the use of diesel powered autonomous TEE international trains from the Nederlands to Switzerland and numerous motive power changes prior to multi-voltage workings.

BTW when were the first true multi-voltage classes introduced on the Benelux routes?

And why have the BR181's been withdrawn?

Tim

 

[Edwin]

I'm pretty sure I've read about border stations with the overhead on each platform individually switched to the correct voltage. However it was a long time ago and I probably wasn't paying attention so I can't say which station it was!

I believe TGVs have different pantographs for different voltage, so they must lower and coast through the voltage change before raising the correct one. The tram-trains in Germany use the same pan for 750V street running and 15kV operation on railways, they just run through a short dead section and when they receive power again the system detects the voltage and sets itself up accordingly.

Incidentally another incompatibility not already mentioned is pantograph width. I believe this used to stop German/Austrian locos running through to Switzerland and vice versa even though the voltage is the same.

 

[john woodall]

Hi Edwin,

This is a simple answer to a complex question.

Swis pantograpgh heads are narrower due to tunnel clearances. A swiss pantograph head will work in germany.

The main reason swiss and german locomotives did not run in either country in the past was because of the signalling systems. Note for every absolute there is an exception. Swiss locomotives did run into Lindau on the Bodensee and to get there they had to run through Austria (the border between the three countries at this point is in the Bodensee!)

Marklin in 1985 (I think it was then but may have the year wrong) arranged for a SBB Crocidile to run to Goppingam but it needed either a DB locomotive behind it to trigger the signalling or there wasa special coach outfitted with the correct detection equipment.

Now days the SBB cargo locomotives run into all parts of Germany with no problems.

Cheers

John

 

[dwb]

QUOTE Now days the SBB cargo locomotives run into all parts of Germany with no problems.

And a DB ICE is a twice daily regular at Interlaken. I believe these may have two pantographs if notes accompanying some models are anything to go by

David

 

[john woodall]

Hi Doug,

looking at the picture it would appear that there are two pantographs.

Just look at all the bugs encrusted onto the front of those locomotives!

John

 

[dwb]

QUOTE looking at the picture it would appear that there are two pantographs.

Just look at all the bugs encrusted onto the front of those locomotives!

I've just taken a look at the original, it's 9M pixel, and I can confirm that there are two pantographs on the ICE. It looks like the retracted one is wider than the one in use. I can take a 1:1 crop and post it if anyone would like a closer look.

The Re460 definitely wins on the bug count. The ICE is quite clean by comparison.

I have a photo of the ICE as it arrived into Interlaken West and it shows the pantograph is raised on the front unit which means this ICE has pantographs raised at both ends. I don't think that happens in the UK?

David

 

[Edwin]

Two electric locomotives running in multiple will have two pantographs raised, but this is unlikely to happen above 75mph as no passenger train requires multiple running. Two or three four-car multiple units can run at up to 100mph with pans raised about 80m apart (the pan is always near the centre of the unit, possibly for this reason).

There was a lot of research done on high speed behaviour of multiple pans with UK catenary, which true to form is more flimsy (though these days probably not cheaper) than continental designs. This was for the Advanced Passenger Train in the 1970s. It was concluded that with a pan at each end the second one would have poor contact because of the vibrations set up in the wire by the first one. Hence the pre-production APTs had the power cars in the middle linked by a 25kV bus line. Things have moved on and it is now possible to run a 25kV bus line over the passenger coaches, and the Pendolino does this.

TGVs also have a 25kV bus line, connecting the power cars either end. However when running in multiple I presume each unit needs a pan raised - I wonder if these must be at the extreme ends of the formation? The catenary on high speed lines is in any case much more solid than traditional UK designs so probably less prone to the problems the APT suffered.

 

[goedel]

QUOTE (Edwin @ 9 Jan 2009, 22:13) <{POST_SNAPBACK}>Two electric locomotives running in multiple will have two pantographs raised, but this is unlikely to happen above 75mph as no passenger train requires multiple running. Two or three four-car multiple units can run at up to 100mph with pans raised about 80m apart (the pan is always near the centre of the unit, possibly for this reason).

It does happen in Europe on the occasional EuroCity service e.g. EC 162/163 Transalpin from Vienna to Zürich has some quite steep bits on the Tauernbahn in Western Austria. In fact I'm sure they bank it as well on occassion at certain points...but then it is a top flight EuroCity with 14+ coaches so it probably does take some oompf to keep the train at the speed limits the whole way, that said two 1016 or 1116s can handle anything.

Also the new ÖBB Railjet service has two high speed push-pull locomotive trains running in pairs on some routes according to the new timetable and so there are two pantographs eight cars apart up at 230 kmph in places!

EC 162/163 Transalpin with the hills a tad on the big side...

http://www.zelpage.cz/fotogalerie/
http://www.zelpage.cz/fotogalerie/big/obb170.jpg

 

[goedel]

QUOTE (Edwin @ 9 Jan 2009, 22:13) <{POST_SNAPBACK}>TGVs also have a 25kV bus line, connecting the power cars either end. However when running in multiple I presume each unit needs a pan raised - I wonder if these must be at the extreme ends of the formation? The catenary on high speed lines is in any case much more solid than traditional UK designs so probably less prone to the problems the APT suffered.
According to this video they have four out of eight pantographs up, although of course if it's running on DC then that might explain why...hmmm, can one of our SNCF experts please help? In fact, given that there were non-TGVs running in the clip it might not even be a highspeed line...so my posting was virtually pointless!

 

[clive hayward]

QUOTE (goedel @ 10 Jan 2009, 00:11) <{POST_SNAPBACK}>According to this video they have four out of eight pantographs up, although of course if it's running on DC then that might explain why...hmmm, can one of our SNCF experts please help? In fact, given that there were non-TGVs running in the clip it might not even be a highspeed line...so my posting was virtually pointless!

I can confirm this clip shows TGV South East versions running on 1500V DC and not a TGV line LGV (Ligne à Grande Vitesse). As for the pantographs, I can't really comment, but I do know a TGV driver, so I'll ask him.

Regards

Clive

 

[christoph]

Hello,

QUOTE (john woodall @ 9 Jan 2009, 22:11) <{POST_SNAPBACK}>Hi Doug,

looking at the picture it would appear that there are two pantographs.

Yes, there are two pantographs. ICE motor cars 401 072 to 401 090 and 401 572 to 401 590 are equipped with narrow pantographs and safety equipment to work in Switzerland.

Kind regards

Christoph

 

[christoph]

Hello,

and back to the original question. There were both variations of current changes at stations.

The situation at Brenner has already been described. Here electric locos coast under the "wrong" overhead with pantographs down and are recovered by diesel locos. This system was or is also used at Venlo on the German/Dutch border to my knowledge.

The other option is to have overhead which can be energised by either current. To my knowledge Aachen and Emmerich in Germany work that way. Travelling from Germany into Holland via Emmerich, the German loco was detached at the platform and went into a siding. Then the overhead was switched to the Dutch current of 1.5 kV DC and the Dutch loco which had been waiting on the main line was attached to the train and moved off. To release the German Loco the current was switched back to 15kV AC again. If you look at Emmerich station on Google Maps or Google Earth you can make out those sidings. Today passenger services are in the hands of dual voltage ICE3-trains which coast through the station with pantographs lowered. Most freight workings are diesel-hauled on the Dutch side nowadays which make life easier.

Kind regards

Christoph

 

[Bigboy]

QUOTE (john woodall @ 9 Jan 2009, 20:14) <{POST_SNAPBACK}>Swis pantograpgh heads are narrower due to tunnel clearances. A swiss pantograph head will work in germany.

Unfortunately this is not the case. The wider German and Austrian pantographs are necessary because the overhead wire is allowed to deviate further from the centre line of the track. On straight track this zig-zag deviation is built in to even out wear over the width of the pantograph head; on curves it requires pull offs at certain intervals to keep the wire following the track reasonably closely. If a narrow pantograph head is used in these circumstances the wire will simply run off the end of the head allowing the pantograph to rise to its full height and become disastrously tangled in the wiring and /or hitting some overhead object.[/color]
The main reason swiss and german locomotives did not run in either country in the past was because of the signalling systems. Note for every absolute there is an exception. Swiss locomotives did run into Lindau on the Bodensee and to get there they had to run through Austria (the border between the three countries at this point is in the Bodensee!)

SBB locos running into Lindau were limited to a small number of Re4/4 II locos fitted at one end with a special pantograph with a wide head and a special mechanism which allowed it to be lowered just a little bit further than usual to keep the tips of the wide head within the normal SBB loading gauge when retracted.

Now days the SBB cargo locomotives run into all parts of Germany with no problems.

Again only specially equiped ones. This is limited to certain of the new Siemens TRAXX locos fitted with four pantographs, two of which are wide head and two narrow head as well as the German LZB signalling system. A small number of SBB Re4/4 II locos are allocated to SBB Cargo and fitted with a wide head panto at one end and dual Swiss/German signal systems for use into Germany.

What may be causing some confusion is that all Sbb locoos with narrow panto heads can work short distances into Germany, mainly to Basel Bad station which is actually a DB station on German teritory. The overhead wires in this area are aranged with the Swiss restricted 'stagger' to suit both wide and narrow panto heads.
With Open Acces BLS Cargo and DB Cargo (or DB Schenker or whatever they are calling themselves today) are only two of several operators using multi-voltage locomotives for run through international freight trains.

On the passenger side there are quite a few EMUs with dual standard electics for short distance working into the adjacent country. Switzerland has recently entered the Shengen immigration area and there are quite substantial numbers of international commuters around Basel, Geneva and Chiasso for instance. There are plans to substantially rebuild the lines around Geneva to cater for this traffic. Geneva Airport is actually an official French regional Airport and handles very many flights for skiers from the French Alps. Some taxiways off the runway at Geneva are within about 100 metres of French territory. The notorious CERN Large Hadron Collider is in a circular tunnel nearby which is partly under France and partly under Switzerland.
Basel is actually in three countries, Basel itself in Switzerland and Germanny and St. Louis entirely contiguous in France. The frontier crossing points actually being in the streets.
At Chiasso the frontier runs through the station
Hope this helps,

Alex/color]

 

[Fishplate]

There is an excellent site with examples of many border stations, showing the electrification system. Taking Venlo as an example (just 'cos I can relate to it, having been there and observed operations), the freight yard is simply split electrically, the German end being 15kV AC and the Dutch end being 1.5kV DC. Electric trains with single current locos coast in, and the locomotives are removed by a diesel locomotive.

The overhead above the tracks between the two main platforms are switchable between the Dutch and German systems, and this can be illustrated by these two pictures: NS 1841 on a domestic Intercity service and DBAG 111 009-7 on a Regional Express service to Hamm, both at the same end of the same platform with pantographs raised.

Cheers

Fishplate

 

[7113]

Just a thought, but didn't the old BR DC electrics (classes 76 & 77) run with both pantos extended?

Regards

 

[Fishplate]

Yes they did. If you look at the pic of 1841 in Venlo, you'll see it also has both pans raised, and like 76s/77s is a 1500v DC locomotive. I have a vague recollection it's because compared with higher voltage systems, trains on DC draw a lot of amps. Taking the french 122200 clas for example (dual voltage 1500v/25000v) with a 4300kW rating, on 25kV we can deduce that it woudl be drawing something like 172 amps (Watts= Volts x amps), while on 1500v it would be drawing more like 2867! The actual current draw may be higher owing to losses in electrical systems, though these will be minimal compared to transmission inefficiencies in a diesel loco. To confuse matters, the French 1500v DC locos only seem to run with one pan raised- the same seems to be true of the new TRAXX locos on Benelux services.

Cheers

FP

 

[Bigboy]

QUOTE (Fishplate @ 13 Jan 2009, 19:51) <{POST_SNAPBACK}>Yes they did. If you look at the pic of 1841 in Venlo, you'll see it also has both pans raised, and like 76s/77s is a 1500v DC locomotive. I have a vague recollection it's because compared with higher voltage systems, trains on DC draw a lot of amps.
FP

If you look at early photos and films of 15KV Swiss locos working they too ran with both pantographs up. I had the opportunity several years ago to study a restored and preserved Crocodile in the Swiss Transport Museum in Lucerne. The pantograph heads were much more primitive compared to what is used nowadays and the contact area was merely a bar of aluminium (or alloy) of about 1/2/" diameter. This of course only gives a very smalll contact area. Improvements eventually came through the use of copper or bronze flat strips and eventually carbon strips. Modern panto heads also have improved arrangements for keeping the contact strips in contact with the overhead wire. Very high speed stock such as TGVs even have a mini pantograph on top of the main panto and a small aerofoil to help maintain stability and close contact. This alllows modern pantographs to handle powers way beyond what were encountered in early days. This also explains why low voltage (1500V and 3000V) systems are tending to be no longer first choice where high powers are required and are superceded by 25KV. France was perhaps the first country to do this and some main lines are 25KV while the branches and earlier electrified station areas are 1500V DC. Many LGV (TGV lines) become 1500V DC at the end of their routes (as into some Paris terminals.

Many years ago I was being bussed down to Geneva from a French skiing holiday and we were driving down a 'B' type country road at about 40 mph. Over a dry stone **** there was a single track electrified very rural branch line. I was suddenly awoken from by dozy state when I became aware we were being SLOWLY overrtaken by a TGV doing all of 50 mph!! This was so long ago it was one of the original orange liveried ones. There are many TGV services like that.

This practice is extending to Italy where the latest high speed lines are 25KV and the new Dutch Betuwe heavy freight line from Rotterdam to Germany is the same. I believe 25KV is now recommended as a European standard as the older DC systems are really at the limit of their capabilities.

We even have an example in Britain where the new line to the Chunnel from St. Pancras is 25KV in an otherwise 750 V DC area.
With modern technology making multi-voltage vehicles relatively cheap and easy to build now a significant and increasing proportion of modern locos should enable this rationalisation to be achieved in something like 20 years or so.

Hope this helps,
Alex