 Joined: 21/02/2011(UTC) Posts: 383
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Okay, I have a few questions about pantographs!
1. Why do some engines/trains have more than one pantograph for the same electrical systems? Do they use one for each direction? Why?
2. What are the benifits of 'Z' pantographs?
Thanks! |
Author of the gritty sci-fi novel 'Stories of Earth: WWIII' (featuring an awesome train chase)
Avid YouTuber (XtremeTrainz and TrainzXtreme) and train person! |
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 Joined: 28/11/2007(UTC) Posts: 8,226 Location: Montreal, QC
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Some lok designers included two pantographs on locomotives as this provides options to the driver/operator. Often, the one closest to the rear of the locomotive is used. Having two pantographs makes it easier to set this kind of standard for operation. Certain types of trains require precautions, including that the pantograph at the front of the lok be used. This includes consists made or including fuel or other tank cars, new cars or trucks (carriers) or flammable goods (i.e. lumber) which could catch fire due to sparks.
Not quite sure what you mean by "z" pantograph. There are two kinds primarily used, scissors type and single-arm. The scissors type involves a diamond shaped frame which connects to the anchor at four points and to the blade on the top. The single arm pantograph is a more recent design which allows for the blade to be mounted on a single arm. New technology and materials have enabled the railways to overcome vibration and other issues that made the scissors type the preferred design in early electrics and this progress can be seen in the modern single arm pantos.
Regards
Mike C
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 Joined: 02/01/2009(UTC) Posts: 1,067 Location: Auckland, New Zealand
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To add to what Mike said, in countries with low voltage, eg Holland(1500V DC) and Belgium(3000V DC) both pantos are up when the locomotive is pulling away from a standing stop or when the loco is under heavy load. In both cases, there is a large amount of current drawn from the catenary. Having both pantos up reduces the electrical load on them. The front panto is usually taken down once the loco has gained some speed except for the cases mentioned by Mike, where the rear panto is pulled down.
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Joined: 22/01/2009(UTC) Posts: 14,875 Location: On 1965 Märklin Boulevard just around from Roco Square
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another reason is to, when locos go into a different volatge system, e.g.country borders one of those loco was the German BR 182 with 3 panthos or some have 4.
regards.,
John |
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Joined: 16/02/2004(UTC)
Posts: 15,443
Location: DE-NW
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Regards Tom --- "In all of the gauges, we particularly emphasize a high level of quality, the best possible fidelity to the prototype, and absolute precision. You will see that in all of our products." (from Märklin New Items Brochure 2015, page 1) ROFLBTCUTS  |
 1 user liked this useful post by H0
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 Joined: 01/03/2008(UTC) Posts: 2,883 Location: South Western France
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Originally Posted by: H0 
I never heard of a German BR 182 with three or four pantographs. Some Austrian Rh. 1116 (technically the same as BR 182) do or did have three pantographs (third pantograph for Hungary or for Switzerland).
I guess John meant the BR185, which has both the BD/OBB wide pantos and the narrower SBB version. And the re 484 multi system Re 484 probably also use one of the wider pantograph(s) under the 3kV DC catenary in Italy, no? Cheers |
Jacques Vuye aka Dr.Eisenbahn
Once a vandal, learned to be better and had great success! |
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Joined: 01/03/2008(UTC) Posts: 2,883 Location: South Western France
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All good info
I will add a few details
In some special cases (unlikely on a model railroad...) both pantos will be applied even if not warranted by the power demand, but in case of poor contact to the overhead wire, like for instance heavy icing.
When loks are opertaing in MU, and to relieve the pressure on the overhead, the distance between the pantos of each loco will be kept as long as possible (i.e. front panto for the head unit, rear one for the second one) but this rule is definitely*not* and absolute one, as I have observed many variations/combinations and permutations!
For example double units of the SBB Re 484 or Re 482 "Cargo" are often observed with both *front* panto raised.
I understand also that with more modern recent designs (low inertia/ smart computer controlled pantos) the pressure on the overhead can effectively be lowered, wich improves the durability of both the whip and the wire, while preserving and enhancing a safe power pick-up.
The system can be described as similar to the ones used in cars with "piloted" smart suspensions.
Cheers |
Jacques Vuye aka Dr.Eisenbahn
Once a vandal, learned to be better and had great success! |
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 Joined: 29/07/2007(UTC) Posts: 1,435 Location: Switzerland
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Originally Posted by: Dimi194
1. Why do some engines/trains have more than one pantograph for the same electrical systems?
Plus (unless I overlooked this in one of the previous postings) if one pantograph is damaged "en route", then the second one usually enables the train to continue its journey without the need of a helper loco.
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Joined: 28/11/2007(UTC) Posts: 8,226 Location: Montreal, QC
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Originally Posted by: river6109 another reason is to, when locos go into a different voltage (voltage) system, e.g.country borders one of those loco was the German BR 182 with 3 panthos or some have 4.
regards.,
John I think that Dimi was referring to multiple pantographs for the same system and not to pantographs for multiple systems. On some multi system loks, there is only one pantograph for each system, which can cause problems as seen here: At 6:25 or so, the pantograph of one of the two black ES64 F4s is damaged. Later on in the same video, you can see the loks being pulled northwards by a SBB Re 10/10. I agree with Tom that the DB 182 was delivered only with 2 pantos. The OBB and MRCE/Dispolol versions may have 2, 3 or 4 pantos depending on the model class (1016, 1116, 1216, etc). Those models may be registered in Germany as 183 or other classes. Regards Mike C
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Joined: 29/01/2012(UTC) Posts: 1,422 Location: Montreal, Canada
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Great info. Just wanted to say thanks for posting this.
I have always wondered why two up sometimes, other times one.
I merely assumed it was a more reliable contact with two up.
- Mark
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DB DR FS NS SNCF c. 1950-65, fan of station architecture esp. from 1920-70.
In single point perspective, where do track lines meet?
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Joined: 14/12/2002(UTC) Posts: 800 Location: Newcastle NSW Australia
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Use to drive trains with 4 engines ,all pans up 1600 ton load freight on 1in 33 grades with the catenary steaming during the winter months . All the elec loco's now cut up for scrap on our 16oovolt DC system now being used for pass EMU service only .
Tom in Oz.
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