Re: Pantographs (was Re: MBTA BREDA Light Rail Cars)

[McFergus@my-dejanews.com]

In article <368833E3.148B@REMOVEiprolink.co.nz>,
  David McLoughlin <davemcl@REMOVEiprolink.co.nz> wrote:
> Silas Warner wrote:
>
> > There are usually two reasons why a locomotive might have two pantos.
> > One is to bridge "dead spots" in an overhead wire, but this is not the
> > usual reason.  The usual reason is that the pantos are designed for
> > one-way operation, and cannot be asily reversed.  This was true of
> > early Faiveley (one-arm) pantographs. which could only be operated with
> > the "elbow" facing backward: a forward-facing wlbow would be forced up
> > by the air rush of the panto's passage and might snag the wire.

Quite a number of years ago, British Rail locomotives always ran with the
trailing pan up, so that if the pantograph snagged the wires the pantograph
would not damage the roof mounted electrical equipment. In more recent years
they had their additional pantos removed, I believe to save on maintenance,
as it turned out that the costs outweighed the benefits of maintaining dual
pans on each loco.

>
> Most of the European trams which use single-arm pans are single-ended
> trams which use loops to turn.
>
> Are there any cities where trams/streetcars are double-ended and use
> single-arm pans that don't have this problem of pantograph-fouling?
> There are the Media and Sharon Hill lines in Philadelphia (the S/S lines
> in Philly still use poles!). AFAIK the new Sheffield system in England
> uses shunts at each terminus for its double-ended cars. Any more?

Most new LRVs follow standard railway practice and use single arm pantographs.
Off the top of my head Paris, Strasbourg, Manchester, Grenoble and of course
Sydney.

>
> David McLoughlin
> Auckland New Zealand
>
> I remember the Ice Age. It was what they claimed was happening to the
> weather before they invented Global Warming.


Rob

Sydney (Australia)
>

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