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

[chris@transdata.co.nz ("chris 'fufas' grace")]

Alan Reekie (delete 'nospam.' to reply) wrote in message
<76e2ib$srg$1@news3.Belgium.EU.net>...
>
>David McLoughlin a Êcrit dans le message
><368833E3.148B@REMOVEiprolink.co.nz>...

>>
>>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?
>>
>Yes, many lines in Brussels (STIB/MIVB) have single-ended operation
>with trams using single-arm pantographs (eg T2000 cars on route 91).
>AFAIK there are no problems in running in either direction alternately.
>But of course pans *do* come to a sticky end from time to time,
>usually because they get snagged on some bit of overhead line that
>is out of place (remember the 'knitting' is not absolutely fixed, and can
>sway quite a lot under dynamic forces). I think that the constraints on
>positioning under pans should be significantly stricter than under


It is of interest to note here that the Faiveley pantograph (and its British
derivative, the Stone-Faiveley) was used for many years on British 25kV
locomotives and although each locomotive was originally fitted with two, one
facing in each direction, it was found that they operated equally well in
both directions so the second pantograph was removed.

Thus it would appear to be an overhead problem. Admittedly the overhead
wiring on a main line railway is substantially less complex than that of a
street tramway, and suspended entirely differently, but 100mph operation for
20+ years would presumably have shown up any difficulty with single arm
pantographs.