Phil Bertram <pbertram@pipeline.com.au> wrote in article
<33C0C789.2976@pipeline.com.au>...
> Bill Bolton wrote:
> >
> > On Wed, 25 Jun 1997 23:43:46 +1100, Carolyn Neumann
> > <neumannc@ozemail.com.au> wrote:
> >
> > > under the SLR's rather unique overhead.
> >
> > There doesn't appear to be anything particularly "unique" about the
> > SLRs overhead construction as far as I can see, it's a normal
> > pantograph set up. Would you care to elucidate your comment?
> >
> > Cheers,
> >
> > Bill
> >
> > Bill Bolton billbolton@acslink.net.au
> > Sydney, Australia
>
> Bill,
> Yes the overhead does appear to be for normal pantograph operation,
> however what is different is that; double contact wire has been hung. I
> am not sure of the reasoning for this maybe someone else can provide the
> answer, it may have something to do with better pick up for the 750V dc
> taction current. I have noted new overseas Light Rail systems also using
> double contact wire as well. (Indeed the SRA uses this method for high
> current demand sections such as coal lines)Aside from Melbourne which
> has sucessfully combined panto and trolley pole operation, the sydney
> system is exclusivly panto only.
>