Re: SLR - Extension construction

[neumannc <neumannc@ozemail.com.au>]

Bill Bolton wrote:
> 
> matthew@mail.usyd.edu.au (Matthew Geier) wrote:
> 
> >  The voltage drop at the far end would be considerable. Especially
> > with 2 or more trams powering out there.
> 
> That depends on where they place the substation and what capacity it
> has.
> 
> > The current SLR system has 2 substations for approx 4 km of track.
> 
> It was engineered with the expectation of extension.  You don't put a
> substation near the end of a line!   One substation would be quite
> adequate to run the existing line.
> 
> > Unless they are going to bury a nice thick 750 volt feed from the
> > Fish Markets sub, they will have voltage drop problems.
> 
> Again, that depends where they put a new substation.
> 
> >  I don't know about the old Sydney tramway...
> 
> The entire North Sydney system, which had many heavily graded routes,
> ran off three substations.
> 
> Cheers,
> 
> Bill


Whilst one substation would be adequate to run the existing line it
would not provide any backup for failure of the substation so you have
to have an alternative supply (= 2nd substation).

The airconditioning load on the variotrams is quite high as a proportion
of the total electrical load of the tram (ditto for tangaras).  The
"natural" air conditioning of the North Sydney trams did not require
electricity!  North Sydney also had extensive feeders.  The ultimate
consideration is the cost of substations versus the cost of feeder
cables and the aesthetics of heavy overhead conductors and catenery -
compare the latest Melbourne installations with the current heavy
overhead of the Sydney light rail.

Chris