Re: Near miss at Victoria (London)

[jjjim <jjjim@bigpond.com>]

 the EMUS in bris  have one pan per train (3 car set)  powering 8 x 135  or  180
kw motors   not sure how that compares to a spark loco ;)

Aus Visitor wrote:

> Chris Downs wrote in message ...
> >SNIP SNIP
> >
> >A question to those in the know:  In many thousands of km travel on
> Brizzie's
> >sparks I have never seen serious arcing between the pantograph and overhead
> as
> >I've seen in Sydney on occasions.  But my old man told me such arcing was
> >common on some trips he made under 25kV in the UK (loco hauled trains in
> all
> >cases I think).  Why is this so, overhead quality/age, higher current for
> >electric locos or?
>
> Arcing is less in AC systems as the arc is self extinguising and the current
> per pantograph is less when the volts are 25 kV.  Multiple Electric units
> often have two pans so current draw is shared, so even less current per pan.
>
> An AC Loco, on the UK system travelling at 125 MPH, is drawing all current
> through a single pan so losts to spark.  Biggest impact is frost & ice in
> the catenary wire.  I remember some IC225 test runs we did in middle winter
> at 5am.  Running out of Kings Cross & up to Peterborough was like travelling
> with our own ARC lights!!!!
>
> AV
>
> >