Re: Near miss at Victoria (London)

[Haggis <wartune@bigpond.net.au>]

As you would know Matt there is a good neutral section coming around the corner
from Moolabin toward Sherwood... Helps to get a good run up first.... (6C49) :)

MattyQ wrote:

> "Chris Downs" <cvdowns@ozemail.com.au> wrote in message
> lS866.170$Ll4.8153@ozemail.com.au">news:lS866.170$Ll4.8153@ozemail.com.au...
> > Sydney has no equivalent to Bizzie's 25kV arrangement (such as between
> Roma St
> > station and the Merivale Bridge or opposite Mayne Car Sheds) where the
> > pantograph traverses a lengthy dead section of contact wire rather than
> what I
> > think of as "air gaps".
>
> These are called "Neutral sections". If my facts are correct, the Neutral
> Section is a characteristic of AC Overhead Traction Wiring Equipment (OHTWE)
> only.
>
> > Brizzie also has "ski jumps"
>
> "Low speed section insulators".
>
> but only for crossovers
> > and sidings.  Other mainline sections (not air gaps or dead sections) have
> a
> > more intricate version of Sydney's old diamonds that does provide truly
> > continuous power.
>
> What you call "air gaps" are referred to in QR as "insulated overlaps"
> althought they serve the same purpose. These are always used in preference
> to "section insulators" (SI's) on main lines. High speed BICC SI's (what you
> call 'diamonds') are used only when there is insufficient room for an
> insulated overlap, which requires at least four stanchions to support. An SI
> can be placed almost anywhere in the OHTWE.
>
> >
> > 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?
>
> QR's 25kV 50Hz AC system is less prone to arcing than Sydney's 1.5kV DC
> system for reasons Dave Johnson would be better off explaining. Suffice it
> to say QR overhead does indeed arc. Try sitting at Northgate one evening and
> watch the Shorncliffe trains depart.
>
> --
> Matt Smith
> Brisbane, Australia
>
> Email - mattyq1009 at dingoblue dot net dot au
>
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