Re: Fate of 85/86 class

[Greg Rudd <grudd@mail.usyd.edu.au>]

Maurie Daly wrote:

> In article <389F5055.4CA642CD@mail.usyd.edu.au> Greg Rudd <grudd@mail.usyd.edu.au> writes:
> >From: Greg Rudd <grudd@mail.usyd.edu.au>
> >Subject: Re: Fate of 85/86 class
> >Date: Tue, 08 Feb 2000 10:08:05 +1100
>
> >"The Railway Rasputin II." wrote:
>
> >> > I seem to recall that in the original analysis for the Blue Mountains
> >> > electrification that it was stated by the various branches of the railways that
> >> > electrification was by far the cheaper alternative than dieselisation of the
> >> > route in running costs.  With the added advantage been that Australia has
> >> > basically an almost endless supply of coal vs a finite supply of oil.
> >>
> >> Back then yes but apparantly technology has made diesel power more
> >> efficient, so the "experts" say.
> >>
> >> rgds
>
> >Remember that a high voltage Ac ie 25kv/50kv electrification is far more efficient
> >than a 1500v dc electrification both in terms of infrastructure and in electricity
> >consumption.  Thus a modern electrification should be still more efficent than diesel
> >system.  Another point that should be made is that the Netherlands is rebuilding its
> >1500v dc system to 25kv 50hz  over a period of aprox 20years.  I am sure that these
> >arguments would have been put forward to them. Because if what these experts say is
> >correct, they would be starting to tear down their 1500v system and replacing them
> >with either dmu for passenger work and EMD/GE diesel locomotives for freight work.
>
> >In the period concered electric locomotive technology has also improved as well.
> >Remember, three phase Ac drive has been around in the electric locomotive world since
> >the late 1970's with the units that BBC built for DB.   The real improvements in
> >diesel technology have been the introduction of electronic fuel injection and
> >computerized management systems coupled with more efficent turbocharger design.
>
> >See ya
>
> >-greg
>
> Theres only so much energy in a litre of diesel fuel.
> Digging back thru some old referance books I discovered that a litre of diesel
> fuel releases 38.6 Mj when burnt,so if we had a 100% efficient diesel engine
> with no losses in the alternator / rectifiers / traction motors we could
> assume that the whole 38.6 Mj was available for traction.
> Converting 38.6 Mj into more reasonable units we get 10.722 Kw/H.
> Now I pay at home 8c per Kw/H so 10.722 Kw/H would cost 85.7 cents.
> Realistically though a diesel engine / transmission isnt 100% efficient but
> more around the 50 - 60 % (anyone know exactly) ,so that a more realistic
> answer would be 6,4 kw/H costing 51 cents.
>

I always thought that a diesel engine is around the figure of 30-33% energy efficient.

> Now its fairly likely that a large electricity consumer like a electric
> railway would be able to get electricity at a much lower price,lets use off
> peak domestic rates of 4 c per Kw/H .
> This gives 6.4 Kw/H costs 25 cents.
> How does this compare with the cost of a litre of diesel fuel without tax.
> Of course one must factor in the electricity transmission costs and the extra
> maintenance costs of the overhead.
>

With modern overhead design i.e. constant tension catinerary coupled with advances in
metallurgy is should be far less maintenance intensive as in the past.

> It could be that diesel is cheaper.

> Is the VFT going to be electric.?
>
> MD