Re: Fate of 85/86 class

["Greg Hunter" <huntergpmj@bigpond.com>]

John MacCallum <johnmac@lisp.com.au> wrote in article
<38A317D5.F5A26922@lisp.com.au>...

> When the concrete sleepers were laid back in the early 90's the
> up and the down overhead on the mountains was separated electrically.
> The effect of this was that it removed the ability to put power back
> into the overhead for a train coming up the hill. 

Not so!  The two tracks were MECHANICALLY separated by removing the span
wires and replacing with all those shiny bits of galv steel.  Electrically
nothing changed.  Power can only transfer between tracks at substations and
section huts - about 4 km apart.



> 86 and 85 class
> engines put their output in Regen back through internal resistors so
> that very little excess current flows in the overhead.

The internal resistors are stabilising resistors to allow the motors to
regen at a higher voltage.  They do not dissipate a lot of energy and then
only when power is flowing into the overhead.  They are not like the
dynamic resistors on diesels which dissipate all the regen energy.


> Any over voltage of the overhead is dissipated by resistors at the
> substations.

These have not been maintained recently with the reduced use of elec locos.
 They still work for interurbans size regen.

 Greg