Re: FA A Class

[mauried@tpg.com.au (Maurie Daly)]

On Fri, 02 Feb 2001 17:33:54 GMT, Mark Bau <markbau@earthlink.net>
wrote:

>in article 95dhi0$6t4$1@nnrp1.deja.com, Doug Mason at dmason@deakin.edu.au
>wrote on 2/1/01 10:45 PM:
>
>> I have been told that Freight Australia's A85 is now able to pull a
>> bigger load than the rest of the A class so when did it get a new engine
>> or what ever done to it.
>> 
>
>Sure it hasn't just had its gear ratio changed back to the same as the rest
>of the class? (A85 was high speed geared shortly after it was rebuilt,
>actually I think it was rebuilt that way)
>
>The other possibility is that its had its gear ratio changed to freight
>gearing, I believe FA have a program to do this to all of their locos.
>
>Mark
>

The A class as they stand seem to me to be somewhat gutless for their
available HP.
Loadwise ,the As seem only to be able to manage about 150 tonnes more
than a B even though they have an additional 1000 HP available.
Likewise the Ns which are the same HP as the As ,are good for around
200 - 300 tonnes more than an A.
The Ns continuous tractive effort is a respectable 260 Kn compared
with the As 212 Kn.
I wonder whether the design of this loco has been somewhat compromised
by using the older style D57 traction motors and not going for a later
type like the popular D77s which the Ns have.
The other surprising factor is the huge load differance (30 % more)
between an N and a G which cant be explained easily by the 500 HP
differance.
If this load differance is due to the super series wheel slip control
in the Gs, then one would think that installing this on the As would
be a worthwile addition .
I beleive that 42220- which at one time had super series allowed its
maximum load to be increased from 640 tonnes to 1000 tonnes on 1:40,a
pretty impressive improvement.

MD