Re: RE: 82's Leading Patrick West. - Where are they now?

[mauried@commslab.gov.au (Maurie Daly)]

In article <01beeecd$8b9a3c80$102e11cb@rodsmith> "Roderick Smith" <rodsmith@werple.net.au> writes:
>From: "Roderick Smith" <rodsmith@werple.net.au>
>Subject: Re: RE: 82's Leading Patrick West. - Where are they now?
>Date: 25 Aug 1999 08:06:49 GMT

>Load through hills is governed by axleload, not by traction-motor power. 
>It is improved by control systems (such as controlled creep).
>Without seeing all of the figures, an 82 should have no more load than an
>81, BL or NR.

>-- 
>Regards
>Roderick Smith
>Rail News Victoria Editor


Yes and no.
For traction motors that are 100% efficient , ie all the input electrical 
power is converted into rotational torque then the above is true,but in the 
real world this is not the case.
81s have D77 motors but the 82s have much bigger D87BTR motors which can 
withstand the same electrical input for a much longer time.
This means that for climbing a long hill with equal load the bigger motors can 
exert the same tractive effort for much longer without overheating than can 
the smaller motors.
The obvious comparison is the continuous tractive effort of 
the NRs (23 tonne axle load,4000 HP,380 kn)) compared with the continuous 
tractive effort of the 82s,(23 tonne axle load,3000 HP,413 kn),ie the 82s have 
 more pulling power albeit at a slower speed.
The 82 vs 81 comparison is even more significant.
81s 340 kn cont tract effort.
The 81s are also slightly lighter than the 82s , (126 tonnes).

cheers
MD