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

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

In article <37B4BA32.83DAD935@MYlisp.com.au> John MacCallum <johnmac@MYlisp.com.au> writes:
>From: John MacCallum <johnmac@MYlisp.com.au>
>Subject: Re: 82's Leading Patricks West. - Where are they now?
>Date: Sat, 14 Aug 1999 00:37:52 GMT

>Maurie Daly wrote:
>> 
>> In article <37afba6c.2105672@news.bigpond.com> gonoNOCRAP@bigpond.com writes:
>> >From: gonoNOCRAP@bigpond.com
>> >Subject: Re: 82's Leading Patricks West. - Where are they now?
>> >Date: Tue, 10 Aug 1999 05:38:13 GMT
>> 
>> >On Tue, 10 Aug 1999 03:24:48 GMT, mauried@commslab.gov.au (Maurie
>> >Daly) wrote:
>> 
>> >>This is a difficult question but does anyone have any idea of what a full
>load
>> >>for an 82 thru the Adelaide Hills is ?
>> >>It will / should be more than an 81 / BL or  an NR due to the more powerful
>> >>traction motors.
>> >>
>> >>Thanks
>> >>MD
>> >My guess Maurie would be the same as a DL they both have 710 12
>> >cylinder engines.
>> >regards Paul Johnston (MNRC)
>> 
>> Thanks Paul .
>> Its not an easy comparison due mainly to the much differant weights and the
>> totally differant traction motors,(DLs are quite lightweight 118T against the
>> 132T of the 82s .
>> The biggest differance is the continous tractive effort of 413 kn for the 82s.
>> (Gruntiest 3000HP loco in the country.)
>> Unfortunately railpage dosent give a starting tractive effort for 82s.
>> Maybe ASR will do some load trials to find out.
>> 
>> cheers
>> MD
>Starting Tractive effort has little to do with what the Loco can
>haul. All diesel electric locos have a much higher starting 
>tractive effort than what they can supply continuously.
>The continuos tractive effort is the tractive effort produced at
>a speed that the traction motors can provide without going into
>their reduced time/load range due to heating from high traction 
>motor currents. 82's have a min continuos speed rating of 15.4 kph.
>81 class engines have a continuos tractive effort of 33700 DaN
>at 19.2 Kph.
>Both 81 and 82 class engines have a nominal load of 1050 tonnes
>on a 1 in 40 ( 2.5% ) grade. Due to the higher adhesive ability 
>of an 82 class and its bigger traction motors it can go slower
>than an 81 and therefore provide more tractive effort. Hence the
>41300 DaN figure for an 82 class.
>As I stated previously though in NSW Freightcorp operates 82s with
>the same loads as 81s. On the long 1 in 40 grades between Molong
>and Orange and Stuart Town to Orange the max load is 1130 tonnes.
>This figure is less than what it appears to be practise in the 
>Adelaide hills. That's probably why so many engines have problems
>with slipping to a stand in SA. 


>-- 

>Pope

>Alias   John MacCallum

>remove MY from MYlisp to get the real email address.


Understand all the above John.
What seems to be inconsistant with the 82 load ratings is the continuous 
tractive effort of the traction motors.
Bearing in mind the the 90 class have exactly the same motors and the SRA
rate the 90s at 1700 tonnes up 1:40 at 15.4 km/h,if we assume that the motors 
are running at 100% capacity under these circumstances,then in the 82 case 
allowing for the lighter axle load and lower HP we should be able to get 
around 1250 tonnes up 1:40 at 15 km/h , with the motors running at only 70% 
capacity , ie the ratio of 4000 to 3000 HP , but as you indicate they are 
rated at no more than an 81 .
If the 82s are adhesion limited then we should get 1475 tonnes or in the case 
of HP limitation we should get 1275 .
The fairly common occurrance with trains slipping in the Adelaide Hills is 
just about always the non super series locos that ASR uses,ie the CLP/CLF/ALFs 
etc.
The BLs dont seem to show the problem , although given the way that NRC 
underload their trains its not likely to ever happen anyway.

cheers
MD