Re: BLs vs NRS

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

In article <36eef3e7.0@nap-ns1> "Grahame Ferguson" <grahamef@users.mcmedia.com.au> writes:
>From: "Grahame Ferguson" <grahamef@users.mcmedia.com.au>
>Subject: Re: BLs vs NRS
>Date: Wed, 17 Mar 1999 11:25:10 +1100


>David Bromage wrote in message ...
>>The IP and Ghan are considerably longer than the overland, so the 4000hp
>>would be needed.
>>
>>Cheers
>>David
>In days gone by the motive power  for the IP was :
>2x46 class later 2x86 class Sydney to Lithgow
>2x44 class Lithgow to Parkes
>1x44 class Parkes to Broken Hill
>1x600 or 1x700 class Broken Hill to Pt Pirie
>1xGM12 or 2xGM1s Pt Pirie to Kalgoorlie
>or  2xGM12s or 1xCL for a combined Trans Australian-IP
>1xL class or 1xK class Kalgoorlie to Perth.

>The only section that required high horse power was Sydney to Lithgow with
>its 1 in 33s Valley Heights to Katoomba.
>2x44s could haul the IP from Lithgow to Sydney, but 3x44s were required from
>Sydney to Lithgow.
>A 3000hp loco could do the section Lithgow to Parkes, but at a greatly
>increased section time because of the 1 in 40 grades.
>Basically 1 BL could do the job west of Lithgow or a single DL could haul
>the IP west of Parkes.  A DL has a higher gear ratio than a BL.
>A single ended loco runs into problems at Perth Terminal, because it can not
>be turned there.


The above comments are very interesting, but using the data from Railpages 
loco info the continuous rated tractive effort for a DL is 370Kn as compared 
to the BLs 337 Kn.
The equivalent continuous tractive effort for a 44 is 204 Kn , so the DL is 
just marginally less powerful than 2 44S.
Could this be partially due to the fact that the DLs are using the more modern 
D87 series motors , same as the 82s , whereas the BLs still use the D77 motors.
In reality its not feasable to use just one loco on the 1:33 part of the 
journey , but from the perspective of the whole travel time , just how much 
time would be lost by using one loco on the Parkes - Lithgow bit.

Of course the real answer is to use a C class with its ultra heavy axle load 
would make short work of the 1:33s.

MD