Re: Bethungra Spiral

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

In article <Rfnz3.4951$1E2.32045@ozemail.com.au> "Garry Hoddinett" <hoddos@netspace.net.au> writes:
>From: "Garry Hoddinett" <hoddos@netspace.net.au>
>Subject: Re: Bethungra Spiral
>Date: Thu, 2 Sep 1999 14:44:00 +1000


>Roderick Smith <rodsmith@werple.net.au> wrote in message
>01bef479$035d0300$4f2d11cb@rodsmith">news:01bef479$035d0300$4f2d11cb@rodsmith...
>> The original line was 1880s.
>> Previous postings have not suggested reducing the southbound track from 1
>in 40 to 1 in 66; they have suggested eliminating the spiral and providing a
>more-direct northbound track at 1 in 40 instead of 1 in 66: ultimately
>faster.
>The spiral was one of many circuitous (and curving) deviations created to
>suit the characteristics of steam locos.  With diesels, it is possible to be
>faster by being straighter and steeper.  This is the design principle of
>French TGV routes.

>Why not convert the double track Cootamundra - Junee section to single track
>using the more direct alignment?  Single tracking the Goulburn - Junee line
>was proposed a number of years ago and was probably an over kill reaction to
>cut costs.  However a lot of traffic heading south on the main south line
>doesn't pass Cootamundra.   With bigger trains and better signalling double
>track beyond Cootamundra may not be necessary.


I must be missing something here  , but how can deliberately increasing the 
ruling grade of a main line like the main south from 1:66 to 1:40 be a 
desirable thing to do.
The total distance gained is approx 4.5 km if we include the spiral and the 
frampton deviation.
The reduction in full load is (if we assume an NR class, 1750 tonnes down to 
1235 tonnes) ie we lose 515 tonnes of gross load , which translates into lost 
revenue , approx $9800 of lost revenue (at 2.5 c/ntk) per train , all to save 
4.5 km in 960 km.
Makes no sense at all.

MD