Hi Andrew
On (14 May 97) Andrew Hamblyn wrote to Alec Cameron...
 AH> Well it was those Aussies that made the biggest heaviest longest etc
 AH> train... 
 AH> powered by Diesels (10 of them I think) hauling some 15000 tonnes of 
ron
 AH> ore 
 AH> i forget the exact deatails..... in my eyes that is sheer power.
Wasn't it 45 000 tons?
Yup. There is a lot of misunderstanding about loco performance. The diesels
are ahead of steamers because-
* steamers are having to stop to refuel and to be cleaned. No way, can these
be available for long hours. The availability hence the miles per week for a
diesel, is probably better than double that for steamers.
* acceleration from rest, is lethargic because the drawbar pull is
proportional to the weight sitting on the drive wheels. Most diesels have
every axle motored, but steamers have weight carried on auxiliary trucks that
are not powered. This was improved on SOME steamers by putting a wee engine
onto the trailing "booster" truck.
* the weight of fuel and water in the [heavy] tender is very much greater 
han
the weight in fuel tanks of a diesel. So the steamer earns less revenue, the
tender is a costly brake on progress.
* steamer deteriorates in power output during the run, as the ash and other
nasties build up on the tubes and in the grate. Hence the need for regular
vigorous cleaning.  The diesel maintains fully availble power for unbroken
months, the cleaning is just cosmetic.
But you gotta admit, the steamer looks great and sounds great and let's keep
them running!   Cheers...ALEC
... Drive? I'll take the train as the good Lord intended!  ^oo   oo^oo   oo^
--- PPoint 1.92
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