>dbromage@metz.une.edu.au (David Bromage) wrote:
>>David Johnson (trainman@ozemail.com.au) wrote:
>>>Maurie Daly wrote:
>>>
>>>> This leads to various differant HP ratings that can be delivered to the
>>>> traction motor sets at differant speeds and for differing times.
>>>> Ideally it would be nice to be able to increase the number of traction motors
>>>> from the usual 6 to 8 as engine HP increases,but loading and curve radii
>>>> prevent this.
>>>
>>>A couple of observations I'd like to share. We ran a 105 wagon coal train from
>>>Kooragang Island to Ulan and return. On the return, we did a test lift on
>>>Whittingham Bank with three 90 class locos and 11670 tonnes hanging off the
>>>back. At 0.5 km/h, the locomotives were exerting about 300 horsepower at 1900
>>>Amps. At 2 km/h, the locomotives were exerting about 900 horsepower at 1800
>>>Amps. At 25 km/h, the locomotives were exerting about 3830 horsepower at 900
>>>Amps.
>>Do you happen to know what the tractive effort at the same speeds was?
>>Cheers
>>David
>These numbers translate to tractive effort (in good old-fashioned
>"pounds mass") and at constant speed to
>360,000
>270,000
>92,000
>So something seems a bit screwy here. It depends on what you mean by
>"exerting"..... at the wheel, at the generator. It also depends upon
>what degree of accelaration there was: to accelarate an 11670 tonne
>train (about 12,000 round figures when you count the locos) at 0.3 kph
>per second requires about 6,000 HP total at about 10 kph. Also, what
>is the grade of Whittingham (I don't have my grades book in front of
>me)? A 1:100 (1%) grade requires a tractive effort of 1% of 12,000
>tonnes to hold the train, i.e about 270,000 lb.
>Geoff Lambert
Whittingham Bank , which I presume refers to the series of slight grades
between Belford , Whittingham , Singleton and Nundah is on average 1:80 against
up trains and 1:66 against down trains.
MD
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Maurie Daly
Department of Communications Lab.
Canberra
Australia
mauried@commslab.gov.au
ph 6 2791331
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