Grade and track curvature

[nw-mailing-list at nwhs.org]

Grades will increase train resistance by 20 lbs per
ton of car weight for each percent of grade.  This is
not an estimate but is calculated based on the effects
of gravity.  Grade is one of the most significant
factors in train resistance, and why rights-of-way are
designed to be as level as possible.  Something as
small as a 0.5 percent grade will increase resistance
by 10 lbs per ton compared to level track. 

Curves increase resistance by about 0.8 lbs per ton of
car weight per degree of curve.  This is a general
estimate based on various tests over the years.  The
range of variation was very wide and the 0.8 figure
was recommended for use by the American Railway
Engineering Association (AREA). The effects are not as
significant as grade.  For example a 10 degree curve,
relatively sharp for a mainline, will increase train
resistance approximately 8 lbs per ton of car weight,
less than a very mild 0.5 percent grade.

Dave Stephenson



> What is the impact of grade and track curvature in

> the effective 

> pulling power of locomotives?

> 

> Clint Smoke

> Arden, NC

> 

> 

> 



		
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