A simple Question on Grades

[boston1943]

I have a question on grades (the slope of track going up). I know that, say 2% gade means that the track rises 2' every 100 feet, but I was wondering, is that in scale measurement or real 1:1 measure?

[BATMAN]

Just change the feet to inches and you have the same thing. Two inches in one hundred inches is a 2% grade.

Brent

[tomikawaTT]

Gradient, measured in percent, is the same no matter what units are used.  A 2% grade is:

• 2cm rise in one meter
• 2" rise in 100" (8'4")
• 2' rise in 100'
• 2 cubits rise in 100 cubits (quick, now, what's the conversion to English or Metric?)
• 2 meters rise in 100 meters
• 2 kilometers rise in 100KM.

HOWEVER - When designing a grade, allowance has to be made for the 'vertical easements' between the grade and dead level, and between two lengths of different gradient.  Exactly how much length this involves IS scale-specific.  A nice easy N scale transition would be a full-scale vertical kink.

Chuck (modeling Central Japan in September, 1964 - with LOTS of grades)

[loathar]

A 1% grade is 1 unit of rise over 100 units of distance. The units can be inches, feet, miles or even those krazy kilometers...doesn't matter. Grade is grade and is not subject to scale.

[bnsf76]

Wouldn't it be 20 mm in a meter, not 2?

bnsf76

[Nagrom1]

 Yup. 100 cm to 1 metre, 10 mm to 1 cm. Therefore, 1000 mm of run with 20 mm of rise, or, if you want it divided by 10, 2 cm rise over 100 cm run.

 

I think a zero may have been missed ealier.

[tomikawaTT]

Wouldn't it be 20 mm in a meter, not 2?

bnsf76

A sneaky teacher always leaves something for the student to catch.  That way the lesson sticks.

If you believe that, I've got a slightly used bridge...

Chuck (modeling Central Japan in September, 1964)

[selector]

One thing to consider is that, while scale matters not when we deal with grades (a 3% grade looks the same no matter what size our trains are), the ability of an engine in any one scale to scale (ahem) the grade with a decent or typical/prototypical train behind it should not be taken for granted.  Weight doesn't scale well, so your N scale engines may not do quite as well as the equivalent HO or O gauge engine.  It may...it may not...it would be wise to check with a mock-up grade first before you glue it all into place.

[doctorwayne]

One thing to consider is that, while scale matters not when we deal with grades (a 3% grade looks the same no matter what size our trains are), the ability of an engine in any one scale to scale (ahem) the grade with a decent or typical/prototypical train behind it should not be taken for granted.  Weight doesn't scale well, so your N scale engines may not do quite as well as the equivalent HO or O gauge engine.  It may...it may not...it would be wise to check with a mock-up grade first before you glue it all into place.

Naw!  Go ahead and fasten everything in place.  If your loco won't pull the train up the grade, it's an opportunity to buy more locos.  This is called "planning ahead". 

Wayne 

[markpierce]

I have a question on grades (the slope of track going up). I know that, say 2% gade means that the track rises 2' every 100 feet, but I was wondering, is that in scale measurement or real 1:1 measure?

It is 2% in any linear measurement.  HO-scale feet, N-scale feet, millimeters, centimeters, meters, inches, feet, yards, ad nauseum.  The only requirement is that the ratio is expressed in with same units-of-measure, that is, inches to inches, centimeters to centimeters, and so on.

Mark