Ballast Coverage

[corsiar]

I am modeling in N scale and using Scenic Express #50 natural stone ballast. Does anyone have an estimate on how many linear feet 1 qt will cover?

[SPSOT fan]

Well I’m going to convert the measurements to metric because that’s easier to do conversions with.

So 1 quart is about 1140 ml (that’s rounded to 3 sig figs). As ml=cm^3 then that means we have about 1140 cm^3. Let’s assume that you balast n scale about 2 cm wide including the shoulder and about 2mm (.2cm) deep. So so 2*0.2*x=1140 cm^3 with x being the length you will ballast. This simplifies to 0.4x=1140 and when you divide both sides of the equation by 0.4 you get x=2850cm.

In feet and inches that is about 90ft. Note this is very much an estimate, the actual value may be different depending on how deep and wide you ballast.

[kasskaboose]

I don't ever recall seeing such a discussion.  Definately worth asking.  Thanks!

[SeeYou190]

There are too many variables to get an accurate answer.

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1) Taller roadbed requires more ballast.

2) Taller tie profiles require more ballast.

3) Putting ballast down before scenery requires more ballast than doing ballast second.

4) Wider shoulders require more ballast.

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Probably more that I cannot think of right now.

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Ballast is inexpensive... just buy enough!

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-Kevin

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[SPSOT fan]

SeeYou190

There are too many variables to get an accurate answer.

Yes, my answer of 90ft is VERY approximate! I would recomemd the OP buy more than he need from a given section of layout and if there is extra then use it on the next section.

Now if the OP would give us some details about how wide the area he’s is balasting is and how thick he intends to apply balast.

An approximate formula for finding the length a given volume of ballast would be l=v/(w*h) were l is length, v is volume, w is width, and h is height/depth. Of course this is just an estimate, as it does not take into account the presence of ties, or the fact that the area we blast isn’t a perfect rectangle. And you need to be sure you use all the same units (i.e. cm and cm^3 or ft and ft^3)

[richhotrain]

corsiar

I am modeling in N scale and using Scenic Express #50 natural stone ballast. Does anyone have an estimate on how many linear feet 1 qt will cover? 

What I did on my last layout and will do again on my new layout is to buy a small lot of ballast and apply it over a small measurable section of the track work. What ever amount is used can then be multiplied by the size of the entire track work to be ballasted. So, for example, if one quart covers 10 feet of track, you will need 10 quarts to cover 100 feet of track. That is probably the only way to get an accurate mesurement.

Rich

[doctorwayne]

Depending on your trackside terrain, you might need a lot more ballast than you think...

Wayne