Model Railroad
Freight Car Weight Guidelines:
The NMRA Recommended Practice 20.1 model railroad freight car weight guideline
provides a consistent rolling stock weight that contributes to a
better running model railroad. Most N scale Atlas, Model Power,
and Roco cars are less than the recommended weight as set out by
the National Model Railroad Association (NMRA), At the other end
of the scale (no pun intended) most MicroTrains, deluxe
innovations and Roundhouse cars are about right. HO rolling
stock vary to the manufacturer, Atlas and Athearn cars are about
right.
For N scale the recommended weight is an initial weight of 0.5
ounce (14.2 grams) + 0.15 ounces (4.3 grams) per inch of car
length. For example, a 40’ box car is 3" long so it should weigh
0.5oz + (3 x 0.15)oz = 0.95oz. Because these end up as odd
weights, it is frequently more convenient to work in grams. The
following table provides recommended weights for various car
lengths:
|
Length |
Weight
(Grams) |
Weight
(Ounces) |
|
30’ |
24 |
0.84 |
|
40’ |
27 |
0.95 |
|
50’ |
30 |
1.06 |
|
60’ |
33.5 |
1.29 |
|
80’ |
40 |
1.40 |
|
85’ |
42 |
1.46 |
Any fine increment electronic scale can be used as a weighing
device especially if it weighs in the 1/4 ounce range, or in
grams. As well, a simple-to-make balance scale can be used. For
balance weights you can use lead sinkers (which come in 1/8, 1/4
and 1/2 ounce sizes), or coins (dime – 2 grams, cent – 3 grams,
nickel – 5 grams, quarter – 6 grams). Car weights need only
approximate the recommended value.
The best way to add weight is by using fishing weights and hot
glue or ACC. The location to place the weight varies widely from
car to car but it is a good idea to work with several small
weights rather than one large weight. It is very important to
keep the car balanced and always add the weight as close to the
bottom of the car as possible.
A small postal scale for weighing letters is adequate to
determine which freight cars may need additional weight.
http://www.nmra.org/standards/sandrp/pdf/rp-20_1.pdf
