how long is a scale mile?

Model Railroader General Discussion (Model Railroader)
1

this may be a stupid question to some but how long is 1 scale mile in feet or inches?

2

60.7 feet

3

An HO scale mile is 66’ feet. Other scales, I have no idea.

4

jadormdrache,

Not a dumb question at all. All you need to do is the following formula:

For HO - Mile (5,280’)/scale (87.1) = 60.62’ or 727.44"

For N - (scale=160)

For Z - (scale=220)

I don’t remember the other scales right off hand.

Tom

5

I love it! Three replies, three different answers. [:D]

6

so which is right?..I got 60.7 feet in HO
33 feet in N
110 feet in O
24 feet in Z

7

60.69 ft

8

HO scale is 1:87
Here is a quote from MR article Intruduction to HO Scale

So if 1:87 is accurate then the following is correct:
1 mile = 5,280 feet
5,280 feet divided by 87 = 60.6895 or 60.7 rounded to the nearest tenth.

9

tstage’s formula is correct.

Scale proportions are:
Z = 220 Z scale mile = 24’
N = 160 N scale mile = 33’
TT = 120 TT scale mile = 44’
HO = 87.1 HO scale mile = 60.62’
S = 64 S scale mile = 82.5’
O = 48 O scale mile = 110’

10

How does 60.68965517 ft. grab you all???
“The Harven”

11

Seems to a splitting hairs issue with HO, is it 1:87 or 1:87.1?

Here is a link to a site that has a Model Railroad Scale Converter, check it out:
http://www.csgnetwork.com/modrrscaleconv.html

BTW, it has HO listed as 1:87.1

Interesting, as I always thought HO was a straight 1:87, where did the point 1:87.1 come from? Has it always been 1:87.1?

Ryan

12

Indeed, it’s been 1:87.1 , with some slight rounding accepted, since the scale of HO was firmly established as 3.5mm to the foot…long, long ago. Divide 3.5 into a real foot measured in millimeters, and you’ll get pretty close to 87.086 .

So…an HO scale mile is 60.63 feet.

CNJ831

13

A scale mile is 5280 scale feet!

14

[%-)] [banghead] WHAT??? [:D]

15

Gee, I didn’t know that a mile weighed that much! I’d never thought about ever putting a mile on the scales before… :-p

Mark in Utah

16

a basic formula is prototype divided by scale
as in, as it has already been shown:
5280 / 87:1
(proto) (scale)

17

basically, you have to remember that 1:87 is a ratio, or scale

If the prototype distance is 1, then scale will be 87 times smaller
if the prototype distance is 5, then you substitute 5 for the 1
now you have 5:87, which is 5 times 1:87, therefore your answer will be five times greater that you would have had with 1:87
these formulas are applied to anything where you are going from full size or the value 1 to scale

18

HO is Half O. In England O is 7mm to the foot (approx. 1:43.5) so Half O is 3.5mm to the foot. BTW English engines are a little small and to fit the motors of the day in the models, the scale was changed to 4mm to the foot and called OO, but they use the track gauge for HO. When O scale came to the U.S. it was changed to 1:48, but kept the wider track gauge.
Enjoy
Paul

19

HO track gauge is 16.5mm

If this is the definition of HO (I don’t know what the real definition is, frankly), then the scale of HO would be found by comparing the prototype gauge to the model gauge.

Prototype Gauge: 4ft-8.5in = 56.5in = 1435.1mm

Scale Gauge: 16.5mm

Scale of HO = 1435.1 / 16.5 = 86.98

Alright - forget it. I just demonstrated that the “definintion” of HO is not the 16.5mm track gauge.

What is the definition of HO? I guess it’s 3.5mm to the foot, as Ironrooster said.

So, let’s see:

1 Prototype foot is 304.8mm
1 HO scale foot is 3.5mm

304.8mm / 3.5mm = 87.08571

So I guess that’s the exact answer - with no rounding: HO scale is 1:87.08571

So, one scale mile would be 5280ft / 87.08571 = 60.62992ft.

There you have it - one HO scale mile is 60.62992ft.

Please make sure your layout is scale properly. That last 2 after 5 decimal places is extremely important :slight_smile:

20

I mentioned the HO track gauge above, because that’s what I thought the definition of HO scale was.

I now believe it’s the 3.5mm=1prototype foot. Because that gives a scale of 1:87.08571.

Also, Silverspike quoted the 3.5mm deal from MR.

Very interesting stuff.

(Being a mechanical engineer, I have to deal with this half-baked units type stuff all the time - converting from one to another, intermingling inches with centimeters, etc. The machine shop thinks you’re an idiot if you talk in metric, people from other countries outside the U.S. think you’re a moron if you try to communicate in inches, etc. - it’s a mess!!!)