I understand the average walking speed of an adult is about 3 miles per hour.
If I am walking along the layout's edge at the same rate of travel as my train, at what scale speed would the train be running? Thank you.
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That would be 264 feet a minute. A scale mile is around 110 feet. So you'd be doing about 144 scale MPH. 
This got me thinking. Time isn't scalable, but you are not scaling time here- it is constant. You are only scaling distance.
So I did a test. I marked out 10' and then walked it a regular pace. It took about 3 seconds. If I multiply that times 1200 I get an hour. So multiplying 10' x 1200, I would walk 12,000 feet at that pace in an hour. Divide by 5280'/mile and I was walking about 2.27 mph.
Now if the train travelled the same 10', multiply that time 48 and it went 480 scale feet. Multiply that my 1200 and divide by 5280 and you get 109 MPH. And I suspect that you weren't even walking at 2 MPH, because that is a brisk pace indoors, so you train was going somewhat under 100 mph.
It doesn't seem to be going that fast because if your eye is 4' from the train, that is like almost 200' in O scale, and speed is less obvious at a distance. Try setting the train's speed at your walking pace, and then take a video with the phone as close to the track as you can, and you will see how fast it is going.
5280 feet in a mile. 48 scale feet in 12 inches.
5280 divided by 48 is 110 real world feet in a scale mile.
Figure out 110 feet of distance on your layout.
If you do that distance in a minute, that's 60mph.
Time is the same regardless of scale.
A guy who can figure out all that curved bench work should be able to figure it out....and there is no such word as cabeese, it's cabooses. 
Simon
@Simon Winter posted:5280 feet in a mile. 48 scale feet in 12 inches.
5280 divided by 48 is 110 real world feet in a scale mile.
Figure out 110 feet of distance on your layout.
If you do that distance in a minute, that's 60mph.
Time is the same regardless of scale.
A guy who can figure out all that curved bench work should be able to figure it out....and there is no such word as cabeese, it's cabooses.
Simon
Yup. To expand on that for smaller layouts.............................
Divide 110 feet by 10, and you get 11 feet. Divide 60 seconds (1 minute) by 10, and you get 6 seconds. So, mark off 11 foot on your layout, then time a train running that 11 foot distance (a stopwatch works best). A train running that 11 foot distance in 6 seconds is doing 60 scale miles per hour.
You can do further calculations from there. A freight train running the 11 foot distance in 12 seconds is doing 30 scale miles per hour. A crack passenger train running that 11 foot distance in 4 seconds is doing 90 scale miles per hour. And so on and so forth.
With a calculator, you can quickly make up a chart with 10 smph (scale mile per hour) increments, or 5 smph increments, or whatever increments you desire. And so on and so forth.
Keep in mind this is for 1/48 scale. If most of your trains are traditional-sized (approx 1/56 scale) or O27-sized (approx. 1/64 scale), you may want to re-calculate everything based on the relative scale size of you your trains. If you're really picky, that is. Otherwise, 1/48 would probably suffice. Sorta' kinda'.
Just another way to have fun with trains. 
So, if two trains are headed toward each other and one train is going 100 smph and the other is going 75 smph, how many scale boxcars does it take to make a real mile? 
Less-math-involved method:
Number of inches traveled in 2.5 seconds=O scale MPH. Done
---PCJ
If you don't want to do the math I did it for you. If your clocking O scale measure out 110' that is 5.75 laps around a circle of O-72. If you are surprised and things seem slow to you remember 1 real MPH is 48 scale MPH in O scale. Attached jpeg and doc versions. j
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@Tom Tee posted:Simon, After reviewing the differing responses from some of the best OGR minds can you see why I put this question out to the greater field?
Because you're into SM? You were looking for a few laughs? To paraphrase Forrest Gump: You ask a question on this forum and you never know quite what you're going to get as an answer? Can't be April Fools...wrong date!
Simon
This is about 53 feet of track. At scale speed of 60 MPH it should take close to one minute to go around twice. That seems painfully slow when I actually do it.
Does time change too?
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Like I said, he's smokin' along the tracks.
FWIW, I walk 10 feet at a normal indoor walking pace in about 2.4 seconds, I timed it a few times and took an average. If a train was running along side me at that pace, it would be moving at 136 scale MPH.
My original calculations seem to be correct.
Tom, this is a good discussion. An eye opener for realistic scale operation.
@GVDobler posted:This is about 53 feet of track. At scale speed of 60 MPH it should take close to one minute to go around twice. That seems painfully slow when I actually do it.
Does time change too?
No. The time does not change.
Get a 1/48 scale figure, and place it next to the track. Turn your train on, set it for 60 scale mph, then get right down there with the 1/48 figurine and eyeball the train as it goes past. Can you see (imagine) the train thundering past at 60 mph?
On the flip side of the coin, stand 100 feet back from a 60 mph highway, and note how fast the traffic seems to be going. Then, jump in your vehicle, and drive 48 time further away (4800 feet, almost a mile). Get out of your vehicle, watch the traffic, and note how fast it seems to be going. Does it look like it's going at a snail's pace, compared to before?
Time is constant, no matter what the scale speed & distance is.
If your accustomed to seeing how fast your 2037 can make it around an oval of track on a four by eight sheet of plywood without jumping off the track then scale MPH is going to seem painfully S-L-O-W. However it is your railroad run it as you see fit.
I think it might be fun to have a large switching layout and set up complicated switching scenarios and see who can solve the problem fastest no speed limits. Better yet two layouts side by side. Maybe we could sell tickets. j
@Mixed Freight posted:Time is constant, no matter what the scale speed & distance is.
Good answer on the time and distance, a great way to visualize the difference. I know when I crank MTH stuff to 60 scale MPH, it seems like it's flying!
@JohnActon posted:I think it might be fun to have a large switching layout and set up complicated switching scenarios and see who can solve the problem fastest no speed limits. Better yet two layouts side by side. Maybe we could sell tickets. j
We could charge extra for each crash. 
@eddiem posted:So, if two trains are headed toward each other and one train is going 100 smph and the other is going 75 smph, how many scale boxcars does it take to make a real mile?
I see you and I had the same math book in elementary school.
In answer to the question:
- Determine the distance covered by the locomotive in 1:1 feet, then multiply it by 48.
- Divide that distance by the time taken to cover it and that gives you the velocity in scale feet per second.
- Multiply that by 3600 for scale feet per hour.
- Divide that by 5280 and you'll have the scale miles per hour.
An O scale mile is 110 feet. A train covering that distance in two minutes is traveling 30 scale miles per hour which is about the fastest I like to run on the club layout. However, running a nice slow freight at 15 scale miles per hour allows you to appreciate the interaction between the train and the scenery.
The math doesn't lie, they're really going that fast, at least in scale MPH.
You have very fast eyes.
@Tom Tee posted:John, agreed, nothing beats truth, facts & reality but what about the lack of a side rod blur?
Depends on what size the driving wheel diameter is. i.e., Smaller drive wheels will spin faster at 60 smph, while larger drive wheels will spin slower.
Typically, Steam engines meant for freight service had smaller drivers, so they could drag heavy freight trains along, but at slower speeds. While on the other hand, steam engines in passenger service tended to have larger drivers, so they could go faster. But larger drivers also limited the tonnage they could pull. Remember, a larger wheel will cover more distance in one revolution than a smaller wheel would. If both wheels turn at the same rpm, then the larger wheel will go further, which equals faster than the smaller wheel.
Model trains however, can out-perform full size trains. For instance, you can run a 2-8-2 Mikado with smaller drive wheels (typically a freight engine) at 90 smph, and the side rods will be a blur. Which may look fine to some, but others with an eye for scale fidelity would probably cringe. If a real Mikado could get up to that speed, the entire valve gear assembly would explode in short order from all that centrifugal force. Ouch!
Interesting thread! eddiem: a scale 50 ft boxcar is 12.5 inches, not including couplers. 5280 feet divided by 12.5 is 422.4 boxcars in a real mile! Add the couplers and it would be less.
@gunrunnerjohn posted:Like I said, he's smokin' along the tracks.
FWIW, I walk 10 feet at a normal indoor walking pace in about 2.4 seconds, I timed it a few times and took an average. If a train was running along side me at that pace, it would be moving at 136 scale MPH.
My original calculations seem to be correct.
That's what I got when I did the math. 136 MPH. 3600/2.4x480/5280=136.36
@Tom Tee posted:John, agreed, nothing beats truth, facts & reality but what about the lack of a side rod blur?
I don't know, must be a perceptual thing. As long as the drivers are scale, then the rods have to be moving as fast as they would on the prototype. But searching for some video of real trains at speed led me to this wonderful video. I can clearly see the side rod action in it- not really a blur, just fast.
You're comparing apples and oranges. There are a lot of differences between a real engine and a model. Weight is probably a huge factor. How does the weight of the model "scale" out compared to the real thing. What about the weight of the fuel (coal, oil) and the water?
Does the action/speed diminish with size? Go look at some live steamers that people ride like over at Reading. That might give you an idea of what is going on, I am guessing they act a lot more like the prototype. It would be interesting to hear the outcome of that if you do so!
Guessing that the speed of things (emphasis her on guessing) may relate to size.
Simon
https://www.youtube.com/watch?v=1Slgte84s9U
I didn't think Lockdown was doing this to you Americans. I'm so annoyed with myself that, instead of starting a new layout I'm staring at the new back garden wondering if plants are weeds or not. And we should all(?) have more modelling time. Ah well, walking shoes on and out in the garage to see how long it takes to walk at 3mph x 1/48 x RS3 flat out with 10 freight cars!!
Jason
@Little Giant posted:Interesting thread! eddiem: a scale 50 ft boxcar is 12.5 inches, not including couplers. 5280 feet divided by 12.5 is 422.4 boxcars in a real mile! Add the couplers and it would be less.
I think you're using the "new math". 5280 / 52 = 101.5 1:1 boxcars in a real mile, I added 2 feet for the prototype couplers. If you're trying to compute how many O-gauge boxcars there are in a real mile, 5280 / 1.042 = 5067 O-gauge boxcars in a real mile. You slipped inches into feet for your computations.
Unit conversion 101: When converting from one unit to the other, you can keep yourself straight by always remembering you are always really just multiplying by unity (1.0).
The units in the numerators and denominators of all the conversion factors will cancel out until you have the units you are looking for (if not, you goofed and missed a part of the calculation). So as the simple example of converting feet to miles is multiplying the feet X (1 mile/5280 feet) = miles. Just keep adding in the "this many of these is equivalent to that many of those" fractions until you have the units you want.
Also, people should just try to buy one of these if they don't like doing math:
http://www.lionel.com/products...speed-sensor-6-14082
Though it's been 17 years since it was cataloged, they may not come up for sale too often on the secondary market.
As for the frame of reference and speed, it may also be helpful to think about how airplanes are perceived from the ground (or how things on the ground are perceived when in an airplane).
Does that airplane going overhead look like it's going several hundred miles per hour? No, but that's because your eye sees so much distance up in the sky that it seems slower. If you had a tube pointed straight up that was only 10 feet diameter, you'd see the blur as the airplane passed over it and wonder what it was.
Similar thing for looking down when in an airplane. It looks like the cars on a highway are going in slow motion, but that's because you are seeing many miles of the highway at one time from the altitude the plane is traveling at.
-Dave
Could a radar gun be used to tell its speed ?
Probably not accurate enough. At 60 scale MPH, you are only doing 1.25 actual MPH. You'd have to have a really accurate radar gun with high resolution to get any readings that would make sense.
You could just buy one of these currently available products and know the scale speed for sure.
https://www.bouldercreekengineering.com/hotshot.php
Of course, that would eliminate all of the fun with speculating, postulating, guesstimating, calculating and thread churning that has been going on here.
On second thought, forget it. Carry on. 
@Will posted:I don't know, must be a perceptual thing. As long as the drivers are scale, then the rods have to be moving as fast as they would on the prototype. But searching for some video of real trains at speed led me to this wonderful video. I can clearly see the side rod action in it- not really a blur, just fast.
Will, The attached video is neat, the composite videos are well done, thanks, however, IMO, they really need a genuine USRA whistle. It would seem that the passenger trains in view are running about 80 mph or so. At what ever their speed is, the rods are moving much faster than my 3 mph walking speed rods.
I have seen a video of the last regular run of PRR T-1 at top speed thought to be 122 mph where the side rods are like the start up of an airplane propeller, just buzzing in the wind.
The smoking gun IMO, is the side rod motion appearance. I would ask those who may have the ability to pace alongside an 0 scale steam engine for a good distance, to note the appearance of the side rod motion.
I believe accuracy would be unavailable doing comparative "walking" along side a steam engine with the short distance of a moderate sized oval with relatively short tangent track.
The rod throwing guesstimated speeds of 130- 144 mph may be mathematically accurate speeds using the values shared but I believe there is a missing equation.
Ever since I got the better part of my layout track done I have been walking along side with my hand held observing the rod action and this issue has raised question.
I have tried to calculate the scale speed but the big numbers just did not translate to the visible rod action?????
Maybe step away from the calculator and walk alongside a lengthy tangent with your steam engines.
Tom, you're missing one important fact. The actual movement of the rods on a 1:1 steam engine will be moving 48 times as much distance as the rods on your 1:48 model. The drivers are rotating at the same rate, but the fact that the pieces are moving at a much greater velocity changes the illusion. Really, the scale MPH calculations we've been throwing around are actually accurate, honest.
If you turn a 1.5" wheel at 100 RPM, it doesn't look that fast. If you are standing next to a 72" wheel turning at 100 RPM, it looks REALLY fast.
Hi,
Mark off a 22 foot section of track. 22 feet is 0.2 miles.
720 divided by the time in seconds to traverse the 22 feet gives you the mph.
Ed
Tom,
I think Gunrunner John has just answered your question.
Well done, John!
Simon
Thanks John! should have given it more thought before using the calculator. just using round numbers would have shown me: boxcar approx. 1 foot, 5280 feet in real mile.
I used a SMPH sensor to measure the speed. I was actually surprised how fast the train was going even when I thought I was going maybe 10 MPH. As stated before, the viewing distance is key.
Brendan
You fine folks are making this much too complicated. I just look at the display on the remote to learn how fast my trains are traveling.
-Greg
@Tom Tee posted:John, If my slow steamer is running 130 - 144 mph dawdling along, Then what kind of scale speed are the hot rod Lionel high speed trains running?
Warp 3, maybe Warp 4.
@Greg Houser posted:You fine folks are making this much too complicated. I just look at the display on the remote to learn how fast my trains are traveling.
Don't get used to that, that's going away.
Whatever your speed is, it's too fast. Slow it down, if it looks like the side rods are moving too fast...close your eyes.
If you guys worked for NASA we'd never have gotten off the ground, let alone to the moon and beyond 
Reminds me of a Monty Python movie
@Tom Tee posted:John, If my slow steamer is running 130 - 144 mph dawdling along, Then what kind of scale speed are the hot rod Lionel high speed trains running?
Crank her up until she jumps the track, then back her off a notch.
Simon
