Here's something I've been thinking about for awhile. How do you measure scale mph in HO, and what is the simplest way to measure it? For example, there is a staff review of an Atlas ALCO RS-3, and in it they said the locomotive reached 78 scale mph at 12 volts. I'm just curious as to how this works.
Boulder Creek Engineering has a speedometer you can buy. I don't have one but I do have their working scale and it's very reliable and well made. A nice video and description is on their site.
https://bouldercreekengineering.com/
I'm sure there may be other speedometers on the market too.
oldline1
Try this:
http://www.stonysmith.com/railroad/speedcalc.asp
I use an Accutrack IR readout but it is more of a fun accessory than a necessary tool.
http://cs.trains.com/mrr/f/744/p/260149/2923972.aspx
Good Luck, Ed
My eye. I think I'm a pretty good judge as to the speed of my train. While watching the real thing, and listening to the box detector, I was surprised that the train was actually doing 46 mph. As it went by, it seemed like it was much faster.
I place myself "trackside" on my lay out, and watch how it passes track side structures.
I have discovered that with the DT400 I use, the speed step number on the screen seems to be real close.
I've watched enough Amtrak, and when I run passenger trains, I use the same judgement.
But I don't to get any closer than that. I've never encountered a problem where I needed to know, or needed to measure the exact speed.
Maybe for some that's important, knowing the exact speed.
Mike.
My You Tube
Try this https://www.bouldercreekengineering.com/hotshot.php
Excellent Mel, I didn't know. Now have to find a stop watch and play around with it. Maybe just to check out my throttle readings.
And NO, I don't have a smart phone or a computor hooked up the my lay out.
mbinsewi Excellent Mel, I didn't know. Now have to find a stop watch and play around with it. Maybe just to check out my throttle readings. And NO, I don't have a smart phone or a computor hooked up the my lay out. Mike.
Thank you all. You've given me some interesting food for thought. I have no urgent need for this, but like I said, I was just curious. But, you never know what you might need and when.
did both the stationary, and the mobile versions a few years ago , worked well ..based on arduino's ..
if you want an inexpensive way to measure speed, just a stopwatch and two spaced markers will do it ...
i use 28 speed steps, and geared steam engines, one smph per speed step ..pretty easy to set up, in jmri or just cv's
Here is a nice, easy. low-tech solution.HO scale is 1:87.1somethingsomething.60 MPH is 88 feet per second.So, for HO scale, you can say that 1 foot per second is 60 MPH HO scale, close enough.1 inch per second is close enough to 5 mph, 2 inches per second is 10 mph, etc.All you need is some colored pins an inch apart and the timer on a cell phone.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
I just push two buttons on my NCC controller and get an audible report.
Having a somewhat inquisitive mind I decided to test the accuracy by timing trains around a 20' x 6' loop that I can isolate from the rest of the layout. The audible report was dead on as far as I could determine.
I just wish the audible report was a sexy babe voice instead of Bob from accounting.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
The early QSI decoders would tell you via voice what the scale mph was at the time by pressing one of the function buttons, F10 or F9...I forget.
I have run enough trains, and have essentially correctly spaced telegraph poles, such that I can get pretty darned close watching the trains move past items how fast they are going. Also, with steamers, I can make a rough estimate of their speed by recalling their driver diameters and counting the cyclic rate of the crosshead or the turn of the main crank per second.
Also, for steamers, their maximum horsepower at the rails would be produced, across driver diameters, at about 4 cycles of the piston/main crank per second, a bit less truthfully. So, if I need my head-end producing maximum horsepower for a given consist and speed, and terrain, I make sure it's not in 'drag' configuration, as a Y6b would be on the Blue Ridge, but churning quite nicely at 'express' speed.
There's a one-page article in the September, 2003 issue of RMC, entitled: "Scale miles-per-hour at a glance".
S.M.P.H. = .6818 X SCALE FACTOR X DISTANCE (in decimal feet) ÷ time
The scale factors are:
O = 48S = 64HO = 87.1TT = 120N = 160Z = 220
The author simplified the formula somewhat, but used a stopwatch and a calculator for timing.
I'm not so fussy, and decided to simplify the formula even more, creating a chart of speeds in increments of 5mph, up to 40mph (the highest allowable speed on my layout) with a rounded-off elapsed time using the second hand on a watch. While I've not formally created "speed traps", the plan is to use measured lengths of straight, level track, each with signs indicating the "Start" and "End" points.In HO scale, for example, the speed trap might be only 5' long in one area, and 10' or 15' in others. Each would have a chart of times and corresponding speeds affixed to the layout's fascia.
For my HO scale layout, travelling through the 5' "trap" in 59 seconds yields a scale speed of 5 mph, in 30 seconds it's 10 smph, 10 seconds 30 smph, and the hogger's hitting the limit when he gets his loco through in 7 seconds.
The main purpose is to allow operators, including myself, to have a sense of what speed is appropriate, especially since most of the mainline does have signed speed limits. On the many grades, most trains will have difficulty reaching allowable speeds on uphill trips, and likely the opposite situation when descending those grades, dependent, of course, on the tonnage trailing.
Wayne
BATMANI just wish the audible report was a sexy babe voice instead of Bob from accounting.
I'm sure they have a CV for that. Check the manual.
I created a printable, at-a-glance table in Excel similar to what Wayne posted and have that up on the wall: (Click table to enlarge)
All I need is the table, a watch or stopwatch, and two fixed points.
To capture a range from 0 to 60 sMPH, I broke down the measuring distances into three main categories: 3', 1', and 3". I use the 3' distance for clocking fast moving trains and the 1' & 3" distance for slower moving units. It's inexpensive, doesn't require electricity, and I can measure it anywhere on the layout. No special device needed. All I'm looking for is a ballpark idea.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Divide scale miles traveled by hours.
Find a large part of your layout, maybe even a couple of laps around the main line. Measure it with a ruler, and convert real feet into scale miles. For HO, multiple real feet by 87 to get HO scale feet. Divide scale feet by 5280 to obtain scale miles. The answer will likely be a decimal fraction of a scale mile or two.
Use a stop watch to measure how long it takes the train to cover the scale mile. Convert from seconds to hours by dividing measured seconds by 3600 (number of seconds in one hour)
Divide the measured scale mile by measured time in hours to obtain scale miles per hour.
A hand calculator makes it a lot easier.
David Starr www.newsnorthwoods.blogspot.com
All of these different formulars and charts ! and methods! They all have fixed points, and a stop watch involved
I'm not the OP, but I'll stick with the simple formula from the NMRA that Mel posted.
EDIT: That is of course, if I was totally out of mind as to how fast my train was running. Hasn't happened yet.
I did all the math one time: In HO the number of inches travelled in 5 seconds equals speed in miles per hour.
Dave
A question for those who use their DCC throttle to indicate scale speed. Does setting your DCC system to run a fast clock affect the speed reading?
dstarrFind a large part of your layout, maybe even a couple of laps around the main line. Measure it with a ruler, and convert real feet into scale miles....
The easiest way to measure your track's length, whether it's straight or curved, is to create a train of a known length - 10' is a good choice, but you can use whatever length works best for your situation.Put a marker of some sort alongside the track, even with the front of the loco pulling the train, and another alongside the back end of the rear car. Run the train until the back end of the last car is beside the marker where the loco started.Now move the marker that was originally beside the loco up to the loco's current position, and repeat the operation until you either arrive back at the marker which originally denoted the back of the train at starting (on a track which affords continuous running) or until you get to the end of the line (as on a point-to-point line).
This is both easier and more accurate than trying to use a tape measure around curves.
Old scchool way. Three foot section of track and a stop watch. This is model railroading, not rocket science. Use math for scale of choice.
My smart phone does the timing and math.
I worked for NASA for fourteen years. I know the difference.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
And then, once we know our train is moving exactly 45 miles per hour, we have to explain why the train left Denver at noon and arrived in Glenwood Springs 2 minutes later.
Ah, this discussion is all relative. Get it?! Einstein aside, I am interseted in simple solutions to complex problems.
Do you keep your locos travelling at a speed reflective of reality or what works for you and your layouts constraints (e.g., elevation, curves, etc.)?
I have a very simple equation for approximating scale MPH in HO scale: inches/sec * 5 = scale MPH.
10"/sec = 50 MPH
8"/sec = 40 MPH
etc
Modeling an HO gauge freelance version of the Union Pacific Oregon Short Line and the Utah Railway around 1957 in a world where Pirates from the Great Salt Lake founded Ogden, UT.
- Photo album of layout construction -
Too much paperwork, formulas, stopwatches. I have a better idea. I'm going to call one of my police buddies ask him to bring his hand held radar gun over and we can have some fun getting the speed of the trains.
Mel,
I have both switchers and non-switchers on my layout and they all have different stop speeds. So, that particular labeling method wouldn't well for me.
A few months ago, I placed a number of telegraph poles so that they aligned with the track centres at 10 inch spacing.
The idea was based on my scale speed method where a train passing a set distance in a given time. In HO scale, the distance in inches that a train covers in 5 seconds is equal to the scale miles per hour. Davidmurray is correct and I also use inches travelled in 5 second intervals.
I was using a set length of track at first then using spikes as a model of equally spaced siting pegs placed at 5 inch intervals.
With the layout renovation after the move, I have been back to using the length of track which at 38 inches gives me 35 smph just short of the length in 5 seconds, 40 just over. It was virtually a speed trap but just at the front of the layout.At the back and around the rest of the layout, a few months ago I installed a number of Telegraph poles. These poles are aligned with 10 inch spacing at the track centre. Therefore they are not totally geometric in their spacing given that they are on the convex and concave sides of the curves around the back of the layout.Here is 1404/1909 Westbound on a through freight starting a sectional count.
5 Seconds later they are just over 4 poles away so the train is doing about 41-42 smph!
I merely count 5 seconds out and you will be surprised how well you can do this. Each of the poles is equal to 10 smph for each on covered in 5 seconds.
As a couple of you are in OO, the spacing for the poles would be 11.5 inches apart, in N they would be 5.5 inches apart. In O scale 1:48 they would be 18.35” apart or about 18 and 3/8” .The system has worked well for me over a number of years and it should for you too!
Cheers from Australia
Trevor