RailRide posted:I used a different table that breaks down speeds according to the number of inches traveled in a specific time period. For O scale, the number of inches traveled in 2.5 seconds is the scale MPH.
---PCJ
That is only a very rough estimate and would depend on your ability to look at a stop watch and the loco at the same time for 2.5 seconds and accurately mark the point you start your measurement and where you end. You end up off by almost 10% if you use 2.5 seconds 2.72727 (2.7) would be closer. I hate to do arithmetic on a key board but here goes. one mile = 5280' X 12" = 63360" in one mile divided by 3600 seconds per hour 63360"/3600 = 17.6" per second is one MPH life size, divide that by 48 for O scale 17.6" / 48 = .366666" per second is one MPH in 1/48th O scale. .366666" X 2.5 = .9166 is short it should equal one. Try 2.72727 X .366666" = .99999 that would be less than 1/10 of one percent off. That's if your able to measure an accurate 2.72727 seconds and at the same time, accurately measure the distance the train traveled. Counting 1001,1002, 1003 would probably allow you to watch the train and mentally mark the start point and end. Still, it would be easy to be off by 10% in both your time and your distance traveled for a 20% cumulative error. You might as well guess, 2.5 or 2.7 seconds is just too short a time for any kind of accuracy. Timing the length of time to travel a known distance is MUCH easier. BTW, about the table in my post, I made it so that I could easily set the top speed of my locos accurately within one or two scale mph in TMCC. It's off less than one percent at each speed. j
