Scale Speeds

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twalton1145
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Scale Speeds

#1

Post by twalton1145 » Sun Apr 19, 2020 6:08 pm

Help please!!
I'm at (friendly) odds with someone who has posted a video on Facebook. How long should a "OO" scale train at 90 mph real speed, take to cover a 1/76 scale mile? My "O" level maths says 1/76 x 1760 = 23.16 yards. Sadly as it's past wine o'clock brain :oops: refuses to go any further :oops:
Any maths experts on here who can help? Stay safe and keep drinking wine.
Ted

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IanS
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Re: Scale Speeds

#2

Post by IanS » Sun Apr 19, 2020 7:03 pm

A scale mile is indeed approximately 23 yards according to my calculations. (I'm a rusty maths teacher who converted to computing, so it should be approximately correct!)

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Walkingthedog
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Re: Scale Speeds

#3

Post by Walkingthedog » Sun Apr 19, 2020 7:22 pm

90mph is 44 yard per second so the answer is about half a second.

You did say a real 90mph didn’t you.
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The Sligo Rover
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Re: Scale Speeds

#4

Post by The Sligo Rover » Sun Apr 19, 2020 10:55 pm

Correct me if I am wrong but if it was doing a scale 60 mph then it should take a minute, if doing a scale 90 mph then 40 seconds - well I think that might be correct, well perhaps.

RFS
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Re: Scale Speeds

#5

Post by RFS » Sun Apr 19, 2020 11:02 pm

If both distance and train are at 1/76 scale, then surely the answer is the same? At 90mph a full size train travels at 1.5 real miles per minute. So in the same time an OO gauge train will travel 1.5 OO-scale miles, which according to my calculations is (1760 X 1.5) / 76 which is 34.73 yards.

For a mile - OO scale or real - that's about 40 seconds?

EDIT: Well Sligo Rover beat me to it!
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LC&DR
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Re: Scale Speeds

#6

Post by LC&DR » Mon Apr 20, 2020 7:16 am

Where people sometimes get muddled is where they try to 'scale' time. There is a school of thought that time should also be speeded up so that 1 hour should only last 47 seconds ! ( (60x60)/76) To my mind this is the pathway to madness. A 24 hour day in this world therefore lasts 18 minutes on the model. And indeed there have been those who created fast clocks to achieve this. Faster clocks can have their uses especially in exhibition layouts where it is possible to compress a day's timetable sequence into a reasonable viewing window, which helps to maintain viewer's interest. A small branch line terminus can be incredibly boring if run in real time, with hours of inactivity. However then running trains at 'scale' speed to adhere to 'scale' time results at trains scuttling along faster than a Hornby 'Smoky Joe' at full power.

Time needs to be a constant. It makes life much more simple. However a timetable can be speeded up provided that running speed remains realistic. I wonder what Albert Einstein would have said! :D
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teedoubleudee
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Re: Scale Speeds

#7

Post by teedoubleudee » Mon Apr 20, 2020 8:52 am

LC&DR wrote:
Mon Apr 20, 2020 7:16 am
..................................................... I wonder what Albert Einstein would have said! :D
Did he have a model railway then?
Most people are shocked when they find out how bad I am as an electrician

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Walkingthedog
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Re: Scale Speeds

#8

Post by Walkingthedog » Mon Apr 20, 2020 9:59 am

It stated a real 90mph to cover a 1:76 mile, not a scale 90mph or a true mile. So about half a second.
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LC&DR
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Re: Scale Speeds

#9

Post by LC&DR » Mon Apr 20, 2020 10:37 am

teedoubleudee wrote:
Mon Apr 20, 2020 8:52 am
LC&DR wrote:
Mon Apr 20, 2020 7:16 am
..................................................... I wonder what Albert Einstein would have said! :D
Did he have a model railway then?
Probably :D
LC&DR says South for Sunshine

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