Large Scale Central

How fast?

General Discussion
#1

Is there a measurement I can take to determine how fast my 3 Truck Shay (or any of my geared locomotives) are running and prototypically should be running?

#2

Bruce Chander (the Joat) made a speedo with a bike computer and a magnet…should be a post around here somewhere or on MLS…!

cale

#3

A calculated mine with a camcorder three flatcars back.
What you THINK is slow is a roller-coaster.
It is VERY slow.
TOC

#4

15 MPH works out to 22 feet per second. Eight miles/hour is about 12 feet/second. So, if you have 24’ cars, they’ll take 2 seconds to pass a single point on the railroad at that speed.

Later,

K

#5
Kevin Strong said:
15 MPH works out to 22 feet per second. Eight miles/hour is about 12 feet/second. So, if you have 24' cars, they'll take 2 seconds to pass a single point on the railroad at that speed.

Later,

K


What scale are you talking about, Kevin?

#6

Perhaps I didn’t word my question correctly. I run my geared locos slow. I would like to try to determine if what I consider slow is prototypically correct (2 fast or 2 slow).

#7
Steve Featherkile said:
Kevin Strong said:
15 MPH works out to 22 feet per second. Eight miles/hour is about 12 feet/second. So, if you have 24' cars, they'll take 2 seconds to pass a single point on the railroad at that speed.

Later,

K


What scale are you talking about, Kevin?

Kevin’s speed determination method is independent of scale. As he wrote, 8 MPH is ~12 feet per second (in 1:1 scale).

Seeing a 24 foot long car (in any scale) pass a fixed point in ~2 seconds produces a speed of ~8 MPH in that scale.
As examples:

In 1:20.3 scale, a 24 foot car is ~14" long. 14" in 2 seconds (7" per second) is ~8 scale MPH in 1:20.3 scale.

In 1:29 scale, a 24 foot car is ~10" long. 10" in 2 seconds (5" per second) is ~8 scale MPH in 1:29 scale.

There are other methods (such as ‘counting the ties over a fixed time’), but they require some calculation. Kevin’s method is really simple and will give a good approximation of scale speed. Depending on trackwork and load, Shays usually operated at something less than 10 or 12 MPH. Kevin’s 8 MPH example is a good operating speed for a Shay working on good track.

Happy RRing,

Jerry

#8
cale nelson said:
Bruce Chander (the Joat) made a speedo with a bike computer and a magnet....should be a post around here somewhere or on MLS...!

cale


http://www.largescalecentral.com/LSCForums/viewtopic.php?id=7422

cale

#9
timmyd said:
Perhaps I didn't word my question correctly. I run my geared locos slow. I would like to try to determine if what I consider slow is prototypically correct (2 fast or 2 slow).
Timmy,

If I read you right, you mean, how fast did such a geared locomotive actually run …

15 mph on a Shay would generally have the parts flying off, but might be achievable. On a Heisler, that might be a bit more reasonable; this is why Cass tends to run its longer “mainline” trips with the Heisler (this from their staff last trip.)

So for a Shay … probably somewhere between 8 and 12 mph tops … for a Heisler a bit faster … Climax, well, depends… there were different gear ratios available, and some of the earliest actually had a shiftable transmission (left over from the Class A, where most had it.) In any case speed would have been comparable.

If you don’t want to build a speedometer to calculate your “scale speed” you’re welcome to borrow mine … I got one from the Accucraft guy at the Big E train show years ago, but don’t use it all that much, so I’d be happy to lend it to you. Short of that, I’m sure you can figure out speed in SMPH …

Just beware… this discussion always seems to precipitate the metaphysical discussion of scaled time … so be prepared to have your mind forcibly expanded if you head too far down this path!

Was that more along the lines of what you meant?

Matthew (OV)

#10

An elegant answer, Jerry, thank you.

#11

Thanks for everyones input especially the email from Mikey in UK and TOCs idea about a camera. Here is a video of one of my Heislers traveling at 1 foot per second which as I understand should be pretty prototypical.

http://timothydehan.com/redmondcreekrr/vids/HeislerSpeedProject.wmv 640x480 Video 18MB

http://timothydehan.com/redmondcreekrr/vids/HeislerSpeedProject_sm.wmv 320x240 Video 8MB

#12

And, if you have a 40 ft car (a common size) and it passes in 2 seconds, you’re going 27 MPH or so. 1 second, 54 MPH. (Actually 27.27 and 54.54)