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TGR Curve Speed Data 1950s | ||||||
Radius (chains) | 3 | 5 | 7 | 10 | 15 | 21 |
Max Speed (mph) | 10 | 20 | 25 | 30 | 35 | 40 |
For those living in... well... most of the world :hehe::
1 “chain” is 20.117 meter.
Wait, so you are saying that an Australian going 60mph would think he was traveling 479.95 cph (chains per hour)? Or does that only apply to pware?
How about track speed up to 100MPH?
How much does TRAINZ adhere to these curve speed specs? Can you derail by taking a curve too fast? The reason I am asking is that I was trying to create a T:ANE version of a local n-scale model railroad club and they had a 180 degree turn that was only maybe a two-foot radius, but I calculated to be High-speed in real life it would have to be close to a half-mile radius, or a mile for the complete turn. That left me with a lot of unused space that wasn't in the real n-scale....
Since centrifugal force determines speed, the latter can be calculated from the formula:
Vmax = k * sqrt(R)
where
R is arc radius in meters
sqrt(R) is square root of radius
k is coefficient to return result in km/h. It equals 4.5 or 4.6 on most European railways.
Vmax is maximum speed
To get result in mph, use coefficient m = k/1.609 = 2.8
For example, to calculate maximum speed a train can negotiate an arc of 600 meters:
Vmax = 2.8 * sqrt(600) = 69 mph
Conversely, to calculate minimum radius of an arc for traveling at 100 mph:
Rmin = (100/2.8) ^ 2 = 1275 meters or 4183 feet
But there are two bigger issues than speed limit on an arc:
1/ Balancing centrifugal force by track tilting. There is no track tilting option in TS12. Maybe there is in TS19, but I don't use this version, so I can't check.
2/ Reducing sudden jump in centrifugal force from zero to some value when trains leaves straight section of the track and engages an arc. On real railways this is solved by laying track in a parabola, but I found plotting parabola in Trainz quite challenging and never seen a route implementing it accurately. So, there is always room for improvement in future versions of Trainz.
Don't weight, height, loading gauge of vehicle, and track gauge play a part in the calculation. What assumptions are made/used in the formula?
So if I go around a curve with a radius, not arc radius, of 75 meters, I can go 24 miles per hour?
The textbook I copied this formula from states no arc should have radius smaller than 190 meters on normal gauge (1435 mm) railway. Some locomotives with axis arrangement Co-Co have problem negotiating arcs tighter than that. If 24 mph seems to be too fast, you can lower the coefficient. In my routes I use coefficient of 1.8, e.g.
R=75m, Vmax=15mph
R=200 m, Vmax=25 mph
R=400 m, Vmax = 36 mph
R=800 m, Vmax = 50 mph
and so on.
This formula does not apply to curves with variable radius (like parabola).
EDIT: On curves that have a variable radius, I use the 'get radius' feature and find the average radius by adding the highest number (largest radius) and lowest number (smallest radius) and divide by two. I then plug that number into your equation to find the speed limit for the curve.