[R H Steele]

I know this has been brought up. Normally I do not check the curve dependent speed limit option - too many warnings. So I decided to try it out again. Rounding a curve at 30mph - posted is 35 and I receive warning. I had to slow to 21 for warning to go away.
Checked running on many different routes and usually the reduction in speed is somewhere around 40% or not quite half before the warnings disappear.
With Autopilot on these warnings disappear - I know this is probably normal for autopilot - it is for testing and not for running. - thought I would mention it.

So...is this really accurate? Or is this an condition caused by the curves being unrealistically laid out by the RE...something no one can control? It seems that one should be able to make a posted 35mph curve at 30 without warnings?
Not have ANY experience (except a fine weekend at Portola) with running 1:1 is this prototypical. Can the real deals manage a 35mph at 35 or do they have to slow to 21?

For now I am still leaving it unchecked....just too many warnings all the time...visual disruption for no good reason that I can fathom.

[Genma Saotome]

I assume the speed limiter on curves is based on real world physics, probably for unbanked curves. Who knows what the route builder used... and if he was following a track chart might it have been a super-elevated curve?

That said, it should be made clear somewhere what guidance was followed when coding the effect so we all know what is actually going on.

[R H Steele]

This curve was on the Sandpatch. Aren't super elevated curves used primarily in high speed passenger lines? A line like the Sandpatch would surely not have super elevated curves. If that is so and the curve speed warning was developed from super elevated curves then perhaps there should be a curve dependent speed warning developed for normal freight track that lack super elevation.

[ConCat]

Gerry, The curves on Sandpatch are indeed super elevated. Not high speed as in the northeast corridor but the Amtrak Capitol Limited runs these rails.

[Guilford309]

Most if not all lines are typically super elevated. If there was ever any passenger service at one time, chances are the line has super elevated curves. Today on the Conway Scenic, we still have super elevated curves along the ROW due to prior passenger service many years ago. It's an interesting feeling when rocking back and forth in the cab..

As for how accurate. Honestly, I am not sure. I always keep this option unchecked. Most railroads around me have restricted speeds anyways.

[eric from trainsim]

I think you'll find most of the freight mainlines have super elevation, as it allows higher speeds and also reduces flange & rail wear.

[R H Steele]

:huh: I love bein' educated, thanks fellas. That is interesting. Not all that important, I'll just leave it unchecked, however, I do check the curve dependent resistance option.

[Lindsayts]

 R H Steele, on 21 April 2015 - 02:03 PM, said:

:sign_sorry: I love bein' educated, thanks fellas. That is interesting. Not all that important, I'll just leave it unchecked, however, I do check the curve dependent resistance option.

For what its worth below is a table showing curve radius in both metres and CHAINS and there speed limits. It was done by reviewing the speed limits posted on various curves both in Victoria and New South Wales both in Australia.

The table would assume what in Victoria is called Class 1 track, ie top quality track.

Hence this could be called a practical table!

Radius M        Ch      Speed KPH
                        lOCO    DMU
160             8       40      45
200             10      50      55
200-240         10-12   55      60
240-280         12-14   60      65
280-300         14-15   65      70
320-520         16-26   75      80
560-660         28-33   85      95
700-900         35-45   100     115
1000-1200       50-60   110     120
1600            80      115     160
2000            100     115     160

I actually made up the table to see if the curve speed warnings in OR did match with reality. I cannot now remember what the result was. It was checked on two routes which I knew the curves were in the most part accurate.

Note in this neck of the woods most Diesel Electrics have a max speed of 115kph, THe only exception to this (other than DMU's) is the NSW XP class locos which have a 160kph max.

LIndsay