Juup wrote:This is interesting information. 40km/h for EW3 and 30km/h for EW2 and 60km/h for curved station track. I guess this is all in the spirit of wanting to be prototypical in our modelling, and then with the knowledge we gain we can compromise with awareness :)

JP, can I ask some questions?

What are these numbers based on? Is it a general rule for real railroads that for curved station track the maximum speed is around 60km/h, for a long turnout 40 and for a short turnout 30?

Or is it a calculation based on radius alone? If so, does that mean the speed limit for curved track of radius 100cm (i.e. the same curve as EW3 turnout) is 40km/h as well?

Or Is the calculation different for turnouts because turnout blades require more caution than simple curved track?

Last question, extending the logic of the speed limits you have provided, what would be the speed limit for a train running through Tillig's 12 degree Wye turnout (the longer one where both directions have a radius of 200cm)?

They say it takes about 10000 hours to become an expert at something. I am clearly not at 10000 hours yet - LOL.

Juup

No, it is not a general rule. It is based on the geometry. If you tried to run a real train through such a short turnout at a high speed, the centrifugal force would derail it. You could see a clear demostration of this in the news not long time ago, about a commuter train in N.Y. (that was a normal track curve though)

"Normal" turnouts have 40 km/h speed to curve. EW3 is shorter than that, but we shorten the lengths somehow on the model railroad.

"Slim" turnouts have 60 or even 80 km/h to curve. TT-Filigran makes the "slim" turnouts for 60 km/h, it is turnout nr. 14 if I remember correctly. High speed trains as TGV, Eurostar, ICE, Shinkansen etc. have special turnouts which allow hugher speed to curve. The length of such a turnout would be more than a typical station on a TT scale layout.

The reason for the different maximum speed on turnouts and on track curves is very simple. The turnout is always placed flat while the track curve has a cant/superelevation which compensates for (some part of) the centrifugal force.

You can find the figures for mph and US turnouts, but the physics is the same.

I tried to google the turnout speed and geometry and found this:

http://www.tillier.net/stuff/hsr/TM-2.1.3-Directive-Dwgs-TurnoutsAndStationTracks-100409.pdf

nr. 9 is 20 mph

nr. 11 is 25 mph

nr. 15 is 35 mph

nr. 20 is 50 mph

Tillig's 12 degree Wye turnout would be a 40 km/h turnout too, in both directions. Maybe our German friends can find DR or DB standards for the turnouts?

The correct speed for the main line curves on this layout would be something like 30 km/h, but up to 60 km/h is accpetable I think. Running BTTB or Tillig's models at full power (=Shinkansen speed) is wrong, even on the straight track.

I use km/h speed of the prototype for explanation. Divide it by 120 to get it to the model speed.