Track Geometry

[Canico]

I am constructing a small layout in a garage and have installed track across the back and now want to make a twin track  90 degree turn to go down the side .I would like to have the shallowest curve for best running experience and looking at the  track diagram on the Hornby website I am confused as to which radius to go for, is the fourth radius the one to go for ?

The shelf for the new extention needs to be as small as possible for space reasons, I am thinking about 300mm wide. Any advice before I start buying track would be much appreciated.

Thank you

[Rog RJ]

Fourth radius is the largest and would go on the outside of a double track curve, third radius is the next smallest and would be the usual choice for the inner curve.  Radius two would be the next smallest and radius one is the very smallest.   Most modern models need radius two or bigger with radius one generally only being suitable for the smallest locos.

 

[Puffed Out]

90 degree, 1st Radius is 371mm. Radius. 

2nd. 438mm

3rd. 505mm

4th. 572mm

[2e0dtoeric]

If you have the room, use flexi-track, to get a more realistic huge sweeping curve, rather than a sharp 'toy train' bend.

[Canico]

Thank you for the replies and advice

[atom3624]

It's the compromise I'm stuck with - in my head for now - depending on where I'll go.

 

I find running a 4th radius circle of 'test track' most can get up to 'normal operating speeds' - equivalent of 85-110 mph estimated at scale - but above that, even 4th radius is 'tight'.

 

It depends what you're going to run on it, and how - obviously slower the better for longevity, but for realism, the expresses rarely surpassed 60-80mph unless in exceptional areas - prolonged flat, straight sections.

 

Going 'Modern Image' is another thing altogether - Deltics, 86, 87 onwards capable of at least 100mpg and sustained, before you get to the HST, Pendolino, Azuma ... 

 

The garage will be restrictive for this, but my thinking is generally, as large a radius as possible for the 'main line'.

Al.