Set Track Points & Modern Stock

[Guest Half-full]

Hi All

 

This might seem a remarkable stupid question, of which I am quite good at.

 

I'm designing a layout based on Aerodrome Park, set in the late 80's/early 90's.  The original layout uses R1 curves and Hornby (I think) set-track points off scene.  My design sees these pushed out to R2 (with one R1 half curve).

 

With modern stock (ie recent designed) being suitable for R2 and above, would they have any issues traversing set track points talking Hornby R612 type?  Looking online, these points are described as R2 , however they seem to have the same radii as the Hornby R1 curves.  One of my pet hates is too large a gap between vehicles (I use Kadee's), I realise I'll need to ease the gaps Im used to for R2 curves, for very short R1 curves, would I need to ease more? 

 

Daft questions I know, I've been used to using flexi-track only for a hundred years, so no idea about set-track!

[giz]

This links to a pdf of Hornby track geometry:

 

https://www.Hornby.com/media/pdf/Track-Geometry-PDF.pdf

 

They do appear to be 2nd radius.

 

The only set track point I have is a Bachmann one from the Highlander set. That is definitely 2nd radius.

 

Edit: R612 are an obsolete item and could well be 1st radius.

Edited June 16, 2020 by giz

[Il Grifone]

According to this they are 2nd radius:

 

https://www.modelrailwaysdirect.co.uk/Hornby-R8072-Left-Hand-Point/

 

However since there is a straight piece up to the blades, it follows that the curved part must be tighter than 2nd radius.

At this sort of radius, Kadees will need to be bogie mounted. To avoid problems, the buffers should just not touch when propelled. Reverse curves should be avoided if possible and will require extra spacing. The real thing either does not have buffers or retracts them out of the way.

[Guest Half-full]

1 hour ago, giz said:

This links to a pdf of Hornby track geometry:

 

https://www.Hornby.com/media/pdf/Track-Geometry-PDF.pdf

 

They do appear to be 2nd radius.

 

The only set track point I have is a Bachmann one from the Highlander set. That is definitely 2nd radius.

 

Edit: R612 are an obsolete item and could well be 1st radius.

You are right there!  Seem to have been replaced with new points that are indeed 2nd radius!

 

Thanks for that, much appreciated!

[ejstubbs]

1 hour ago, giz said:

Edit: R612 are an obsolete item and could well be 1st radius.

 

The R6xx catalogue numbers are the old System Six part numbers.  System Six turnouts were (nominally) second radius.  AIUI the newer R8xxx turnouts are the same geometry (length, nominal radius etc) but they have shallower flangeways through the common crossing and so on, so can cause problems with older stock with coarser wheel profiles.

 

Almost all of the plain track sections (straights and curves, and even the diamond crossings) in Hornby's current catalogue/in their web shop for OO still have the old System Six R6xx part numbers because there's no flangeways to have been modified.  The 4th radius curves have R8xxx part numbers because there wasn't any 4th radius in the original System Six range.

[giz]

4 minutes ago, ejstubbs said:

 

The R6xx catalogue numbers are the old System Six part numbers.  System Six turnouts were (nominally) second radius.  AIUI the newer R8xxx turnouts are the same geometry (length, nominal radius etc) but they have shallower flangeways through the common crossing and so on, so can cause problems with older stock with coarser wheel profiles.

 

Almost all of the plain track sections (straights and curves, and even the diamond crossings) in Hornby's current catalogue/in their web shop for OO still have the old System Six R6xx part numbers because there's no flangeways to have been modified.  The 4th radius curves have R8xxx part numbers because there wasn't any 4th radius in the original System Six range.

Yes, thinking back to the early 70s I had some of the first System 6 points and they were 2nd radius. The older Series 3 I had were 1st radius I think.

 

I believe that the geometry of Hornby, Peco and Bachmann Setrack is interchangeable nowadays.

[ejstubbs]

2 hours ago, giz said:

I believe that the geometry of Hornby, Peco and Bachmann Setrack is interchangeable nowadays.

 

By and large this is correct, although there are variations e.g. the Peco diamond crossing is symmetrical while Hornby does left and right handed versions (and Bachmann doesn't do one at all).  Also, Peco does two straights which are shorter than the standard 168mm single straight, at 41mm and 79mm respectively, whereas Hornby and Bachmann each do a single 38mm short straight.  And Peco don't do the larger radius "express" points which are roughly 1300mm nominal radius at a diverging angle of 11.25°, with a crossover of express points giving the same 67mm track spacing that a crossover of the normal 2nd radius points does.

[frobisher]

6 hours ago, giz said:

I believe that the geometry of Hornby, Peco and Bachmann Setrack is interchangeable nowadays.

 

The Bachmann track items are in fact made from the tooling used by Roco to produce the Hornby items before production was transferred to China.