Distance between track and platform

[johna]

All

What is the minimum clearing distance I should allow between the platform edge and rails in oo gauge please?

 

Johna

[philsandy]

18mm from platform edge to track centre. 

[ejstubbs]

4 hours ago, johna said:

What is the minimum clearing distance I should allow between the platform edge and rails in oo gauge please?

 

According to this diagram from Brian Lambert's web site it should be 19.25mm:

 

 

Since you refer to the minimum distance I assume you are already aware that you will need to allow a greater distance when using curved platforms, to allow clearance for end swing at loco release crossovers etc.  Cutouts in platforms edges to accommodate end swing at loco release crossovers were sometimes seen in the prototype as well, see within this thread:

.

 

[The Johnster]

May I suggest the following method to establish clearances.  A tip picked up many years ago in Model Railway Constructor, and may have come from the great Cyril Freezer himself; it has served me well over many years. 

 

.Build Baseboards, do not paint them yet

.Lay track but do not permanently fix it down yet

.Obtain the following items; a pack of felt tip pens of different colours and a roll of sellotape.

.Taking your longest rigid framed vehicle, usually a coach, tape a different colour pen to each of the end corners and one to each side at the centre line between bogies, with the tip of the pen resting on the bare baseboard

.Push the coach gently round the layout, leaving different colour felt pen lines on the board which will, where they intersect, mark the point of clearance for all stock (we will deal with locos in a minute) with a safety margin of half the width of the pen to accommodate stock wobble when running.  The end pens will show the overhang and the centre-of-the-side pens will show the 'underhang' where the centre of the coach runs inside the radius of a curve

.Now, repeat the process with your longest and widest loco; steam locos with outside cylinders are usually widest across the cylinders, so tape the pens here and at the front of the running plate; some RTR pacifics have a fairly large overhang here, and 2-6-4Ts can have a similar overhang at the bunker end.

 

When you are happy with the results, you can permanently fix and wire the track and position your platforms, along with any other lineside structure that needs to be clear of moving trains such as bridge parapets and retaining walls.  This is the time to decide if your platform is going to have an overhanging edge.  if so, decide how much it is going to overhang and mark off the platform face position accordingly.  When you fit the platform surface, pens taped to locos and stock as above but set to draw on the platform will show you where to trim the platform edge to, including any curvature.  You do not need to measure anything, just stay within the pen lines, and so long as you don't move the track or platforms post fixing the track down, a realistic minimal but effective clearance is guaranteed (until you buy a longer coach, of course).

 

Now you can paint baseboards and start ballasting!