O-16.5 Track Centres. Is it a Secret?!

[BG John]

I'm sure this question is rather like asking the length of a piece of string, but after using every term I can think of on Google, and browsing all 20 pages of topic headings in this forum, I'm starting to think that recommended track centres for O-16.5 is something you only discover when you roll up your trouser leg and become a member of some secretive organisation!

 

Can anyone recommend a suitable minimum? I'm just having a little dabble in the gauge, so I can tick it off my to-do list, but I can't find any track standards online. I can't do it by trial and error, because I need to make up a rather complex bit of track to go at one end of a run-round loop, that I need to draw up in Templot. I'm planning to scratchbuild locos and rolling stock to fit on OO chassis, and am rather tempted by some of the Glynn Valley Tramway stock if that helps.

 

It looks as though a crossover using Peco O-16.5 track gives 50mm, but is that enough?

[hayfield]

BG John

 

I have gone for 60 mm track centres, which seems to give me 10 mm gap between coaches. My Peco tram is 45 mm wide, as are Peco coaches. Depending on your curves radii and maximum stock length, this may need increasing. To me the track centres I have look about right

[Grovenor]

There is no standard because all ng lines are different! And rarely have double track, for sidings and passing loops you need two to three feet between vehicles so take the widest vehicle and add 15 to 20 mm. If your widest vehicle is 7ft then a reasonable track spacing on the straight would be 49+15 = 64mm.  A 50mm spacing would allow for a vehicle width of 50-15 = 35mm or 5ft only. Maybe Ok for some mineral lines with tiny locos.

Regards

Keith

[BG John]

Thanks. I assumed it would vary, but as I haven't got any stock so far, except a bodyless Hornby Pannier chassis, I've no idea how wide it will be! On the other hand, as I haven't got any, I can build it to fit!

 

I'm thinking of building something based on the Glynn Valley Tramway 0-4-2s to go on the Pannier chassis, and according to the drawing I've got they were 6' 6½" wide, so around 60-65mm should do then. I don't think the loop will run parallel to the platform road, so may be more than that for some of its length, but I'll aim for that as a minimum.

 

Now I've just got to see if this mad plan fits the baseboard I've just built for it!!!

[martin_wynne]

I'm sure this question is rather like asking the length of a piece of string, but after using every term I can think of on Google, and browsing all 20 pages of topic headings in this forum, I'm starting to think that recommended track centres for O-16.5 is something you only discover when you roll up your trouser leg and become a member of some secretive organisation!

 

Hi John,

 

Forget "0-16.5" and search for "0n30" and "On30". See for example the NMRA standards at:  http://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-3.2_2010.05.08.pdf

 

Generally there is no track spacing standard for narrow-gauge lines, which are almost always single-track.

 

Martin.

Edited July 3, 2015 by martin_wynne

[Loconuts]

I made the same mistake of laying my track at 60mm centres and then found at a later date that I could not run the larger D&RGW 'K' series locos.  I now use the accepted 80mm centres which gives plenty of clearance.  I also believe that is the quoted NMRA standard.

 

Loconuts

[BG John]

I made the same mistake of laying my track at 60mm centres and then found at a later date that I could not run the larger D&RGW 'K' series locos.  I now use the accepted 80mm centres which gives plenty of clearance.  I also believe that is the quoted NMRA standard.

 

Loconuts

I don't need to worry about that. An entire train will be about the length of one of those! This is going to be part of a micro layout, so saving space is important, and all the locos and stock will be based around British OO chassis.

[martin_wynne]

Here's a pic of Devil's Bridge showing the track spacing. Generally when creating narrow-gauge crossovers you should expect to need a length of plain track between the turnouts, rather than having them back-to-back as for most standard-gauge.

 

 

 

Martin.

 

Edited July 5, 2015 by martin_wynne

[Jeff Smith]

Nice picture Martin.

[BG John]

Generally when creating narrow-gauge crossovers you should expect to need a length of plain track between the turnouts, rather than having them back-to-back as for most standard-gauge.

 

Martin.

I think this is an even bigger "challenge" than track centres, especially on a micro layout! It's easy to look at the narrow gauge and think you can squeeze a lot in, however the gauge may be around 50% of standard gauge, but rolling stock is more like 75% of the width. My neat little plan ended up with sidings that would only take one wagon! I've made big changes to the track plan, and now I've got sidings that will take three wagons, that I'm happy with.

 

It would be good if some of this was mentioned in the various introductions to narrow gauge modelling I found on the web, as the proportions are so different to what standard gauge (and in my case broad gauge too) modellers are used to!

[Jeff Smith]

John - the rule of thumb in On30, which is all bogie vehicles, is 3" centres; see this web site for some more inspiring info - http://www.pacificcoastairlinerr.com/on30/beginner/

 

Here are some recent pictures of my GVT stock on my On30 layout which is ME code 70 track on 3" centres. I would stick to this in case you want to run bogie stock (L&B?) at some time.

 

 

[BG John]

I've got an island platform in the middle on the plan now, so stock won't collide, but there will be fixed obstructions! I've been using bits of paper cut to the dimensions of GVT locos and stock to test clearances, and I'll build stock that fits the layout! If I like O-16.5 I'll build something bigger in the future.

[Pacific231G]

I'm sure this question is rather like asking the length of a piece of string, but after using every term I can think of on Google, and browsing all 20 pages of topic headings in this forum, I'm starting to think that recommended track centres for O-16.5 is something you only discover when you roll up your trouser leg and become a member of some secretive organisation!

 

It looks as though a crossover using Peco O-16.5 track gives 50mm, but is that enough?

It is the length of a piece of string but fortunately some string comes in regulation lengths.

On the 60cm gauge Tramway de Pithiviers-Tours where the max vehicle body width was 1.9 metres (2.2 metres across footboards) the centre to centre distance on passing loops was 2.56 metres so 59mm in 1:43.5 scale. That gave a minimum distance beteen closest rails of 1.9metres and the minimum clearance between vehicles and any fixed structure was the usual 2 metres for passenger platforms and 0.45 metres elsewhere. Body widths on the most extensive 60cm system in France, the 224km (140miles) long Chemins de Fer du Calvados* were also 1.9 metres for passenger stock and 1.7 metres for goods wagons so this may have been something of a standard for 60cm roadside tramways.

On the outdoor military 60cm gauge lines built to supply the Maginot Line forts the standard centre to centre distance for double track was 3.5 metres which is far wider and about 80mm in 0 scale so about three inches and looks to be about the same as the separation in Martin's excellent pictures of Devil's Bridge.

 

*It was the last line of the roadside CF du Calvados from Caen to Luc-sur-Mer that appears in a number of shots from the British archive film of D-Day. On the morning of 6th June 1944 the 07.00 train was in the depot at Luc-sur-Mer raising steam when the invasion of Sword beach by British and some Free French troops began. The train didn't run that day or ever again.

Edited July 10, 2015 by Pacific231G

[BG John]

Whenever I want to check dimensions, I refer to the data in my Model Railways Handbook 7th Edition from around 1963 (except for broad gauge!), but it doesn't mention narrow gauge!

[Phil Traxson]

From notes and measurements taken late one evening last year on the Welsh Highland run round loop at Porthmadog I have these figures. (after the last train had moved but before I went into Spooners bar)

 

Track centres 8' 6"

Sleeper spacing 2' 9" (at rail joints 2' 9"- 2' 6"- 2' 0"- 2' 0"- 2' 6"- 2' 9") 

Sleepers 4' 6" long x 9" wide x 6" deep(approx. depth as I wasn't disturbing the ballast to measure)

Platform height  10" above the sleeper top

 

Under pointwork the sleepers were 2' 0" centres reducing gradually to 1' 6" under the crossing nose.

 

At Minffordd the track centres varied through the loop from 7' 2" to 6' 9" but were a constant distance from the platform edges, but then the old FR has a tighter envelope than the new WHR. 

 

Hope this helps

 

Phil T.

Edited July 11, 2015 by Phil Traxson

[BG John]

Thanks Phil. The sleeper spacing doesn't matter for almost all of the track, as it will either be set in cobblestones, or ballasted over the sleepers, to hide the Peco OO track. But in a few places I may replace the Peco sleepers so I can make them visible.

 

The platform height is interesting. Did you measure the height above the top of the rail, and the distance of the platform edge from the rail? Presumably trains can overhang the platform if it's that low, which could help me. Being a micro layout, everything has to be compressed, so I can make the platform a bit wider than I could otherwise.

[Phil Traxson]

Thanks Phil. The sleeper spacing doesn't matter for almost all of the track, as it will either be set in cobblestones, or ballasted over the sleepers, to hide the Peco OO track. But in a few places I may replace the Peco sleepers so I can make them visible.

 

The platform height is interesting. Did you measure the height above the top of the rail, and the distance of the platform edge from the rail? Presumably trains can overhang the platform if it's that low, which could help me. Being a micro layout, everything has to be compressed, so I can make the platform a bit wider than I could otherwise.

I didn't measure from railtop to the platform height but the coaches do overhang the platforms or certainly the foot boards do, the rail to platform distance is 2' 0".

 

If you go onto the FR/WHR site www.festrail.co.uk ,click on "more info" and then onto "webcam" there is a good view of the WHR loop at Porthmadog which might help, in fact at the moment (13.20)there is a train in the platform! Under "Plan your visit" there are timetables so you can work out when to look at the webcam for some action.

 

Phil T.

Edited July 11, 2015 by Phil Traxson

[BG John]

No train in the station at the moment. Of course that's a new platform, and mine will be as it was before WW1, so I can probably get away with pretty much anything that doesn't make the trains derail! I'll try something around 14mm from the rail, and low enough to clear anything overhanging, which may mean rail level as something based on the GVT Beyer Peacocks is on my to-do list.

 

I suppose I ought to wander up to North Wales and look at these things for myself!

[Sturminster_Newton]

Guys,

 

Hornby/Peco standard set-track centres are 67mm so for most items of 0-16.5 this will be enough.

 

The addition into all legs of special straight R610 of a passing loop using left and right or left/left right/right pointwork  will spread the rails a little wider & make the loop a little longer.

 

for more detail perhaps:

 

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

 

will help the grasp of the basics of geometry.

 

Not much in the narrow gauge world is standard and, as most here as has been observed, single track lines so centres are mostly academic.