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Discussion Starter · #1 ·
Does anyone have any idea what the NEM standards for the spacing of track at stations, sidings, straights and curves are in HO?

I have found the website of the NEM but find the sheet to be quite difficult to understand...

If anyone could advise me on this, that'd be fantastic!

Thanks for the help!
 

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having had a look....NEM #112 gives the recommended spacings, from track centre-line to track centre line, as 46 [mm?] for 'open country' track..and 52 [mm] for yards/stations.

This is for HO.

The distences [from centre line to centre line of each adjacent track] for curves are also outlined....but subject to various criteria.

These criteria are to be found in NEM # 103.

They seem to be......based upon the LENGTH of vehicles used...and these are defined as A,B,&C

What you need to do is MEASURE the length of the LONGEST vehicles you will be using...[ie coaches]

Then compare those lengths with the table on NEM# 103....obviously looking up under the SCALE you are modelling in...[I assumed HO?}

having decided which letter applies to your stock.....you then refer back to NEM#112......which will give you the separation distance...ON CURVES....for the radius of your curves..[referring to the minimum..or sharpest radius you are using]...and the category your longest vehicles fall into....

.for example, if your longest stock falls within category C, and your tightest radius on a curve happens to be 500mm...in HO your centreline spacing will be opened up to 59 mm.

to find out how much CLEARANCE you need to leave...OUTSIDE and INSIDE each curve...you need to refer to table E, on NEM# 103.

again, table E gives you your radius for the curve..and you cross reference that figure, with teh category [A,B,orC] that your longest [coaches] fall into....this gives you a value.

for example, if your coaches fall into category C for length...and the radius of your curve is 500mm.....then cross-referencing gives you a VALUE of 11 [for HO]

now, going to the bottom of page 2, NEM #103.....there is a dsiagram showing how the clearances outside the track line are measured.

the width of clear space required on your curve, is noted at B(1) +2E.

Going to the top of page 1, NEM#103, another diagram defines B(1)...this value is the WIDTH of your coaches [or stock, if using wagons only]....this MAY vary according to age of prototype...or fidelity to scale of your models.

so..to find out how much space to leave outside and inside your curve.... add B(1) dimension to 2X value of E.

thus, in my example......the value of E was 11.....so....the overall amount of clearance needed on our 500mm curve, for a coach in category C [length]...is......2x11 + the width of those coaches.
 

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Discussion Starter · #3 ·
Thanks for that, that's a really useful guide!

For me, this is going to be an interesting conundrum - I know more or less what trains I want to run but have no idea what the coach would have the largest width --- I'm planning to run ICE and TGV high speed trains, and modern rolling stock...

Do you know if there is a "safer" dimension to go for in that situation?
 

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If you were to need the values for 00, to convert from HO to OO you would multiply the spacing dinension by 4/3.5

Rob
 

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Given that 00 scale is a compromise between 3.5 mm scale track and 4 mm scale rolling stock, I do not believe that a straight forward conversion using 4/3.5 will work when you are considering the interaction of track and rolling stock.

I'd be happy to be proved wrong, as then 00 scale modellers can use these NEM tables safely. I checked the DOGA website but they do not have such standards yet, but perhaps we could ask them to develop a DOGA standard based on these NEM standards, or confirm their applicability.
 

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nip down to a dealers shop with a tape measure......if you currently don't have any stock?

In the bad old days, I used to lay out the curve [track], find the longest coach[with the longest overhang beyond the bogies]...with fingers, clamp a felt tip of suitable colour to an outside end, and push the coach around, marking the board. This gave the minimum outside clearance......then I'd clamp the felt-tip to the centre of the coach, on the INSIDE of the cure, and do similar.

Anything of height within those two lines will get clouted.

For my son's OO gauge layout, i tried to steer him towards short, bogie coaches, due to limited space.....he wanted an autocoach, and this became the marker coach, [hornby]...since it had so much overhang, compared to Thomas stuff...and Bachmann Mk1's...
 

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QUOTE (John @ 4 Jan 2008, 11:53) <{POST_SNAPBACK}>Given that 00 scale is a compromise between 3.5 mm scale track and 4 mm scale rolling stock, I do not believe that a straight forward conversion using 4/3.5 will work when you are considering the interaction of track and rolling stock.

I'd be happy to be proved wrong, as then 00 scale modellers can use these NEM tables safely. I checked the DOGA website but they do not have such standards yet, but perhaps we could ask them to develop a DOGA standard based on these NEM standards, or confirm their applicability.

You are probably correct. I had assumed that as its the size of the rolling stock and not the track itself that dictates the spacing between the track that a direct ratio of 4/3.5 would work best. I may be totally wrong though!

Rob
 

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I use the Peco spacing at 50mm and find that a curve radius of 1000mm or larger on visable sections of track looks good with scale 1/87 (303mm) length coaches.
My minimum radius in hidden areas is 750mm, which works perfectly with the 50mm spacing.
I use NEM standards for all my other civil engineering.
David
 

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Let's see if I can explain this simply.

This is taken from an example I have, which has a station building on the left hand side with double track to an island platform then a single track on the other side.
Wall of station building to platform edge 46mm
Platform edge to centre line of track 1, 20mm
Centreline of track 1 to centreline of track 2, 51mm
Centreline of track two to island platform edge 20mm
Width of island platform 79mm
Edge of island platform to centreline of track 3, 20mm.

Heights of platforms are taken from the top of the rails.
Station building platform height 5mm.
Island platform height 8mm.

Goods shed platform distance from track centre line 20mm
Edge of goods shed roof to track centre line 20mm
Height of goods shed platform 11mm.

Height of bridges above rail height 75mm.

Minimum distance of track side structures (including signals) 27mm, from track centre line.

Bahnsteig-Abmessungen Nach NEM.

All the best,

David
 
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