# Width needed for parallel Tracks



## Jcutter (Dec 16, 2015)

I am planning my garden railway and plan to use the top of my 120' retaining wall for parallel tracks. I will exit the wall with R5 at each end but the rest is straight. It is currently topped with 8" bricks which is great for a single track but too narrow for parallel tracks. I was told you need 8" on center for two tracks so, with another two inches on each outside rail, would 12" pavers work?


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## riderdan (Jan 2, 2014)

It's hard to say for sure, because the "safe" distance between the tracks is controlled by the width of your rolling stock/locos and track geometry. If you're going to have parallel curves, you also need to allow for any overhang if you expect trains to pass each other. 

I have a bridge that's about 14" wide (probably 13" on the inside) with the tracks spaced evenly. Trains that pass on this track are probably about 1/2" inch from each other and from the sides. It's on a straight and still pretty tight.

Your best bet is probably going to be to lay out some track on the ground and then push some trains along it to check overhang on the corners, loading gauge, what-have-you. You might be able to figure some of this out with track planning software, if you have access to it.

<edit>
Just another thought: if you're running along the top of a wall, you might want to keep further away from the drop off than you'd get centering the tracks. In other words, the track on the "uphill" side would be close to the edge and the track on the "downhill" side would be further. If the wall is at all high and you have a derailment, a car or loco could fall off the top of the wall if the track is only 2" from the edge.
</edit>


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## Paul Burch (Jan 2, 2008)

What scale do you run? Makes a difference.


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## Pete Thornton (Jan 2, 2008)

As the wall is straight, you should be able to get away with tracks on 7"+ centers. The widest model locomotive is about 6.52" wide (K-37) - unless you plan to run 7/8n2 rolling stock!

I share riderdan's concern about running 120' on top of a wall. Anything that happens (twig, heat buckling,) will dump your train on the floor. I'd put a 1" side on the edge where the drop-off is to contain any derailments.


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## Garratt (Sep 15, 2012)

One possible idea prior to fixing your track is to lay some square wire mesh (6"~8"?) with the edges bent up to form a fence either side of the track in case of derailments. It would be cheap, simple to do and not too obtrusive. Easy to trim away if not wanted later. Keep the wire 'posts' on the outside to avoid damaging your rolling stock.

Andrew


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## Greg Elmassian (Jan 3, 2008)

I believe prototype spacing can be down to 13' center to center, in 1:29 that is 5.4", but in 1:20.3 that is 7.7"

So, as long as you move the tracks apart a bit before curves, you should be fine.

Greg


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## NTCGRR (Jan 2, 2008)

I've run 7" center on center on my bridge and no problems with any scale and 8" min on curves. and 11" off rail for bridge and tunnels.


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## Trains (Jan 2, 2008)

I laid USA Trains large switches to make a crossover. Measured the distance between them and
came up with 8 ". So that what I used.

Don


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## SD90WLMT (Feb 16, 2010)

Often times it is prudent to consider possible sky hoook operations to remove or rerail cars.... Using the 5 finger crane system...!


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## Greg Elmassian (Jan 3, 2008)

That's why I use 9" on center in most places, also #6 switches in a crossover gives that spacing too, but the original question was on top of a wall, and how wide is needed. I believe the increments available for concrete block would be 6" , 8" and 12", so the only logical choice is 12". Spreading the track as wide as possible gives about 8" center to center I think.

So I believe there's only one reasonable answer, use 12" cap stones, and spread the track so the ties are flush with the edges of the stone.

Greg


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## BigRedOne (Dec 13, 2012)

When I calculated a dual-track railway using LGB standard parallel curve spacing, I came up with a 14" "right-of-way-width," I suppose it's called. In other words, using the same distance on the inside and outside perimeter as the factory track-to-track spacing provided between them.

Outdoors, though, track will settle and shift over time, may tilt to the side, etc.

Although I share the concern about a train falling, it does seem common for live steam operators to run right up to the edge of elevated railways. I think I'd let the appearance settle this for me: if ballasted track, I'd try to give enough to the sides to look realistic, whereas if I wanted a prototypical non-ballasted bridge appearance, I'd go narrower. (Probably to the 12" or so.)


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## Greg Elmassian (Jan 3, 2008)

While the OP stated the track is on top of a wall, he indicated a retaining wall.

I think we can assume it's 2-4 feet in height, but maybe the OP will come in here.

Greg


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## Jcutter (Dec 16, 2015)

*Wall height*

The retaining wall separating my grassed yard from the marsh has, at a low tide, a height of 4 feet. The area 2 feet adjacent to the bottom of the concrete block retaining wall is firm and dry enough to support walking and operating the trains (except with full moon high tides when a 10 foot tide will rise up the wall a foot or so.). A during these spring tides, a derailment would drown all passengers and turn the locomotive engines to rusty junk! If a derailment occurs during low tide, a train would find a soft, grassy landing with very little pluff mud. Hopefully the fiddler crabs would not attack the passengers before they could be rescued!

After all the recommendations, I believe I can find a paver at least 12" wide or wider to top my wall on which I will be able to run parallel tracks which will connect the two towns on each side of my back yard. Choosing the right color, it will blend with my landscaping.


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## Greg Elmassian (Jan 3, 2008)

Sounds great, how about some pictures?

We all like to see layouts in progress.

Regards, Greg


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## harvey (Dec 30, 2008)

Hi, Irrespective of what scale your rolling stock is your track needs to be spaced enough a part to prevent the handrails being ripped off when the locomotives pass each other and also to prevent the engineers from hi fiving each other as they pass!
On the curves make sure the coach overhang does not clip the passing train.
Have fun,
Cheers.


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