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Wednesday, April 9, 2014

Can a 7/8n2 be a micro?

Four square feet, that is the size limit for a micro layout according to the late Carl Arendt, a micro layout master.

So far, just about every scale has been shown in a layout less than 4 square feet in area.  However, there does not seem to be a 7/8n2 scale layout under 4 square feet.  Carl has two examples on his website that I am aware of, both are quite large in size.  But I may have found a micro plan for this scale.

7/8n2, the BIG scale:

7/8ths scale stands for 7/8" equals a foot, or a ratio of about 1:13.7.  The largest commercial scale that is ready to run is 1:20.3 from manufacturers such as Bachmann and Accucraft.  1:13.7 is, by scale, almost twice the size of 1:20.3, yet runs on the same 45mm track.  This configuration means that in 7/8n2, the trains represent 2 foot gauge prototypes.  The picture below gives an idea of the difference in size.  The drawing on the left represents 1:20.3, which is only slightly larger than the standard garden train in physical size.  The drawing on the right represents 1:13.7, which is about 148% larger, assuming the exact same prototype locomotive is being modeled between the two scales.

So while a 1:20.3 locomotive might only be 5.5 inches wide, a 1:13.7 model of the same locomotive would be 8.15 inches wide.

However, 7/8n2 uses 45mm (gauge 1) track, which is the same as all other garden scale trains, only to represent 2 foot gauge instead of standard gauge or 3 foot gauge like 1:32 and 1:20.3 does.  This works in a similar way to comparing On30 and HO scale, both use the same track gauge, but represent different prototypes which, in real life, used separate gauges.

If doesn't make any sense, think of the scale changing, but not the gauge.  Still confused?  If so, here's all you need to know: these are big trains!

So no wonder no one has built a true micro, these trains are big, and therefore will take up a lot of space on a layout.  However, if very careful in the designing process, I think it is possible to build a micro for such a large scale.

There are two things that must be taken into consideration:  The width of the trains, and the length of the cars.  This helps determine the minimum track length you can have for a given spur.

First, we need to establish the width the display must be.  The track is 45mm (1.77in) wide, but we also need to add at least another 2 inches on each side for clearance.  So each track will need a width of  about 6" to be workable, perhaps slightly thinner.

Length is a bit more lenient.  I look for about 6" of length per car, and 9" for the locomotive.  With that information we know tracks must be 6" apart, on center, and we now have a rough idea of the lengths of the locomotive and cars.  The next step is to pick a track plan.

I personally love Inglenooks, they're prototypical, and they offer a lot of fun for a small space.  After some working, here's the plan:

Total area for the layout, if given the dimensions above, would be 573 square inches, three inches shy of 4 square feet.  This was done by taking an 18 inch by 40 inch rectangle, then shaving off the unnecessary corner to the point that it is under the 4 square foot area.

What we get from this is a 2-2-3 micro inglenook that uses a traverser to double as a turnout and as the head shunt.

This layout could be operated as a game, with up to 720 different combinations, or can be operated in a more realistic fashion using waybills or car-cards.  The view of the traverser would be blocked by a frontal wall, which merges into a building as it meets the visible part of the layout.  In my example, I decided to go with an industry on the middle spur which covers the track, perhaps for grain loading, or simply to keep the rain off the workers.  The spur on the bottom, which would be the front of the layout, has a deck built for trans-loading from vehicles to the train.  In Europe, 2 foot gauge would have been common up until about 40 years ago when their highway system was upgraded.  Even today, there are several examples in the UK.

In the US, because of generally larger space, 2 foot gauge has never been as common.  But, industries would have used narrow gauge in large facilities up until the 1950's when trucks became cheaper and more reliable.  Not to mention the famous Maine 2 foot gauge and all the short-lines in Iowa, Illinois, Wisconsin, and Minnesota which were narrow gauge, then those that survived into the 1950's were bought and re gauged by all the large,consolidated railroads.

(Historians: I may be wrong about the dates, please let me know through a comment if I am wrong and I will correct the dates)

Thus far, this is the only plan I've come up with that looks promising.  I might do a small 7/8ths layout in addition to the Bard Creek project over the summer.

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