5.5mm Association

The Harold Minkwitz Archive

Modelling 3 Foot Narrow Gauge on HO Track

Real 3 Foot Narrow Gauge for Everyone

Objects aren't "N, HO...S, O, etc. SCALE". An object is what it measures.

That is the idea behind 55n3, we are taking models from other scales and converting them to 55n3. No one makes 55n3, Bachmann makes models that can be used in 55n3 because they match plans in Scale55. That is why we have a scale rule. Measure a model, if it is the right size for Scale55 it is Scale55. The Bachmann On30 equipment is small O scale narrow gauge, but put a Scale55 ruler on the equipment and it becomes 55n3. Now it is realistic three foot equipment.

"I don't get the 'it has to be 3 foot' deal. There were plenty of 30" and 24" and other gauges as well." No, not in North America, look in any narrow gauge publication and Narrow Gauge in North America is essentially THREE foot, 'nough said.

Many of the images on these pages can be clicked on to view a larger version of the picture.

Ronald Halma's American Civil War 55n3 Layout

You can see more about this layout by visiting Ronald's Blog Spot.

You can also visit Ronald's Build Thread on Railroad Lines.

You can also view some Youtube videos of the layout in action.

Kennesaw GA 1863 video from onTraxs! 2013.

Kennesaw GA 1863 video from Modelspoordagen 2017 in Rijswijk.

Thanks Ronald, knew this was a good idea!

Common carrier United States narrow gauge railroads were THREE foot. Here is how it goes, HO track is 16.5mm. If we divide 16.5 by 3 we get 5.5mm. That scales to 1/55 for an inch, strange scale right, 1/55? Military modelling has 1/56 or 28mm figures, there are figures, wagons, vehicles in the 28mm world. Why not make the models to 5.5mm/ft?

There are two narrow gauge eras: the era of narrow gauge fever and the era of survivors after the narrow gauge crash. Historians consider narrow gauge dead after 1893 because very little new narrow gauge was built in the United States. There were pockets of survivors that lasted into the 1960's.

This graph shows the two eras of narrow gauge. The mass of extinction of "narrow gauge" began about 1885. That was the end of narrow gauge fever and standard gauging or abandonment.

The remaining narrow gauge lines existed because they were hauling coal or gravel to build the roads that eliminated the railroad.

Won't we have to scratchbuild everything? Where will we get cars and locomotives? Bachmann On30 gives us the inside frame 4-4-0 and HO locomotives can be converted to represent the narrow gauge before the crash. Bachmann's other On30 locomotives are good representatives of after the crash. Bachmann On30 freight cars convert to 55n3 easily, becoming a more typical 29' car.

This website shows articles about modelling in 5.5mm scale on HO track. Hopefully someone will follow me in this venture.

I guess it has to have a name, Scale55 sounds good, we don't want to go into that "letter jungle". Sorta like the proto guys with P:87 and P:48. 55n3 being a subset.

"We don't need no stinking letter!!! 5.5mm/ft - 1/55 - Scale 55 sounds good.

The first thing you need is a "scale rule", click here to download our Scale 55 ruler.

Bachmann Built Us A 55n3 Mogul

The Bachmann On30 Mogul mechanically matches the Quincy and Torch Lake #4.

The Q&TL #4 Mogul plan superimposed onto a Bachmann Mogul.

And a 2-4-4-2 Mallet

HO Gauge IS Scale 55 Three Foot Track

Track is what sets 55n3 apart from other scales. You can go to any hobby shop and buy 55n3 track, it is ALWAYS readily available HO gauge track!!! HO gauge track brings mechanisms and wheels that are the right size.
The "Modern" American Narrow gauge Uintah railroad looks like our 55n3 track and flatcar, Model Power Code 83 and a Bachmann On30 flatcar. But 55n3 ISN'T about the track. 55n3 IS about the mechanisms, the vehicles, the people, the accessories available to make THREE foot narrow gauge running on HO track. If your head is in the box it ain't for you. This endeavor requires imagination and free thinking.
HO track looks good as 55n3 is cheap and available. Here is no longer available Model Power HO Code 83 and Atlas Code 100 switches.

Wish I had discovered 55n3 in 2008 when I tore down the PcalRway. D-oh!
Since the original presentation have discovered that the MicroEngineering "On30" track perfectly represents most three foot gauge track. Giving Scale55 track that represents the majority of narrow gauge track.

6" wide x 6' 8" long with 2' cl to cl.
Comparison to On3 track, commercially available track is usually the D&RGW super narrow gauge profile.

Sn3 offers similar track but who can afford Sn3 and it is only Colorado.
Peco 0-16.5 track has a good reputation. Upon investigation fits 55n3 pretty good for late period narrow gauge.

Readily available from Hattons in the UK.
Got a good deal on the package of HO Kato Unitrack for Model Railroader's Black River Junction layout about four years ago.

Found that the track can be painted to look like narrow gauge track.

Rolling Stock

The Bachmann On30 box car comes close to the Pacific Coast Railway boxcar and is a closer match to the Uintah boxcar.
The Bachmann On30 boxcar is slightly shorter than this 1905 Unitah boxcar and is bit wide for early narrow gauge.

If the image is placed on a Unitah boxcar photo the cross section matches.

The Bachmann On30 gondolas and flats also match the Unitah rolling stock of the later period. The gons and flats can be narrowed a scale foot to represent a typical early era narrow gauge gondola. An hour is all that it takes to narrow a gondola or a flat car.
The Bachmann On30 stock car has no known prototype except Bachmann's large scale rendition using a standard gauge car. It will suffice.

The bobber caboose needs to be lowered but the sidedoor is fine.
Found On30 trucks at Shapeways that make converting Bachmann On30 freight cars to 55n3 easier.

Nice Scale55 woody there, available on Ebay for about 5 - 10 dollars.
Bachmann On30 cabooses have a body about six inches too high.

The new red logging caboose is lower and look better.
Lowered one to depict an earlier era version.

Not really worth the efforts to take the six inches out of the body.
Click this link to go to the section on converting Bachmann 0n30 cars to 55n3.

The Bachmann On30 passenger cars sit about a foot too tall for a narrow gauge car.
The Bachmann passenger cars are 10'-3" high in the body, most narrow gauge cars are about 9'-3". Standard gauge cars match the 10'-3" height of the Bachmann cars. That works for me.
Were there 10'-3" high narrow gauge passenger cars? Mexican narrow gauge railroads had them in steel and wood.
The Bachmann passenger car's interior is actually Scale55. These Scale55 figures fit the seating. O scale figures are too big.

"Modern" Narrow Gauge - Modelling Narrow Gauge Survivors

The Bachmann On30 rod locomotives can be used to model the "second generation" three foot narrow gauge equipment. After 1900 the locomotives got a lot bigger mainly geared for the export market. The only On30 Bachmann locomotive that doesn't translate to 55n3 is the "Tweetsie" ten-wheeler. It is an example of a "second generation" narrow gauge motive power. The 4-6-0 is very large. The remaining Bachmann On30 locomotives represent very small thirty inch gauge prototypes. This translates very well to 55n3.

The Mogul moves to 55n3 even though it is a three foot prototype. It is a small early three foot locomotive that is similar to Baldwin's later catalog locomotives. The Mogul can be used without modification.

The Bachmann On30 freight cars are very small early 3 foot prototypes. They scale better as 1/55 cars of the "modern" era than 1/48. The ladders and grabs are the right size and placement also.

The Bachmann On30 2-8-0 scales out to a Baldwin Catalog 10-28-E. It matches this NdeM locomotive in dimensions.
The Bachmann On30 2-8-0 scales could be converted to a K-27 like the large scale version of the 2-8-0.

Click this link to go to the section on converting Bachmann 0n30 locomotives to 55n3.
Broadway Limited Imports "C-16" matches this Ferrocarril de la Sabana "late era" 2-8-0 Baldwin Catalog locomotive. Shown with a more appropriate Bachmann On30 Mogul tender.
Click this link to go to the section on converting the BLI 0n30 C-16 locomotive to 55n3.
Click this link to go to the section on Building 4-6-0's (Wheelin' and Dealin').

Bachmann HO 2-8-0 to 55n3

This was a conversion that showed up in the early days of On30. The mogul body can be adapted to the HO Bachmann Consy or the Mogul cab and domes can be used on the HO boiler to make a 55n3 SP style consy. The drivers never scaled well for Scale48.

American Models S Scale Hoppers

The American Models Rib Side hopper scales 8ft wide x 28ft-6in in Scale55.

The Myner trucks fit just right.
The mogul is close to the EBT moguls. Brian Budet's HO model.
What about a EBT Mikado? The old BLI On30 C-16 has an almost right mechanism, boiler dia and tender. Bowser HO 69" drivers are close to the 48" prototype. The axles are .125 on the Bowser and the BLI are .109 but that is an easy fix. The BLI has separate bearings.

Motor Vehicles

There are large variety of vehicles available for the 1920's to 1930's

Click this link to go to the section on Motor Vehicles.


Click this link to go to the section on People for Scale 55.

Horse Drawn Vehicles

Click this link to go to the section on Horse Drawn Vehicles.


Click this link to go to the section on Structures.

Modelling the Fever

Narrow Gauge fever swept America during the 1870's until it's precipitous crash 20 years later. There is no other scale that provides equipment to model early narrow gauge. On30 won't do it, On3 won't do it, Sn3 won't do it. This is a great idea to do it, believe me. Common carrier narrow gauge railroads in the United States were THREE FOOT gauge.

Early North American Narrow Gauge can be modelled because HO loco mechanisms, trucks and track convert easily to the early period.

55n3 has the only affordable Ready-to-Run 3 foot gauge 4-4-0.

Click this link to go to the section on the Bachmann 4-4-0.

The On30 Bachmann inside frame 4-4-0 is really too small to be a 1/48 scale locomotive. In 1/55 it is great representing a late 1880's loco. The other Bachmann On30 locomotives are suitable for the post narrow gauge crash era 55n3.

Early three foot locomotives can be made from HO locomotives. The Mantua HO ten-wheeler is a good starting point for a 5.5mm/foot three foot gauge loco.
The Bachmann 4-4-0 matches this 1897 Rodgers locomotive. Note how the appliances "scale" before the era of standardization.
Bill Allen's Bachmann On30 4-4-0 conversion was posted on Railroad-line Forum as On30 in the fall of 2010. Sure looks like that picture. Sure looks like 55n3. It is possible to model early THREE foot narrow gauge.

Click here to go to the Rail-line Forum article.

HO Locomotives as Early 55n3

A Mantua HO Ten-Wheeler against a 1/55 scale plan of an early 4-4-0. Shown here with Scalelink 19mm self-quartering drivers. Here the crew is trying to get the rear one back on the track.

Click here to go to the section on Locomotive Resources.
Roundhouse HO locomotives make it possible to model early three foot locomotives. The 2-6-0 matches the seminal three foot locomotives.
On30IMA has a line of small On30 freight cars that are good examples of early era cars in Scale55.

Click here to go to ON30IMA.

Modelling 1870's Pioneer Narrow Gauge

My original intent with 55n3 was to build 1870s three foot narrow gauge. Then someone asked if On30 Bachmann equipment could be used for 55n3 and got diverted to that tangent.

Scale55 is the only scale that early three foot narrow gauge works easily. Being HO gauge the use of HO mechanisms and locomotives come into play.

Click here to go to the section on Pioneer Narrow Gauge.

Modelling Small Loggers and Others

HO locomotives translate to small loggers and plantation locos in 55n3 better than any other scale. Always knew there was a loco that would match the HO Bachmann Alco 2-6-0. A good match for the Godchaux #4 2-6-0 sugar plantation loco.

Others have been here

Ted Hawkin's pioneer 55n3 layout.
The late Dave Scott's 55n3 layout.
Steve Jones's 55n3 layout.
Herb Kephart built these Scale55 cars back in the Mid-50's.

Two foot in 5.5mm Scale

There has been modelling of 2 foot prototypes in 5.5mm/foot since 1963.

Here is Malcom Savage's model of Tasmania's North-East Dundas Tramway locomotive K1 - the first Beyer-Garratt.

Forums and Associations Discussing 5.5mm/ft

Click here to go to the main 5.5mm Association website.
Click here to go to the Narrow Gauge Railway Modelling Online site, they have a 5.5mm section.

What does only 10-15% scale difference mean?

A linear difference of 10-15% doesn't sound like much, right. Here is our rogues gallery of figures of major scales HO(3.5mm, 1/87), OO(4mm, 1/76), S(3/16",1/64), 55(5.5mm, 1/55), American O(1/4", 1/48). Notice the big difference in volume. That is our HO gauge track representing three foot track in Scale55 next to PSC On3 track. Big difference, more railroad in less space.

Why 55n3?

55n3 gives a modeler the ability to model both periods of THREE FOOT American narrow gauge in the same space as HO scale within a realizable budget. It is a format that EVERYONE can build in and AFFORD. There is enough available to accomplish this goal, more than any other scale.

When I first presented this idea in 2010 it was greeted with undue criticism. Now we are back.

Amazed at how much of the equipment talked about on the website is now unavailable, the hobby has become a world of RTR diesels.

Hope you join me in this endeavor.

Why Narrow Gauge? Click here and read about why there was narrow gauge in America in an 1876 treatise from Google Books. You can download this as a PDF.