[TABLE] [TR] [TD]MM/Foot [/TD] [TD="width: 66"]Ratio[/TD] [TD="width: 76"]Name[/TD] [TD="width: 85"]Gauge[/TD] [TD="width: 66"]Scale[/TD] [/TR] [TR] [TD="width: 65"]1.87 mm[/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]N[/TD] [TD="width: 85"]9 mm[SUP]1[/SUP][/TD] [TD="width: 66"]N[/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]N[/TD] [TD="width: 85"]8.97 mm[SUP]2[/SUP][/TD] [TD="width: 66"]N[SUP]3[/SUP][/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]N6.5[/TD] [TD="width: 85"]6.5 mm[SUP]4[/SUP][/TD] [TD="width: 66"]N[/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Nc[SUP]5[/SUP][/TD] [TD="width: 85"]6.66[SUP]6[/SUP] [/TD] [TD="width: 66"]N[/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Ne[/TD] [TD="width: 85"]4.5 mm[SUP]7[/SUP][/TD] [TD="width: 66"]N[/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Nf[SUP]8[/SUP][/TD] [TD="width: 85"]3.8 mm[SUP]9[/SUP][/TD] [TD="width: 66"]N[/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Nm[SUP]10[/SUP][/TD] [TD="width: 85"]6.5 mm[SUP]11[/SUP][/TD] [TD="width: 66"]N[SUP]12[/SUP][/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Nn2[SUP]13[/SUP][/TD] [TD="width: 85"]4.5 mm[SUP]14[/SUP][/TD] [TD="width: 66"]N[/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Nn3[SUP]15[/SUP][/TD] [TD="width: 85"]6.5 mm[SUP]16[/SUP][/TD] [TD="width: 66"]N[SUP]17[/SUP][/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Nj[/TD] [TD="width: 85"]6.5 mm[/TD] [TD="width: 66"]N[SUP]18[/SUP][/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]Ni[SUP]19[/SUP][/TD] [TD="width: 85"][/TD] [TD="width: 66"]N[/TD] [/TR] [TR] [TD="width: 65"][/TD] [TD="width: 66"]1:160[/TD] [TD="width: 76"]N18[SUP]20[/SUP][/TD] [TD="width: 85"]2.85 mm[/TD] [TD="width: 66"]N[/TD] [/TR] [/TABLE] 1 4 feet 8 7/10 inches / 56.692 inches / 1439.6768 mm @ 1:1 2 4 feet 8 ½inches / 56.503 inches / 1435.1762 mm @ 1:1 3 NMRA specification 4 1 meter / 3 feet 4 9/10 inches / 40.944 inches / 1039.9776 mm @ 1:1 5 Cape Gauge 6 3 feet 6 inches / 42 inches / 1066.8 mm @ 1:1 7 2 feet 4 inches / 28.346 inches / 719.9884 mm @ 1:1 8 600 mm Feldbahn 9 2 feet / 23.937 inches / 607.9998 mm @ 1:1 10 Meter Gauge 11 1 meter / 3 feet 4 9/10 inches / 40.944 inches / 1039.9776 mm @ 1:1 12 NMRA specification 13 2 Foot Gauge 14 2 feet 4 inches / 28.346 inches / 719.9884 mm @ 1:1 15 3 Foot Gauge 16 1 meter / 3 feet 4 9/10 inches / 40.944 inches / 1039.9776 mm @ 1:1 17 Australian Scale 18 Japanese Scale 19 Industrial Scale 20 18 inch Gauge I just realized I haven't seen any references to Nb gauge, where "b" is a broad gauge: Irish, Indian, Russia, etc.
What is the Australian Scale (17)? There is no 3' gauge in Australia to my knowledge, unless there was some obscure industrial railway somewhere. Our most common narrow gauge is 3'6", the so called cape gauge, to which Z gauge track is actually closer than it is to 3' gauge. I've never heard the Nc label, I've always called it Nn3 1/2. Nj by the way AFIK uses the Japanese N scale of 1:150 rather than 1:160 so that commercially available models can be used.
When I first started collecting Japanese prototype N scale models, I was a bit confused. Most Japanese trains are 1:150, the Shinkansen are 1:160 and then there's that odd H10 By Kato that's 1:140. I know the reasons for the 1:150/1:160 differences, but I still haven't figured out the 1:140.
I've always seen N commonly referred to as round numbered 9mm. Have never before seen it broken down in such tiny increments.
9mm gauge in TT scale (1:120 ) works out to 42.52" or almost exactly like the 3'6" gauge used in Japan. The bigger the scale (1:140 vs. 1:150), the more like the prototype but it also takes up more space in small Japanese homes. I'm guessing the 1:140 scale just didn't catch on. It looks to be a case of exactly true to scale (8.97mm) vs. convenience (9mm). 56.5" x 25.4mm = 1435.1mm. 1435.1/160 = 8.97mm. (My HS science teacher would be proud of me right now.) Personally, I'm not going to worry about 3/100 of a millimeter. Andy Tetsu Uma
I think the odd larger than 1:150 scales used by Kato and others for their steam locos were to get the large motors in use at the time to fit rather than an attempt to start up a new scale.
So, a brief history of British scales and gauges (Often defined as mm/ft) O Gauge; 7mm/ft: Was the "standard" for a while, but it's rather large. This scale works out to be 1:43, not the 1:48 used in North America In search of a smaller scale, HO was tried. IE half of O or 3.5mm/ft. The track gauge is 16.5mm. This works fine in theory except that British trains are very small. The rail lines were all built to a small loading gauge and it's too expensive to change it. The reason this matters is that when HO was first developed in the 1920s there weren't any electric motors small enough to fit British models. Someone then came up with the idea of increasing the scale slightly but still using 16.5mm gauge track as this was now available commercially from Germany. Thus was born OO gauge. 4mm/ft on 16.5mm track. Unfortunately, having the track 8 scale inches too narrow is noticeable. In the 1950s a group of modelers decided to rectify the problem by re-gauging everything to 18mm. This is known as EM gauge from Eighteen Millimeters. This is much closer to true scale but still slightly under gauge. In the late '80s or early '90s another group established P4 at 18.83mm. This is the correct gauge. However, the P4 standards are based off scaled down prototypical dimensions and can be quite fiddly to get to work reliably. Both EM and P4 require hand laid track and re-gauging all rolling stock. For Futher confusion, OO has been sold in the past in North America with North American prototypes operating at a gauge of 19mm. I believe it is still 4mm/ft or 1:76. The same thing happened in N scale as well. There weren't small enough motors available so the models were enlarged to 1:148. The finescale option is 2mm/ft (1:152) with a track gauge of 9.42mm
That's what I ment about OO. They couldn't fit the motors of the time ('1920s/1930s) into the models so the changed the scale to 1:76.2 and ran it on 16.5mm track.
Australian N wobbled between 2mm (1:152) and 1:160 in the 70s before settling on 1:160. There were a couple of 2mm scale kits. To my mind this was a poor choice as we have some very small locos and an extra mm or so under diesel hoods would have been handy space to play with. A typical US C-C EMD loco truck at the larger scale would have scaled out better too as many modern Australian EMDs have 6'3"+6'3" rather than 6'9 1/2" + 6'9' 1/2" trucks. It also means Australian N is stuck between the need to use 1:148 spoked wheels from the UK for older British inspired wagons and smaller ones for modern wagons, which can look a bit odd. Australia had some 3' gauge, albeit minimal, and yes, mainly industrial. Some was even electrified, at a tin mine in Western Tasmania and a coal mine in Victoria. Ben
I do not think that was the major reason. The more difficult ones are to do with steam loco splashers over English steam loco wheels, the room needed for complicated valve gear, the fact English trains run through high platforms, and the curves train set models are expected to go around. Motors got smaller in time, but the other factors continued to present a problem and still do. The whole story can be found in postings by 'bertiedog' on http://www.rmweb.co.uk/community/index.php?/topic/5780-specifying-scale-gauge/page-3 Ben
Following up on my original post, here are the track sizes for N Scale for various broad gauge tracks. [TABLE] [TR] [TD]Track size [/TD] [TD]1:1 Gauge[/TD] [/TR] [TR] [TD="width: 186"]9 mm[SUP]1[/SUP][/TD] [TD="width: 257"]Standard[SUP]2[/SUP][/TD] [/TR] [TR] [TD="width: 186"]18.75 mm[/TD] [TD="width: 257"]Breitspurbahn[SUP]3[/SUP][/TD] [/TR] [TR] [TD="width: 186"]13.38 mm[/TD] [TD="width: 257"]Brunei[SUP]4[/SUP][/TD] [/TR] [TR] [TD="width: 186"]10.47 mm[/TD] [TD="width: 257"]Indian[SUP]5[/SUP][/TD] [/TR] [TR] [TD="width: 186"]10.44 mm[/TD] [TD="width: 257"]Iberian[SUP]6[/SUP][/TD] [/TR] [TR] [TD="width: 186"]10.00 mm[/TD] [TD="width: 257"]Irish[SUP]7[/SUP][/TD] [/TR] [TR] [TD="width: 186"]9.52 mm[/TD] [TD="width: 257"]Russian[SUP]8[/SUP][/TD] [/TR] [TR] [TD="width: 186"]9.50 mm[/TD] [TD="width: 257"]Russian[SUP]9[/SUP][/TD] [/TR] [/TABLE] 1 4 feet 8 7/10 inches / 56.692 inches / 1439.6768 mm @ 1:1 2 4 feet 8 1/2 inches. 3 3 000 mm 4 7 feet 0 1/4 inches. 5 5 feet 6 inches. 6 5 feet 5 2/3 inches. 7 5 feet 5 2/3 inches. 8 5 feet 0 inches. 9 4 feet 11 5/6 inches. Does anybody model broad gauge in N Scale?
