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Discussion Starter · #1 ·
I have always modelled in OO gauge although always unhappy about the scale gauge discrepancy. (I know all about the historical reasons for this.) I realise that I could try EM or P4 if I had the patience and skill but I was recently dreaming of the possiblity of one day moving to a larger scale.

Then I read that O gauge is 7mm to the foot (why the mix of metric and imperial?) on 32mm gauge. This corresponds to almost 4ft 7in so is much more accurate than OO. By the way, since HO is supposed to be half O gauge I expected to find that O gauge was 33mm. Why isn't it?

The next thing I read was that gauge 1 (why not 1 gauge?) is 10mm to the foot with 45mm gauge. That corresponds to exactly 4ft 6in so is not even as accurate as O gauge or even EM which corresponds to just over 4ft 6.5in.

Why is this? One would have thought that with that sort of size you could have had a perfectly accurate gauge/scale combination. It means that even if I can afford it I won't be moving to that scale but might, just might, one day try O gauge.

Cheers, Robert.
 

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Unfortunately a perfectly accurate scale/gauge combination means dead scale clearances , working tolerances etc etc. Try scaling down prototype clearances to 1/43rd of the real value and you'll be in trouble, fast.....

A degree of compromise is necessary on practical grounds unless you are a very skilled precision craftsman

I think gauge 1 has used 2 different scales with 45mm gauge and there are adherents of each....

It's always been "so many mil to the foot", as a convenient way of resizing dimensions , tthough there are a few cases where the "so many" is imperial. For example 1/72 scale for plastic aircraft kits started as 1/6" = 1 foot. But measuring /calculating in 1/6ths of an inch is a lot less convenient than counting off mm
 

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QUOTE (Robert Stokes @ 19 Jun 2008, 17:59) <{POST_SNAPBACK}>One would have thought that with that sort of size (gauge 1) you could have had a perfectly accurate gauge/scale combination. It means that even if I can afford it I won't be moving to that scale but might, just might, one day try O gauge.
There was no grand plan when the real railway started. George Stephenson and the various parties associated with him settled on what we now know as standard gauge, but it was not apparently obvious to all the other groups who started railway enterprises of their own in the UK, that using the same gauge would facilitate a national system. The Brunel broad gauge is the best known, but there were also lines built a few inches larger or smaller than standard gauge. But in time 'the penny dropped' and use of a single gauge was standardised.

There was no grand plan when making models of the railway started. The various parties involved used whatever scale and gauge they liked, and it took years for a consensus to emerge on scale and gauge combinations. There were strong opinions about how to achieve good looking working models, and many argued that using slightly narrower track than true scale was advantageous, not least to provide more working space for overscale mechanical parts as mentioned in Ravenser's post. One of the exponents of this view was Henry Greenly, and a good example of his legacy is the Romney Hythe and Dymchurch Railway, sometimes referred to as the world's largest model railway. It uses roughly 1/4 scale track (15" gauge), with locomotives built to 1/3 scale.

But that's all history. For an almost exact scale/gauge combination that is extremely well supported commercially, HO takes a lot of beating.
 

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QUOTE (34C @ 21 Jun 2008, 23:13) <{POST_SNAPBACK}>But that's all history. For an almost exact scale/gauge combination that is extremely well supported commercially, HO takes a lot of beating.
It certainly does, but even with HO there are quite a few slight variants (some early Fleischmann for example.)
 

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Discussion Starter · #6 ·
Ravenser. You say that the difficulty is scaling down clearances etc. My point was that if P4 can do it in 4mm scale then it should be very much easier to do it in 10mm scale. There still remains my question as to why gauge 1 is LESS accurate than O gauge.
 

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QUOTE (Robert Stokes @ 20 Jun 2008, 00:59) <{POST_SNAPBACK}>I have always modelled in OO gauge although always unhappy about the scale gauge discrepancy. (I know all about the historical reasons for this.) I realise that I could try EM or P4 if I had the patience and skill but I was recently dreaming of the possiblity of one day moving to a larger scale.

Then I read that O gauge is 7mm to the foot (why the mix of metric and imperial?) on 32mm gauge. This corresponds to almost 4ft 7in so is much more accurate than OO. By the way, since HO is supposed to be half O gauge I expected to find that O gauge was 33mm. Why isn't it?

The next thing I read was that gauge 1 (why not 1 gauge?) is 10mm to the foot with 45mm gauge. That corresponds to exactly 4ft 6in so is not even as accurate as O gauge or even EM which corresponds to just over 4ft 6.5in.

Why is this? One would have thought that with that sort of size you could have had a perfectly accurate gauge/scale combination. It means that even if I can afford it I won't be moving to that scale but might, just might, one day try O gauge.

Cheers, Robert.

***Most of the original gauges were never created to be overly accurate - they were arbitrary choices by tinplate Mfrs, and its the later emergence of "scale modellers" that led them towards greater accuracy. Additionally, you have to look across the globe to see the twists and turns towards standardisation for production and their compromises.

OO is a good example: Actually outside UK it was originally supposed to be 3/4" gauge and the US actually created a standard with 3/4~19mm gauge which many modellers adopted - this was overtaken in the immediate post war period and died, although there are still some superb US layouts to this gauge.

Gauge 1 is another - G scale, US Gauge i and EU gauge i are different - the EU ratio is pretty close to scale but US has the same sort of gross error as English OO...

Given the constant "Gauge wars" in UK, It amused me to read THIS on the US Aristocraft site as an excuse for geting it wrong... talk about selectively ignoring reality of living in a world of their own!!

"The English commonly use OO scale. OO scale is slightly larger then H.O. but still runs on HO gauge track.

Hornby and Bachmann Branchline trains produce OO scale and have 98% of the English market.

Not a word is said about the difference between scale vs. gauge and these two companies make amongst the most scale models in the world.

The discussion of the gauge in relation to the scale is a non-event as it is here with 1/29th. "

As to O scale - its only 7mm scale in places, the most prolific modelling in O is in 1/4" to the foot which is 1:48. Ignoring the classic tinplate stuff from anywhere there are actually at least SEVEN sets of "scale and semi scale" track standards for O scale - again, a couple from across the world but at least 4 of them are fighting among themselves in the UK - just like with 4mm scale.... nothing ever changes :)

Stick with HO if the compromises bother - its close enough and if you also make the odd modification to those things that really grate against reality (says he whispering the words cr**py inaccurate track and "flanges") then it becomes a nice easy way to acurate modelling.

Richard
DCCconcepts
 

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Discussion Starter · #8 ·
Thank you Richard for another very informative reply.

I would gladly model in HO if there was easy access to British outline in this scale. I know that it is most unlikely to happen, but if a manufacturer started making British HO I'd spend large amounts on it straight away. (I know that Lima tried it in the 70's but it was very limited in extent and somewhat basic.)

The reason that I'm keen on British HO is this; consider what happens to someone like me who wants a more accurate scale/gauge combination. There are basically two choices if you want to stay at about the same scale - change to EM/P4 or change to HO.

The former means ripping up and replacing all the track which would take a great deal of time and expense. The track could be sold if in not too bad condition but would only fetch a small fraction of its original price.

The second alternative of changing the stock could be done one piece at a time with no reconstruction of track. O.K. it would look a bit ridiculous for a while but only if you ran things side by side. What's more the old stock could be sold on Ebay usually at well over half its original price (that is if anyone would buy it with HO available).

British HO, the holy grail of many modellers. Cheers, Robert.
 

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3rd option is to invest in a dremel cutting tool, and slice all the 16.5mm track down the middle,spread out a bit, and get some new wheels?.


why not flog the lot, and start over in a new scale altogether?

after all, as one gets older, one's eyesight diminishes....
 

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QUOTE (Robert Stokes @ 22 Jun 2008, 16:40) <{POST_SNAPBACK}>British HO, the holy grail of many modellers. Cheers, Robert.
There are actually quite a few UK outline modellers in HO, including the intrepid & slightly mad (in the nicest possible way) BRITHO hailing from these very forums.
 

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On a slightly madder approach, I collect both HO and OO scale and the problems arise when you run a HO train through OO points, they usually derail.

In collecting these, I will eventually move from the collecting drawers (workshop drawers I tell myself) to laying out a model layout where I will mix the different guages in a fantasy layout. I am mostly intetested in setting up dioramas and authenticity is not top of my list (but playability is) . I am also collecting some HO track.

Not being a purist (although I admire the layouts of those of you who are), these sorts of inconsistencies don't bother me.

On with the fun
 
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