16.2mm gauge - who uses this and why?

[Dan6470]

Hi,

 

I have just been looking at the NMRA web site and in the NMRA STANDARDS AND RECOMMENDED PRACTICES S-1.2 General Standards it mentions a 4mm gauge that I have not come across before, a 16.2mm gauge. See

 

http://www.nmra.org/...2%202009.07.pdf

 

From the above mentioned pdf file see note 5, quote "Principle among the options is the 16.2mm and 16.5mm gage OO scale".

 

 

So what is the 16.2mm gauge? Can anybody advise where this 16.2mm gauge is used? Has anybody used it and if so why? I mean, we're talking about 3/10ths of a millimetre.

 

Dan

[Mod6]

You might care to read through this topic http://www.rmweb.co.uk/forum/viewtopic.php?f=4&t=6685 on the old site from 2007. It is a subject that provoked 'strongly held views' and eventually the topic was locked. If anyone has anything new to say then go ahead (carefully) but we don't want a repeat of all that went before please.

 

There is also a lot more to be found if you Google "00-SF".

[bertiedog]

The NMRA list it because it exists, as does 4mm OO US standard, disregarded in the UK, and almost faded away in the States.

 

Put simply .........it tightens the pointwork to 16.2mm to prevent the wheel dropping into the frog gap. It's nick name was "click free running".

 

This is achieved anyway with the 16.5mm NMRA standards, and DOGA etc.,

 

Read through the complexities if you want, .....as they say "therein lies madness"...( no attack on 16.2 mm users!!!!!) the madness refers to the intestinal arguments around this subject.

 

Stephen.

[RedgateModels]

Dave Long of this parish produced a layout to this gauge too

[Horsetan]

Is this not a bit like O-gaugers going down to 31mm gauge?

 

 

[bertiedog]

Is this not a bit like O-gaugers going down to 31mm gauge?

 

 

 

Yes the same principles as the tight pointwork of the 16.2mm 4mm scale track. It allows a wider selection of wheels to pass through points than usual, without the "drop"(click free), but of course the better alternative is standard wheels for the gauge, and as there is a perfect system for 16.5mm, and O gauge, so why bother? (Don't answer this without reading the whole other posting, seriously, if this post expands it risks locking.....)

[bertiedog]

And just to annoy.......I custom adjust my points for strict NMRA HO in code 55 individually, as required after laying with gauges, to get the very best running possible, and often the gauge is reduced a few thou through the frog!!

 

I lay to gauge and then use a test vehicle to test the whole lot, shifting rails or check rails slightly, and filing away the frog point, chamfering the rails top, and smoothing the lot with a flat abrasive block.

 

It may need small tweaks to suit the exact frog angle etc, and I use a curved line through the frog in HO to gain the smoothest running possible, most locos don't click, (drop), at all.

 

Stephen.

[meple]

Hi,

 

I have just been looking at the NMRA web site and in the NMRA STANDARDS AND RECOMMENDED PRACTICES S-1.2 General Standards it mentions a 4mm gauge that I have not come across before, a 16.2mm gauge. See

 

http://www.nmra.org/...2%202009.07.pdf

 

From the above mentioned pdf file see note 5, quote "Principle among the options is the 16.2mm and 16.5mm gage OO scale".

 

 

So what is the 16.2mm gauge? Can anybody advise where this 16.2mm gauge is used? Has anybody used it and if so why? I mean, we're talking about 3/10ths of a millimetre.

 

Dan

 

Its principal rationale is to permit good quality running and 1mm flangway gaps (as per the fine scale std. of DOGA) for unaltered propriety rolling stock. i.e. no alteration to the BB.

 

If you adopt the DOGA fine scale standards but use 16.5mm gauge then you have to widen the BB to, I think, 14.8. The reduction in gauge to 16.2 enables the flange way to remain at the Fine scale dimension but the check gauge dimension is appropriate to the propriety BB dimension. The reduction in gauge is to ensure support to the wheel through the crossing nose. Plain track can remain, if you wish, at 16.5mm.

 

By the way it is normaly refered to as 00SF

[bertiedog]

Although it works well, and it is fully acceptable to users, why use a system to do the job that makers should have done, deliver goods that are workable to start with.

 

If I pay for an OO product I expect that, not to have to re- lay trackwork to suit some bad wheel manufacturers practices? They should deliver items made to standards, not some vague "it will do " regime, and then expect the poor bemused customer to alter his ways to suit the rubbish he is selling.

 

I fully know the intention is to allow a wider range to run well on the modified track, wonderful, but it is still curing a problem that should not exist in the first place.

 

It rates with adding stabilisers to bikes to stop people falling off, rather than showing them how to ride a bike.

 

Stephen.

[coachmann]

It's 16.5 gauge for poeple with dyslexia KO?

 

 

(Before bodyany cuts in, I'm a sifferer).

[meple]

It's 16.5 gauge for poeple with dyslexia KO?

 

 

(Before bodyany cuts in, I'm a sifferer).

 

 

No it's for people who want support for their wheel through the course of the crossing but do not want to alter the BB of coarse 00 standards that the manufacturers have adopted.

 

This was not a problem until manufacturers moved to use narrower wheel treads. In so doing the wheel lost support as it passed through the coarse 1.25mm flangeway. The only way to stop that is to narrow the flange way to 1 mm. However this means that the check gauge pulls the oposite check rail away from the opposite rail giving a flange gap there of 1.5mm. In order to reduce that gap you reduce the track gauge to 16.2mm which ensures support to the wheel.

 

The alternative is to open the BB to 14.8mm which gives the same effect. What you can't do is adopt 1mm flangways, fine scale check gauge and 14.5mm BB as your wheel will jam at the crossing.

[dave_long]

Its a very good gauge to work in if you ask me and as many who commentate on such gauges I have actually built a layout to this gauge. Click on my Pensnett link below. Trackwork looks realistic and has been mistaken for EM. Its original name and its origins are derived from EM and its original nickname contrary to other reports was EM-2 (ie EM gauge minus 2mm hence 16.2mm)

 

The main beneift was to avoid wheel drop in flangeways using rtr stock without adjustments to wheel alignments, whether or not there are other ways for this to be done for better or worse this is one way it can be achieved. This is done by using 1mm flangeways and narrowing the gauge further to 16.2mm to avoid having to change the wheel b2bs. Which is needed when using 1mm flangeways in both DOGA fine and EM.

 

Why this brings up such heated discussion is beyond me. I model mainly in P4 now but its a great gauge to start scratchbuilding in IMHO.

 

 

 

 

Please also see these links:

00-sf website

yahoo group

 

Were qute well supported now with gauges kept in stock.

 

Dave

[bertiedog]

It is a fine system, it works, it is a cure to an ill, but you are not addressing is why you buy stock that is badly made, badly engineered, and out of an acceptable standard, would you buy a four wheeled car with three wheels, and all lean out of the window to make it drivable?

 

Just because the wheels were narrowed to make them match modern standards means the track is wrong, so you pays your money and correct the track, or you insist the whole thing is brought to book and standardised to prevent this happening, as it never has in the States.

 

The drop that happens on Peco code 100 is down to the horrid legacy of poor standard that Peco have had to live with and have striven to provide decent points for for 50 years, to call them course is wrong, they cater for a problem, and do offer other points.

 

Narrower tyres do not stop US modellers, and such wheels run over code 100 Peco points quite adequately, slight drop, but if your using code 100 universal points you cannot expect absolutely prefect running. Smaller codes from Peco have no drop as long as the wheels are RP-25 profile.

 

Yes, the 16.2mm makes the tyre run without drop, but this advantage is a god send to the makers who have the pressure to improve wheels and points relaxed a bit.

 

To test this a bit I got out several RP-25 old type wheels, (the usual, not the newer narrow type), and ran 50 year old assorted HO Locos over a small stock of Peco code 100 points, none glitch, none dropped the wheels, all sailed through without any trouble.

 

So where's the problem? It s plainly not a narrow tyre problem, this simplifies it too much, and I do know the answer, it is the lack of the root radius on most UK produced wheels until recently.

This is the heart of the trouble, the UK non standard wheels rub the face of the flange against the rail side.

 

A wheel with the root radius does not allow the flange to touch the rail, the flange does not guide the loco. The US wheels have a root radius that does the work of guiding the wheel.

 

So when the gauge is tightened the wheels with no root radius are now still guided by the flange , but the edge of the tyre runs across the frog gap supported by the edge of the two rails.

 

This occurs naturally with RP-25 on 16.5 properly implemented without any adjustment of gauge.

 

I an not new to this problem, I worked on model wheel design, and making, both in the UK and the US, met and discussed this at length with Mr Pritchard of Peco, and with NMRA Officials, and with Linn Westcott of Model Railroader, during a visit to the UK.

 

I can assure you I also fully support anybody's right to do as they like on their layout, but the information each way must be fully put to the modeller, and some explanations, (not on here), of 16.2 display a lack of understanding of model railway engineering.

 

At best the 16.2mm track offers a sound solution to using assorted wheels, all types, with or without root tyres, but there is a penalty that ordinary users get from this, the makers stand back and still will not improve products.

 

The final point, I talked to an engineering designer from one major maker, mentioned wheels, and he did not know that wheels are coned or that the root radius was important.........it shook me very deeply that he was designing the models and knew nothing at all about wheel design. I asked him what guided the wheels through pointwork, and he replied the flange, and he really meant that........I give up ......

 

Stephen.

[bertiedog]

I should add for clarity I fully realise the need to narrow to 16.2 to get the wheels to work without adjustment has another effect, the tightening of the flangeway to 1mm which is what makes the track appearance so much better.

 

The Standard HO track and 16.5 used in the States does not have this visual advantage, but decent running is far more important to most people. 16.2 seeems to score highly here both appearance and running, but introduces a non standard gauge and points to cater for bad makers, you pays your money and takes your choice though.

 

Stephen.

[Ron Solly]

Stephen, your posts #13 & 14 - well said sir .

[Allegheny1600]

Hi all,

At a risk of sounding like a bit of a creep to 'bertiedog', (sorry Stephen!) but i'm so in agreement with him, i can only point to previous posts on the "back 2 back" topic, http://www.rmweb.co...._1entry134439

Once again, apologies for the rather harsh message of this post, i believe this is what it will take to REALLY improve things for us all.

Sincerely,

John E.

[bertiedog]

I certainly should say again this should not get seen as an attack on 16.2mm, or anybody on here!!!

 

Just being a devil's advocate about the actual problems behind the issue, the bad practices indulged in by the older wheel makers in the UK, whose legacy is still crippling the whole hobby.

 

16.2mm is a perfectly workable solution, but should never have been needed. if UK suppliers had got their act together.

 

IF Meta wheels standards had been standardised to match NMRA and Lines Bros and other UK makers had adopted the NMRA standards in the late 1950's, the whole model railway community would be running on the same tracks.

Fine scale OO would have developed, just as Proto 87 has in the States, but even those models would still run on standard 16.5mm track as well, and of course P4 could have developed as well.

 

The base line is we use 16.5mm, and it should be the very last dimension to have to fiddle with.

The appearance improvement wth SF 16.2 is a very tempting extra attraction, a lollipop added to the mix.

 

But in the end it is up to the builder, SF needs custom track, either scratch or modified, not easy for some modellers, especially as it attracts those who do not want to change or adjust the wheels.

 

Stephen.

[bertiedog]

In case anybody does not realise what the root curve is the picture may make it clear, the top shows real profile and the toy type so beloved of older makers in black, and the root is as X in the worse case, known as a Knife edged flange.

A wheel set like this will go through most points, with the right back to back, and can be guided through a 16.2 without any trace of drop, as the outer edge of the tyre runs on rail support at all times.

 

The lower shows RP 25 type (yes, a simplification, it varies and has different names), where, like the real thing, the tyre sits on the curve that goes from the cone to the flange, which does no work at all, ( within reason!!). In the real world the flange does work and touch etc, as the wheel rolls along.

 

But it guides the wheel into the point complex by use of the root curve and as the forces to turn in a point are felt the wheel rides on the curve, and drop is only possible by a tiny amount, as again the outer tyreedge runs on rail all the time. Although with RP 25 there seems a chance of drop , in real world it does not happen on decent track.

 

On Peco 100 there is a drop, NOT Pecos fault as they aim the size to allow everything to run, quite rightly. But they offer tight NMRA as an alternative. Peco have strived to cater for all despite all the toy derived standards foisted on modellers over the years.

 

What leads on to SF was the narrow tyre adopted slowly in the UK, that dropped more in commercial points than before, an improvement became a problem. The SF 16.2mm standard was offered as a cure, but the real cure should have been forty years ago, and Peco would never have had to make wide tolerance points.

[dave_long]

Thanks for your informative posts Stephen. I agree with you on 16.2mm should never have been needed. I share your shock at the wheel manufacturer and their apparent lack of real world engineering consideration for model wheels. I hope we've managed to show the OP the reasons for 16.2 00-sf and a good deal of info to go with it. A civil discussion what ever next.

 

 

 

 

 

[Mark C]

So...(deep breath)...if I'm going to build my own (C&L) track and turnouts and use current RTR Bachmann, Heljan and Hornby locos with rolling stock on Alan Gibson (or equivalent) wheelsets: what gauge do I go for to avoid the crossing wheel drop?

 

I did say take a deep breath...

[bertiedog]

So...(deep breath)...if I'm going to build my own (C&L) track and turnouts and use current RTR Bachmann, Heljan and Hornby locos with rolling stock on Alan Gibson (or equivalent) wheelsets: what gauge do I go for to avoid the crossing wheel drop?

 

I did say take a deep breath...

 

• Well, of course, if you do not adjust the wheels there is SF16.5mm 14.2BB..........and C&L parts are compatible, fully!!(gauges from the SF group). No drop, and fine appearance. Any wheels with flanges under 1mm should run.

• If you use modern Bachmann and Hornby, and adjust and change a few to RP25 type, then use 14.5mm.......possible drops could happen if not adjusted correctly, but you are building the track and it can be adjusted, but nowhere near the 14.2 figure. This track would also suit a collector who may want to run US and Euro stock as well, most would run just fine.

• If you use Gibson, DOGA finescale etc., more re-wheeling and adjustment, and you can use modern Hornby etc re-adjusted, then use 14.8mmm........no drop with most wheels accurately set.

• Go to Protofour........

Isn't life interesting for UK modellers, they don't get this choice, or entertainment in the States!!!!!!!!!!!!!!!!!!

[dave_long]

Hi Mark

 

Personally as I already have I'd choose 00-sf 16.2. But then I like to be different. I built my layout to prove the theory which I believe I did. If you wish to scratch build your track then without going to EM or P4 then SF will do the trick without altering the wheelsets although Heljan wheelsets are set slightly wider which does cause an issue with SF. 

 

Its a choice really you have to take on what you require from the hobby really including time and money in the equation as we could all say the gauge is better or worse without taking a breath really

 

hth

 

Dave

 

 

[dave_long]

• Well, of course, if you do not adjust the wheels there is SF16.5mm 14.2BB..........and C&L parts are compatible, fully!!(gauges from the SF group). No drop, and fine appearance. Any wheels with flanges under 1mm should run.

• If you use modern Bachmann and Hornby, and adjust and change a few to RP25 type, then use 14.5mm.......possible drops could happen if not adjusted correctly, but you are building the track and it can be adjusted, but nowhere near the 14.2 figure. This track would also suit a collector who may want to run US and Euro stock as well, most would run just fine.

• If you use Gibson, DOGA finescale etc., more re-wheeling and adjustment, and you can use modern Hornby etc re-adjusted, then use 14.8mmm........no drop with most wheels accurately set.

• Go to Protofour........

Isn't life interesting for UK modellers, they don't get this choice, or entertainment in the States!!!!!!!!!!!!!!!!!!

 

A bit of a freudian slip in there Stephen. But I fully concur so many things to choose from but hey we're British, doing things the easy way is certainly not our calling!

 

 

Dave

 

 

[Dan6470]

Wow, Thanks for all the comments. I've looked at a number of the links that have been provided and can see that there has been a lot of passion extolled by both camps. It wasn't my intention to cause any arguments, I'm relatively new to this hobby. Sure, as a kid I had a train set, still got it, but now I would like to build a MR and recognise that in trying to cater for my old locos and rolling stock on code 100 track I'm perhaps doing myself a disservice. I want my new MR to look good and run well, with a minimum of derailments and the likes. I fancy building my own pointwork but I'm not at all interested in building locos or rolling stock unless they're from a kit and even then I'm not altogether sure. EM trackwork looks very nice but of course if I built my MR to this gauge then I would have to adjust the wheels of every piece of rolling stock that I would want to run - I not sure that I really want to do that, I'll have to stick with OO but code 100 doesn't look nice. I want to achieve the look of EM without the difficulties involved in adjusting/replacing wheels. I also don't particularly want to have to adjust wheels for the B2B to run on finescale track whatever the gauge. Out of the box and onto the rails is what I'm after, is that possible?

 

Perhaps I haven't understood everything that has been written and will probably have to reread it several times over, it should be apparent that I'm a novice in this regard and I don't want to become involved in the politics of what the manufacturers have done/will do/should do, I just wants to play trains!

 

Once again, thanks for all your comments.

Dan

[James]

It's 16.5 gauge for poeple with dyslexia KO?

 

 

(Before bodyany cuts in, I'm a sifferer).

 

Ah, a fellow sifferer I see!