Minimum radius for industrial sidings in 00-SF

[Tiptonian]

I have to confess I "blanked out" of this thread a couple of pages ago. Even though I realize it is to make a point, talk of main line locos and "scale" curves is off-topic. I imagine poor old DavidBird wishes he'd never started the thread and has taken up baking cakes instead.

 

Lets have a little reminder of what this topic is supposed to be about.

 

Look at this from 35.00 mins.

 

[trustytrev]

Hello,

        I think I feel some confusion arising from this.

 

Code 110, Code 88, Code 72, P4, P:87.

 

I always thought Code 110, Code 88, Code 72 along with Peco code 100 and 75 referred to the rail height. As to P4, P:87. I thought they referred to a modelling standard http://en.wikipedia.org/wiki/Protofour. There seems to be large amounts of obfuscation combined with FUD in posts attacking UK OO and OO-SF in general. Is there a point being made ? I would think the smallest radius possible would rely on ones personal requirements along with the vehicles  involved on the layout. I would suggest that can only be ascertained by experimentation/trial and error in each individual case. Minimum limits can be espoused all day long in theory but real practical exceptions are nearly all ways found. As far as I am aware when railway vehicles in Victorian times could not negotiate the required radius of track they introduced turntables, horses, and capstans but only when something could not be squeezed round the required radius.

trustytrev.

[Grovenor]

Posted Today, 14:49

Hello,

I think I feel some confusion arising from this.

I always thought Code 110, Code 88, Code 72 along with Peco code 100 and 75 referred to the rail height.

Unfortunately, in this case you thought wrong, the use of "code" is a feature of the NMRA standards and recommended practices which has carried through into UK/Europe to some degree, it is used to denote a dimension in thousandths of an inch for both rail height as in the Peco examples and for wheel tyre width as in the code 110, 88 and 72 references.

Regards

Keith

[Andy Reichert]

Hello,

        I think I feel some confusion arising from this.

 

I always thought Code 110, Code 88, Code 72 along with Peco code 100 and 75 referred to the rail height. As to P4, P:87. I thought they referred to a modelling standard http://en.wikipedia.org/wiki/Protofour. There seems to be large amounts of obfuscation combined with FUD in posts attacking UK OO and OO-SF in general. Is there a point being made ? I would think the smallest radius possible would rely on ones personal requirements along with the vehicles  involved on the layout. I would suggest that can only be ascertained by experimentation/trial and error in each individual case. Minimum limits can be espoused all day long in theory but real practical exceptions are nearly all ways found. As far as I am aware when railway vehicles in Victorian times could not negotiate the required radius of track they introduced turntables, horses, and capstans but only when something could not be squeezed round the required radius.

trustytrev.

 

It's what people don't know, but want to believe instead, that has driven this thread into almost 200 posts away from the continually overlooked, one simple truthful answer, that 16.2 mm gauge is not necessarily going to work as reliably for tighter radius industrial sidings as sticking to 16.5 mm gauge. Because fundamentally and indisputably, narrowing the gauge by 0.3 mm increases the usable minimum radius considerably. Even Terry Flynn accepts that.

 

"Code" is a mostly Westernized Model Standards shortcut way of saying wheel width or rail height in 0.001" units. So code 70 rail is 0.070" in height, while code 72 wheels are 0.072" wide overall. (and the RP 25 wheel profile is usually implied when describing wheels by "code").

 

What keeps coming up, is that my occasionally referring to the typical EM standard wheels as code 88 or near to it, is somehow being interpreted some how as a nasty foreigners HO input designation with the result that the British Empire Restoration Misplaced Patriotism Dept, trots out another 10 or so even more confused and confusing posts.

 

16.5 mm is 16.5 mm no matter where in the World it is measured.

 

Andy

[mightbe]

Well EM doesn't have "standard" wheels. Any modern RTR wheel will also work on EM and that's what people usually end up doing--spacing out the wheels to run on 18.2 mm gauge track. Code 88 wheels are merely the finer wheels that are used for kits of EITHER OO or EM gauge. They won't run smoothly and without wheel drop on OO-BF. 

 

This is why there is an OO-SF in the first place.

[Ravenser]

EM does have standard wheels. The 1979 EMGS standard lays down a wheel profile which is what Gibson and Ultrascale work to. NMRA RP25/88 is vey closely compatible 

 

Anyone pulling out RTR RP25/110 wheels for EM is bodging, not working to EM standards. And most stock in EM is kit built , not RTR

 

The traditional wheel for kit building in OO is the Romford wheel, which is not RP25/88. It claims to be RP25/100 , which is not on any NMRA data sheet, and Markits have in the past claimed that they got the data from a table printed in a US modelling magazine in the early 1960s.  (I am personally a little sceptical that Romfords are actually any form of RP25 - they may still be the old BRMSB OO wheel) 

 

This is more deliberate misstatement and obfuscation by an advocate of OO-SF to hide the basic salient facts , blur key differences, and create confusion and chaos.

 

And boy do they seem to hate proper consistent publicly available standards.......

[mightbe]

You have just confirmed the lack of a standard, if only "most" use the official standard. The only gauge that seems to have an inflexible standard is P4.

[martin_wynne]

It's what people don't know, but want to believe instead, that has driven this thread into almost 200 posts away from the continually overlooked, one simple truthful answer, that 16.2 mm gauge is not necessarily going to work as reliably for tighter radius industrial sidings as sticking to 16.5 mm gauge.

 

Hi Andy,

 

But no-one is suggesting using 16.2mm gauge for sharp industrial sidings. At such radii gauge-widening is used to bring the gauge back out to 16.5mm. Which as you keep telling us, works perfectly. A 3-point 00-SF gauge tool is available from C&L which automatically widens the gauge on sharp curves.

 

The crossing flangeway (but not the check rail gap) remains at 1.0mm to provide proper support for kit wheels. 

 

Martin.

[Andy Reichert]

Hi Andy,

 

But no-one is suggesting using 16.2mm gauge for sharp industrial sidings. At such radii gauge-widening is used to bring the gauge back out to 16.5mm. Which as you keep telling us, works perfectly. A 3-point 00-SF gauge tool is available from C&L which automatically widens the gauge on sharp curves.

 

The crossing flangeway (but not the check rail gap) remains at 1.0mm to provide proper support for kit wheels. 

 

Martin.

 

Errrr. . . .Actually that's exactly what's implied in the title of this topic.

 

Secondly, there are pages and pages of comments all over the 16.2 mm gauge topics, saying that the one KEY definition and purpose and benefit of 16.2 mm gauge, is to have that narrowed gauge along with a 1mm crossing flange way always at crossings, even if it is gauge "widened" at other curved places, or for the convenience of using some RTR flex track, etc. But If you need to widen the gauge at crossings for tight radii too, you aren't talking about a 16.2 mm gauge system anymore at all .

 

And cosmetically the check rail flange way at those locations is going to be as wide or wider than it would be for normal 00.

 

Andy

[martin_wynne]

Errrr. . . .Actually that's exactly what's implied in the title of this topic.

 

Not for the first time I don't understand a word of what you are saying. The title of this topic is about using 00-SF for industrial sidings. The definition of 00-SF means using 1.0mm for the crossing flangeways and a check gauge of 15.2mm. The actual track gauge in the running rails varies with the radius. Please refer to note C below.

 

I can't believe I have to post these notes yet again on RMweb, but here we go:

 

A is the check gauge. It is the most critical dimension in pointwork. If this dimension is too small, wheels running from left to right can hit the nose of the vee and very likely derail, or at least bump. If this dimension is too large, the wheel backs will bind or jam on the check rail. To make sure it's correct, the check rail is set using check gauge tools. For 00-SF and 00-BF this dimension should be 15.2mm. You can use the same check gauge tools for both these standards (they are both running the same wheels).

 

B is the crossing flangeway gap. It's also important. If this dimension is too small, the wheel backs will bind or jam on the wing rail. If this dimension is too large, the gap in front of the nose of the vee will be too wide, and the wheels may drop into it with a bump. This gap is set using a small piece of metal shim called a crossing flangeway gauge shim. For 00-SF it should be 1.0mm thick. For 00-BF it should be 1.3mm thick.

 

C is the track gauge. It shouldn't be less than the specified dimension, but it can be wider. It is often widened on sharply curved track to ease the running of long-wheelbase vehicles. The track gauge is normally set using roller gauge tools, or alternatively using a 3-point gauge tool, which automatically widens the track gauge on sharp curves. For 00-SF this dimension shouldn't be less than 16.2mm. For 00-BF it is normally 16.5mm.

 

D is the check rail gap. The width of this gap doesn't matter a damn, providing it is wider than the wheel flanges. It's whatever you end up with after setting A and C correctly. But where the check rail is combined with a wing rail in complex formations (i.e. in parallel-wing V-crossings) it must be the same as B.

 

regards,

 

Martin.

[hayfield]

Andy

 

Sometimes I do wonder which planet you are on, you are also showing a complete misunderstanding of how some of us who model in 4mm scale are using 00sf, Using your reasoning either EM of P4 would not be EM & P4 gauge when they use gauge widening, that's not the case

 

It is quite common for those who build turnouts to 00sf gauge couple their turnouts and crossings to 00 gauge flexi track. Gordon S has a thread (thankfully you seem not to have found it) where he uses 00sf through the crossings but gauge widens to couple it up to 00 gauge flexi track, this is the norm (and perhaps answers the OP's initial question

 

Now in both EM and P4 gauges it is perfectly acceptable to gauge widen the track when the radius goes below a certain radius, logically then it's OK for 00sf to do likewise

 

I have just been repairing some Peco points for my club, these 00 gauge products are worlds apart from the turnouts we are building in 4 mm scale. We are now so far off topic its embarrassing, rather than push your own philosophy can you at least once see if you could post something which may add a constructive reply to the OP's initial question

[Junctionmad]

Errrr. . . .Actually that's exactly what's implied in the title of this topic.

 

Secondly, there are pages and pages of comments all over the 16.2 mm gauge topics, saying that the one KEY definition and purpose and benefit of 16.2 mm gauge, is to have that narrowed gauge along with a 1mm crossing flange way always at crossings, even if it is gauge "widened" at other curved places, or for the convenience of using some RTR flex track, etc. But If you need to widen the gauge at crossings for tight radii too, you aren't talking about a 16.2 mm gauge system anymore at all .

 

And cosmetically the check rail flange way at those locations is going to be as wide or wider than it would be for normal 00.

 

Andy

Andy, having read everything on RMweb you have said in relation to 00-SF and 00 16.5 etc, I just cant see what point you are making, you seem to be continuously on a mission to either run down or denigrate 00-SF , confuse people by mixing H0 and 00 , misstate " standards" and make strange claims, none of which help the process here

 

00-SF isn't in essence a 16.2mm track gauge , as in a whole layout etc.  it a set of modifications of turnout dimensions , that offers a set of improvements under certain circumstances.  As a builder of copper clad turnouts, I can appreciate the improved flange way dimensions, etc.  

 

 

to suggest that simply because we might gauge widen the 16.2mm gauge at the flange way point , on sharp curves so that " hey presto " 00-SF disappears is disingenuous , even for you .

 

stating things like "And cosmetically the check rail flange way at those locations is going to be as wide or wider than it would be for normal 00." again is obfuscation, 00-SF in essence does not set a check rail gap dimension, the check rail gap falls out of the 15.2mm gauge plus whatever gauge widening is going on as a result of the radius through the turnout  ( if ones chooses to gauge widen at all) .  I mean equally in 16.5mm in very tight curves , you will be forced to gauge widen as well, so does suddenly a gauge of 16.55mm invalidate 00 or even H0 , seriously 

 

I remain bewildered at your motives 

[Junctionmad]

 

 

I can't believe I have to post these notes yet again on RMweb, but here we go : 

isn't the first step " beatification " , ( excuse the limited religious knowledge ) , so you must be well on your way at this stage Martin.

[Arthur]

Not for the first time I don't understand a word of what you are saying.

 

 

 

Seriously, I'm relieved to know that I'm not the only one.

 

 

Andy, Sometimes I do wonder which planet you are on, you are also showing a complete misunderstanding of how some of us who model in 4mm scale are using 00sf,

 

 

 

Which is why some of these postings are so irrelevant and frustrating.

 

 

 

I remain bewildered at your motives

 

In a nutshell, my own thoughts exactly.

[highpeak]

Martin, I think that post 185 ought to be pinned and locked. Most 00-SF threads end up like a untended garden, the flowers are there somewhere but they're choked by weeds.

 

Ravenser, I just bought two or three Parkside wagons, the wheels included with them were Gibson's no doubt because they are now cheaper than Markits wheels.

[Ravenser]

Parkside have always stated that they will exchange Romfords for Gibsons on request. I assume that the kits you bought had been prepared on that basis.

 

If however Parkside have switched wheels as a general policy to save a few pence, then that is bad news for the OO modeller, because Gibson wheels are not suitable for the vast majority of OO layouts (ie anything using either Peco or OO Intermediate/ BSMSB OO. I suspect that probably accounts for 98% of all OO layouts, albeit not all of them will be willing to build a wagon). Parkside would have made a change that will result in the finished wagon being significantly more likely to derail on nearly all layouts (and Gibson plastic centred wheels are more likely to wobble, shed tyres and the like than metal wheels) 

 

At that point I will have to do what I had to do when I bought a Ratio kit a few years ago and found that Peco (of all people!) had supplied Gibsons - pull out the wheels to EM using the EM back to back gauge, stick them in the EM wheel compartment in the relevant box, and fit replacement Hornby wheels from stock.

 

If it really comes to that, then I'd rather Parkside did what Cambrian do - leave the wheels out so I don't pay for something unsuitable and let me source my own wheels to standard   

 

Wheel and track standards are not really about prettification. They are about rigourous engineering compatibility of the various components to ensure maximum reliability of running.

 

(For the same reason I'd strongly advise against anyone in OO replacing the wheels on RTR locos with Ultrascales. You're simply spending time and money making your loco less reliable on the track) 

[AndyID]

that is bad news for the OO modeller, because Gibson wheels are not suitable for the vast majority of OO layouts

That may be, but we are not talking about the vast majority of 00 layouts in this thread. Will the Gibson wheels run smoothly through 00-SF turnouts?

[Ravenser]

That may be, but we are not talking about the vast majority of 00 layouts in this thread. Will the Gibson wheels run smoothly through 00-SF turnouts?

 

 

If it were true that Parkside have switched from Romfords to Gibsons, it would be bad news for 95%+ of their OO market

[DavidH]

That may be, but we are not talking about the vast majority of 00 layouts in this thread. Will the Gibson wheels run smoothly through 00-SF turnouts?

 

I'm not sure if I dare say it, but as a relative track-building novice, I've just built (and fettled and laid) four copperclad points built to 00-SF ... yes, only through the crossing, as I use SMP flexitrack elsewhere ... and I have been testing the track with a Hornby rebuilt Bulleid (original wheels except Gibsons on front bogie); a Bachmann C class as built; a Romford-fitted SE Finecast M7; one RTR van; one kitbuilt bogie wagon (Gibson wheels).

 

All stock works (so far) very well  through the points. No bumping, no lurching, and no derailments (post-fettling and testing anyway). I still have to lay more track to do a proper test mind you, but so far, Gibsons work for me as well as the others.

 

The radius isn't very minimum though - 54" apart from one built in situ that is approx 36".

 

But this isn't very scientific - it's just my experience.

 

David

[Ravenser]

You have just confirmed the lack of a standard, if only "most" use the official standard. The only gauge that seems to have an inflexible standard is P4.

 

This is a conceptual confusion . The existance of a published standard is not affected by adherence to the standard by less than 100% of potential users 

 

Those putting out RTR wheels are not working to EM gauge standards.

 

To see the point , consider the situation in DCC . Hornby's implementation of the XpressNet control bus standards is rather  "approximate". This doesn't mean the XpressNet standard and the data protocols it lays down don't exist. It means Hornby DCC equipment doesn't talk very well to other XpressNet equipment, resulting in seriously limited functionality. Equally the very messy signal output from Hornby's Select is never going to get certified as meeting the NMRA DCC standards - that doesn't mean the NMRA standards don't exist (though I'm sure you'll find pplenty of Select users who'll tell you the system works fine...)

 

By the way there isn't 100% adherence to the P4 standards - you've obviously missed the advocacy of using EM wheels for P4 in MRJ by Martin Goodall and others "It works fine and improves P4" - and the existance of Ray Hammond's S4 standard. The existance of Ray Hammond and Martin Goodall does not compromise the continued existance of the P4 standards 

[Ravenser]

I suspect he is not alone. And C&L still have 190 DOGA-Fine roller gauge sets in stock, still don't explain that they are for DOGA-Fine only, and still include them in turnout kits. Brian Lewis started this nonsense at C&L, which would have been fine if it had ever been properly explained to unsuspecting buyers.

 

Martin.

 

I agree that it would be a great deal better for everyone if wheel and track products were clearly labelled and everyone was told what standard they were for.  The "silence and fog" approach is not helpful

 

But C+L's roller gauges predate both Brian Lewis and the DOGA Fine standard. They've sold roller gauges to that standard as long as they've sold OO roller gauges. At least a decade before the DOGA Fine standard was first issued

 

At least the publication of datasheets covering that standard has allowed everyone to work out what is being sold - and what wheels it is compatible with.

 

The fact that their pre-assembled crossings aren't suitable for the vast majority of OO modellers is another case of "flying under the radar"

[hayfield]

I'm not sure if I dare say it, but as a relative track-building novice, I've just built (and fettled and laid) four copperclad points built to 00-SF ... yes, only through the crossing, as I use SMP flexitrack elsewhere ... and I have been testing the track with a Hornby rebuilt Bulleid (original wheels except Gibsons on front bogie); a Bachmann C class as built; a Romford-fitted SE Finecast M7; one RTR van; one kitbuilt bogie wagon (Gibson wheels).

 

All stock works (so far) very well  through the points. No bumping, no lurching, and no derailments (post-fettling and testing anyway). I still have to lay more track to do a proper test mind you, but so far, Gibsons work for me as well as the others.

 

The radius isn't very minimum though - 54" apart from one built in situ that is approx 36".

 

But this isn't very scientific - it's just my experience.

 

David

 

 

It is wise to buy a decent back to back gauge and try and have all wheels to the same B to B dimensions, if using Markit/Romford wheels then use a Markit gauge 

[Ravenser]

well I would contend that DOGA is not really a standards body, it has no authority and in effect a standards body would have defined track and wheel standards AND have a mainstream following.

 

my comment about 00 and standards is that in effect we have none, certainly nothing of the scale of US NMRA standards. ( for good or bad)

 

so whats exists today in 4mm 00 is a set of modifications , which to some extent refer back to PECO as the original "standard".  Ie we mod away from PECO in an attempt to fix the shortcomings of the track issue in 00.

 

I would dispute this 

 

Firstly I would contend that many 00 layouts are not using hand built track.  where they are, I suspect we are seeing all sorts of combinations of so-called standards. Again I suspect its quite a small handful of relatively experienced modellers that are hand building turnouts in 00 and I suspect no-one is hand building straight track, all are using some form of flexi. This is merely based on my own view of layouts in 00

 

in this regard 00-SF, is a useful " modification " to the standard 00 16.5mm track installation, its not a 16.2 gauge in reality is a modification of the flange way dimensions in turnouts. I fail to see what criticism can be attributed to that 

 

 

Please read what I said - "what a very large majority of those using handbuilt track in OO actually work to. " . We are all aware that most people in OO use ready made track.

 

However checking amongst  DOGA's membership and with those involved with exhibition layouts in OO using handbuilt track has shown that a large majority are building track to the old BRMSB OO standard. (which falls within the tolerances of DOGA's OO Intermediate) . A minority work to DOGA Fine. You don't see "freelance" standards, for the simple reason that you need gauges to build track , these determine the flangeway and gauge, and very few people indeed are up to making their own gauges. You buy them

 

We've checked, widely over a good few years. You're guessing wildly in complete ignorance

 

DOGA has a great deal more "mainstream following" than anyone else who has established 4mm standards - apart form the 1979 EMGS standards    

[Ravenser]

Andy,

 

It's clear from your post you have not looked or measured any of these wheels accurately. Firstly Hornby wheels look nothing like a NMRA RP25 flange, and do not comply with the NMRA standard, as the flange depth is to deep. Secondly If they are derailment free on Peco code 100 turnouts, then they do not use the NMRA check gauge. Peco code 100 turnouts are lucky to have a check gauge of 16.2mm, some are less. Bachman also needs to work on Peco code 100, so again it uses the smaller PECO check gauge. I have done the measuring, and the sums, the NMRA standard is incompatible with current Peco track designed for the non US markets. How many times do I and others need to say, the NMRA H0 standard is irrelevent for UK 00 and 00-SF standards. 

 

Terry Flynn.

 

 

Very simply , the flange depth is almost completely irrelevant to this whole discussion (For the benefit of David Bird - who has raised the one situation where it may be an issue - I'll come back to the exception). So long as it doesn't strike the chairs on C_L flexitrack it doesn't matter

 

Guessing the back to back on the basis that it must be related to Peco code 100 is a mugs game. Bachmann UK use - and always have used since they entered the British market in 1990 - Kadar's understanding of RP25/110. That has a nominal B2B of 14.4mm . Allowing for manufacturing tolerances , what comes out of Kadar factories actually measures 14.3mm-.14.5mm . I have quite a bit of Bachmann, a set of dial calipers, and I've checked a reasonable number of items to get those measurements. Thre can be 0.2mm variance in B2B on the different axles of the same loco.

 

The fact that Peco Streamline (both code 100 and code 75 - for the flangeways are identical on both to the best of my knowledge) does not properly fit modern OO RTR wheels is well known and I know DOGA have tried several times to persuade Peco to tighten up their pointwork to around 1.25mm flangweway for modern RTR. There was some talk a few years ago that they might do so as tooling was renewed - but because Peco don't publicly admit to making such changes , for fear of "frightening the horses" I don't know if they did.    I can't go measuring every item in the Peco range every 6 months to see if it's been changed on the quiet

[Ravenser]

 

This has taken me ages to draw, but I think it is worthwhile:

check rail calculation two wheels.png

 

Do the maths on the segment behind the flanges:

Lines OA, OB, OD and (from above) T are the inner radius of the check rail

Line A thro’ D to B is an arc

Line OE is the apothem

Line ED is the segment height

 

From Pythagoras’s theorem on either triangle, T^2 = ( F/2 ) ^2 + OE^2

For a 1.0 mm check rail gap and a 0.5 mm flangeway thickness,

OE = T – 0.5

 

Do the substitution to remove OE, gives (very nearly) T = ( F/2 )^2 which is easy to plug the numbers into.

 

For a Hornby J94/Austerity, consider the two outer wheels and assume no sideplay, dimension F measures 54 mm and T = 729 mm which might be reasonable for the prototype (if it had the same wheel flanges!)

 

The model wheels have considerable sideplay and it is more realistic to consider the two adjacent wheels which are farthest apart. On the Hornby model this means F measures 38 mm and so T =  361 mm. About the same as a radius 1 curve.

 

The 1 mm gap is reasonable on an 18-inch radius curve, and this is evidenced by the way the loco runs through the check rail. And, for the purposes of this topic, this is an industrial curve, not a so-called "train set" curve.

 

QED?

 

- Richard.

 

 

Thanks to 47137 for a diagram that shows clearly what I clumsily tried to explain in words - the situation where the flanges are not presented parallel to the flangeway , but at a diagonal .

 

This is the case where a deep flange might cause problems - because the deeper the flanges , the longer that diagonal is going to be, and the more likely it will be to jam across the flangeway.

 

Similarly , the narrower the flangeway , the more scope for it jamming

 

I am not attempting to discount 47137's practical experiment , backed up by theoretical calculation , to show that he has got a Hornby J94 to current specification round an 18" radius curve with a check rail spaced at 1.05mm , in 16.2mm gauge 

 

The result is counter intuitive - I would have agreed with Martin Wynne's view that at these radii it would be necessary to widen to 1.25mm flangeway and 16.5mm gauge 

 

However before this result gets hardened into a rigid dogma that is quoted as valid under all circumstances (as it will be...) , I'd enter some cautions.

 

Firstly there's only one flangeway / check rail here. DavidBird was talking about inset tracks where there are two flangways, and that was the situation where I found coarse wheelsets on a Pacer jamming diagonally across the flangeway. In other words you might get away with it where there's only one check rail to worry about - but a second check rail might mean that one side of the wheelset is forced into a position incompatible with fitting into the other flangeway

 

The other posible issue is that if it is the length of the diagonal that causes the wheel to jam, then increasing the diameter of the wheel would have the same effect as increasing the depth of the flange. In other words - an Austerity driving wheel may be fine - but will the same apply to a 6'8" driver  (Or a Rapido Stirling Single - to take a worst case)

 

Without disputing 47137's result, it may be prudent to check other cases before elevating thisinto a hard and fast result that can be quoted without qualification and applied under all circumstances