EM wheels on 18.83mm track

[Colin Parks]

There are lots of P4 layouts that run extremely well - St Merryn etc. There are also many OO and EM layouts that don't. It's surely not the gauge that is often the problem - it's the building/maintenance etc that needs examining.

Hi Ealing,

Yes there are lots of very good P4 layouts that run extremely well and there are plenty of 00 ones that I have seen that didn't, but I don't think anyone is claiming that the gauge is the issue. I certainly wasn't. The point is that several experienced P4 modellers have said that they have eradicated derailments by changing the wheels and nothing more.

I have already invested many hundreds of pounds in changing to P4. That includes both track parts and a fair number of P4 profile wheels. I am going to do my level best to build everything as accurately as I can, but if the trains don't stay on the track and it's not down to the gauge being too narrow, I think I now know what the solution is.

Colin

[Jol Wilkinson]

Colin,

I think that you have to be careful when reading claims that P4 layouts don't perform well. You rarely hear it said about OO or EM layouts, possibly because there seems to be a reluctance on several forums to criticise individual layouts for fear of upsetting the owner. It seems acceptable to criticise RTR products (probably justifiable on occasion) whereas mediocre individual modelling efforts often get sycophantic applause. However, criticising anonymous P4 layouts and modellers is seen as acceptable.

I also don't get the bit about "fine tuning" wheels to layouts. If you build your track and models to the same standard, then you have already fine tuned them to one standard.

I find that if several derailments happen at one specific location, then it is usually down to the trackwork. If a piece of stock falls off at several locations, then check the B2Bs, etc. If only one piece of stock falls off at one specification, check both. There is more to good running than just the wheel/track "interface". We have found that bogie rotation "stiffness", gangway rubbing, buffing forces, etc. can all have an impact. Propelling stock is more likely to cause derailments than pulling it. How many of the P4 layouts we see involve some propelling/shunting, whereas many OO layouts are rather more one directional. Most of our carriage derailment problems come down to the running gear rather than the track. Would deeper flanges help? Undoubtedly to some degree, although you would still need to build your track well. Worrying about two decimals of tolerance is also a bit of a red herring, just use the available gauges to set the dimensions you need.

There is no doubt that P4 display layouts are more likely to suffer from issues associated with transport to exhibitions, temperature variations, etc. owing to the finer tolerances, so careful design of baseboard joints, etc. helps. It also important to ensure you can check the layout before taking it to a show. For those of us that can't set the layout up permanently in its entirety, that means some extra effort. For me it means renting the local village hall. When London Road appeared for the first time in its new format at a show (S4um 2013) I hadn't put enough time/effort into this and so the layout didn't perform as well as we would have liked and the operating team weren't sufficiently familiar with the new layout.

For the next outing (expoEM North 2014), I rented the village hall for five days (hang the expense!) so we we able to sort out the layout and stock issues and go thorough the operating sequence fully. The layout performed much better than before although we had one electrical problem(a broken dropper) and several operating issues (more familiarity needed, not easy as the operating team are spread wide and far), which were nothing to do with P4.

The only way to know if you can make P4 work for you is to try it. Would I go back to OO, definitely not. Would I try EM? Having given it some real consideration in the light of this topic, probably not. I would still have to build my own track and I think that would be no more easy or difficult to do well than with P4. As I model the LNWR I would still have to build my own locos and stock. Despite the wide range of kits available most of these still would need modifying to run well (new etched bogies, decent couplings, etc.). So still as much work as P4 and probably with the same components, just different wheels.

And then there is the enjoyment of doing something a little more challenging. If I didn't get satisfaction from that, I could go back to running my Hornby Dublo collection.

Jol

[Colin Parks]

It is indeed. P4 wheels on P4 track, and using the agreed P4 standards work. There is no need for anything else.

Hi Terry,

That's a strange choice of words.

In the grand scheme of things there is no "need" to build a model railway at all.

Your post has caused me to be seized with the intention to create "004" and add it to Templot -- using P4 wheels on 16.5mm track.

Martin.

I'm getting really confused now Martin.

The title of your own topic is: 'EM wheels on 18.83mm track'. You have posted details of a new set of standards available in your (very fine) Templot program for EM wheels on 18.8mm gauge track and now you are proposing standards for P4 wheels on 16.5mm gauge track!

Surely the point of what Jeff George said in MRJ 234 (and for that matter, Martin Goodall has said on both RMweb and this forum), is that all that was required to prevent derailments on their P4 layouts was to fit EM wheels to troublesome stock?

Colin

[Noel]

There are P4 layouts which do, by all accounts achieve good running. These seems to be of the permanently installed type or ones where the wheels are fine-tuned to the layout.

Some years ago I lent stock to a group with a continuous run P4 exhibition layout until they had enough stock of their own within the group. One train consisted of an 8F and 40+ goods wagons. The loco was not mine, the wagons were. A couple were failed because they had issues unrelated to track and wheel standards, which basically came down to errors in building the stock which might have been less of a problem in other gauges or might not. Portable layout, no tweaking [by me anyway], several owners' stock, not all from group members.

Problems I have seen with stock include axles not parallel or not perpendicular to the centre line, or wheels not parallel, any which will be liable to cause problems in any gauge, and which deeper flanges will probably not cure 100%.

As a steward at an exhibition [not Scaleforum] I once operated an 18.83 challenge layout with owner's stock. It was a first effort, I believe, and decidedly unreliable because of avoidable mistakes with both track and stock. There have been first layouts which have excelled, but not many. I would suggest that it takes time for most people [definitely including me!] to develop the necessary skills. There is also the temptation to quick fixes and the 'it'll do' syndrome. Perhaps it is not altogether realistic to make the first layout as an exhibition layout without giving yourself the chance to practice a bit first?

We live in a society which values quick results, however inadequate, and is prone to see taking time to learn and practice skills as unnecessary, possibly because the 'failure' of early efforts implied by this is unacceptable. Perhaps this is behind some of the problems with some P4 layouts? Also, without practice you don't know what you don't know, and may make mistakes you are not aware of until the problem surfaces.

Noel

[Martin Wynne]

I'm getting really confused now Martin.

The title of your own topic is: 'EM wheels on 18.83mm track'. You have posted details of a new set of standards available in your (very fine) Templot program for EM wheels on 18.8mm gauge track and now you are proposing standards for P4 wheels on 16.5mm gauge track!

Hi Colin,

There was a smiley on that -- you shouldn't take anything I post too seriously, it is all just a fun hobby. Ask your friends and family if the depth of wheel flanges on your model railway keeps them awake at night.

If you have decided to model in P4 I would suggest that you do exactly that using P4 wheels. If stuff falls off the track there is likely to be a reason which can be fixed, rather than changing the wheels. That is likely to cause you just as much trouble as it cures, if the new wheels don't match the track standard -- which is certainly the case using unmodified EM wheels on P4 track.

The small P4 flanges work fine -- but only if the wheel is maintained in firm contact with the rail top. The prototype does that by putting several tons of weight on top of it. On a model we can't do that, so it is important that P4 rolling stock is adequately weighted and well fitted with working compensation/springing to keep all the wheels in contact with the rail.

That can be a lot of work, so many modellers choose the easier option of 00/EM with deeper flanges to allow the odd uncompensated wheel to lift off the rail a bit occasionally. That doesn't make it right or wrong -- one man can only do so much when building a large working model railway. But deeper flanges must also be thicker, because they have to be tapered. Thicker flanges need wider flangeways to work properly. Putting a thicker EM flange in a P4 flangeway gap will sooner or later cause you grief. Especially in the form advocated by Martin Goodall where the back-to-flange dimension exceeds the check gauge. Don't do it if you value your sanity.

regards,

Martin.

[Colin Parks]

Colin,

I think that you have to be careful when reading claims that P4 layouts don't perform well. You rarely hear it said about OO or EM layouts, possibly because there seems to be a reluctance on several forums to criticise individual layouts for fear of upsetting the owner. It seems acceptable to criticise RTR products (probably justifiable on occasion) whereas mediocre individual modelling efforts often get sycophantic applause. However, criticising anonymous P4 layouts and modellers is seen as acceptable.

I also don't get the bit about "fine tuning" wheels to layouts. If you build your track and models to the same standard, then you have already fine tuned them to one standard.

I find that if several derailments happen at one specific location, then it is usually down to the trackwork. If a piece of stock falls off at several locations, then check the B2Bs, etc. If only one piece of stock falls off at one specification, check both. There is more to good running than just the wheel/track "interface". We have found that bogie rotation "stiffness", gangway rubbing, buffing forces, etc. can all have an impact. Propelling stock is more likely to cause derailments than pulling it. How many of the P4 layouts we see involve some propelling/shunting, whereas many OO layouts are rather more one directional. Most of our carriage derailment problems come down to the running gear rather than the track. Would deeper flanges help? Undoubtedly to some degree, although you would still need to build your track well. Worrying about two decimals of tolerance is also a bit of a red herring, just use the available gauges to set the dimensions you need.

There is no doubt that P4 display layouts are more likely to suffer from issues associated with transport to exhibitions, temperature variations, etc. owing to the finer tolerances, so careful design of baseboard joints, etc. helps. It also important to ensure you can check the layout before taking it to a show. For those of us that can't set the layout up permanently in its entirety, that means some extra effort. For me it means renting the local village hall. When London Road appeared for the first time in its new format at a show (S4um 2013) I hadn't put enough time/effort into this and so the layout didn't perform as well as we would have liked and the operating team weren't sufficiently familiar with the new layout.

For the next outing (expoEM North 2014), I rented the village hall for five days (hang the expense!) so we we able to sort out the layout and stock issues and go thorough the operating sequence fully. The layout performed much better than before although we had one electrical problem(a broken dropper) and several operating issues (more familiarity needed, not easy as the operating team are spread wide and far), which were nothing to do with P4.

The only way to know if you can make P4 work for you is to try it. Would I go back to OO, definitely not. Would I try EM? Having given it some real consideration in the light of this topic, probably not. I would still have to build my own track and I think that would be no more easy or difficult to do well than with P4. As I model the LNWR I would still have to build my own locos and stock. Despite the wide range of kits available most of these still would need modifying to run well (new etched bogies, decent couplings, etc.). So still as much work as P4 and probably with the same components, just different wheels.

And then there is the enjoyment of doing something a little more challenging. If I didn't get satisfaction from that, I could go back to running my Hornby Dublo collection.

Jol

Yes Jol, I was being careful, but here are some quotes re. P4 layouts and their running by S4 Society members: S4 News188 p37 - letter from Brian Self (which also quotes a remark by an S4 Soc. member re. a layout where nothing fell off in an hour of observation); S4 News 189 p.7 a letter from Eddie Bourne re. bad running (six out of eight layouts etc., etc..). Sorry if these are what you would call 'anonymous P4 layouts' but these are criticisms published in the S4 News, not the Railway Modeller! What am I,as a newcomer to P4, to make of it all?

'Fine-tuning' refers in particular to Brian Harrap's most excellent layout QUAI:87.

As for derailments on 00 layouts at exhibitions, I have seen a number. More commonly, bad running on 00 layouts was down to operator error or electrical faults. I am not wishing to defend 00 layouts, but are you sure they are 'more one directional' than P4 ones?!

I can envisage all kinds of potential problems with converting and running my scratch-built EMU stock on P4 track, most of which you have listed. I have indeed learnt a great deal about track-building these past few months, so it is clear that the basis of good running and keeping things on the track is well-made and accurate track work. I am going to give P4 my best shot and I don't mind a challenge. If all goes well then I shall be happy, but it seems a bit patronising to suggest that if P4 can't be made to work then it's best to go back to Hornby Dublo.

Colin

[Colin Parks]

There are P4 layouts which do, by all accounts achieve good running. These seems to be of the permanently installed type or ones where the wheels are fine-tuned to the layout.

Some years ago I lent stock to a group with a continuous run P4 exhibition layout until they had enough stock of their own within the group. One train consisted of an 8F and 40+ goods wagons. The loco was not mine, the wagons were. A couple were failed because they had issues unrelated to track and wheel standards, which basically came down to errors in building the stock which might have been less of a problem in other gauges or might not. Portable layout, no tweaking [by me anyway], several owners' stock, not all from group members.

Problems I have seen with stock include axles not parallel or not perpendicular to the centre line, or wheels not parallel, any which will be liable to cause problems in any gauge, and which deeper flanges will probably not cure 100%.

As a steward at an exhibition [not Scaleforum] I once operated an 18.83 challenge layout with owner's stock. It was a first effort, I believe, and decidedly unreliable because of avoidable mistakes with both track and stock. There have been first layouts which have excelled, but not many. I would suggest that it takes time for most people [definitely including me!] to develop the necessary skills. There is also the temptation to quick fixes and the 'it'll do' syndrome. Perhaps it is not altogether realistic to make the first layout as an exhibition layout without giving yourself the chance to practice a bit first?

We live in a society which values quick results, however inadequate, and is prone to see taking time to learn and practice skills as unnecessary, possibly because the 'failure' of early efforts implied by this is unacceptable. Perhaps this is behind some of the problems with some P4 layouts? Also, without practice you don't know what you don't know, and may make mistakes you are not aware of until the problem surfaces.

Noel

Hi Noel,

I am not looking for a 'quick fix' and do not remember saying that I was. If items of stock are really badly constructed, then deeper flanges are not going to help. As a newcomer to P4, I am interested in looking at all sides of the debate and considering all the options, but I am intending to build a layout to P4 standards using all the right gauges and wheels. If it takes some time to develop all the skills needed to produce a P4 layout, so be it.

As for exhibiting a first layout, if isn't good enough, I won't let it be seen in public!

Colin

[Crepello]

Hi Jol,
There is a clue in MG's earlier post:

... Martin Wynne and Bill Bedford (among others) seem to have got very steamed up about what name should be given to the use of EM wheels on P4 track. I have coined the name "Coarse-scale P4" for it, which clearly irritates the purists (and is, of course, intended to do so)...

a bit tiresome innit?

Indeed. Seems like the very definition of a Troll!

[Colin Parks]

I'm getting really confused now Martin.

The title of your own topic is: 'EM wheels on 18.83mm track'. You have posted details of a new set of standards available in your (very fine) Templot program for EM wheels on 18.8mm gauge track and now you are proposing standards for P4 wheels on 16.5mm gauge track!

Hi Colin,

There was a smiley on that -- you shouldn't take anything I post too seriously, it is all just a fun hobby. Ask your friends and family if the depth of wheel flanges on your model railway keeps them awake at night.

If you have decided to model in P4 I would suggest that you do exactly that using P4 wheels. If stuff falls off the track there is likely to be a reason which can be fixed, rather than changing the wheels. That is likely to cause you just as much trouble as it cures, if the new wheels don't match the track standard -- which is certainly the case using unmodified EM wheels on P4 track.

The small P4 flanges work fine -- but only if the wheel is maintained in firm contact with the rail top. The prototype does that by putting several tons of weight on top of it. On a model we can't do that, so it is important that P4 rolling stock is adequately weighted and well fitted with working compensation/springing to keep all the wheels in contact with the rail.

That can be a lot of work, so many modellers choose the easier option of 00/EM with deeper flanges to allow the odd uncompensated wheel to lift off the rail a bit occasionally. That doesn't make it right or wrong -- one man can only do so much when building a large working model railway. But deeper flanges must also be thicker, because they have to be tapered. Thicker flanges need wider flangeways to work properly. Putting a thicker EM flange in a P4 flangeway gap will sooner or later cause you grief. Especially in the form advocated by Martin Goodall where the back-to-flange dimension exceeds the check gauge. Don't do it if you value your sanity.

regards,

Martin.

Hi Martin,

Missed the smiley!

These things do not really keep me awake at night, but the proposed solution to random or sporadic derailments of P4 stock on specific layouts does interest me. I thought that the point Martin Goodall made was that in fitting certain makes of EM wheels, no adjustments to his P4 track had to be made. The same was said by Jeff George. I still do not understand why there should be a problem in doing that if both parties claim success without altering the track in any way.

Still sane (just),

Colin

[Martin Wynne]

I thought that the point Martin Goodall made was that in fitting certain makes of EM wheels, no adjustments to his P4 track had to be made. The same was said by Jeff George. I still do not understand why there should be a problem in doing that if both parties claim success without altering the track in any way.

Hi Colin,

Ask them if they propel long trains through a curved double-slip and over a scissors crossover? Jeff George is good friend and I know that he doesn't.

If you follow Martin Goodall's method sooner or later a wheel flange will hit a crossing nose and either bump or derail. Even if everything stays on the rails, the running through complex pointwork will be rougher and bumpier than with an accurately constructed and properly compensated P4 vehicle. The problem is that such a thing takes 50 times longer to build than putting EM wheels on an RTR wagon.

If you really want to use the deeper EM flanges for an easier life, do yourself a favour and build the track to match. Either in EM itself, or blaze a trail for the EM4 dimensions which I posted at the top of this topic.

regards,

Martin.

[Will L]

On the subject of the running quality of layouts you should be aware that

My layout runs very reliably, although if pushed I will admit we do see the very occasion minor imperfection but I know why it happens and I'll fix it after the show.
Yours is Ok but is that the second time I've seen that wagon come off just there.
Stuff falls off on their layout all the time.

Most people who exhibit will tell you how they make real effort to eliminate running problems but all of them can have a bad day. Years of leaning on exhibition barriers (or not as Scaleforum) suggest that layout that don't performing very well on the day come well distributed across all scales and gauges.

[Andrew Ullyott]

I model in both EM and P4, but not simultaneously (for the time being that is).
Wheal Elizabeth has its moments and I generally know what causes them. Fiddle yard cassettes being the primary source of derailments. Scenic section derailments are rarer.
I have a constant conundrum about whether I should stay with P4 or go EM, where the increased flange depth does make a difference. I don't think I had any derailments on Weston or Clevedon (both are EM) at their last outings.
Each time I have the conversation about this, I decide to stick with P4 for the time being, because I think I can still get it to work.
EM4 would be an option, once I have tried all others or reached the limit of my ability.
Having witnessed Martin's progress with Burford over the last 14 years or so, one of the points I'd make is he has tried other things first before embarking on 'the Shirehampton heracy'.
Wasn't it the propelling of coaches over the curved C10 crossover that was the cause of this? (Happy to be corrected here).
Just my twopenneth worth.

[martin goodall]

I thought that the point Martin Goodall made was that in fitting certain makes of EM wheels, no adjustments to his P4 track had to be made. The same was said by Jeff George. I still do not understand why there should be a problem in doing that if both parties claim success without altering the track in any way.

Hi Colin,

Ask them if they propel long trains through a curved double-slip and over a scissors crossover? Jeff George is good friend and I know that he doesn't.

If you follow Martin Goodall's method sooner or later a wheel flange will hit a crossing nose and either bump or derail. Even if everything stays on the rails, the running through complex pointwork will be rougher and bumpier than with an accurately constructed and properly compensated P4 vehicle. The problem is that such a thing takes 50 times longer to build than putting EM wheels on an RTR wagon.

If you really want to use the deeper EM flanges for an easier life, do yourself a favour and build the track to match. Either in EM itself, or blaze a trail for the EM4 dimensions which I posted at the top of this topic.

regards,

Martin.

I confirm that on my Burford layout I back a rake of Mark 1 bogie coaches over a C10 crossover on a curve (of between 3ft and 4ft radius), in a regular carriage shunting manoeuvre. Using EM wheels, they have never come off (but when I used P4 wheels, they rarely came off either, here or anywhere else on the layout - the difference is between 'rarely' [P4 wheels] and 'never' [EM wheels]).

[martin goodall]

I forgot to answer the second part of Martin Wynne's query. No wheelset has EVER hit the crossing nose, and we are talking quite a few years' running by now. I made very sure these two C10 turnouts were set out so that there was no possibility of a wheelset getting anywhere near the crossing nose.

I have mentioned in another thread how this trick is done, but I'll leave everyone guessing for now, or hunting for the reference where I explained it before.

[martin goodall]

These things do not really keep me awake at night, but the proposed solution to random or sporadic derailments of P4 stock on specific layouts does interest me. I thought that the point Martin Goodall made was that in fitting certain makes of EM wheels, no adjustments to his P4 track had to be made. The same was said by Jeff George. I still do not understand why there should be a problem in doing that if both parties claim success without altering the track in any way.

Still sane (just),

Colin

I confirm that fitting certain makes of EM wheels (Ultrascale, KM, Gibson) set to the P4 back-to-back (17.7mm) requires no adjustment of track built to the P4 standards, so long as you have not inadvertently allowed the track gauge to go below 18.83mm anywhere on the layout (and it can happen, even when you are careful with your track gauges, but on soldered Brook Smith track this is easily corrected).

The problem with the theorists is that they have never actually tried it, relying as they do solely on calculations and theory, whereas I (and no doubt others) prefer an entirely emprirical method - 'suck it and see'. When I began to experiment with the use of EM wheels on P4 track (about 8 years ago now) I had no idea whether it would work or not, but so far as I was concerned there was only one way to find out, and it wasn't going to be by poring over figures and punching numbers into a calculator.

[Terry Bendall]

but I am intending to build a layout to P4 standards using all the right gauges and wheels. If it takes some time to develop all the skills needed to produce a P4 layout, so be it.

If that is what you intend Colin then I am sure that everyone on here will wish you the best of luck and will respond to your queries. P4 can be made to work succesfully and it has been. At Scaleforum this year, that was prooved by Calcutta Sidings with trains of prototypical length running at scale prototypical speeds. Yes i think there were a few derailments but not many, and i did not see any in the small amount of time that I was able to watch it.

There is no escaping the fact that working in P4 does take longer, and does take more care but it can be done, has been done and will continue to be done. First time layouts can be made to work successfully and they do. Manston Brewery is an example which was also at Scaleforum. Noel has it right when he says

I would suggest that it takes time for most people [definitely including me!] to develop the necessary skills. There is also the temptation to quick fixes and the 'it'll do' syndrome.

Anyone who starts in P4 has to be aware that it is not a quick process and I don't think anyone would deny that. It needs a bit of determination to sort out where the problems are and to fix them. I have spend many hours doing such things and you do get there in the end if you have the patience. Good quality running is by no means limited to those layouts that stay at home but it can make things easier.

I have a constant conundrum about whether I should stay with P4 or go EM, where the increased flange depth does make a difference. I don't think I had any derailments on Weston or Clevedon (both are EM) at their last outings.
Each time I have the conversation about this, I decide to stick with P4 for the time being, because I think I can still get it to work.

I spend quite a lot of time on the Society stand at exhibitions and over the years have had several people say something like "I started in EM 25 years ago but I wish I have started in P4" Andrew has build some very nice layouts in both EM and P4 and I admire his work. There are lots of other good EM and OO layouts out there but for me it is the look of the track that means that I will only model in P4 when working in 4mm scale. What other people do is up to them and I hope thay have fun and enjoy themselves.

Terry Bendall

[jim s-w]

It's worth pointing out that Calcutta sidings is its second version. The first was EM. The p4 version is a lot bigger and a lot more complicated and to be fair no less reliable. Em layouts have derailments too as do 00. No layout is 100% reliable so a mix of 2 standards isnt going to be either. With apologies to Martin G but until you've take your layout to a show, run it for 2 days with absolutely no derailments what so ever your claim's are nothing more than wishfull thinking.

This is going to keep raising its head until you prove it to be true. I wonder why you haven't dared try in all these years?

Cheers

Jim

[martin goodall]

Just to pick up what Jim said, neither Jeff George's layout nor mine (Burford) is an exhibition layout. Neither of these layouts was designed as an exhibition layout, and Burford is certainly too big and heavy to take to an exhibition.

[Just, as an aside, I have always firmly believed that if you intend to exhibit a layout, it should be designed as an exhibition layout right from the outset. This doesn't just mean light portable baseboards, but careful attention to presentation, lighting. etc. and many the other factors that will ensure that it forms an attractive and interesting display.]

If we are building a home layout, we really don't have to prove anything to anyone - except to ourselves. But most of us are fairly demanding in this regard. If I had found that the running of EM wheels on P4 track was less than perfect, I certainly wouldn't be writing about it as I have. I would have quietly dropped the experiment and said nothing about it. It was because I was so surprised and pleased at the results I obtained by running EM wheels on P4 track that I wanted to tell people about it.

The only way that anyone can obtain proof that EM wheels really will run well on P4 track is by trying it for themselves. There is no substitute for practical experiment and actual experience. The only reason for the rather lengthy discussion on this topic here and on RM Web is that certain people have asserted rather noisily that it can't or won't work, whereas those of us who have actually done it know that it does.

For those with long memories, this debate bears an uncanny resemblance to the fierce disputes that were aroused by the original introduction of P4 standards in the late 1960s. Even the arguments are the same! - "It won't work" "It can't work" and (as a last resort) "Well, it's unnecessary anyway, because '00' [cf P4 now] works perfectly well."

Unlike some of the correspondents on RM web, I have never asserted that 'P4 doesn't work'; but to quote Terry Bendall (in his comment above) "Anyone who starts in P4 has to be aware that it is not a quick process and I don't think anyone would deny that. It needs a bit of determination to sort out where the problems are and to fix them. I have spend many hours doing such things and you do get there in the end if you have the patience." Even then, there will be the occasional random derailment, as I have reported in previous threads, and as Jeff George has also confirmed in his article in MRJ 234. It was to eliminate that (admittedly very small) element of unreliability that I decided to try using EM wheels on my P4 layout, with the results I have reported on this forum passim. Jeff George has now reported similar results independently in his MRJ article.

Ultimately it is just a matter of personal choice. If you are entirely satisfied with using P4 standards, or are reluctant to deviate from them (for whatever reason), then there is no reason why you should do so. But if you are rather more open to experiment and the empirical approach that I prefer, then you might well give it a try yourself, and see what happens.

[iak]

Ultimately it is just a matter of personal choice. If you are entirely satisfied with using P4 standards, or are reluctant to deviate from them (for whatever reason), then there is no reason why you should do so. But if you are rather more open to experiment and the empirical approach that I prefer, then you might well give it a try yourself, and see what happens.

An ounce of practice is worth more than tons of preaching.

Mahatma Gandhi

[Noel]

I am not looking for a 'quick fix' and do not remember saying that I was.Colin

Sorry if I have offended, Colin, it wasn't intentional; I did refer to "the temptation to..." It was intended as a general observation about human nature when carrying out complex tasks, not specifically about your modelling [or anyone else's for that matter].

Noel

[grovenor-2685]

The only reason for the rather lengthy discussion on this topic here and on RM Web is that certain people have asserted rather noisily that it can't or won't work,

I don't recollect reading any such statement, can you quote the relevant posts.

But if you are rather more open to experiment and the empirical approach that I prefer, then you might well give it a try yourself, and see what happens.

You are very fond of disparaging remarks about theoreticians, why do you assume that those of us happy to use P4 wheels don't experiment for ourselves?

Regards
Keith

[Martin Wynne]

certain people have asserted rather noisily that it can't or won't work, whereas those of us who have actually done it know that it does.

Hi Martin,

What we are disputing here is what you mean by "work"? No-one is disputing that deeper flanges will help to avoid derailments on less than perfect track. But a derailment is a catastrophic failure which has a cause, and could if you wished be fixed. Derailments don't just happen as random acts of God.

More important to me at least is the general quality of running which results from using unmatched wheels and track. At present you are using wheels where the back-to-flange dimension exceeds the check gauge. That can and will produce rough running through crossings, even if there is no derailment.

I have just set some EM wheels to 17.7mm back-to-back and measured the back-to-flange dimension. The answer is 18.3mm. That is 0.15mm (6 thou) greater than the P4 check gauge, more than enough to cause bumpy running when a crossing is in the outer rail on a curve. It may be of course that you are satisfied with rough and bumpy running provided there is no derailment? Or maybe your check rails are not in fact set to the P4 standard?

regards,

Martin.

[jim s-w]

Sorry Martin (g) but you are wrong. If you are making claims like 100% reliable and 'never' derails then yes you do have to provide some sort of proof, especially if you are comparing a home layout to exhibition ones. Of course a perminant layout is considerably easier to get running reliably anyway

I'm sorry but you have just shot your entire case completely out of the water. To put it bluntly, you can claim what you like. I choose to not believe you until you can provide some proof that what you say is true. So far from an external point of view EVERYTHING you have said is purely theoretical. Something you are so keen to attack others for.

Jim

[Colin Parks]

I am not looking for a 'quick fix' and do not remember saying that I was.Colin

Sorry if I have offended, Colin, it wasn't intentional; I did refer to "the temptation to..." It was intended as a general observation about human nature when carrying out complex tasks, not specifically about your modelling [or anyone else's for that matter].

Noel

No offence taken Noel, I have been scratch building models for a number of years, so I am not expecting an 'RTR stock/Peco' track type of quick fix with P4!

Colin

[Colin Parks]

Well I wish I hadn't written anything on this subject now!

There is no conclusive argument to be made for EM wheels on P4 track as being better than P4 wheels if everything is built carefully. If Jeff George's trains do nothing but go round and round on his layout with no shunting that does not really prove the method works in all applications.

I had been swayed towards Martin Goodall's ideas, but there is no guarantee that they would work any better on an exhibition type layout. Plus, why does Mr Goodall take such delight in being coy about his methods? He claims to be able to prevent wheels from striking the crossing nose but won't explain, leaving it as some kind of puzzle. Not very inspiring.


Colin