EM v P4

[John CutlerParticipant]

A question I have often been asked by my non-modelling friends is why I choose to model in EM gauge rather than the more precise P4. It is quite difficult to give a single satisfactory answer, other than it should be easier!

It is a bit surprising that there is no readily available summary of the pros and cons of EM to help prospective EMGS members which direction they want to take. Maybe a Manual Sheet is needed?

So here are my thoughts for what they are worth.

Advantages of EM:
1. Tolerances are generally looser than P4, making it easier for a novice without sophisticated tooling or skills to achieve reasonable running. (Do you have the capability of accurately measuring and building to a 0.01mm tolerance?).
2. Wider tyres and greater flange-to-rail gap allows tighter track radii to be employed (36” compared to 42” practical minimum for P4; source Iain Rice. Note that successful layouts in both gauges have been built with lesser radius curves).
3. Deeper wheel flange helps prevent derailments without the need for compensation or springing of vehicles. But some P4 heretics successfully run EM wheels on P4 track.
4. Availability of ready-to-lay turnouts.
5. Narrower frames allow greater tolerances for setting up outside cylindered locomotives. RTR OO locomotives can often be simply adapted.
6. The existence of a fairly comprehensive Manual for referral.
7. Despite RP25 wheels not conforming to the EM standard, OO RTR wheels can often be used successfully if eased out on their axles. This seems to be increasingly so as RTR makers are becoming more finescale oriented.

Advantages of P4:
1. Looks better, especially the track and wheels. But still not 100% prototypical (=S4).
2. In the absence of perfectly engineered track to mainline standards, P4 locomotives require compensation or springing. Electrical pick-up is therefore better than rigid EM locomotives but EM vehicles can also be sprung or compensated.
3. Wider locomotive frames give more space for springing, compensation, gears and motors. Split axles are also easier to use because of the greater clearance between gearbox and frames. The wider frames also make it easier to incorporate representations (or even working) of inside cylinder mechanisms.
4. A better and more informative magazine (Scalefour News).
5. If you are an engineer, the EM standards allegedly contain some inconsistencies for track and wheels not found in the P4 standards.

Please agree/disagree and offer amendments.

Hopefully we will end up with something that helps the newbies out there.

[Ray BydeParticipant]

As a member of both the EM gauge society and Scalefour Society, modelling in EM, I would have to agree that the the Scalefour News is a better, more informative journal. Also you receive five issues a year – excellent value. As a new member of the Scalefour society, I was pleasantly surprised on renewing my membership to find a letter I could exchange for FREE entry to one of three Scalefour shows in the coming year – just for renewing membership.
On the plus side for the EM gauge Society, the Manual, and I have mine in both hard copy and the new disk, is excellent and very helpful, espescially to a newcomer.

[Dai DaviesParticipant]

Ray Byde said
As a member of both the EM gauge society and Scalefour Society, modelling in EM, I would have to agree that the the Scalefour News is a better, more informative journal. Also you receive five issues a year – excellent value. As a new member of the Scalefour society, I was pleasantly surprised on renewing my membership to find a letter I could exchange for FREE entry to one of three Scalefour shows in the coming year – just for renewing membership.
On the plus side for the EM gauge Society, the Manual, and I have mine in both hard copy and the new disk, is excellent and very helpful, espescially to a newcomer.

Agree with this, but add that EMGS stores is better.

[Dai DaviesParticipant]

”

John Cutler said
A question I have often been asked by my non-modelling friends is why I choose to model in EM gauge rather than the more precise P4. It is quite difficult to give a single satisfactory answer, other than it should be easier!

It is a bit surprising that there is no readily available summary of the pros and cons of EM to help prospective EMGS members which direction they want to take. Maybe a Manual Sheet is needed?

So here are my thoughts for what they are worth.

Advantages of EM:
1. Tolerances are generally looser than P4, making it easier for a novice without sophisticated tooling or skills to achieve reasonable running. (Do you have the capability of accurately measuring and building to a 0.01mm tolerance?).
2. Wider tyres and greater flange-to-rail gap allows tighter track radii to be employed (36” compared to 42” practical minimum for P4; source Iain Rice. Note that successful layouts in both gauges have been built with lesser radius curves).
3. Deeper wheel flange helps prevent derailments without the need for compensation or springing of vehicles. But some P4 heretics successfully run EM wheels on P4 track.
4. Availability of ready-to-lay turnouts.
5. Narrower frames allow greater tolerances for setting up outside cylindered locomotives. RTR OO locomotives can often be simply adapted.
6. The existence of a fairly comprehensive Manual for referral.
7. Despite RP25 wheels not conforming to the EM standard, OO RTR wheels can often be used successfully if eased out on their axles. This seems to be increasingly so as RTR makers are becoming more finescale oriented.

Advantages of P4:
1. Looks better, especially the track and wheels. But still not 100% prototypical (=S4).
2. In the absence of perfectly engineered track to mainline standards, P4 locomotives require compensation or springing. Electrical pick-up is therefore better than rigid EM locomotives but EM vehicles can also be sprung or compensated.
3. Wider locomotive frames give more space for springing, compensation, gears and motors. Split axles are also easier to use because of the greater clearance between gearbox and frames. The wider frames also make it easier to incorporate representations (or even working) of inside cylinder mechanisms.
4. A better and more informative magazine (Scalefour News).
5. If you are an engineer, the EM standards allegedly contain some inconsistencies for track and wheels not found in the P4 standards.

Please agree/disagree and offer amendments.

Hopefully we will end up with something that helps the newbies out there.

Plus easier conversion of stock to EM. Indeed some locos can just have their wheels pulled on their 00 axles.”

[John CutlerParticipant]

As some of you may know, this is a resurrection of a post on the old forum. My intention was to end up with something that can be used to persuade non-members to try out EM, perhaps instead of, or before, progressing to P4 (not for me, I am afraid!).

So if you think I have missed out anything important, please comment.

[Trade OfficerKeymaster]

Some thoughts

Track formations can be tighter e.g. minimum radii.

RTR flexitrack combined with the points eliminates track building for those used to “OO” RTR

Easier transition from “OO”, even if it is only part of the journey to P4.

Quicker to build a close to prototype layout

Not sure if I have worded the above correctly but to sum up:
If you are willing to compromise just a small amount (.63mm to be precise) you can quickly get a layout up and running that from the viewing aspect is prototypical

 

[Alan DurhamParticipant]

For me the two biggest things that attracted me to EM gauge are:

1) the wheels never look far enough apart in OO (which of course they aren’t), from the front end view it seems glaringly obvious to me that compared to the buffers the wheels look completely out of place.

2) I was never really satisfied with OO track.  Proprietary in recent years has come along way and on the whole great products, however the sleepers never look right.  They are either too small on proprietary track or look somehow odd when hand built at home.

I find that EM gauge is achievable with my modest skills and that perhaps P4 would be a step too far, that said I am always in admiration of those who have such skills and I appreciate the results.  I realise that what I model may not be to everybody’s taste or exacting standards, but the most important things for me are that I enjoy what I am doing and being happy with what I achieve, even if I am unlikely to win any awards.

Finally a disclaimer of sorts – my comments above are not intended as any form of criticism or judgement, there are some excellent proprietary products available now and there are some wonderful “non-finescale” models as well as “finescale” or “non-finescale” with compromises, in all gauges.  After all I am forever making compromises!  My ethos is if you get joy from your hobby then enjoy it, whether it be an exacting model running to a timetable or a circle of track on the dining table.

 

[Author]

Posts