How will TT:120 differentiate itself from N, OO and 3mm scale?

[brossard]

On 17/06/2022 at 16:27, Revolution Ben said:

Hi there,

 

For me one over-riding reason:  It is the only RTR British scale that has the correct track gauge/scale combination.  N, 00 and 0 are all out, to varying degrees.

 

Ben A.

 

Just want to take issue with Ben's comment that 0 gauge does not have the correct gauge scale combination.  Technically true I suppose since 32mm gauge (assuming Fine Scale here) scales to 4' 7" (rounded) so not really visible to the naked eye.  Certainly way better than 00 which has two major disadvantages: 1)  narrow gauge which is noticeable and 2) horrible couplings.  Both are solved in 0 gauge, for me anyway.

 

So, Ben, without getting too far off topic can you elaborate?

 

John

[Rivercider]

I have an 8' long OO shunting plank, which really does not get played with enough to justify house space.

Looking ahead to future possible domestic re-organisations, either house move or fitting it into a smaller room, I would still like to keep open the option for the layout.

 

I have attended many exhibitions over the last 15 years and seen only about three N gauge layouts that really appealed to me, and those were layouts that took advantage of the scale to recreate large stations. N gauge is not for me. On the other hand, the limited number of TT layouts I have seen include several that did appeal to me, to me they seem much closer to OO than N for effect.

  

I confess I am not really a modeller, more of a box opener, and remember the RTR availability from the 1970s. If, in a few years, there was a decent basic range of RTR locos and stock in TT gauge I would seriously consider a modest layout, this would be a similar track plan to my OO layout, but in a smaller space,

 

cheers

[mdvle]

40 minutes ago, Rivercider said:

On the other hand, the limited number of TT layouts I have seen include several that did appeal to me, to me they seem much closer to OO than N for effect.

 

I think that is one of the things that can't be measured, and thus gets missed in any comparison that just looks at it as 1:120 vs 1:148

 

From a strictly numerical point of view it may not be much of a difference but at a more practical level that little extra bit of mass, that little extra bit of volume (both for fitting things inside locos as well as for handling and the visuals) all make a big potential difference in the acceptance with the hobby public.

 

 

[spamcan61]

5 minutes ago, mdvle said:

 

I think that is one of the things that can't be measured, and thus gets missed in any comparison that just looks at it as 1:120 vs 1:148

 

From a strictly numerical point of view it may not be much of a difference but at a more practical level that little extra bit of mass, that little extra bit of volume (both for fitting things inside locos as well as for handling and the visuals) all make a big potential difference in the acceptance with the hobby public.

 

 

Presumably the TT layouts 'rivercider' has seen are much more likely to have been 3mm/ft than 2.5mm/ft, quite a size difference, 1:100 versus 1:148 for N.

Edited June 19, 2022 by spamcan61

[Rivercider]

6 minutes ago, spamcan61 said:

Presumably the TT layouts 'rivercider' has seen are much more likely to have been 3mm/ft than 2.5mm/ft, quite a size difference, 1:100 versus 1:148.

I am no expert modeller, I honestly could not say, other than I am sure one or two were members of the 3mm society (if I have got that right),

 

cheers

[spamcan61]

3 minutes ago, Rivercider said:

I am no expert modeller, I honestly could not say, other than I am sure one or two were members of the 3mm society (if I have got that right),

 

cheers

I would say with 99% certainty that if they were models of the British scene then they were 3mm/ft, which is not what's being introduced by Peco/Heljan/Gaugemaster.

Edited June 19, 2022 by spamcan61

[britishcolumbian]

39 minutes ago, spamcan61 said:

I would say with 99% certainty that if they were models of the British scene then they were 3mm/ft, which is not what's being introduced by Peco/Heljan/Gaugemaster.

The difference between 1:101.6 and 1:148 is roughly comparable to the difference between 1:120 and 1:160, and over the decade+ that the Vancouver TT modular group has been doing public displays the commentary from viewers on the noticeable difference between TT and HO and between TT and N has been extremely consistent. As I've mentioned before, the difference in length of a class 31 in 1:120 and 1:148 is a full inch... and that's just in a single dimension. If you can't notice that big a difference, then I dunno what to tell you.

[spamcan61]

My point is that 'rivercider' was commenting on the size comparison between OO, TT and N, so I was clarifying that the size difference between 3mm TT and N is rather different to the size difference between 2.5mm TT and N (as amply demonstrated by the various comparison shots posted in one of these intertwined threads)

[whart57]

When I was Chairman of the 3mm Society I had this idea of writing a series of articles called "Layouts for 21st Century Living". The idea was to extol the virtues of 3mm scale by showing how it could fit into the type of properties someone in their forties might be living in or the sort of space they might have available. The thinking was that the target modeller needed to be settled down, any children needed to be at least teenagers else any model railway would be Thomas the Tank Engine in 00, and that they would be living in a property built no earlier than 1980 - i.e. with rooms smaller than someone like C J Freezer would have had in mind. Someone of that age would probably be returning to modelling but was not committed to another scale. Working in 3mm scale does require some experience it is not a newbie's scale.

 

A similar exercise might be useful for TT:120 since this 21st Century Living is behind Steve Flint's piece.

 

I wrote one article but it was never presented for publication, partly because I didn't want to do all the designs myself. However the sort of spaces we considered were:

• The "third" bedroom, a room 7' x 5' or slightly larger
• A living room shelf, up to 12' long but only 12" wide
• A fold up layout made of two 3'6" x 18" boards plus a 30" long fiddle yard. Something this size would fit in the boot space of most cars for taking down to a club for working on

In all these cases it would be hard to fit in a 00 layout without frustration. The smaller scale is quite doable though. Maybe something for another topic?

[britishcolumbian]

What you seem to be saying is that the difference between 1:120 and 1:148 is insignificant; my point is that the difference between 2.5 mm TT and 1:148 N is a full inch on a class 31. I dunno about you, but that's significant enough to me...

[spamcan61]

No I'm not saying that at all, essentially what I'm saying is that if somebody thinks that TT (3mm) is the ideal size between 00 and N (as rivercider was  AIUI ) then they're possibly going to be confused/disappointed if they start buying TT:120 and notice that the relative sizes are different.

Edited June 19, 2022 by spamcan61

[Nearholmer]

13 minutes ago, whart57 said:

In all these cases it would be hard to fit in a 00 layout without frustration. The smaller scale is quite doable though. Maybe something for another topic?

Struck me earlier that many CJF style small BLTs, designed to cram the most possible into a small space in 00, could be built to exactly the same dimensions, and would look far better, in TT (3mm or 2.5mm). The change down scale would allow everything to breath a bit, and details like trap points, which tend to get squeezed out, could be included.

[Tim Dubya]

14 minutes ago, Nearholmer said:

Struck me earlier that many CJF style small BLTs, designed to cram the most possible into a small space in 00, could be built to exactly the same dimensions, and would look far better, in TT (3mm or 2.5mm). The change down scale would allow everything to breath a bit, and details like trap points, which tend to get squeezed out, could be included.

 

Exactly!

[Rivercider]

23 minutes ago, spamcan61 said:

No I'm not saying that at all, essentially what I'm saying is that if somebody thinks that TT (3mm) is the ideal size between 00 and N (as rivercider was  AIUI ) then they're possibly going to be confused/disappointed if they start buying TT:120 and notice that the relative sizes are different.

I am probably not the target market here, as my model railway purchases over the last 10 years have been minimal, though I have probably been to over a hundred exhibitions.

I will admit to being confused between 2mm/N/3mm/TT etc,  before we even get into OO/EM/P4, but something of an 'in between' scale might well appeal to me. 

When looking at a possible distant future downsizing of my OO layout I would certainly want to wait until I had seen a number of new TT layouts at exhibitions.

 

cheers

[Pacific231G]

1 hour ago, Nearholmer said:

Struck me earlier that many CJF style small BLTs, designed to cram the most possible into a small space in 00, could be built to exactly the same dimensions, and would look far better, in TT (3mm or 2.5mm). The change down scale would allow everything to breath a bit, and details like trap points, which tend to get squeezed out, could be included.

That was also CJF's advice right from the start of TT-3. "If we look at a minimum-space 00 layout, we find nothing wrong with the arrangement of tracks in themsevles, it is rather that they are too short and the siding space is barely sufficien. In most cases the same layout replanned in TT-3 can be just as large, the reduction in scale ensuring that the facilities for operation are improved."   (RM March 1957 p60  "TT is Here!") He then proved the point with a 5ft x 1ft plan for a similar BLT in both scales but  looking far less cramped in TT-3. 

[Revolution Ben]

6 hours ago, brossard said:

 

Just want to take issue with Ben's comment that 0 gauge does not have the correct gauge scale combination.  Technically true I suppose since 32mm gauge (assuming Fine Scale here) scales to 4' 7" (rounded) so not really visible to the naked eye.  Certainly way better than 00 which has two major disadvantages: 1)  narrow gauge which is noticeable and 2) horrible couplings.  Both are solved in 0 gauge, for me anyway.

 

So, Ben, without getting too far off topic can you elaborate?

 

John

 

Hi John,

 

I am not quite sure what there is to elaborate.

 

As you said, 32mm is, in British 0 1:43.5 scale, 4'7.  So, as I said, it joins 00 and N which are all out to varying degrees.  If you're happy with 0 that's great, and the degree of error is less, but it's still wrong. 

 

Unless you're modelling in European 0 gauge at 1:45 of course which is correct.

 

Apologies for thread drift.

 

cheers

 

Ben A.

[brossard]

17 minutes ago, Revolution Ben said:

 

Hi John,

 

I am not quite sure what there is to elaborate.

 

As you said, 32mm is, in British 0 1:43.5 scale, 4'7.  So, as I said, it joins 00 and N which are all out to varying degrees.  If you're happy with 0 that's great, and the degree of error is less, but it's still wrong. 

 

Unless you're modelling in European 0 gauge at 1:45 of course which is correct.

 

Apologies for thread drift.

 

cheers

 

Ben A.

 

Thanks Ben, worried I might have missed something.  I didn't want people to read what you wrote and lump 0 gauge in with 00.  I tried to set the record straight, the point being that 0 gauge discrepancies in track gauge are tiny.

 

Cheers

 

John

[TT3]

10 hours ago, Pacific231G said:

That was also CJF's advice right from the start of TT-3. "If we look at a minimum-space 00 layout, we find nothing wrong with the arrangement of tracks in themsevles, it is rather that they are too short and the siding space is barely sufficien. In most cases the same layout replanned in TT-3 can be just as large, the reduction in scale ensuring that the facilities for operation are improved."   (RM March 1957 p60  "TT is Here!") He then proved the point with a 5ft x 1ft plan for a similar BLT in both scales but  looking far less cramped in TT-3. 

IIRC the original CJF Minories urban termius in 5 x 1 was originally meant as a TT layout, always wanted to try it with the triang track geometry just for fun but would so suit an AIA and a few mk1 suburbans

[F-UnitMad]

19 hours ago, brossard said:

 

Just want to take issue with Ben's comment that 0 gauge does not have the correct gauge scale combination.  Technically true I suppose since 32mm gauge (assuming Fine Scale here) scales to 4' 7" (rounded) so not really visible to the naked eye.  Certainly way better than 00 which has two major disadvantages: 1)  narrow gauge which is noticeable and 2) horrible couplings.  Both are solved in 0 gauge, for me anyway.

 

So, Ben, without getting too far off topic can you elaborate?

 

John

I knew what Ben meant re O gauge; yes 32mm is underscale width by just about 1mm, but the discrepency isn't glaringly obvious. The only way I've ever noticed that a layout has S7 (33mm gauge) track is that the wheel flanges are so much finer than standard O.

So while standard O might be considered 'close enough' (apart from the Scale7 modellers) where it does fall down of course is in the amount of space it takes up.

 

In the case of the OP question - "How will TT120 differentiate itself from...?" I think it has to be the size & space aspect that is key even more than the correct scale-to-gauge. It certainly won't be price; OO & N seem to level-peg for a lot of stuff; proposed price for the Heljan TT120 Class 31 seems a tad higher than 'average' N/OO 12v DC diesel prices, but it is a first shot at a new market, and O Gauge is just more expensive anyway, but considering it is 8 times the volume of an OO model we can consider ourselves lucky it is not usually 8 times the price!!

I'm of a mind that the best selling point for TT120 is that it can copy an OO layout plan in the same sized space, and look better with longer trains and more space for scenery.

 

 

[Nearholmer]

One thing that it would be nice to see, as a differentiator from much r-t-r 00 and N would be a  reasonably fine wheel and point-work standard. When you see the fine wheels and flanges on some Japanese N (do they use NMRA or something else) it is quite apparent that modern production techniques can deliver something that both looks very good, and works, and a “green field” scale is an ideal opportunity.

Or, is it compromised from the start by the existing global TT market being based around a fairly coarse wheel profile?

[F-UnitMad]

8 hours ago, Nearholmer said:

One thing that it would be nice to see, as a differentiator from much r-t-r 00 and N would be a  reasonably fine wheel and point-work standard

Unless I've missed it (highly likely!!) I've not seen mention of what couplings are intended, & I'm not familiar with whatever EU TT models use?. For me that would be an issue that could add/detract to/from the "temptation" factor. 🤔

Edit: having a 'Big' Heljan 31, having a 'Little 'un" as well could be quite a temptation!!

Cue gratuitous 31 picture...

 

 

Edited June 20, 2022 by F-UnitMad

[britishcolumbian]

14 minutes ago, F-UnitMad said:

Unless I've missed it (highly likely!!) I've not seen mention of what couplings are intended, & I'm not familiar with whatever EU TT models use?

 

They'll have NEM pockets, but from what I've heard the default will be the Tillig close coupling... these look like Tillig close couplings and nothing else, but they do make a rake look very good, buffer to buffer and all that. Their drawback is that they can be a bit fiddly to couple/uncouple, and they're a bit touchy about uneven track. The old standard BTTB coupling (which Piko has by default on their models) is big and clunky and ugly but doesn't care about uneven trackwork.

 

For my part, I use the Tillig couplers on my Hungarian/Continental stock; but I use MicroTrains N scale knuckle couplers on my North American stock (they look almost exactly to scale in 1:120) because they're reliable and easy to uncouple (better for shunting).

 

Given the presence of NEM pockets on the Heljan (and I imagine others') offerings I'm giving serious thought to using the Dapol N scale knuckle coupler on my British stock, they mate with the MT couplers and the functionality/ease of shunting will be an important factor for me. I'm actually giving thought to replacing the Tillig couplers on my Continental stock as well - the knuckles are just as non-prototypical on it as the Tillig ones so 6 of one...

[britishcolumbian]

Tillig coupler:

 

BTTB coupler:

[Pacific231G]

On 20/06/2022 at 10:20, TT3 said:

IIRC the original CJF Minories urban termius in 5 x 1 was originally meant as a TT layout, always wanted to try it with the triang track geometry just for fun but would so suit an AIA and a few mk1 suburbans

Yes: I'm sure  he mentioned that in one of his later articles. The key feature of Minories, the use of  opposite handed points to form each of the  the two crossovers, may well have occured to him earlier but the plan was published in April 1957, the month after the launch of TT-3 which had been planned for months. The fact that the published plan was exactly five feet long in TT but its length for 00 was misquoted as 6ft 6ins length when it was actually 6 ft 8ins (as given in 60 plans) does imply that he first drew it for TT.

Tri-ang's own track geography with 12 inch radius "set track" points would give an approach over which trains would lurch rather than flow. Tri-ang's points were 4.5 inches long but if you look at the version with a goods depot you'll see that the right hand board is effectively five points long giving 6 inches for each point. That suggests to me that it was designed - not suprisingly- for Peco's new 19 inch radius TT points which were 5 inches long and slightly more generous than 24 inch radius 16.5mm gauge Streamline points.

I've experimented with the Minories pointwork and, even with  nominally 2 ft  radius Streamline small points, bogie coaches do look a bit silly staggering though the reverse curves. With 3ft radius "medium" points the effect is far more satisfactory so it would be interesting to try equivalent rolling stock in 1:120 scale with Peco's "Medium " TT points.

Edited June 25, 2022 by Pacific231G
clarity

[Flying Pig]

11 hours ago, Nearholmer said:

One thing that it would be nice to see, as a differentiator from much r-t-r 00 and N would be a  reasonably fine wheel and point-work standard. When you see the fine wheels and flanges on some Japanese N (do they use NMRA or something else) it is quite apparent that modern production techniques can deliver something that both looks very good, and works, and a “green field” scale is an ideal opportunity.

Or, is it compromised from the start by the existing global TT market being based around a fairly coarse wheel profile?

 

I doubt that manufacturing is the limiting factor when it comes to wheel profiles as very fine wheelsets are perfectly practicable and not just from the specialist suppliers (e.g. P4 wheelsets available from SLW  and Accurascale). The fact that Peco have to accommodate existing stock is far more likely to be an issue.  Their points will determine how fine rtr wheelsets can be and still run comfortably.

 

BTW - there is another thread in this section started to discuss wheel standards.