0 gauge fine-scale on tight radius curves

[goldfish]

22 hours ago, F-UnitMad said:

Can we have all that in Old Money, please????  

 

In NEM 103 Bogie cars are classified into three groups:

Group A - Body length up to 65' 7" Distance between bogie pivots up to 45' 11"

Group B - Body length up to 79' 5" Distance between bogie pivots up to 56' 5"

Group C - Body length up to 89' 2" Distance between bogie pivots up to 64'

 

NEM 111 Section 3.1 gives minimum radii where the coupling prevent contact between buffers:

 

NEM 111 Section 3.2 gives minimum radii where the coupling allow contact between buffers:

 

The MOROP recommendations are based on a number of factors, including providing an acceptable overhang.

Edited November 26, 2020 by goldfish

[Northroader]

Pssstt.. still using grams!

[goldfish]

1 hour ago, Northroader said:

Pssstt.. still using grams!

My mistake, MOROP use 'G' as an abbreviation for gauge throughout NEM 111. For some reason in section 3.1, I changed this to 'g'. In practice I don't think anybody will interpret 'g' in the table as being grams, anymore than they will interpret 'G' as being Gaus, or 'g' as being gravity.

 

Now corrected, thank you for the nudge.

Edited November 26, 2020 by goldfish

[goldfish]

I am not a member of the G0G, so I do not have direct access to their documents, but I understand that the frequently repeated manta "The G0G minimum recommended radius is 6ft", is in fact an over simplification of the actual recommendations. The recommended minimum radii are given in Part 2, Section 1 of the Guild Manual.

 

I have added multiples of gauge (G) for comparison with the NEM recommendations.

 

Table 1 is accompanied by the following note:

 

"Note: The above figures are based on stock being pulled.
Where stock has to be propelled through curves into sidings or station areas the type of coupling employed is important. With loose couplings where the thrust is carried by buffers of scale diameter, (tighter curves need bigger buffers - up to 12mm diameter depending on wheelbase) it is recommended that the minimum be increased by at least 30% to limit the possibility of buffer locking."

 

[MarcD]

This shows that Peco set track is for small industrial layouts and that's about it. Anyone wanting to run anything bigger than a terrier and short goods stock over them should think again.  

 

Marc

[Donw]

2 hours ago, Furness Wagon said:

This shows that Peco set track is for small industrial layouts and that's about it. Anyone wanting to run anything bigger than a terrier and short goods stock over them should think again.  

 

Marc

 

Or be prepared for some work and a bit of trial and error. I think my Tower King might make round a set track curve but it would look rather like a dog  with its tongue hanging out. However my Bulldog will go round quite a tight curve probably 36 inch rad and with shome shortish coaches wouldn't look too bad. No 70 footers though. What you do have to accept tis that some things may be real trouble.  I think if peco had made a four foot radius curve it would have been very useful.  

 

Don

[doilum]

A different challenge from personal experience. At the previous house I had a continuous run with 5' 9" curves at one end and a 5' & 7' curves at the other.  I found that whilst my A4 and J25 had no problem with trains of 40+ wagons they struggled with more than 3 of my Kirk Gresley coaches. There was no buffer lock or derailment, just an insurmountable level of friction on the wheels. The coaches are individually free wheeling and have run successfully on a club layout. Perhaps that quoted minimum of 6' radius is not far off the mark.

[Donw]

4 hours ago, doilum said:

A different challenge from personal experience. At the previous house I had a continuous run with 5' 9" curves at one end and a 5' & 7' curves at the other.  I found that whilst my A4 and J25 had no problem with trains of 40+ wagons they struggled with more than 3 of my Kirk Gresley coaches. There was no buffer lock or derailment, just an insurmountable level of friction on the wheels. The coaches are individually free wheeling and have run successfully on a club layout. Perhaps that quoted minimum of 6' radius is not far off the mark.

 

That sounds to be like a problems with the coaches perhaps the couplings were too tight for the curves causing the buffers to be hard together on the inside and forcing the wheels against the rail.   Yes for 8 or more coaches I would expect the extra drag on curves to be noticeable  but three coaches on that radius doesn't sound right.

Drag on curves is a factor ideally trains should be no longer than 1.5 times the radius and twice the radius is a good limit.  So for a 5ft train i would expect to be able to run 7.5ft to 10ft trains quite happily.  You may get away with more but I would want a bigger space for long trains. If you can put a bit of straightway in the middle of the curve it does help to make it easier to have a long train as the bit in the middle is adding much drag.

 

Don

[doilum]

9 hours ago, Donw said:

 

That sounds to be like a problems with the coaches perhaps the couplings were too tight for the curves causing the buffers to be hard together on the inside and forcing the wheels against the rail.   Yes for 8 or more coaches I would expect the extra drag on curves to be noticeable  but three coaches on that radius doesn't sound right.

Drag on curves is a factor ideally trains should be no longer than 1.5 times the radius and twice the radius is a good limit.  So for a 5ft train i would expect to be able to run 7.5ft to 10ft trains quite happily.  You may get away with more but I would want a bigger space for long trains. If you can put a bit of straightway in the middle of the curve it does help to make it easier to have a long train as the bit in the middle is adding much drag.

 

Don

Sadly the railway was never reassembled after the house move and was sold as a project. The coaches use a solid bar connection that is spring loaded and can be replaced with a conventional coupling hook and 3link chain. The wheels are the heavy fine scale items from the Home of O gauge and run freely.

[Hesperus]

My layout (Leintwardine) isn't exactly finescale as I use a few older items of stock such as Leeds and BL but stick to fairly fine standards with code 100 rail.  I've got a ruling radius of 36" which does need slightly extended links on the couplings through the reverse curves in Y points. 

 

I'm planning to run a track around the walls in my dining room which will require a slightly tighter radius in some places but should be OK as I've done some tests with my stock.  Biggest loco is a Lima 4F along with a BL based Jinty and a Dapol Terrier.

[Philip Davies]

In This month O guild mag there is an article from one modeer who is running 3foot 6 in ccurves with no problem

[Nearholmer]

If Hesperus is still watching this thread: I'd be interested to hear more of what you are upto, especially whether there is pointwork involved, and how that plays out with both modern Dapol and old BL operating together.

 

I've found that the b-t-b on some postwar BL locos is pretty tight, challenging pointwaork that I have set to work well with 27.5mm b-t-b, let alone 29mm (that is right for G0G 'fine', isn't it?).

[F-UnitMad]

1 hour ago, Philip Davies said:

In This month O guild mag there is an article from one modeer who is running 3foot 6 in ccurves with no problem

What stock is he running on it? That's the key to "no problem".

[MarcD]

My layout "Boggs and Son" has the set track points on it, never again shall I go below 5ft radius.

To get things to work "OK" I have had to

• modify the couplings.  To get the Dingham's couplings to work I have had to make the loops bigger also I have spring the hooks.
• Reduce the size of the wagons in use I'm still getting buffer lock on any wagon longer than 16ft LOH so most are 15ft or shorter. Its ok to pull stock through but pushing is a different kettle of fish.
• I use short 0-4-0ST with dead buffers

I should say  can run my terriers light engine through all the track work in both directions but if I'm pushing stock they have to be chimney first other wise the over hang is to much. 

 

Marc

[Donw]

One of the things that helps is to make sure there is only minimal side play on wagon axles. When putting a kit together I make sure there is just enough side play to allow the axle to spin freely. Otherwise when pushing around curves the excess sideplay allows the wagon to twist increasing the problems of buffer locking.

 

If you look back to the previous Guild Gazzette you will find the previous article by Harold Jones on laying tight curves stresses the advantage of a small easement at the start of curves. This is because the offset of the buffers is greater when one vehicle is on the straight and the other on the curve, than with both on the curve. When using settrack you will not have an easement. It really does make a difference. Using set track points for cossovers cancan be particularly troublesome as 

these create an S curve where the radius changes from one hand to the other with no straightway in between which effectively doubles the offset of the buffers as the wagon ends are offset to different sides.

THe other thing is some of the people who use very tight curves such as Frank Roomes who had 3ft 6in curves, use autocoupling that incorporate some form of buffing action. However some of these while they will go round tight curves coupling up on the curves may be troublesome.

 

If you have the room using 4ft curves and 5ft radius turnouts  would be much better even at the expensense of a simpler layout. Mind you if you want an oval in an 8ft wide garage you cannot keep to 4 ft minimum.

I hadn't realised that the overhang on terriers could be an issue I shall have to compare mine with the 1365 dock tank I have.

 

Don

[New Haven Neil]

12 hours ago, MarcD said:

My layout "Boggs and Son" has the set track points on it, never again shall I go below 5ft radius.

To get things to work "OK" I have had to

• modify the couplings.  To get the Dingham's couplings to work I have had to make the loops bigger also I have spring the hooks.
• Reduce the size of the wagons in use I'm still getting buffer lock on any wagon longer than 16ft LOH so most are 15ft or shorter. Its ok to pull stock through but pushing is a different kettle of fish.
• I use short 0-4-0ST with dead buffers

I should say  can run my terriers light engine through all the track work in both directions but if I'm pushing stock they have to be chimney first other wise the over hang is to much. 

 

Marc

 

This made me think about how I manage OK, and then a light clicked on.

 

I cut the curved section of the Setrack points back quite a lot, 3 or 4 sleeper  lengths if I recall correctly, to reduce the amount of curve on the diverging line.  This has enabled the use of Panniers (I have Lionheart, Dapol and Minerva examples) with very few issues.

 

 

[Nearholmer]

Thats "the big issue" with the setrack points in a "model railway" context: the arc of curvature is too great, rather than the radius of curvature being too small (for short locos and vehicles). once chopped back they are far more accomodating, and don't look anything like so "toy".

 

This is part of my half-finished, study-shelf photo-plank, and the points are almost exactly the same geometry as the Peco settrack ones, but I think you will agree that it flows OK, which is because the arc of curvature is modest 18 degrees. This uses G0G "coarse", rather than "fine" clearances, 'cos that's what I run, so will look strange to "finescale eyes", but that is immaterial to this part of the discussion really. I can happily shunt trains on here using three-link couplers, and although they have wide (Leeds Model Company) buffers, I'm confident that scale-sized buffers would work on here with small locos if it the track had "fine" clearances.

 

As a footnote: many real industrial railway locos for use on tight trackwork have/had "oversize" buffers, because exactly the same issues arise in reality as do on models.

 

As has been said in this thread before, the trick is not to try and have your cake and eat it. You can have tight curves, you can have hi-fi scale couplings and buffers, you can have engines with lots of end-throw, and you can have rolling-stock with lots of end-throw. What you can't have is all of those things, all at once.

 

 

 

Edited August 4, 2021 by Nearholmer

[Northroader]

Ooh! Goody!! A “pop up” takes shape!!!

[Nearholmer]

Its the same one thats been taking shape since the start of Lockdown 1, so taking shape at glacial speed, yes.

[F-UnitMad]

7 hours ago, Nearholmer said:

the trick is not to try and have your cake and eat it. You can have tight curves, you can have hi-fi scale couplings and buffers, you can have engines with lots of end-throw, and you can have rolling-stock with lots of end-throw. What you can't have is all of those things, all at once.

I have my cake & eat it too - I have nearly all of those things - 3ft radius curves, scale couplers (or at least couplers that look like the protoype), and locos with some end-throw.

What I don't have, of course, are buffers....  

 

 

Edited August 4, 2021 by F-UnitMad
Spelling!!

[Alan Kettlewell]

Looking for advice please.  I've made a mistake when designing my 0-MF layout .  Using Templot, I've designed and built a crossover in my storage yard but the turnout angles are far too small/short to enable reversing without buffer locking.  In short, I should have made the pair of crossover turnouts to a much shallower angle.  My plan for operating requires 60ft bogie coaches to be reversed over this crossover and of course, buffer locking prevents this.  I should add that I'm using Dingham couplings so the common fix of soldering a bar across the buffers to prevent buffer locking is not viable.  (Yep - made a rod for my own back here ...)   

 

My question is: is there a set of standards recorded anywhere which sets out a range of minimum turnout angles in order to avoid buffer locking when reversing?  For example, is it A8, A9, A10 turnouts?  

 

If I have a definitive answer, I may be able to rebuild this crossover, but I'd need to know first what enormous length the crossover may end up as it may not fit!

 

Cheers ... Alan

 

Afterthought - in the meantime, I've remembered that I can simulate vehicles on the track in Templot, so I can experiment a bit there.

Edited September 27, 2023 by Alan Kettlewell

[PeterStiles]

On 13/11/2020 at 08:32, MarcD said:

modified Dingham coupling that can cope with the reverse curves.

I've added a 3" piece of Flexi track between reversing curves with exactly the same stock (give or take a paint job). It extends the layout a little, but means I can use the stock as purchased.

 

There's something immensely satisfying about 3 link coupling when 'playing' with an Inglenook..

[brossard]

4 hours ago, Alan Kettlewell said:

Looking for advice please.  I've made a mistake when designing my 0-MF layout .  Using Templot, I've designed and built a crossover in my storage yard but the turnout angles are far too small/short to enable reversing without buffer locking.  In short, I should have made the pair of crossover turnouts to a much shallower angle.  My plan for operating requires 60ft bogie coaches to be reversed over this crossover and of course, buffer locking prevents this.  I should add that I'm using Dingham couplings so the common fix of soldering a bar across the buffers to prevent buffer locking is not viable.  (Yep - made a rod for my own back here ...)   

 

My question is: is there a set of standards recorded anywhere which sets out a range of minimum turnout angles in order to avoid buffer locking when reversing?  For example, is it A8, A9, A10 turnouts?  

 

If I have a definitive answer, I may be able to rebuild this crossover, but I'd need to know first what enormous length the crossover may end up as it may not fit!

 

Cheers ... Alan

 

Afterthought - in the meantime, I've remembered that I can simulate vehicles on the track in Templot, so I can experiment a bit there.

 

When I built Balmoral Road, see link below, I was space constrained and didn't want to use standard Peco straight turnouts since they are very long.

 

My first idea was to use Peco 00 small radius turnout templates (blown up by 199% to compensate for gauge) and build turnouts for the crossover.  When done most stock ran OK through the turnouts but two locos, FSB J39 (0-6-0 tender) and Connoisseur G5 (0-4-4T) complained mightily when going through.

 

I had a rethink and decided to try using Peco 00 Medium radius turnout templates.  To my delight, this worked great.  I had to give up some space but still have just enough.

 

 

HTH

 

John

 

BTW, for another project I looked at the difference between Peco Set Track turnout and Medium radius turnout based on the 00 template.

 

 

If it's not obvious, Set Track is on the left.  For me, the turnout on the right looks about right.

Edited September 27, 2023 by brossard

[Alan Kettlewell]

Hi thanks.  Are you saying you can reverse 60ft bogie coaches through these Peco turnouts?  

 

Cheers ... Alan

 

[F-UnitMad]

40 minutes ago, brossard said:

...use Peco 00 small radius turnout templates (blown up by 199% to compensate for gauge) ....

I did that for a curved switch (turnout, point, etc!) that I needed in O with 4ft outer radius & 3ft inner. There were no O templates with those radii, but enlarging the Peco OO (setrack, I think) curved point template worked a treat.

This photo was taken while ballasting it. Of course it's for American O; with buckeye couplers & no buffers, curves can be much tighter than for UK O, & still use long locos & stock.

AFAIK, for long British stock minimum radius is 6ft really. Even auto-couplers can't take long stock through much tighter curves; they are not really a direct equivalent of the 4mm tension-lock coupler.

Edited September 27, 2023 by F-UnitMad