turnouts the more i learn the less i get

Source: TU Delft(the Netherlands)
Turnouts differ in sizes. Some commonly used ones are shown below. The number after '1:' stands for the angle of intersection. The length and the maximum allowable speed to pass the turnout in the divergent direction are given below as well.

1:9 - 32 meter - 40 km/h
1:12 - 38 meter - 60 km/h
1:15 - 47 meter - 80 km/h
1:34 - 99 meter - 140 km/h

.......

So when i am wanting to build my tracks prototypical correct and my "average real life speed" will be 70 km/h i will need a 1:15 turnout.
But when i do my calculations for 1:32 modelling i can not get the 47 meters, i get a 1 meter turnout that should be 32 meters in real life.
32 / 47 meters is in my scale 68,01 cm...
But i get a turnout of 102 cm...(would be in real life 99 meters aka 1:34---->140 km/h
With a radii of 581cm in: 1:9, 1:12, 1:15 and 1:34
What do i miss here, where did i go wrong?
I dont think this question is appropriate to ask in class sinds we are handling prototypical and not model?
(studying railway engineering)
Thanks in advance, with best regards Igor
 
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Martin Wynne

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Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add helpful replies.
32 / 47 meters is in my scale 68,01 cm...
Hi Igor,

That should be 47000 / 32 = 1469mm on your model.

Where did you get those figures from? What dimension does the 47 metres represent? Do you have a drawing?

Here is a UK 1:15 turnout using a curved size CE switch and generic V-crossing, which may (or may not) be close to your prototype:

p32_ce_15.png


As you can see the overall length is about 1460mm, very close to your desired size (if the 47 metres is the overall length).

cheers,

Martin.
 
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Matt M.

Member
Location
Australia
Hi Igor,

Like Martin I'm slightly confused about some of the figures you quote.

In 32nd scale a meter is 3.125cm or 312.5mm. Multiplied by 47 gives a length of
146.875cm or 1468.75mm.

Also like Martin I'm assuming that this is the overall length of the formation.
The big difference from a construction point of view would be the increasing
lengths of the switch blades and crossing.

I'm also not sure were you are getting the radius figure of 581cm from.
Usually the higher the slope angle number the bigger the radii measurements
it takes. 1:9 should not be the same as 1:34.

Also remember that there will be differences in design and speeds through
formations depending on the period you are modelling. You would be learning
modern turnout design at the moment.

For quite a long time the NSWGR had vertical formations with speed restrictions
due to the fact that planing switches for inclination was too much of a problem
to deal with.

Also to remember the first thing that is compromised in model railways is track.
The real life measurements are just too large fo most people to cope with.
On the NSWGR the main line minimum radius was 8 chains, (a chain is 66 feet),
which in 7mm, the scale I nominally model in, is a radius of 369.6cm.
That means I would need seven and half metres or 24 feet to replicate a
minimum radius loop. Your AA20 would not make it around that.

The knock on effects on the rolling stock is un-prototypical bogie or truck swing
that kills some of the accuracy that you would like to have.

I've spent a couple of hours at a time trying to explain to modellers how a front truck
on a steam locomotive actually works because they just don't move that far in real life.

You appear to be suffering a little bit of information overload with the course, which is normal.
It takes time to assemble all the bits of information so that it makes sense. Take your time
and keep trying to apply some of it to your modelling. It will click at some point.

I'll be back to answer your previous question about the crossing lead in length in the other thread.

Regards, Matt M.
 
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Where did you get those figures from? What dimension does the 47 metres represent? Do you have a drawing?
I made a big calculation error, this is entirely my mistake. I turned around the two numbers and dived them...
That is why it did not make any sense in my head...To tired of all:

I am pretty busy last couple of weeks.
Tax for my first company, starting up a company with my brother, i could not resist..to good offer..(plan of business cooperation, investment ect) and studding 2 different things...

Like Martin I'm slightly confused about some of the figures you quote.

In 32nd scale a meter is 3.125cm or 312.5mm. Multiplied by 47 gives a length of
146.875cm or 1468.75mm.
I was just tired, you put it down very polite:
You appear to be suffering a little bit of information overload with the course, which is normal.
I'm also not sure were you are getting the radius figure of 581cm from.
Usually the higher the slope angle number the bigger the radii measurements
it takes. 1:9 should not be the same as 1:34.
When i was entering this 1:9, 1:12, 1:15 and 1:34 in Templot, the program give me this radii for all four.
When i go to 1:8 or lower than the program will give other smaller radii.
Also remember that there will be differences in design and speeds through
formations depending on the period you are modelling. You would be learning
modern turnout design at the moment.
Yes i am aware of this, better to point out than not point it out(y)

The real life measurements are just too large fo most people to cope with.
Lucky i have the room to do it "semi prototypical"
1:15 switches is no problem.

The knock on effects on the rolling stock is un-prototypical bogie or truck swing
that kills some of the accuracy that you would like to have.
With this one i am not sure if i understand this correct.
But the first experiments where satisfactory, my (model) flange is 0.5 mm thick, 1.50 mm deep, the bearing surface is at 3 degrees.
Clearance between flange and rail is 0.5mm.
(The AA20 is for now 1.5 mm clearance between flange and the rail.)
The trucks and even the lose axles roll down very smooth without to much wobble.
The slope was 1 cm at 1 meter 25 to 0.
In strait and a curve of 4 meters.
The whole bogie is placed exact as on drawing on the car.
I think i am on the right track?

Matt M thank you very much for your extended reply, it is appreciated(y)
Just for my curiosity if you dont mind me asking:
What did you do or still doing for a living?
When i finish this course(6 weeks from now) i can roll in to "road and railway engineering" in September.
Am i wrong to suspect you did something similar?

With best regards Igor, cheers
 
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I was making a box file yesterday and i did not save it.
I made a new one and clearly i am doing something wrong with Templot
I tried to make all 4 switches.
But this time i get different radii?
I will have a better look/try when i have more time.

Thanks
 

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Matt M.

Member
Location
Australia
Hi Igor,

While scaling down may not affect you so badly, due to the room you have,
for most modellers it is a big problem. And also for manufactures of ready to
use rolling stock and also kit designers.

The example I gave for the minimum main line radius for the NSWGR of 8 chains
which is equal to 24 foot in 7mm (1:43.5 scale) is not readily available for most people.
And remember that you also lose 24 feet out of your layout's length if you want to
have an oval layout. And that is before you add transitioning to the curves.

7mm finescale guys expect to be able grind around 5 foot radius curves if they want to
have an oval layout. Scale 7 minimum is recommended at a 7 foot radius.
To do that you are indulging in gauge widening track which is fine and sort of prototypical.

But mostly the compromises are with the rolling stock.

Looser wheel standards. Narrower frames which gives extra clearance to radial trucks.
Cutouts in the frames to allow the enthusiastic over-swing of Bissell / pony trucks.
Cutouts in the back of cylinders to allow the same with bogies. Setting the cylinders
fractionally further apart. That also gives you more clearance for the motion gear.
A 10mm or half inch clearance is fine in real life but try scaling that down and it will
either cost too much to manufacture or be extremely hard for a kit builder to get
right.

When you see a locomotive model that doesn't look quite right it is usually the
compounding issues of clearance that has left it with a strange relationship between
what is above the footplate and what is below it.

And we haven't even got to the problems with carriages and wagons.

Your 4 metre radius seems a little small for the AA20 simply because at 9.5mm to a foot
it works out a slightly over a 6 chain radius in real life. So if the AA20 is going around that then
there are lots of compromises in your frames and wheels. Not that there is anything wrong
with that. It is unavoidable.

In your previous thread regarding frog/crossing rules of thumb I mentioned long crossings and
long leads. On your V crossings on turnouts I would be looking for an 8 metre radius minimum.
Let the ridged frame clear before adding to the curve or doing a reverse curve. That should
make it more reliable. With diamond crossings a straight lead in that is as long as the rigid frame
so that there is little side pressure going through the crossing would increase the reliability.
Especially at speed.

I don't mind you asking what I do/did for a living.

I'm a musician. Classically trained piano. When I left school I work in the automotive industry
in spare parts. Specialised in Italian cars. Fiat, Alfa, Lancia, Maserati, Lamborghini and Ferrari.
Suburban music teacher for quite a number of years so given a reality check by lots of children that
really didn't want to work at music. Not an engineer though I know quite a few and can cope
with talking to them about their particular specialties.
Can happily read blueprints. Rebuild car engines and gearboxes though I haven't done that for a while.
Currently being a carer for an elderly infirmed parent for the second time so time and money are at
a premium at the moment.
Do railway history research for various people and get my free copies of their books.
Currently compiling an index for the third consignment of Mechanical Branch drawings that were moved
over a decade ago from the State Rail Authority to the NSW State Archives, without an index.
Answer questions from State Records about railway plans and drawings when they are having
problems. Do the same for the Australian Railway Historical Society of which I'm a contributing
member.
Currently running a project to work out how many of the NSWGR Mechanical Branch drawings
from 1883 Drawing No.1, (the start of the sequential numbering system), to 1969 drawing No.99,999
have survived and where they are.
I was supposed to write a book for the ARHS about NSWGR Permanent Way from 1848 to 2000,
but that is on hold at the moment due to the carer situation and also the fact that the person I was
originally working with, Don Hagarty, died a couple of years ago. Don was the last Chief Civil Engineer
under the State Rail Authority in 1998 before the restructure and privatisation.

Other than that I read a lot over a wide range of subjects in history, science, medicine and engineering.

Regards, Matt M.
 
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@Matt M.

Precious information, and you are absolutely right on all things, incl the AA20...
Yes i made some compromises.(wont say a lot) for the AA20, but still testing and improving.

I will read your replay again in the weekend to give you a proper replay that you deserve, for now i have to little time for reasons mentioned earlier, sorry about those, but i want to move on in life, must study again:cool:

Thanks for all with best regards Igor.
 
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Acfield

Member
Location
Nottingham
Real name
Tony Overton
Here in the UK we have easy access to track fittings, chairs, sleepers and rail for various scales from various suppliers. Can I ask, are the same items easily available to modellers living in Germany and the Netherlands who wish to build their own track and turnouts?

Cheers
Tony
 
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Martin Wynne

Admin
Location
West of the Severn UK
Info
Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add helpful replies.
I made a new one and clearly i am doing something wrong with Templot
I tried to make all 4 switches.
But this time i get different radii?
@Justme Igor

Hi Igor,

It is difficult to help without knowing anything about your country's prototype trackwork. But you are failing to set an appropriate size of switch to match the V-crossing angle. Only some combinations of switch size and V-crossing angle make sense.

startup_pad.png


Explanation of the above is in section 5. at:

https://85a.uk/templot/companion/gs_firstoff.php

I suspect that the best match to UK turnout sizes will be to set a generic pattern V-crossing, and use the curved FB range of switches:

generic_xing.png


curved_FB_switches.png



After making those settings, use the F5 size mouse action to set the V-crossing angle:

curved_FB_switches_f5.png


Templot will automatically change to the most appropriate switch size for the V-crossing angle as you adjust the angle (although not necessarily the switch size which will give the best match to your prototypes).

cheers,

Martin.
 
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Here in the UK we have easy access to track fittings, chairs, sleepers and rail for various scales from various suppliers. Can I ask, are the same items easily available to modellers living in Germany and the Netherlands who wish to build their own track and turnouts?
Not to my knowledge in the Netherlands.
Besides the costs for what i want, i am really a do it your self person.
From my point of view it is easy to buy something with the money you earned, but the fun part?
It's for me: diy and the learning curve, plus i would like to make a profession chance.
I can combine atm, win win.

Aldo i am pretty handy with my tools and I have really lot of tools and machinery for woodworking, i can not win from my 3d programs and my 3d printer
Just out of curiosity, can you share a link or two?.


Martin thank you for your effort to explain it crystal clear.
Again one step closer to reality.
I will tackle this in the weekend.

Thanks and Cheers!
 
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@ Matt M
I am sorry that i did not had time to give you a proper reply this weekend, like i promised.
But this is keeping me busy all week:

In your previous topic regarding frog/crossing rules of thumb I mentioned long crossings and
long leads. On your V crossings on turnouts I would be looking for an 8 metre radius minimum.
Let the ridged frame clear before adding to the curve or doing a reverse curve. That should
make it more reliable. With diamond crossings a straight lead in that is as long as the rigid frame
so that there is little side pressure going through the crossing would increase the reliability.
Especially at speed.

How did you get to the 8 meter radii?
That is big..I think i can implement 8 meters in my "nightmare corner"
For the diamond crossovers i understand fully.
Go strait or go over, it makes a lot of sense.
With 8 meters i dont have to do so much trouble also to adapt the AA20 or other really big ones.
Yes a single track dedicated for loco's over 25 inch, instead of adapting the loco's..
A lot of food for my thoughts.
But how did you get to that 8 meter radii?
I don't suspect a "gut" feeling.

With best regards Igor
 
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