Rail Superelevation/Banking/Canting/Camber Question

[Railwaygun]

Xi

I use the Kato double track with superelevation as my test circuit, and I found that Revolution's Sturgeon wagons would uncouple on the transitions, which I eventually attributed to the fact that they are so long that one was at full tilt while the one behind was still flat, causing too much twist on the couplings. Just something else to chuck into the calculations.

Did you use the transition rail piece ( in video) to link flat  and superelevated sections?

[Yet_Another]

Did you use the transition rail piece ( in video) to link flat  and superelevated sections?

Yes, you pretty much have to, because the canted tracks on the superelevated curves don't connect to straight flat sections at all well.

[Greygreaser]

Interesting that only cant for speed is mentioned but several question slower line speeds. One of the main reasons for cant is to balance the rolling radius on both wheels of the same axle.
With a solid axle both wheels would turn at the same RPM so the 'tyres' are chamfered with the larger diameter adjacent to the flange. The flanges are not fixed at gauge distance apart but slightly under so the axles can 'float' between the rails.
The chamfered tyres in straight line running keep the wheels from hunting side to side together with the rounded rail top.
On a bend the rolling stock is forced outwards and this causes the wheels to move outwards too. The outer wheel now runs on the larger diameter adjacent to the flange whilst the inner wheel runs towards the track centre and contact with the rail is by the smaller diameter of the tyre.
In this way the wheels on the axle have different rolling radii to stop friction and squealing on the curve - mostly!
This diagram is from 'Curving Behaviour' on Science Direct website applicable to a right hand curve.

[Safety Engineer]

Believe On LU circle line trains used to be turned end for end on the Gloucester Road triangle to balance out the wheel wear.

[LeftToMyOwnDevices]

Believe On LU circle line trains used to be turned end for end on the Gloucester Road triangle to balance out the wheel wear.

Yep, I also believe that's true (unless it's an urban myth...!).

Mind you, there's also the Aldgate triangle as well, to turn the units. It was probably not that difficult to diagram into the Working Timetable, given that C69//C77 stock also worked on the H&C and Wimbledon-Edgware Road services. A set of late evening ECS move(s) would surely achieve that.

I would guess that it still happens, even though the Circle Line is not strictly a circle; and now that S7 stock also operates the main District Line. It would also be easier to diagram, as well, I would imagine.

In this way the wheels on the axle have different rolling radii to stop friction and squealing on the curve - mostly!

Yep, true. I distinctly remember the 'squeal' from the wheels on the section between London Bridge and Waterloo East; also Victoria SE - and being pleased that I knew what the noise was (and what was causing it...!).

To get back 'on track' and 'on topic'...
...thank you (all) for this thread, as this is something I would seriously like to do, when I get round to building something myself. I have been wondering about some of the pitfalls referred to above, so will bear them in mind. I did once see an N gauge layout which had done this - and felt that they hadn't tilted (or canted) the track enough. But may be they had done it, just enough.

Although Kato track is not really for me, I do like the way they have gone about it, complete with transitional curves.

Charles.