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General Category => N Gauge Discussion => 2mm Finescale => Topic started by: GKman on January 13, 2017, 12:14:07 PM

Title: Gradients
Post by: GKman on January 13, 2017, 12:14:07 PM
I want to place a gradient in my new layout.
The spec of my gradient is - 2" rise over 14"of rising rail.
Never done this before.
Will this be too steep ?
Regards
GKman
Title: Re: Gradients
Post by: keithfre on January 13, 2017, 12:27:55 PM
I would imagine so, but the only way to know for sure is to make a test setup and try the rolling stock you want to use on it.
Title: Re: Gradients
Post by: Bob G on January 13, 2017, 12:28:16 PM
Sorry but that is way too steep! That is almost a funicular railway.

That is 2 in 14 or 1 in 7 gradient. Steepest gradient likely to work is 1 in 20, so you will need 40" to rise 2".
If you include bends on the gradient then you have to have a lower gradient too, say 1 in 30.

These figures are generic ones - a lot depends on the locos you run and what they are expected to pull.
In general, diesels will also cope with steeper gradients than steam locos.

On small layouts, if you want two levels, it is often possible to have two separate lines at different levels which are not connected.

HTH
Bob
Title: Re: Gradients
Post by: GKman on January 13, 2017, 12:30:53 PM
Thanks Bob, thats that layout out of the window
Regards
GKman
Title: Re: Gradients
Post by: Newportnobby on January 13, 2017, 01:51:52 PM
As has been said, 1 in 7 will not work. I'd suggest 1 in 30 as a minimum and more if possible.
Bear in mind you can mitigate the length by having the earth 'sink' by 1" whilst the land rises by 1"
Title: Re: Gradients
Post by: Old Crow on December 04, 2018, 12:30:37 AM
I made a long run at 1 in 50 and heavy locos have no problem whatsoever so, in retrospect I could have saved space and maybe gone 1 in 40 or less??? What has anybody done that works?
Title: Re: Gradients
Post by: Chetcombe on December 04, 2018, 02:46:39 AM
Also bear in mind that putting an incline on a curve puts extra stress on a loco. I have found that there is no impact on a loco's hauling power on a 2% incline (which I think is 1 in 50), even if you include a tight curve.
Title: Re: Gradients
Post by: LAandNQFan on December 04, 2018, 08:12:35 AM
I have 2% and 3% slopes on my GWR steam layout- the 3% being on a 9" radius curve.  UM locos have no problem at all   :thumbsup:.  The autocoach set has problems on the 2%   :thumbsdown:  Panniers can haul two coaches up the 3%  which is all I need on my Carmarthen- Aberystwyth line. 

You really need to make a test track to make sure; Put a length of flexi on a bit of ply, assemble typical trains and keep raising one end of the ply until there are problems.
Title: Re: Gradients
Post by: njee20 on December 04, 2018, 08:36:27 AM
Holy thread resurrection Batman!

I made a long run at 1 in 50 and heavy locos have no problem whatsoever so, in retrospect I could have saved space and maybe gone 1 in 40 or less??? What has anybody done that works?

It depends on how long your trains are and how powerful your locos are. Iíve got a 2% gradient and find most stuff can get up it, but not the longest freights, nor anything hauled by a Dapol 66! A Farish 60 will romp up with 16 bogie wagons, but my sole steam loco (an A1) wonít manage 8 mk1s and a dummy 67.

If everything you have goes up then Iíd say thatís a success, maybe youíd have been ok with a 1:40, but then if some stuff ground to a halt thatís not much use. You want a bit of margin.
Title: Re: Gradients
Post by: NGS-PO on December 04, 2018, 10:17:21 AM
Holy thread resurrection Batman!

I made a long run at 1 in 50 and heavy locos have no problem whatsoever so, in retrospect I could have saved space and maybe gone 1 in 40 or less??? What has anybody done that works?

It depends on how long your trains are and how powerful your locos are. Iíve got a 2% gradient and find most stuff can get up it, but not the longest freights, nor anything hauled by a Dapol 66! A Farish 60 will romp up with 16 bogie wagons, but my sole steam loco (an A1) wonít manage 8 mk1s and a dummy 67.

If everything you have goes up then Iíd say thatís a success, maybe youíd have been ok with a 1:40, but then if some stuff ground to a halt thatís not much use. You want a bit of margin.

I'd agree with this. I've done a bit of research into gradients and helices. My requirement was for 12 coach/30+ wagon trains, hauled by tender driven steam engines and diesels. The diesels perform much pretty well, but to get consistent results with steam engines (including the A1 mentioned above - I found the same issue at 2%), with virtually no wheelslip, my gradient is 1% (1:100). This gives a margin as talked about by Nick.

Equally, if your trains are shorter, or all diesel hauled, or only DMUs etc, you will get away with steeper inclines. You have to test it with the stock you're actually going to use, as there is no one-size-fits-all.

Best

Scott
Title: Re: Gradients
Post by: BobB on December 04, 2018, 11:20:04 AM
Running diesels (Farish and Dapol) with all wheel drive allows locomotive + 4 coaches around 180 degree radius 1 with about 100 mm section at either end as a transition going up 50 mm. 0-6-0 steam locomotives can pull two coaches with some wheel slip !

I have not tried 5 coaches on the diesels but who knows !
Title: Re: Gradients
Post by: emjaybee on December 04, 2018, 11:36:09 AM
I found that a current model Farish Jubilee will pull 7 carriages up a 3.5% incline around a 10 inch curve with a little slip.

More than enough for my needs.

 :)
Title: Re: Gradients
Post by: jpendle on December 04, 2018, 02:13:27 PM
You really have to try it out first.

I burnt out the motor on a Farish 66 hauling 22 HTA's up a 3% incline on a curve.

Since then I have settled on 2% inclines with no large radius curves.

But I also have the benefit of having a large shed to house my layout.

Regards,

John P
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