British N Gauge Grade Tolerance

[scottmitchell74]

My first layout has a frustrating 3.3 to 4% grade. It's very limiting.

On my new proposed layout I want elevation, but I'm only allowing 2% at most.

I'm wondering how British locos handle 2%?

Thanks!

[ntpntpntp]

There's no single correct answer.   It really does vary by model, and depends on loco weight, number of driven axles, whether or not there are traction tyres,  weight and drag of the train, whether there are curves on the gradient etc.  I would say British N locos generally don't have traction tyres  

2% is generally considered the steepest to go for, but some trial and error is wise.

[Bazza]

I'm wondering how British locos handle 2%?

Some do and some don't, and even those that do will struggle with long heavy trains. It's best to avoid gradients all together (in your layout plans) and if that's not possible then make sure they are as gentle as possible and not greater than 2%.

[Southerngooner]

I took advice from Steve Wright, the builder of James Street, and kept to 1:100 (1%) on my layout. It has 12" radius curves at both ends, and all of my stock, tyres or not, can pull 8 coaches or 25 wagons up the bank and round the corners, which at one end are still on the gradient. If you want long trains (8+ coaches, 25+ wagons) keep the gradients shallow or use locos with tyres; if you need to use steeper gradients be prepared to have to compromise on train length or stock capable of being used.

Dave

[Jollybob]

I have a 8% gradient on my layout , I think I worked it out at, going around a bend. I found the the older Farish and Union Mills locomotives handle it with no problems, due to these being made of metal and therefore quite heavy. The newer locomotives struggle to pull and will stall. However the newer locomotives will go up it on their own.

Rob.

[Newportnobby]

An alternative is to lower the ground by 1% and raise the track(s) over it by just 1% thus getting the same clearance but with a lower gradient

[EtchedPixels]

My first layout has a frustrating 3.3 to 4% grade. It's very limiting.

On my new proposed layout I want elevation, but I'm only allowing 2% at most.

I'm wondering how British locos handle 2%?

Thanks!

Some of the Dapol steam in particular has enough trouble on the flat. Heavy minitrix locos go up steep grades (except the unfortunate ivatt). Farish varies a lot - diesels generally do better than kettles.

2% is a good number, or model yourself a banker (and you can do that for UK stuff up to the 1980s trivially, and even later but it became a much less common movement).


If it's purely a visual grade then tilt the layout at 2% and run the track flat

[scottmitchell74]

All great info guys! Thanks so much.

[scottmitchell74]

An alternative is to lower the ground by 1% and raise the track(s) over it by just 1% thus getting the same clearance but with a lower gradient

This is where my mental deficiencies rear their head the most: as simple as this might seem, I can't visualize what you mean by this. 

[Newportnobby]

I'm (maybe wrongly) assuming the gradient is for one line to cross another, as in a figure 8. Where they cross, lower the bottom line into a shallow 'trough' instead of it being on the level. Then the gradient for the upper line doesn't need to be 2% to clear the lower track.

[Southerngooner]

Here's what is meant. The two pairs of lines crossing are at the same level on the right hand side.The near pair descends by 1:100 (1%) while the far pair rise by the same grade. They cross in just over 1.5m. My layout is a looped eight similar to your plan., and getting these lines to cross was a key part of the design.

Dave

[scottmitchell74]

I'm (maybe wrongly) assuming the gradient is for one line to cross another, as in a figure 8. Where they cross, lower the bottom line into a shallow 'trough' instead of it being on the level. Then the gradient for the upper line doesn't need to be 2% to clear the lower track.

Got it. Thank you.

[Firstone18]

I've got a helix on my layout made from No3 radius curves. It is 2% and covers 3 and half turns. My Union Mills and older GF steam locos can manage 4 or 5 coaches, the newer GF steam sometimes struggle a bit. Big diesels like Deltics and Class 47s have no problem with this gradient even though on a curve.
The old version of the club layout had two big oval helix units one at each end, these were also at a nominal 2%; as a test one evening I tried my UM J39 and at 14 coaches it was still showing no signs of slipping and there were no more coaches available.
HTH
Cheers!