How To Build Inclines Your Trains Can Climb – Maximum and Recommended Gradients UPDATED

don't screw up your slopesIf you want a fun and interesting model railway then you’ll want your trains hauling up hills and hurtling down. Here’s how to work out the vital length and gradient numbers needed to start building inclines.

Watching tiny trains trundling around a model railway is fun but if the track is just flat it can get boring before long. Using cuttings to obscure them adds mystery helps but seeing your trains hauling up hills, now that’s something else!

On my N gauge Cornish-themed layout. I’m changing the track plan so my GWR pannier engines and wagons now climb up to the Tin mine by winding their way around a hill. The vertical action breaks up what would otherwise be a dull terrain track plan and adds interest for the viewer, will the little engine make it…

Why can’t trains go uphill?

Building inclines isn’t just a matter of titling some track upwards to the height required.

Given the small amount of surface area of a train wheel that comes into contact with the rails, there’s actually little traction that can be brought to bear when climbing a hill. If the slope is too steep there won’t be enough traction to compete with the downhill drag the engine will stop or even roll backwards!

Watch James May elaborate on this and explain why trains can’t go uphill:

In a discussion on this very subject on the Bachmann trains forum, Doneldon noted that building inclines to prevent trains from stalling and backsliding means giving “careful attention to track and wheel gauge, rolling stock clearances, transition curves, moderate grades, electrical integrity, precise coupler adjustments and adherence to correct weight for your rolling stock” (see original post here).

That’s a lot to consider.

Luckily others have been here before.

What’s needed is to reduce the incline to a gentle slope. You can see this in real railways where the approach to hills is done gradually over many miles.

The problem is that this requires long stretches of track.

On real railways, this is expensive and ingenious designs have been developed over time to provide the length of track required without the distance. These include spirals that work their way around hills and mountains, zig-zags and horse-shoe designs. And on our model railways — where space is a premium — it’s even more of a problem.

This predicament has been tackled by other model railway engineers and the optimum ratio for the rate of climb that trains can manage while eating up the minimum distance of track is well established.

And a proven ratio has been figured out.

This tried and tested ratio for model railways is a grade of 1 in 50. Or a 1cm increase in height over 50cm of horizontal travel.

You can use any unit distance as long as the same is used in both dimensions — eg 1 inch over 50 inches — and as such this applies for N, OO and HO scale layouts.

Did you know? The steepest prototype mainline railway in Great Britain is Lickey Incline, south of Birmingham, with a bonkers gradient of 1-in-37.7 (2.65%). The line through the Luxulyan Valley in Cornwall, which I’ll be featuring as a spur on my layout, reaches 1 in 37 in places but only for short stretches.

So building your layout is just a case of working out the height of the vertical to be reached and multiplying this by 50. This is how long the track will need to run to go from the “ground” level to the top of the hill or bridge needed.

If you want the track to climb from baseboard level to a bridge that runs over another section of track measure from the top of the bottom rail to the top of a rail on the bridge. On my layout, this will be 5cm. Multiple this by 50 and I need to start the incline 250 centimetres from the bridge, creating a gentle rise to the crossing.

This ratio is called the grade and is usually expressed as 1 in 50, or as a decimal percentage (divide rise by the run, eg 1/50 and multiply by 100, giving 2%).

In experiments, I’ve had modern locos pull approximately 10 wagons or five-passenger cars up such a grade. For longer trains, do what the real railways do and double up or even triple up on locomotives.

Steeper inclines can be used but the steeper you get the more chance of problems emerging.

The consensus from experienced railway modellers is not to go beyond 1 in 40. With 1 in 30 being the absolute maximum considered by modellers on Model Railway Forum and the Anyrail forum (here and here). 1 in 30, by the way, equates to 3.33% – compare this to the 2.65% Lickey Incline figure above to get an idea of how models compare to the real thing.

These calculations assume you have a height you want to reach and need to know the run distance you’ll need to get there. Rather than repeat some simple maths, take a wander over to the Credit Valley Railway Company which has written an excellent article on the calculations needed.

I’d love to hear about your inclines and track plans, drop a line via the contact page or add a comment below.

Happy incline hauling!


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> A final, personal, note: I spend a huge amount of time testing, photographing, writing and researching techniques for these articles and pay for all the running costs of MRE out of my own pocket. If you found this article useful you can support me by making a donation on my fund-raising page. Thanks and happy modelling, Andy.
  1. I have a small model railway in OO and have found steep gradients with short trains to be no problem. The more coaching or wagon stock you put behind the loco the more problems you will have. DCC Concepts have their “Power Base” which is magnets under locos and under the track and that alleviates a lot of the problems with locos that can’t haul decent loads up gradients.

  2. Hi Andy and all

    Just a note which I hope will help those planning a layout. Lay a 2400 mm straight [or curved] length of track on a piece of plywood. You can then test your locos pulling ability BEFORE laying your track. I also use SCARM to test the layout feasibility. Good luck. Sutty

  3. Thanks Andy for a very comprehensive and clear explanation….am looking to build a large layout gong from a sea port across the desert to a mountain range. Hoping to have my trains climb to a high pass up to 2ft-3ft…..will need a lot of track then.

  4. Hi Andy,
    Useful article , thanks. I model a mountain region in North America and feature a challenging 4% winding gradient that causes some trains to stall if under-powered just like the real thing. Until about 2002(?) the steepest mainline gradient in USA was the Saluda gradient which was between 4 & 5%. The Canadian Pacific of course famously had to introduce spiral tunnels to lengthen the run to reduce their mainline gradient.

  5. Maximum permitted gradient on UK underground locomotive hauled track was a whopping 1 in 15. !!! This was primarily dictated by the braking limitations rather than traction for haulage and all locos were fitted with sanders. I had a 1947 Hudswell Clarke 100h.p. Loco that regularly pulled a full load up 1km of a very borderline gradient. Holding it back on a downhill run was a work of art.

  6. Thanks for the help i’m new to modelling and was worried about how to manage giving my new track some height for a bridge without having the layout permanently split on 2 levels

  7. Hi Andy.
    A great post and incredibly helpful, I got my first train set in the 70’s sadly life got in the way and just getting back into it so things are very different and it’s like learning all over again for the very start. This has really helped me. I’m designing my layout with one level and an underground layout beneath with Underground station scene. Thank you, I really appreciate the time taken to share with others.

    • Thanks Nick, underground station scenes are very cool. I’d love to incorporate one in to a future layout of mine at some point. I’d love to see some photos of yours as it progresses. Take care, Andy

  8. Hi Andy
    I’m building an n gauge rack and pinion mountain railway. I’m starting by testing what gradients I can achieve, how to gradually increase/decrease the gradient so the locomotive stays in contact with the rack and how much bends affect things.
    What I’m struggling with is what to build the track base layer out of. It obviously needs to be “solid”, but it also needs to be a material that I can gradually bend both vertically and horizontally.
    Any suggestions?

    • Hi Tasso, how about a thin strip of plywood as the track bed and then supporting this underneath with off cuts of wood. The ply will bend as wanted. Once you’ve got the incline working, build the scenery around it? Andy

  9. i am building an 009 scale layout, Once again I have looked to you for advice, this time about inclines having a top aea 4 inches above lower base. Thanks again fo r your detailed comments. Keep up the good work. Laurie

  10. Thanks Andy,
    I will now make shure there is the necessary distanse from start of incline to where it crosses over itself.
    Keep up the good advice.

  11. I wish I’d known about the ratio on inclines when we built my railway. Some engines go ok but others just wheel spin. I’m too scared to check my inclines
    Keep up.yr great work Andy, I really love and appreciate your help

  12. Hi Andy, i’m currently building a 00 gauge layout that includes a 55cm height crossing over lower level track. My incline length will be 130cm. I’ve tried a large diesel pulling three coaches and it seems okay, but small hornby loco struggles pulling two rolling stock, so will may be consign it to flat level work!
    Thank you so much for the time and trouble you take putting out the information.

  13. I’m considering building a coaling stage for my layout and thinking about the incline needed to bring the coal wagons up to the hopper floor level. This has been really useful information!

  14. Hi,
    I’m designing an N layout and was looking for this information about track grade. Thanks! You’ve answered my question nicely. My layout will be small. 2’x4′ max. I’m wanting to make a double loop, where one track crosses over the other, so by the time it makes one turn around the layout, it should be close to 100″ and give me 2″ of clearance. That should work nicely. Thanks for the info.

  15. Thanks for this Andy. Good information in your own words and also very useful links for further reading. Saves me re-inventing the wheel.

  16. This was a really helpful read. I am in the planning stages of my first build, so it’s easy to get carried away with elaborate ideas for hills etc so I’m glad I stumbled across this article. Thanks !

  17. Great instruction even for an old-timer like myself who has never put in an incline on any layout. Now that I have the correct information will now proceed with my next layout. So much for people saying you must use a helix.

  18. Hi Andy,
    I have just trialled my HO layout with a 4 degree gradient that works with 6 wagons. I used a right angle triangle with 4 degrees and a length along the wall to give me the height. I then used this height as the starting point against the next wall and so on. You can see the results if you go to You Tube and search for Trainroom Trial

  19. Thank you for taking the time and trouble to help others. This item was very useful – I will be reading some more of your posts. Regarding the bridge over another track – I assume the 50mm track top to track top dimension is for N gauge… what would you suggest for OO? Also – any tips for the all important transition from level track to the incline? BTW Thanks also for the links to other sites dealing with the subject.

    • Hi Dustyk, I think you’re referring to another article as this article isn’t about bridges but in general I’d aim for 30mm for the bridge height on N gauge and 55mm for OO. Thanks, Andy

  20. Hi must say glad I stumbled across your website. Just in the process of building a layout in my shed and wanting to include different levels. Reading this has given me food for thought and inspiration
    Many thanks , will look at other articles you have posted, thanks.

  21. I currently have a layout that cimbs and descends 6-1/2 ” in 49″. It`s in O gauge and is the vital parts for my disapearing tunnel. My mth engine is a 4-6-0 and hauls 17 cars around it flawlessly. 

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