0Model rail gradients

Model railways, like the real thing, tend to be fairly flat.  If you want ot have more complex layouts with gradients you need to plan carefully in advance, and avoid the temptation to create an unrealistic (and undriveable!) incline.

Many modellers wish to build models that look realistic, so let’s start with what sort of gradients are found on the real railways.  The Worsbrough incline on the former woodhead mainline from Manchester to Sheffield was a 1 in 37 incline, and regularly used 4 engines.  Parts of Mersey rail are claimed to be as steep as 1 in 27 as is the Middleton Junction to Oldham Werneth line.  More sustained gradients include examples such as around Portsmouth where the line from Goldalming to Haslemere has a gradients of around 1 in 80.  The Lickey incline near Birmingham is a 1 in 38 incline for 2 miles.

Put another way, short inclines on the real railways have been as severe as 1 in 27 (3.7%), but these required special banking locos or multiple locos.  The steepest sustained inclines that are operated without special locos don’t exceed 1 in 80 (1.25%)

To cross over tracks with 00 gauge requires a height of 60mm from top of track, to bottom of baseboard above.  With a baseboard+track thickness of 10mm this means to cross one track over another will require a relative height difference of at least 70mm.  Achieving this in the shortest distance can be achieved by 1 track sinking 35mm and the other rising by 35mm.

With a realistic incline of 1.25% this requires a length of 2.8m!

Unless you have a lot of space it will be hard to build a layout with a cross over that sticks to realistic real world inclines.  So the next question is – what is the steepest incline that can be operated successfully with typical 00 gauge locos, and is there anything that can be done to improve this.

Users on the hornby forum suggest that around 1 in 75 seems to be the limit for a 6-coach train. Another recommendation is around 1 in 60. This can be pushed to 1 in 50 with shorter trains, but with full length (8-10 carriage) trains pulled by steam locos anything steeper than 1 in 50 is unlikely to work. Using the same formula as above the length required it still 1.75m. Another good summary is ModelRailwayEngineer.

Can we improve this

One way modellers have improved loco grip in the past has been to increase loco weight. This has the obvious downside of increasing the weight that the motor has to pull up any incline, and there is often limited space inside locos to fit weights. I recently wondered if it would be possible to improve the grip of locos by placing a magnetic material under the track and using super-strong modern magnets (cheaply available from ebay) in locos to improve grip. Well – it turns out it is – and there is already specially designed kit called Powerbase being sold for exactly this purpose. DCC concepts guarantee that Powerbase will double the pulling power of locos up 1 in 30 gradients, but what will your locos pull up those gradients to start with, and how much will powerbase help with a 1 in 50 incline?

One test of powerbase found a 2-6-0 loco on a 1 in 35 gradient improved from pulling 8 wagons to pulling 29 wagons and could have done more.

Another example of the improvements available was recently in the Hornby magasine. On a 1.5% incline (1 in 66) almost every loco tested doubled what it could pull, with smaller 0-6-0 and 4-4-0 locos able to pull 6 or 7 carriages, and larger 2-6-0 and 4-6-0 locos able to pull 12+ carriages.

Using Powerbase it seems that inclines of 1 in 30 are possible with good length trains, taking the length required for such an incline to only 1m.

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