Newbie and new layout. Help with gradients

[RichD1]

I've come back to the hobby after a 25 year absence. Previously only had a round-roundy in the double garage 16' x 16' just to run trains.

 

I've now managed to agree a space in the spare bedroom and have drawn out the attached design. It has an L-shaped fixed area in grey and removable boards to provide the roundy-roundy as I do like to see trains running. 

 

My initial plan was to have a folded figure 8 to provide the maximum running length but then realised that I needed gradients. The attached plan shows the mainline around which will be double track including through the station area. I'm hoping that I can fit in an express straight through design with side loops to the platforms. Track off to the goods area, engine shed and industrial areas would be single tracks.

 

Now my dilemma about gradients. As you can see to the left of the layout is the crossover which I'm thinking of having the min. clearance track to track of 80mm. I'm also going to slope track both up and down from the datum level which is the station area. Hopefully this will give less of a degree of slope. To the right of the layout there is plenty of track length from the storage area down or up to use at least 1:60 and maybe even less. But on the left hand side I'm struggling to fit in a 1:40 slope from the crossover area up to the storage tracks and that includes using the curves into the storage boards.

 

I intend to run steam and early diesel so 50's/early 60's era and hopefully have enough space to run four carriage racks. 

 

So, will I have a problem? Especially having to include some of the curves to the bottom left. If so would Powerbase magnets provide a solution?

 

All help would be well received.

 

Richard

[ITG]

My space initially was a little smaller than yours at approx 2 meters square, but I found out the hard way on my return to modelling about the risks of gradients, being:

1. Modernish models of steam locos seem to struggle on gradients, diesels seem more comfortable.

2. curves on gradients increase resistance still further, and obviously the tighter radii more so.

3. I did have 1:40 gradient,  but in reality it can be steeper than it seems on paper, because of the need for transition sections between level and the 1:40. Some locos, depending on wheelbase and pick-up wheels, really don’t like a sudden change from level to 1:40, so you need to find a gradual transition, which will eat into your distances.

 

I’ve now scrapped that layout and expanded the space to 3.5m x 2m, now using 1:50 gradient to/from a terminus station, and all locos seem more comfortable with this. I have installed Powerbase, but not yet had to use it (magnets not yet fitted to locos as may not need them).

[Kris]

I have a slightly steeper gradient on my sons railway (about 1:35). Steam loco's struggle to pull 3 coaches up this. On the 1:50 gradient that I also have they will manage 5 or 6.  

[RichD1]

Ahh, I thought you might say that I would have a problem. I hadn’t thought about the initial transition from flat to gradient which will add to the length required. 
 

What about using Powerbase, is that a possible solution?

 

Richard

[RichD1]

Having done some more reading on gradients and minimum clearances it looks like my 80mm rise is rather generous. 

 

I've found that the recommended minimum clearance is 54mm from top of track to underside of the bridge over. The track height to the top of the rail is about 4mm when using no track underlay. The bridge over will have a 3mm layer of plywood so the overall elevation from top to top of each track bed will be;

 

54mm + 4mm +3mm = 61mm.

 

So based on that I can reduce the elevation is say 65mm. At 1:40 this would drop the incline run from 1550mm to 1300mm plus the transitions. The 1:50 would reduce from 2000mm to 1625mm plus transition.

 

The other option could be to relocate the crossover to the top left board where there is more run distance to cope with a reasonable gradient of around 1:50 or even 1:60.

 

Richard  

[LNER4479]

Hi

 

I've messed about with gradients over the years and have come to a conclusion that, although not an exact science, 1:50 is about the tipping point for a workable gradient. So would recommend that you work with 1:50 and try and make everything else fit around that. A four coach train is relatively modest and most RTR steam should copy with that on a 1:50 gradient.

 

As has already been mentioned, curves increase running resistance - one 'trick' here is to reduce the gradient for the curved sections, even to the extent of making it slightly steeper on the straights.

 

Another thing worth trying is simply to do some tests? If you already have some stock, fix up some temporary lengths of wood / track to create a gradient and see how they get on - can be quite fun! That will give you confidence (or not!) before committing to the build.

 

That clearance of 54mm sounds a bit tight for my liking. I have a gauge set at 58mm that I use. You'll be surprised what might catch even though - in theory - 54 mm should be enough.

 

Finally, when you do lay your tracks, take care to ensure it's all 'true' with no noticeable dips or twists. Model steam locos certainly will struggle on gradients if the track is uneven, because it will dramatically reduce the number of driving wheels that are in effective contact with the rails (not so much as problem with diesels as they can cope with a certain amount of twist from bogie to bogie).