incline gradient

[phil s]

i am planing on having a viaduct running along to rear of my new build, the size of the base is 8ft x 4ft, wil the incline be to steep?? i am starting the incline and it runs up to 70mm max height the length of incline is 900mm long, so from 0mm to 70mm over 900mm how do i work out percentage of incline

thanks phil

[Ditape]

If I remember my school maths it is about 8%

[Agrippa]

Yeah . 1 in 13. A bit steeper than the real thing.

[Dorsetmike]

Or about 1 in 12.8 which is way too steep, 1 in 40 is about limit for N gauge unless you're just running a single car DMU when you might manage 1 in 30.

Best way to test is to get a long plank, pin some track to it and try some of your locos with typical loads you want them to pull on it, and gradually prop up one end until a loco with your intended maximum load starts to slip, that's your steepest gradient. Try as many locos and loads as you can, you may find a diesel with 8 coaches sails up, whereas a Dapol M7 with 2 coaches may struggle.

[scotsoft]

I make it 4.447°

cheers John.

[edwin_m]

Remember also you can't just put an angle in the track, or the trains will ground at the top and probably derail at the bottom.  It needs a gradual vertical curve at both ends, which means if you have a fixed length to climb a fixed height the middle part of the gradient will need to be steeper.  I did mine by cutting two slots in my baseboard surface and bending up the 6mm ply strip in between until it was at the correct gradient.  Probably a good idea also if the vertical curve is on a straight in plan view. 

I've found 1 in 40 is about the limit for diesel-hauled trains about 2m long.  Steam locos are usually a bit lighter so can probably manage less load. 

[zwilnik]

For Ivebridge I used threaded rods and plastic blocks underneath strips of hardboard to make adjustable incline sections. That way I could tune my incline so that my trains could climb it before I applied the scenery around it.

http://www.ngaugeforum.co.uk/SMFN/index.php?topic=7041.msg80442#msg80442

[phil s]

thanks for all replies,

i have decided to extend the right hand side of the track by another 1 metre that should drop the incline down by over half hopefully, a couple of pics if the load up this time



phil

[Jerry Howlett]

Phil, I don't want to be negative but I suggest you only lightly fix any track work and test this thoroughly. My concern is the trains will be negotiating tightish curves at the same time as climbing the gradient. There is a possibility that this will increase the drag.
Of course it could be that the picture is a bit deceiving.
However this is based on problems I had with a dreaded "00" set up I had 40 years ago.....
Good luck with the project.
Jerry

[phil s]

Voice Of experience here...

When I built my old layout, I had a 1 in 30 (Sprintex will verify ) incline, on a curve of 1000mm.... It was bad... very bad..... Loco wheels would lift as they travelled up the incline and constantly derail... The only things that would traverse ok were my Class 122 and old GWR Railcars.... things would also frequently uncouple whilst traversing the incline too and cause lots of damage to stock... I eventually hacked it out to about 1 in 45 by increasing the length of the incline.....
As Jerry says above, tight curve and incline creates crazy camber and we all know that track likes to be level and parallel to itself which certainly on your run it would create a level where one rail is lower than the other.....

thanks for the advice, the base is 2.4metres x 1.2 metres, if you look from the right side of the base the corner from where it goes into the turn and from the point where it comes out of the turn is 450mm, do you think it will be to much of a tight turn, going to get the track laid out over the weekend and power it up hopefully.

phil

[phil s]

Unfortunately because you have your picture in Photobucket I cannot see it (blooming firewalls) if you upload it to the forum and create yourself your own album I could see it

Sorry

hi there

uploaded into my album

phil

[phil s]

The slope however looks pretty steep!

yes is a bit steep so i am going to extend it along the right hand side and bring it around the front slightly, will the decline on the left of the picture be ok

phil

[steve836]

Have you considered raising the front tracks so that the incline is shared between the track going up the viaduct and the track going down under it?

[jpendle]

Hi,

I'd advise against gradients unless you have loads of space.
As an example of what you can get away with I have 2 long shallow gradients on my layout. I used Woodland scenics Subterrain formers and each slope has a 2% gradient, each one rises 2.5 inches over 9 feet. A Farish Class 66 or 60 can just manage 18 HTA hoppers on these slopes. Most of my Dapol loco's can only manage around 12 wagons. My EMU's and DMU's are fine.
I did try to use a curving 3% gradient, 2.5 inches over 6 foot 8, and succeeded in burning out the motor on one of my 66's.

The moral here is go as shallow as possible and try not to out the gradient on a curve.

Regards,

John P

[phil s]

managed to get the outside loop done today, pinned into place and soldered wire on to some of the fish plates, all powered up and loco runs around fine



also in my album