Curved Inclines ?

[DRG11]

Hi All,
Help is required if possible ??
I am looking at coming down on a curved incline and would like to know if anybody has done this ?
I realise that a large curve would be best but does anybody have an idea on the smallest diameter that could be used ?
I am looking at coming down from approx 18 inches high,

Many thanks to you all for any help,

 

[bobg]

Over what sort of distance Steve, and is it all curve?

 

[stockers]

Over what sort of distance Steve, and is it all curve?

or, perhaps the question is - what grade do you want. 1:25 is steep but perfectly workable. You want to drop 1 and a half foot = 37.5 ft. Using good old Pi, you need a twelve foot diameter circle ( or bits of circle and straights to equal 37.5ft)

 

[duncan1_9_8_4]

If its one direction traffic with trains just coming down, i wouldn't worry about gradient too much. I just built mine and lucky for me it worked. I measured my gradient (which is on a curve, using a mixture of r1 r2 and a few straits. it rises 12 inches over approx 10.5ft, thats the only maths i have. Trains go up and down fine. the only problems i have are LGB locos which are pathetic at gripping, compared to bachmann and usat.

 

[stockers]

Well thats 10.5:1. Your in rack territory

 

[duncan1_9_8_4]

oh dear, and no rack locos.............

 

[spike]

Well thats 10.5:1. Your in rack territory

Cass Scenic is 1 in 9
Nilgiri is 1 in 12
Bernina is 1 in 14

 

[beavercreek]

I have a very steep incline over a fairly short distance which has three curves (to left, to right which then goes to a decreased radius to the right) that is about 15% gradient. Also in the track are three switches/points 2 X LGB R5 and one LGB R3. The radius of the curves vary from 20ft to one place near the top of the gradient where it is about 10ft to 8ft (hard to give accurate as I used flexitrack to fit how the garden curved). Everything operates well providing: speed is not great, the weight of cars behind the loco(s), the couplings used.
As the train comes down the hill the weight of the cars (up to 6 aluminium streamliners or 18 freight cars max) is a lot bearing onto the coupllings behind the loco and front cars. This can cause derailments if the track is not even laterally (from one rail to another) as bogies can be twisted enough to ride the rails under the pressure from behind. This is one area where iI have really checked recently, and keep checking, the lateral level and so far (fingers crossed) not much untoward has occured.

 

[DRG11]

Hi ..Emmm sounds like I may have a few problems then ??
I was looking at using 8 foot diameter curves !
Yes it will be complete circle with trains going both ways
many thanks..steve

 

[DRG11]

Hi, yes all curves as over & under,,
poss looking at aristocraft 8 foot diameter curves
also both way running
many thanks steve

 

[stockers]

a full circle of 8 ft deameter will give you a run length of about 25ft. As you want to change height by 1.5 ft, that a grade of about 1 in 17, rather steep but do-able.
If you can aford the track, you could have a double spiral, one on top of the other, nine inches apart. This will give a grade of about 1 in 34. Now this is a realistic grade.
Alternatively, have you the room to add a couple of straights to your spiral to lengthen the run

 

[DRG11]

Sounds like a good idea but im not up to that, thanks for the idea..
will have to take another look to see if i can make it bigger or not so much of an incline,
many thanks for your assistance
regards steve

 

[garrymartin]

I was about to suggest using an "embankment" to lessen the angle of the incline, or a cutting depending on the topography, groundworks are generally cheaper than track.

 

[coyote97]

i think most points were made on the issue:
-it depends HEAVYLY of what roling stock u will drive. Regarding both the models itselves (what CAN they do...my bachmanns for example are no well pullers, because they are constructed for prototypical grades) and the scene u want to show with your RR (me...i dont like highspeedtrains on 8ft dia curves on heavy grades).

My RR has a grade of about 4 percent, what makes 1:25. That allows a bachmann connie to pull arround six or seven 1:20,3 freightcars from AMS or Spectrum.

A while ago i had a LGB-RR with a Stainz-loco and a second loco nearly the same like the Stainz, but with powered tender.
We had a loop of 8 ft dia to run across the line, but i always didnt really like it.
It made about 7 % and we needed both locos to bring 6 or 7 cars up the line...and i am talking about the light cars of LGB.

Comparing to the prototypical trainsthere are some interesting facts:
7% is the technical border engineers lined out in the 1920th, a rule that fits even up to nowadays. But running 7% with adhesion means an extremely high level of technical safety and operation rules.

exceptions are interesting. Like the mentioned cass railroad.
We have to look at what that RR had to do:
Extremely slow and powerful locos -therefore to be considered as mountain specialists- brought emptys up a hill and loaded cars down.
So it was a question of high-level-brakes to come down savely. but it was not really a problem to come up.
They would never be able to reverse a downhilltrain uphill.
The fact that today they are bringing passengers up and down the line shows how save the "shay"-factor is considered.

But shays are much to slow to "make miles". So most other RR have to deal with the 7% rule. And even on that grade, u need to use heavy and strong locos.

Back to topic:
2 or 3 cars behind a Stainz may be ok for a 7% Grade in 8 ft dia.
But it looks neither good nor works well (oh, i know, soem guys will kill me now).
Using Stainz-Stuff the diameter may be o.k., but i wont go over 4% (1."5), max. 5% (1:20).

For a good running, its clever to reduce the grade in curves. The sharp 8 ft dia. curve is ok with 2%. Use a bigger diameter (12 or more) at both ends of the 8 ft. curve where u can go up to 3% and then use 4% in the straight track.


And never forget: All those tips are just experiences and no "nailed rules"


Greetings

Frank

 

[Don Gilham]

Hi Steve, the Broome lake Short Line is in the process of building one at the moment - 1:24 was planned but has been eased to about 1:30. A Bachmann Conso seems to cope easily with the gradient (although there's mot much of it yet)

Keep you posted

EDIT : I forgot to mention - the curve in view is approximately 6 ft radius.

 

[Tony]

Steve i notice you say "coming down" meaning the trains will not be expected to "go up"........... I have a couple of these steep downs mainly hidden in mountains to save space, i havnt used rad1s as i want to be able to run big locos sometimes and min rads are 3s....... the only issue i have with anything is if a long train (10 +)suddenly stops you get the concertina effect derailing the front wagons on the curve. i think you mention 8' dia well thats rad 3 and i have one thats drops 2' in 45% (quarter of a circle) and normal trains have not a problem,,,,,,,,,,,, and as long as it keeps going neither will a 25 wagoned length train............ just a hell of a mess if you have a power cut

Tony

 

[Don Gilham]

I must say, Kim, that looks very nice

 

[DRG11]

Hi Kim
Seeing the photos makes it a lot easier for me to sort out now..
Poss now on going to drop 12 inches (vice the 18 i was looking at)
The trackwork looks superb and you have done nearly what i was hoping to do, many thanks for yours and everybodys help out there,

Regards steve

 

[Netty]

Mine is similar to Kims. From flat to 10" over a 10 LGB R3s and a 4 foot straight. Poss a touch steep but most things go up it with a reasonable train.

 

[KentKeith]

.....don't know what it is in 1:? but it's "half-a-bubble" on my spirit level:

One or two parts of the railway are "three-quarters-of-a-bubble" on the spirit level - ok for two-motored locos but some of the single-motored locos struggle.....