Making a cross over grade using lbg r-2 curved track

[choo-choo rick]

  Hello All,

 I'm new to the Garden Railroad sceen. I need advice on using the L.B.G. - R -1500 curved track.What i'm trying to accomplish is to use the R-1500 curved track in a full circle to gain the height to get the 12" 's needed to cross over the main level track. I laid out photo copies of the R-1500 curved track end to end to make the complete circle. I found that at the half way point of my circle going up one piece of the curved track passes directly over the straight track on ground level track. If i can't gain enough height to pass over this straight track on a 3% grade format can i use some of the L.B.G. - R - 1100 curved track to off set the start of the previously mentioned R-1500 circle so it won't cross over the bottom straight track. If i used two sections the R - 11 in a "s" configuration to make it work will this cause the train to derail before it starts the R-1500 sweeping turn. I'm using the short starter kit train set engine and rolling stock.

 The other question i have is can i use one or two sections of straight track to lengthen or widen the R-1500 radius curve to gain mor height to get the 12" needed to clear the bottom track? Will this cause a derailment when having no more than six pieces of rolling stock behind the engine?

 Thanks for you help,Rick.......La Crescenta,Ca.

[markperr]

You'll probably want to put a section of straight track in the middle of your "S" curve that is the equivalent of at least one car length, otherwise that "S" will become a source of potential derailments.  If you can avoid doing that by putting in a piece or two of straight track further back in the curve to extend your curve out to where it would be with the "S" in place, that would be a better option.

 Mark

 

[choo-choo rick]

 

  Thank You Mark for your advice.I will go with one or two 12" straight tracks in the middle of the curve.

If i wanted to try and put a 12" straight track in the middle of the "s" turn just to move the track over to gain space will i still have de railment issues?

The other question that i have is this.....Will i be able to gain the cross over height of 12" in order to pass over the bottom track? I'm trying to keep the grade of climb down to 3% while using this curve track with a few straight tracks like you mentioned.

 Thanks Again, Rick M........LA Crescenta,Ca.

[Anonymous]

I am known for poo hooing things and i am going to do so now.

1/ have you done any calculations to do with gradient; i have 4% on an R2 curve and i wouldn't recommend it. Its an "S" bend as well.

2/ what makes you think you need 12 " clearance?

Dont forget R2 etc is a metric measurement and when using it you should try to think metric.

I have an American double dogbone configuration in my area 3 and the track crosses over itself 3 times and you can get away with 200 mm from the top of the lower rail to the lowest part of your overhead but i would recommmend this as a last resort but 220 mm is quite adequate.

Rgds Ian

[ttrigg]

Rick;

You have me confused here a bit. You said "the curved track passes directly over the straight track on ground level track" Did you mean that the top curved piece crosses the bottom straight at an angle or does it curve on top of it. If you mean it curves on top then yes, that is what happens when you make a rising curve, it will run on top of itself. If, however you meant that it crosses at an angle, then either you have a faulty copy machine, or you did not make the joints correctly. Remember a full circle will run on top of itself.

Always try to open up the radius of a climbing curve, tightening it up with the R1 sections will cause additional drag on the locomotive when going up hill and make for possible derailments and definitely fewer cars..

When trying to stretch out a curve, use straight sections, throwing in a "counter curve" will make the locomotive work harder. Longer straight sections inside a curve will reduce the load on the locomotive.

I have to agree with Ian when he asked "what makes you think you need 12 " clearance?" unless you have some very thick bridge work to clear, or a tunnel portal to run over. My cross over (under construction as we speak, hopping to have it "in the dirt" this weekend) has only 10 inches of rise.

[choo-choo rick]

 

    Hello Iandor,

    I have been craming the "Garden Railway" how to books for a few months now.I have also been to two Garden Railway train stores for advice. The book says that 9" of track cross over hight os ok but if i made it a 12" cross over height would let any train cross under the over pass with out a problem.The people at both of the train stores told me the same thing.I guess they try to make it simple for people who don't know how to convert metric measurments from inches like me.They did tell me that if i was to raise the track 3" in a 100" span that i would wind up with a 3% grade of climb.If you can tell me how to convert inches to the metric system this would help me quite a bit. Give me a hint here.What is 220mm in inches?

 Thanks,RickM.

[choo-choo rick]

 

 Hi Tom,

 Thanks for getting back to me.Sorry for the confusion.The rising R-2 curved track crosses over the bottom straigt track on an angle at the half way point of the turn going up.The rest of the curved track does not cross over any part of the curved track climbing the last half of the circle going up to top grade.

The reason why the curved track only passed over the straight track on an angle was because i put a R-2 curved track going the opposite direction from my straight track to off set the start of the full circle.

 I will not do this because you said that doing this was a bad idea.

You were right when you said that a circle will always be stacked on top of itself using the same radius. I guess i will have to either start with the R-3 radius at the bottom half of my circular climb and then switch to the R-2 curved sections  on the last half so they wont cross over each other in order to finish  my circle.

 If I  were to try streching the curves out could i get by with one sraight track to strech the curves in different areas? Or should i use two 12" straight tracks at a time in between the curves.

Yes,i tried using the copy machine to lay out my track plans to see the size of layout i could get away with in my limited space.True i cant connect the tracks correctly but it did help me visualize things.

 The idea of making 12"  clearance space between the base level track to the underside of the cross over bridge was told to me by three different train store people and The Garden Railway" how to book said that 9" of pass over clearance might not let all of the L.B.G. rolling stock pass under the top track.The book also recomends 12" clearance between the bottom track and the cross over bridge.

Your only going 10" of clearance so i will try it your way. This way i can take up less space trying to do a 3% grade of climb.The train stores also told me that to get a 3% grade that i could only raise the track 3" over a 100" legnth.I did not matter if i used straight track or curved track. I was wondering what type or radius of switch track to use to make a siding for tains to pass each other.

 Thanks Again, Rick M.

[Anonymous]

Rick this is why i never hang around hobby shops (stores), the blokes there are employees and most have little real experience at constructing a garden model railway.

I can tell you in my area 3; i have 60 m track in 21 m2 and i have had every challenge that you can imagine in this area. It is quite right if you measure with a ruler from the top of the lower rail up 220 mm a bit under 10 " you will have no trouble unless you have some very tall rolling stock. It doesn't matter what the configuration of the under or over pass is.

I do have an R2, a couple of them actually on a 4 % gradient and i wish i didn't, the difference between R2 and R3 under the same circumstances is more than you wqould think.

I have a couple of American tankers and concrete (cement) mixer and i have more trouble with them than you would know, ie hitting  overheads. I even have goldebn mountain carriages which can only be run in one direction, because on one side they have a stink pipe for the toilet and it is higher than anything else i have. I also have a very large Mallet loco and i use it as a rule of thumb, if it fits everything else should but inreality not quite.

Rgds ian

[ttrigg]

Rick;

Like I said, I probably got confused reading your question.  Did not understand you had an opposing curve at the start.  

As far as inserting straight sections to open up the curve, do it where ever you can and what ever length of straight will accomplish the look that you desire.  
In an "S" curve, I would highly recommend at least a six inch (or longer) straight between the opposing curves.  Helps the lead wheels "settle down" before turning the opposite direction.  I have found it STOPS a whole bunch of derailments!  My 4-4-0 will jump track every time if there is not a short straight between the curves.

A 10 inch space should do just fine.  Larger spacing just makes everything a little bigger and safer when it comes to first runs with new equipment.  My cross over bridge works fine as My GRR is 1890-1915 Steam only.  Some of the more modern stuff might not clear my 10 inch bridge.  The top of the smoke stack on my 4-4-0 is 8.75 inches above rail top, so it will be about the tallest thing ever to run here.  If you want to have the options of running the more modern stuff, especially some of the "center slung" heavy lift cars (you know the ones with the big electric transformers as cargo), or using the "transformer" as cargo on a standard flat cars, then you will definitely need the extra clearance.

In my case the 10 inches of clearance were dictated by the physical layout of the area.  This is the section of track that climbs to the top of Rosebud Falls. It starts on the inside of the mainline and then must cross over to avoid going over the pond.  To accomplish this I am having to suffer with a 7.5% grade.  Yes I said seven point five percent.  My trolley makes the trip fine, the 4-4-0 can only push two "shorties" (from the original starter set) when going backwards, the little handcar has no problem, but the New Bright just cannot make the grade.  I would have preferred a grade of 3~3.5% but you live with what space you have.  Eventually I plan on getting the required parts to make it a "cog/rack" railway.

[choo-choo rick]

 

 Hi Ian,

   Thanks for your help and advice! If i can get away with using the R-3 curved track i will do it.How ever i might have to switch to the R-2 curve track on the last half of my climbing circle due to my lack of space.I dont know if making this change in the curved track climbing a grade will mess things up or not. I will go with your 10" cross over clearance. I plan on using the smaller starter kit rolling stock to match my starter kit that i have started with.

 Thanks Again, Rick M.       La Crescenta,Ca.

[choo-choo rick]

 Hi Tom,

  Thanks agin for your help and advice! I will go with the 10" cross over clearance.Between you and Ian a beginner could not ask for better helpers...lol.

 What did you mean by putting the transformer on a flat car? How does this work? You must be talking about a radio controlled roam around type of control ?

  I will only be using the  smaller or shorter rolling stock that would look right with my starter kit that i purchased.I mentioned to Ian that i was considering using the R-3 curved track at the bottom half of my circular climb and i might have to switch to the R-2 track going up on the last half of my circular climb. Will this work?

 Thanks for the tip on putting straight track in between the "s" curves.Also streaching out the circle with some straight track.

What type of switch tracks will i need to use to make a passing siding track on a curved section of track...i.e. a half a circle legnth. If you could tell me what switch track to use for straight track for use in laying out passinger train stations and freight yards ,etc.

 Thanks Again,Rick M.   LA Crescenta,Ca.

[markperr]

Rick;

If you absolutely have to have an "S" curve, I'd recomend a straight piece that is at minimum, the length of whatever the longest piece of rolling stock that you'll be running through it is.

Conversion of metric to inches is 25.4mm per inch or 2.54cm per inch (10mm=1cm).  So in Ian's case 220mm/25.4 = 8.6614 inches.

To figure out what your grade will be, lets take 10" of rise at crossover as your starting point.   Radius equals 1/2 diameter.  Circumference equals Pi x diameter.

LGB R2 is 30.5" radius or 61" diameter.  Take the 61" times Pi (3.14), and you have 191.5" circumference in a LGB R2 loop of track.

1" of rise for every 100" of run equals a 1 percent grade.  2" in the same 100" equals a 2 percent grade.  Since you have a 10" rise in roughly 200", you have about a five percent grade. 

If you were to use LGB R3 track, which has a 47" radius, or 94" diameter, and multiply that by pi (3.14), you get 295" in an R3 circumference (you could round it to 300" for our purposes).  This would give you a grade of a little over 3.33%. 

If you throw in straight pieces of track, simply add their length to the circumference before doing the math, provided you continue the climb along the straight pieces as well as the curves. 

It can get more complicated than that, but that's the basic formula for calculating rise, run, and grade.

Mark

 

[Anonymous]

Nothing will be mucked up but every time you increase your grade and tighten you curve the nukmber of waggons a given loco will pull is greatly reduced.

I would also recommend the use of aMTS under these circumstances to compensatew for tough climbing and to stop runaways on descents.

Rgds Ian

[ttrigg]

What did you mean by putting the transformer on a flat car? How does this work? You must be talking about a radio controlled roam around type of control ?

NO NO NO NO NO!!!!!  What I meant was the "heavy load" three axle truck cars with the center depressed that carry LARGE (model) loads.  like the "transformers" you find in the electric company power relay stations, NOT the real one used to power my trains.

Now that I NEED a pic I can't find one.

This kind of car carrying the FAKE transformer.

[vsmith]

Rick, I'm down the street from you, in North Pasadena. i'd be interested to hear a better description of the area you have to work in. I dont think anyone has less space than me for a layout.

Been following this topic, the absolute minimum verticle clearence is about 8" CLEAR, thats from rail top to underside of anything above. Its important to consider how you plan to support that crossover track. The more lenth of track you can have the better to minimize the grades.

HeyTom, dont feel too down about the 7.5 grade, I'm considering a plan that will yeild a 5% over most of my mainline

[tomgb]

For those of you not wanting to do the math of metric conversions, there is a conversion website at

http://www.onlineconversion.com/ 

That can save you some trouble. There's lots of conversion tables there that you just plug your numbers into to convert but in this case from the home page you would want to go to the "most popular conversion" heading (which includes length) and pick one of the choices there that suits you (which would probably be  http://www.onlineconversion.com/length_common.htm  ).

[choo-choo rick]

 

   Tomlgb,

  Thanks for the conversion web site.This will be great!

         Thanks,Rick M.   La Crescenta,Ca.

[Anonymous]

Rick,

You can still do it in " and ft.. Not all of us are in the sunny down under!

And remember it's your railway! Have fun and don't stress.

If you want I have a program you might like, just email me.

 

William.......Santa Fe lives on!

[Anonymous]

William, some time its not so good down here in sunny down under, its 32 deg C every day around 90 % hum and wont get under 21 deg c at all for a few months. Sleeping not so good and i can't start work till 4 pm as its just too hot.

Rgds Ian