Author Topic: Double crossing  (Read 989 times)

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BobS

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Double crossing
« on: January 07, 2022, 11:17:57 AM »
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Can anyone post a diagram of a 30 degree 4 track crossing. I have purchased 4 Atlas crossings and can't figure out what to trim where.
Thanks
BobS

djconway

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Re: Double crossing
« Reply #1 on: January 07, 2022, 12:08:03 PM »
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Bob,

Before we can answer your question --  Code 55 or 80?
-- Can you sketch up what you are trying to do?

muktown128

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Re: Double crossing
« Reply #2 on: January 07, 2022, 01:13:35 PM »
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Are you wanting to have 2 double tracks crossing each other? 
What is the distance between each set of double tracks (center line to center line)?

C855B

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Re: Double crossing
« Reply #3 on: January 07, 2022, 01:32:36 PM »
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I did that with 90° crossings (C55), but that was easy-ish. 30° will be a challenge. My advice is make the cuts halfway down each rail of each leg and they should mesh. IOW, don't cut straight across both rails.

Your biggest problem is going to be operational, dead spots where the plastic frogs comprise much of the crossing. Mock-up the end result to verify that 4-axle locos won't have both trucks on the frogs at the same time.

davefoxx

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Re: Double crossing
« Reply #4 on: January 07, 2022, 02:28:52 PM »
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I don't know these particular crossing pieces, but, instead of cuts halfway between each crossing, is it possible to pull one rail each out of two crossings and cut the remaining rail in each crossing to the length of the distance between the crossings?  Slide the opposing rail into the other crossing, and voila!  If so, this will eliminate as many as eight rail joints, depending on how these crossings are fit together.

Hope this helps,
DFF

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Rossford Yard

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Re: Double crossing
« Reply #5 on: January 07, 2022, 03:53:58 PM »
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I did that with 90° crossings (C55), but that was easy-ish. 30° will be a challenge. My advice is make the cuts halfway down each rail of each leg and they should mesh. IOW, don't cut straight across both rails.

Your biggest problem is going to be operational, dead spots where the plastic frogs comprise much of the crossing. Mock-up the end result to verify that 4-axle locos won't have both trucks on the frogs at the same time.

I had that exact same problem on my last layout, where I did the IHB Blue Island Crossing in C55.  Had to run at least one six axle in each consist to keep the visual highlight of the layout running well.  Funny, but I measured the crossing on Google Earth, and it was actually 11 deg., so I started with their 11.25 deg. but it took too much room.  Then went to 22.5 and finally 30 deg, which actually didn't look bad and fit well.  Sort of selective compression at work, using angles instead of actual linear distance.

But, as you say, the distance between tracks at 30 degrees, unfortunately, works out to the exact wheelbase of a GP40 (also by Atlas in IHB scheme) and they would stall there every time.

Maletrain

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Re: Double crossing
« Reply #6 on: January 07, 2022, 04:42:50 PM »
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Sounds like you need crossings with isolated metal frogs and at least a double Frog Juicer.

randgust

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Re: Double crossing
« Reply #7 on: January 11, 2022, 09:57:39 AM »
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Long story, but this is as close as I've got.    This is an actual track configuration of the Hickory Valley Railroad (1896-1938) at West Hickory, PA, that I adapted to T-trak.   This resulted in a double 60-degree Atlas crossing across the T-trak main line, which happened when the HVRR crossed the PRR at the end of a single-track railroad and highway bridge over the Allegheny River.

Here's the 1917 valuation map showing a rather bonkers situation:  http://www.randgust.com/West%20Hickory%20Valmap%20Extract.jpg

This took an absurd amount of work to get it right.  It got complicated because I could NOT have metal frogs; the typical T-trak layout runs DC on the inside layout and DCC on the outside at Altoona, they had to be isolated, as well as my branch has to be isolated.  And, the curve geometry to get the third parallel track had to be spot-on as well using the Peco switches.   But it has worked, worked reliably in T-trak setups.  The vertical curves had to be completely eliminated as well.



T-trak runners haven't had any problem with it EXCEPT the BLI centipede that hates everything anyway, it kept stalling.   Nothing else did.

On my HVRR branch, the only thing that runs on it is either an Atlas or Rapido 2-6-0 under DC with 8x8 tender pickup, so no stalling issues.

It's all soldered with jumper and feeder wires everywhere; I don't assume that anything works across the diamond anywhere.   I fit the diamonds precisely for parallel track spacing first, soldered them up, and then started to fit them into the mains.    Cutting rails precisely is done with marking it with a Lambert rail nipper and then cutting it with an abrasive disk a little long, then slowly filing and grinding down the exact fit.

If you're wondering how a logging railroad crossed a PRR main at the end of a bridge, I've discovered since there was a manual highball signal controlled by the toll booth attendant.

Back in the day I had Shinohara 60-degree crossings with Code 70 rail, those were sweet and very well made, but there's something to be said for commonly-available Atlas stuff that is easily replaced when you just muck it up and have to get another one to get it right, even if they are C80, at least they are durable, insulated, and fairly well made.

BobS

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Re: Double crossing
« Reply #8 on: January 13, 2022, 06:08:16 PM »
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Having done some judicious trimming I fit together 4 Atlas 30 degree crossings. Increased my track spacing by half a track which I can live with
Four axle diesel negotiates it without a hitch. [ Guests cannot view attachments ]
« Last Edit: January 13, 2022, 06:11:23 PM by BobS »

dem34

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Re: Double crossing
« Reply #9 on: January 14, 2022, 12:08:32 AM »
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How tight are the short rails on the 45 secured? I can see it being tightened a bit by taking out the short pieces of rails going into each crossover then using the long rail from the opposing crossover to go straight into the frog molding.

edit* Dave F already said this.  :facepalm:
« Last Edit: January 14, 2022, 12:10:04 AM by dem34 »
-Al