Large Scale Central

The Diamond Crossing 🛤️ A Friend or Foe in the Garden?

Track and Trestles
#1

It seems to me from my limited research, that railroads would avoid diamond junctions, AKA level junctions, AKA Flat crossings in their system if they could.

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I’m going to have to place one, maybe two or more diamond crossings so I can fit both point to point and roundy-round operations in the two raised garden beds as the beds will eventually be connected by a double track bridge.

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Does anyone have any opinions or advice on using diamond crossings and trouble shooting the prevention of crashes? I’m basically looking to find out what I might need to wire or support under the ballast before laying track.

I’m going to run (MASSOTH) after I get through Stan’s DCC book.

#2

I used one for years before I changed my layout. No problems, But, mine was mounted solidly on a bridge, not on the ground.
So I guess my reply is probably not what you need.

#3

You want “straights” coming in from all sides and they need to be longer than your longest cars. Curves coming in/out are a receipe for disaster.

And of course, you need to consider collisions.

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#4

Bummer, I thought I’d done the first garden plan (phase 1) well, as it was the based on prototype crossing pictured below and helped best to minimise sharp curves in the small garden bed.

I also thought I might be able to have a double tracked bridge with this design…

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Ignore the track that’s roughly 90 degrees. I placed it there to keep the other from falling into the hole.

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I may have overindulged in track ideas here to supply the ore tipple too…. But I might be able to approach from the other side….

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#5

I have a 90 crossing (diamond) on my mainline. It is well supported on concrete. The mainline track leading into and out of the crossing are broad curves. I Have never had a derailment on the crossing so long as the flange ways are clear of ballast or debris.

I don’t see a problem with what you have planned.

I’m not home tonight so I can’t post a picture, but I can take and post a pic of one on the mainline of one of the layouts at the show.

#6

Seems like it would depend on what you intend to run through it. I run the AristoCraft streamliners in an “S” configuration which are very long and prone to derailment. I do have straights in and out.

#7

I added a 90 degree diamond to my RR a few years back. I installed a bypass track on the RR to keep a train on the lower half and the best way to do that was to cross the main. I put a patio block under the spot and the diamond sits on it.
It is fun to throw the switch to the bypass track that sends the train over the main then in about 8’ it rejoins the main. When multiple trains are running it is a great way to keep them from catching each other but there has been some very close calls at that diamond.

I do not think that you would have any issues with running trains over that diamond from any direction but crashes are a concern. You just have to keep your eye on the trains and be ready to hit the emergency stop.

#8

That’s it exactly. Best to plan for the longest car you will ever want to run.

I got pics of the funky home-made one on the Big Green layout at NELSTS…

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Even Larry’s super long train made it over that with no problems. I took video, but it still on my phone. The main is the straight route.

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#9

Here is the video…

On Youtube -
https://youtu.be/RK9Ufjwik1Q

3 Likes
#10

Thanks all.

Todd B, I got the impression that LGB didn’t like the switch combination either, as I’ll have to make adjustments to either the sleeper or rail to get the switch and the crossing to fit with each other. The fixed position of the sleepers keeps the rail from fully connecting. Herself has said that she is happy to run her long orient express passenger cars inside for the time being, but I might be able to fit a bit of straight rail between the two crossings.

Todd H, you hit upon my biggest fear, the Gomez Addams train crash. I’m thinking that some sort of sensor relay to get one section of track to be dead when the other is occupied. I suspect I have a bit of reading to do to get there. I know virtually nothing about arduino and rasberry Pi and how it fits with running analog or DCC. So I might be very hands on like you until then.

Jon that’s quite impressive amount of gap the wheels jumped certainly has given me confidence that my shorter wheelbase trains will be ok.

#11

I went looking for diamond crossings in Oz and thought I’d share something they is uniquely Australian.

Reportedly when Queensland Railway adopted high speed tilt trains to run on narrow gauge 1067mm track, diamond crossings were going to cause significant speed restrictions, so they installed drawbridges to solve their problem. Brisbane to Rockhampton is now a 7H 45M trip down from 9-10 hour trip.

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:point_down:LINK TO SOURCE
Drawbridge Crossing link to Amusing Planet

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VIDEO:point_down:

#12

if you want always the same track to be waiting, it is easy.

take twoo reed contacts one LGB switchmotor with the doublethrow adapter and a magnet under the locos.
put the reeds on the track with the right of way.
aproaching the first reed cuts off the power of the secondary track, leaving the crossing, the other reed after the crossing connects the power again.

the most complicated part is counting cars in the trains, to put the reeds far enough from each other.

#13

Two observations here if I may.
Korm,
What is the safe guard if the train on the second track is already occupying the controlled space ?

And second,
the concern seemed to also include the train having issue going through a crossing in a curve. Nice video of the train going through on a straight main line but does the train handle the crossing as well when crossing the main line on the curve going into an apparent switch? As Bills main seem to be crossing a straight on a curve.

#14

ooooops… - then you have to have the video camera ready.
you are right. i simply didn’t think about that.

(as i am always setting up automated traffic, my trains get “paced” at the passing sidings. so i never have trains coming out of scedule to any choking/crashing points.
for these effects i use cats)

so he would need at least two more reeds.
may be - stopping any first train untill the second has passed?

#15

In my video example, that would never happen since the track crossing over is a storage track where trains enter and exit quite slowly. And on my railroad. the main through the diamond has very broad curves entering and exiting the crossing and the track crossing is a siding with straight track only.

#16

How broad are the curves entering the diamond?

#17

I developed the Tortoise Bump Accident Sentinal System (Bump ASS) to take care of this eventually. If you run track power and can brandish a soldering iron, you could make your own.

Whichever a train reaches a predesignated spot (the detector) placed just beyond all four sides of the crossing first turns off the power to the other track before that train reaches the crossing. I use 555 timing chips/relays.

To spectators, this is one of the most delightful aspects of the railroad as they wait for the inevitable crash, that just doesn’t happen (typically) unless a railcar gets left (decouples) in the crossing (ca ca occurs).

The detectors are nothing more than two LGB track insulators placed next to each other with a short piece of rail to fill the gap and a wire soldered to this short piece. When a train approaches a detector, the wheels short the track to the detector and that starts the 555 chip which opens a relay that interupts power flow to the opposing track for as long as the chip is set for. It works with any engine or railcar with metal wheels.

Actually, we use the 555 chips for lots of our effects.

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#18

Hand bent, but hard to say. Maybe 20’ radius or more? Here’s a pic…

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#19

Love the video Todd.

So many questions…

Where do you suggest I look first to learn more about 555 chips and their use on garden railways?

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#20

https://www.electronics-tutorials.ws/waveforms/555_timer.html