Welcome to the forum   
Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Share
Options
View
Go to last post in this topic Go to first unread post in this topic
Offline ccranium  
#1 Posted : 25 January 2021 21:57:31(UTC)
ccranium


Joined: 30/11/2011(UTC)
Posts: 71
Location: Seattle area
I'm setting up an analog M-track layout with working catenary. At crossings (not double slips), I'm trying to figure out how to keep the two catenary lines' circuits isolated from each other similar to the way the 3rd rail is isolated on a 5114/5211/5215 crossing. The 7277/70131 won't do it, at least as-is, and cobbling something together with 7022's would leave a ~1" gap which won't work with single pantograph loks (they'd stall in the crossing or would be momentarily powered by the other lines' catenary; if that line is off then it stalls in the crossing also).

I'm going old school on purpose; I like the vintage look and operation of the M-track with the classic analog controls and their version of automation. I appreciate the digital capabilities; just not my style for my layout!

I've perused the site and haven't found the answer, and the old Marklin catenary set up manual doesn't appear to have the answer either.

Thanks for any help or ideas.

PS I actually have one older 5215 with common (not isolated) 3rd rails. Will be careful where I place that one, if I ever do!
Offline fkowal  
#2 Posted : 26 January 2021 03:25:48(UTC)
fkowal

Canada   
Joined: 01/02/2012(UTC)
Posts: 69
Location: Toronto
It cannot be done with catenary from Märklin. Even as you described Cranium, the pantograph will short out the two circuits. The only way you can achieve your goal is to have the entire portion of the crossing isolated from both circuits. Then have the crossing fed by a solenoid relay which can toggle between the two circuits. The relay can be triggered by switch tracks (Schaltgleisen) so the correct circuit can be connected to the crossing depending on the approaching train. You will need, at the very least, a single pole double throw latching relay. Märklin has them. Viessman too.
Offline mike c  
#3 Posted : 26 January 2021 04:12:17(UTC)
mike c

Canada   
Joined: 28/11/2007(UTC)
Posts: 7,880
Location: Montreal, QC
It can be done, but the actual crossing will have to be on one of the circuits, most likely on the circuit that corresponds to straight through. The merging track(s) can be equipped with an isolating section(s), so that once the train enters that track section, it will be controlled by the power for the through track until it reaches the next isolated section and into the zone of the next track.
Maerklin 7022 is the part number. On the crossing line, you would connect a pair of 7022 to a single 7277 for the actual crossing. The through track (straight) would use 7014 or 7015.
I suppose you could use 4 x 7022 and then set up power feeds for the main (through) and for the crossing track which would allow you to select whether the crossing was powered from the through track or from the crossing track. You would have to run wires from the line to a mast, then run the cables down to the ground and to a switch. If the switch does not completely isolate the two options, you run the risk of having two power sources connected, so it will have to be a switch that will cut one off if the other is selected. A DPDT Knife Switch should do. To do this electronically or using solenoids implies a significant risk of a problem.

I do not know what would be required to do this with the newer version of Maerklin's catenary.

Regards

Mike C
Offline ccranium  
#4 Posted : 26 January 2021 05:29:58(UTC)
ccranium


Joined: 30/11/2011(UTC)
Posts: 71
Location: Seattle area
Thanks mike c! I may not always have power to the main line, so I think I can make a go of it with fkowal's idea; I could use a 7277 and four 7022's connected to each of the legs. Then connect a 7003 from a 7022 to each line, through a 7039 semaphore to control each line, with a circuit track in front of the crossing and a contact track following on each line. Each line is unidirectional. I'll need to think it through but I'm optimistic. And I'll need to be sure to never park on the contact tracks so the other line can run, and so I don't burn up a solenoid.

Thanks to you both, and also to Mitch S in my local train enthusiast group for helping me piece this together. I'll reply back when I get a mock up working!
Offline Michael4  
#5 Posted : 26 January 2021 12:58:45(UTC)
Michael4

United Kingdom   
Joined: 02/02/2017(UTC)
Posts: 637
Location: England, South Coast
I was thinking about something similar the other day.

My problem was a fear of having one pantograph controlled by one track and the other pantograph by the other. Nasty.

It occurred to me to have the crossing powered by a separate third controller permanently set to an 'average speed' and use four 5146 contact tracks to switch the power from one to the other using the control switch 7045 (which is something of a forgotten item but really useful).

Loco powered by controller 1 or 2 arrives on a contact track that switches power via 7045 using 5146 to controller 3 for crossing then when leaving switches it back again to 1 or 2 using another 5146.

For a controller I'd just use a little 6699 fed from one of the others.

The problem as I see it is the position of the 5146 contact tracks and teh points of insulation which must allow all the loco to be able to go from one source of power to the other...or alternatively run with one pantograph down...haven't thought too hard about coach lighting.


NOTE: I HAVEN"T TRIED THIS YET!!!







Offline mike c  
#6 Posted : 26 January 2021 15:57:46(UTC)
mike c

Canada   
Joined: 28/11/2007(UTC)
Posts: 7,880
Location: Montreal, QC
Originally Posted by: Michael4 Go to Quoted Post
I was thinking about something similar the other day.

My problem was a fear of having one pantograph controlled by one track and the other pantograph by the other. Nasty.


Most manufacturers (and railroads) normally recommend operation with only one pantograph raised.
Some railroads use both pantographs when beginning to move due to the load required to get the machine moving.
Some people run their models with both pantos up due to better contact, but this can damage locomotives and transformers when bridging two power supplies.

If you are running multiple analog circuits on catenary, this is definitely NOT recommended, especially for digital locomotives.

Regards

Mike C
Offline Michael4  
#7 Posted : 26 January 2021 16:05:47(UTC)
Michael4

United Kingdom   
Joined: 02/02/2017(UTC)
Posts: 637
Location: England, South Coast
Fear not 100% old analogue apart from some lighting LEDs on a different circuit but will remember what you say because I am about to install separate power supply for steep inclines in order to maintain constant speeds on an automated circuit.

Everything works fine using one pantograph so will run like that from now on.

Offline ccranium  
#8 Posted : 26 January 2021 19:38:13(UTC)
ccranium


Joined: 30/11/2011(UTC)
Posts: 71
Location: Seattle area
Agreed on the concern (fear) of running both pantos with 2 circuits; I'll need to think through the way to make this be fail-safe.
Adding the 3rd controller would seem to make this more complex, so for mine I'll toy with the 2 controller/ power the 7277 by one or the other model.

I'm curious how the prototype in Germany back in its analog era would signal a crossing of two lines to prevent collisions?
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

| Powered by YAF.NET | YAF.NET © 2003-2024, Yet Another Forum.NET
This page was generated in 0.624 seconds.