Date   
Re: Offset Rail Gapping

Michael Maioriello
 

What gauge are you using, also what system do you use. I uses Lenz system 3.6 and must use circuit breakers. The science behind this is that LENZ Invented that’s out there and smart people ran with free technology. I am not up-to date on the newer systems to pick from. Good Luck!

On Sat, Mar 21, 2020 at 10:18 PM Michael Boyle <boyle10017@...> wrote:
Greetings,
I've read, and been told, to offset the rail gaps between power districts. What is the science behind this and do we do that everywhere (for example in a reversing loop)?
Thanks,
Michael

Re: Offset Rail Gapping

wirefordcc
 

In this case, short means, makes a connection.  If the polarity of the two sections are the same, no shutdown of a booster or electronic circuit breaker should occur.

Allan Gartner
Wiring For DCC

Re: Offset Rail Gapping

john
 


Gentlemen,

The only place a short should occur is at a reverse loop or at a "Y. It doesn't matter if the polarities are reversed or not because your reverser, your PM42, or separate booster will make them the same almost instantly when they sense a short. It doesn't matter if the gaps are directly across from each other because when the wheels touch either rail with the reverse polarity, you reversers will correct both rails.

I have noticed that when engines cross a gap between power blocks, especially reverse loops there is sometimes and miniscule spark. No, I am not crazy but it has to be Black Out Dark to see it. 

I have see a decrease in jerks and starts over gaps when I fill in the gap with plastic. It also allows the gaps to be much smaller and keeps the rails from creeping and shorting together. Our layout is in a basement but rails still expand and contract down there. 

Keep you wires in a twist and your fun in a bunch.
jd
 

On Thursday, March 26, 2020, 10:48:34 AM EDT, Tim <tarumph@...> wrote:


I wonder about this fascination with gap locations. If you're using an autoreverser it will detect the short when when a wheel hits the first gap, flip the polarity, and everything will be fine. As far as wheels connecting power districts (or track circuit blocks) that will happen as long as the wheelbase of the loco straddles the gap (assuming all wheel pick-up). The gap locations don't make any difference (within reason). Steam locos with pick-up on one side of the loco and the opposite side of the tender will pick up from both sides of the gaps. This is why boosters are bonded. Trying to space the gap so that the lead wheel on the loco hits one gap at the same time as the lead wheel on the tender hits the opposite gap can only work for one type of loco moving in one direction.

Having the gap distance longer than the locomotive should probably be avoided, but shouldn't really cause any problem. See steam loco example above. :)

Tim Rumph
Lancaster, SC

Re: Offset Rail Gapping

Tim
 

I wonder about this fascination with gap locations. If you're using an autoreverser it will detect the short when when a wheel hits the first gap, flip the polarity, and everything will be fine. As far as wheels connecting power districts (or track circuit blocks) that will happen as long as the wheelbase of the loco straddles the gap (assuming all wheel pick-up). The gap locations don't make any difference (within reason). Steam locos with pick-up on one side of the loco and the opposite side of the tender will pick up from both sides of the gaps. This is why boosters are bonded. Trying to space the gap so that the lead wheel on the loco hits one gap at the same time as the lead wheel on the tender hits the opposite gap can only work for one type of loco moving in one direction.

Having the gap distance longer than the locomotive should probably be avoided, but shouldn't really cause any problem. See steam loco example above. :)

Tim Rumph
Lancaster, SC

Re: Offset Rail Gapping

Jerry Michels
 

There is momentary shorts between blocks as metal wheels (Or Locos) cross the gaps.  

Is this true?  If the polarity and phase is the same for two blocks there should not be any shorts in my opinion.  If this was so, a train with all metal wheels would cause a large number of shorts to occur, and if a train stopped with a set of metal wheels bridging two blocks, the short would be constant.  I have not seen this.

Jerry Michels

Re: Offset Rail Gapping

John Melvin
 

Nothing wrong with this technique. It does what you state about stabilizing the track on curves. My railroad teachers from 70 years ago to present have taught me the same but also taught me that rail gaps should always be parallel at any change in electrical status, ie., ladder tracks in yards, engine storage tracks, mainline blocks, signal detection blocks, and moving from one booster region to another booster region, etc.

John
El Paso

In a message dated 3/25/2020 11:21:32 Mountain Standard Time, jjc3382@... writes:

I was taught to slide one rail on flex track halfway onto the next piece on a curve to maintain the curve without parallel cuts to avoid kinks. I solder my joints and never gap on a curved section. Is this wrong? It seems like the new thinking is to join the two pieces with joints across from each other but soldering the joints while they are straight and then bending them to the radius you want. Doesn’t my way stabilize the radius and prevent kinks better?

joint gaps

Michael Shockley
 

I found two pictures of rails that have a joiner on only one rail.  Both of these are straight tracks.  I'm not sure what prototype curves require.

Mike Shockley

Re: Offset Rail Gapping

jjc3382@...
 

I was taught to slide one rail on flex track halfway onto the next piece on a curve to maintain the curve without parallel cuts to avoid kinks. I solder my joints and never gap on a curved section. Is this wrong? It seems like the new thinking is to join the two pieces with joints across from each other but soldering the joints while they are straight and then bending them to the radius you want. Doesn’t my way stabilize the radius and prevent kinks better?

Re: Offset Rail Gapping

thomasmclae
 

the reason for gaping both rails is to prevent current/power/signals from one block to another.
There is momentary shorts between blocks as metal wheels (Or Locos) cross the gaps.
These are usually handled fine, but offset gaps extend the short times for Locos and lit coaches/cabooses.
The only reason to stagger gaps is mechanical, and if you need to do this, your technique needs to be revised.
Thomas
DeSoto, TX

Import Conversation

 

Hello Allan,
I posted the topic "Offset Rail Gapping" both here and at the NCE-DCC@groups.io site. On that site Bruce Petrarca generalized the discussion to "Rail Gaps" and the discussion really took off with many very interesting inputs by some of the most knowledgeable people, on the topic, that I know. Is it possible to import the conversation to this site so that members of this site could benefit?
As always,
Michael Boyle

Re: Offset Rail Gapping

prandn
 

RealWorldApplication ... joints in rails are ALWAYS* parallel to each other, a practice also required in model railroading.... 🙃

Now the staggering of joints is a completely different subject......

* Exception: when a “ sun-kink “ or derailment or some other phenomenon has caused the rails to become unparallel.....

loren martell
Aloha, OR 97007

Re: Twisting Wires

Mark Gurries
 

A twisted cable is defined as pair of wires twisted together with each other AND carrying the same signal/power/current going out and back.

Twisting random wires together that have nothing to do with each other will potentially create problems because the noise in one wire will become coupled to the other wire. -Or- Two signal that have nothing to do with each will interfere with one another.

Hence a cable with multiple wires that have different purposes but collectively contain in a single multiwire cable where they all follow one big twist together does NOT qualify as a twisted cable.


On Mar 23, 2020, at 5:54 PM, Carl <carl.blum@...> wrote:

Hello Charles:

These are not communication cables, just industrial control cables. They are cool the way they are arranged: a green/yellow ground in the center and then numbered wires starting at "1" radiating around the ground. So with ground there are 7, 13, 37 conductors. Some cables have place holding fillers to stack nicely. I think the whole cable does twist, but very slowly, perhaps one turn every 2 meters.

Carl.

On 3/23/2020 3:57 PM, Charles Brumbelow via Groups.Io wrote:
Your industrial cables may already be twisted. CAT 5 Ethernet cable uses twisted pairs inside the plastic jacket, for example. 

Charles




On Monday, March 23, 2020, 1:32 PM, Carl <carl.blum@...> wrote:

Hi Gang:

Here is a question about twisting the bus wires. Would it work to twist the wires after they are installed? Like a tourniquet, put a stick at the mid point and start twisting. Like this:

=/////////|\\\\\\\\\\=

Sure one side would be clockwise and the other counter clock wise. I think the telephone company did flip their wires every ten poles or so.

I didn't twist anything and the layout runs OK. But if I had problems this might help. ( For me it would be hard, I used 10 conductor industrial cables )

I did add a snubber to Ruth Mountain, the longest wire run.

Thanks, Carl.



Best Regards,

Mark Gurries
Electrical Engineer
DCC Website & NMRA DCC Clinics: www.markgurries.com



Re: Twisting Wires

Carl
 

Hello Charles:

These are not communication cables, just industrial control cables. They are cool the way they are arranged: a green/yellow ground in the center and then numbered wires starting at "1" radiating around the ground. So with ground there are 7, 13, 37 conductors. Some cables have place holding fillers to stack nicely. I think the whole cable does twist, but very slowly, perhaps one turn every 2 meters.

Carl.

On 3/23/2020 3:57 PM, Charles Brumbelow via Groups.Io wrote:
Your industrial cables may already be twisted. CAT 5 Ethernet cable uses twisted pairs inside the plastic jacket, for example. 

Charles




On Monday, March 23, 2020, 1:32 PM, Carl <carl.blum@...> wrote:

Hi Gang:

Here is a question about twisting the bus wires. Would it work to twist the wires after they are installed? Like a tourniquet, put a stick at the mid point and start twisting. Like this:

=/////////|\\\\\\\\\\=

Sure one side would be clockwise and the other counter clock wise. I think the telephone company did flip their wires every ten poles or so.

I didn't twist anything and the layout runs OK. But if I had problems this might help. ( For me it would be hard, I used 10 conductor industrial cables )

I did add a snubber to Ruth Mountain, the longest wire run.

Thanks, Carl.


Re: Twisting Wires

Charles Brumbelow
 

Your industrial cables may already be twisted. CAT 5 Ethernet cable uses twisted pairs inside the plastic jacket, for example. 

Charles




On Monday, March 23, 2020, 1:32 PM, Carl <carl.blum@...> wrote:

Hi Gang:

Here is a question about twisting the bus wires. Would it work to twist the wires after they are installed? Like a tourniquet, put a stick at the mid point and start twisting. Like this:

=/////////|\\\\\\\\\\=

Sure one side would be clockwise and the other counter clock wise. I think the telephone company did flip their wires every ten poles or so.

I didn't twist anything and the layout runs OK. But if I had problems this might help. ( For me it would be hard, I used 10 conductor industrial cables )

I did add a snubber to Ruth Mountain, the longest wire run.

Thanks, Carl.


Twisting Wires

Carl
 

Hi Gang:

Here is a question about twisting the bus wires. Would it work to twist the wires after they are installed? Like a tourniquet, put a stick at the mid point and start twisting. Like this:

=/////////|\\\\\\\\\\=

Sure one side would be clockwise and the other counter clock wise. I think the telephone company did flip their wires every ten poles or so.

I didn't twist anything and the layout runs OK. But if I had problems this might help. ( For me it would be hard, I used 10 conductor industrial cables )

I did add a snubber to Ruth Mountain, the longest wire run.

Thanks, Carl.


Re: Wiring a Yard

Tim
 

For that situation, the most important thing is keeping things organized. Consistent color coding is vital. Then come up with a sensible approach and stick with it.

Tim Rumph
Lancaster, SC

Re: Wiring a Yard

dsabourne
 

I use the following online calculator for my wire sizing needs.

David

http://wiresizecalculator.net/

Re: Offset Rail Gapping

mgj21932
 

David,
Now that answer makes sense.
Bill D

On Monday, March 23, 2020, 11:18:20 AM EDT, dsabourne via Groups.Io <dsabourne@...> wrote:


This is a real world application ... where you never have joints in rails parallel to each other.  Not a practice required in model railroading.

-David

Re: Offset Rail Gapping

dsabourne
 

This is a real world application ... where you never have joints in rails parallel to each other.  Not a practice required in model railroading.

-David

Re: Offset Rail Gapping

dsabourne
 

This is a real world application ... where you never have joints in rails parallel to each other.  Not a practice required in model railroading.

-David