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To fix a problem or not?

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  • Member since
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  • From: Dearborn Station
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Posted by richhotrain on Monday, April 18, 2022 8:20 PM

hbgatsf

Answers to some questions:

- all joints were soldered while straight and then formed into curves.  There are no kinks.


OK, good to know.

hbgatsf

- locomotive's driving wheels derail.  They can't navigate the 24" radius.  

- I checked curves with some 24" radius sectional track that I bought for that purpose.  Except for the section that started this thread all curves are laid correctly.   The Northern derails on any that are less than 26.5".  

So, it is the driver wheels. I did have problems with BLI 2-10-2s and 2-10-4s on anything less than 28" radius curves, but my Northern could handle 24" radius curves. The fact that you tested the loco on 24" radius sectional track certainly indicates that the radius is constant. That would sure point to the loco itself as the problem. 

Rich

Alton Junction

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Posted by hbgatsf on Monday, April 18, 2022 8:46 PM

Just to clarify, I didn't run the locomotive on the sectional track.  I put it on top of the flex track to check the radius.  I also used a metal yardstick bent around the curves to check for problems and didn't find any. 

I just realized I haven't put a gauge on the locomotive's wheels.   I will check them.

Rick

Rick

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Posted by richhotrain on Tuesday, April 19, 2022 6:14 AM

hbgatsf

Just to clarify, I didn't run the locomotive on the sectional track.  I put it on top of the flex track to check the radius.  I also used a metal yardstick bent around the curves to check for problems and didn't find any. 

ahh, well that changes my opinion once again. I thought that you ran the loco on sectional track. When using flextrack, the broader the curves, the more forgiving the performance of larger steam and six axle diesels. The tighter the curves, the less forgiving the performance of larger steam and six axle diesels.

A layout with minimum radius curves of 40" or broader can handle any loco without derailments if the curves are soldered, the rails are level with one another, and the track is in-gauge. In my experience, any curves less than 32" radius cannot guarantee flawless performance unless the curves are "bullet proof". Once the curves get narrower than 28", problems are likely to arise except for smaller locomotives.

Rich

Alton Junction

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Posted by richhotrain on Tuesday, April 19, 2022 6:39 AM

Regarding steam locomotives, I follow a 4x guideline. A 4-wheel driver configuration (e.g., 2-4-0) needs a minimum 16" radius curve (4x4). A 6-wheel driver configuration (e.g., 4-6-2) needs a minimum 24" radius curve (4x6). An 8-wheel driver configuration (e.g., 4-8-4) needs a minimum 32" radius curve (4x8). A 10-wheel driver configuration (e.g., 4-8-4) configuration (e.g., 2-10-2) needs a minimum 40" radius curve (4x10). Some modelers use a 3x guideline, but in my experience that is too tight.

Rich

 

Alton Junction

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Posted by snjroy on Tuesday, April 19, 2022 7:30 AM

I have a number of 2-8-2s and 4-8-4s (Mantuas,  Bowsers, Bachmanns, brass) that can go through four 22" curves on my layout. Track is level in both directions. My old brass 2-10-4 can handle them too. Turnouts are more often the cause of derailments than the curves.

Simon

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Posted by wrench567 on Tuesday, April 19, 2022 7:44 AM

  How many holes in the drawbar? You have to use the furthest drawbar hole to get the tighter turns. I run some really large steam on some small radius turnouts and yard tracks. My BLI J1 2-10-4 is probably my longest wheelbase locomotive and it can go where my 0-6-0 can go on my little modular layout.

     Pete.

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Posted by hbgatsf on Tuesday, April 19, 2022 8:28 AM

wrench567

  How many holes in the drawbar? You have to use the furthest drawbar hole to get the tighter turns. I run some really large steam on some small radius turnouts and yard tracks. My BLI J1 2-10-4 is probably my longest wheelbase locomotive and it can go where my 0-6-0 can go on my little modular layout.

     Pete.

 

 

By furthest do you mean the one that is closer to the tender or to the locomotive?

Rick

Rick

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Posted by richhotrain on Tuesday, April 19, 2022 9:19 AM

snjroy

Turnouts are more often the cause of derailments than the curves.

Maybe, but you raise a good point about turnouts. Quite often, the derailment begins on a turnout preceding the curve. I always go back and watch what happens to the wheels (pilot truck, drivers and rear truck) as the steamer crosses the turnout before it ever reaches the curve. A turnout immediately in front of a curve is always a "person of interest".

Rich

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Posted by rrebell on Tuesday, April 19, 2022 10:36 AM

As far as BLI their quality control is pretty bad at times. Had (note the had) a diesel by them and one of the main truck holes was off by a bit, enough so that it derailed at one point on my layout, only item that did. Was going to fix it once I discovered the proubem but desided the handrails were to cunky for my liking so sold it.

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Posted by hbgatsf on Tuesday, April 19, 2022 11:59 AM

richhotrain

I did have problems with BLI 2-10-2s and 2-10-4s on anything less than 28" radius curves, but my Northern could handle 24" radius curves. 

Rich

Thank you for stating several times that your Northern would negotiate 24" curves.  That gave me the motivation to keep working on this.

I checked the wheels on the locomotive and they were in gauge.  I then ran it through a 24" curve that covers about 200 degrees.  Going back and forth a number of times revealed that it only derailed in one spot and it was the same spot all the time.  The front drivers would climb the rail.

The track there was a little tight on the gauge but otherwise it looked fine.  When I put the sectional track on top of it in that spot the ties between the two did not line up perfectly for about an eight tie lenth.  I moved the track about 1/32" and nailed it back down.  After that the loco ran through the entire curve without a problem.

I am now going to meticulously check every curve on the layout.  The challenge will be if a section that is ballasted has a problem.  If I get them all fixed I will go back to the problematic curve that started this discussion and do whatever needs to be done to fix it.  

Thanks for all the suggestions.

Rick

Rick

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Posted by richhotrain on Tuesday, April 19, 2022 3:09 PM

hbgatsf
 
richhotrain

I did have problems with BLI 2-10-2s and 2-10-4s on anything less than 28" radius curves, but my Northern could handle 24" radius curves. 

Rich 

Thank you for stating several times that your Northern would negotiate 24" curves.  That gave me the motivation to keep working on this.

I checked the wheels on the locomotive and they were in gauge.  I then ran it through a 24" curve that covers about 200 degrees.  Going back and forth a number of times revealed that it only derailed in one spot and it was the same spot all the time.  The front drivers would climb the rail.

The track there was a little tight on the gauge but otherwise it looked fine.  When I put the sectional track on top of it in that spot the ties between the two did not line up perfectly for about an eight tie lenth.  I moved the track about 1/32" and nailed it back down.  After that the loco ran through the entire curve without a problem.

I am now going to meticulously check every curve on the layout.  The challenge will be if a section that is ballasted has a problem.  If I get them all fixed I will go back to the problematic curve that started this discussion and do whatever needs to be done to fix it.  

Thanks for all the suggestions.

Rick 

Rick, that is great news that you found the problem. Patience and persistence pays off. I have had those same problems from time to time, especially when building a new layout or modifying a current layout.

Some years back, I bought a number of Ribbon Rail Metal Track Alignment Gauges with various curve radii, ranging from 26" to 40". I initially bought one of each. When I settled on 32" minimum radius curves on my new layout, I bought five more 32" radius gauges. I won't settle for less than 32" radius. If the curve is broader, you can see it as the 32" gauge is placed between the rails.

I have had to re-do some ballasted track from time to time. No problem. I soften the glue to release the track and correct the problem, then re-ballast.

Rich

Alton Junction

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Posted by hbgatsf on Tuesday, April 19, 2022 3:42 PM

Now that I know what I am looking for I am going to use the sectional track to check each curve to help find problems.  Once I am done with that I'll go back to the misaligned curve.  

To help resolve that I was thinking of soldering the sectional track together and replacing the flex track with it.  It is in an obscure spot and won't be noticeable.  That should make any roadbed realignment that is needed easier. 

Any thoughts on that?

Rick

 

Rick

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Posted by richhotrain on Tuesday, April 19, 2022 5:15 PM

hbgatsf

Now that I know what I am looking for I am going to use the sectional track to check each curve to help find problems.  Once I am done with that I'll go back to the misaligned curve.  

To help resolve that I was thinking of soldering the sectional track together and replacing the flex track with it.  It is in an obscure spot and won't be noticeable.  That should make any roadbed realignment that is needed easier. 

Any thoughts on that?

Rick 

I suppose if most of the layout, or even just part of it, were sectional track, then I would see nothing wrong with replacing faulty flex track with sectional track. But, I quit using sectional track years ago because it is a fixed radius without any provision for easements.

What I really like about flex track is that you can determine a minimum radius and then allow broader curves to occur, whether intentional or not, to form easements. To do this, I use and recommend the Ribbon Rail Metal Track Alignment Gauges.

Let's say that your layout is designed to include 24" radius curves. If you had three 10-inch long curved alignment gauges, all 24" radius, that would be sufficient to lay out a minimum, consistent, 24" radius curve, moving the alignment gauges forward along the formed curve in the flex track, nailing the track down as you move along. If you do that carefully, you will form a perfect 24" radius curve.

Rich

 

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Posted by woodone on Tuesday, April 19, 2022 6:49 PM

This a trick question?

Fix it right and move on!

 

 

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Posted by rrebell on Wednesday, April 20, 2022 9:17 AM

As far as ribbon rail gauges which I use, I have fould that you have to make sure it is loose in the flex or you could have a hair less. My whole layout is mostly 18" radius and if I did it again I would use 19" for a bit of wiggle room. I'm not saying fore sure that that was the proublem with the one curve I reworked but I do know that it would not have been an issue with wiggle room.

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Posted by John-NYBW on Wednesday, April 20, 2022 9:57 AM

I used the rail gauges on my shortline which runs much shorter equipment and therefore tighter radii. I have both a 28" and a 30" gauge which is the minimum on my shortline. On my mainline, 36" was the minimum or so I thought. I discovered that an Altas #8 curved turnout has a tighter inside radius than advertised and has been a source of derailments with my fully lenghth passenger cars. I am currently replacing it with a Peco #7 curved turnout which actually has broader curves, both inside and outside. I was able to salvage the #8 by carefully breaking it free from the ballast and discovered that the inside curve matches my 30" gauge almost exactly. I'm going to repurpose it on the shortline where I am adding a turnout on one of my 30" curves. The Atlas #8 seems to fit it perfectly. 
"

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Posted by richhotrain on Wednesday, April 20, 2022 10:55 AM

John-NYBW

I discovered that an Altas #8 curved turnout has a tighter inside radius than advertised and has been a source of derailments with my fully lenghth passenger cars. I am currently replacing it with a Peco #7 curved turnout which actually has broader curves, both inside and outside. I was able to salvage the #8 by carefully breaking it free from the ballast and discovered that the inside curve matches my 30" gauge almost exactly. 

You did good to carefully free that #8 from the ballast without breaking the turnout. To avoid damage, I always soften the ballast so that I can easily remove the turnout. I use a matte medium/water mix as the glue, so I soften the ballast with an isopropyl alcohol spray. The loosened ballast is easily fixed, so the repair is never noticed.

Rich

Alton Junction

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