I have been building a mountain railroad with a couple internal helix's. I have been running two Proto 2000 locmotives on the helix sections to be sure the track is okay before I start to do the mountain shell over them. I will still have inside access but track work will be impossible. One loco is a SD9, the other a SD7. Basically identical. The SD9 runs over all the track with no problem, the SD7 derails at a couple of my soldered flex track joints. I flipped them over to check the wheel gauge and noticed that the one that derails has LIfe Like on the bottom and the other has Proto 2000. Both were bought new on EBAY and both came in a proto 2000 series box. The one that says proto 2000 on the bottom has Limited Edition on the box.
Besides the fact the my track work needs to be better does anyone know why the one would be so sensitive and the other seem to ride over my less than perfect track joints. As far as I can tell the wheel sets are the same. Same play side to side, same wheel base length. Thoughts?
Lifelike, a lower end maker, decided to start a premium line back oh maybe 20 years ago now. Proto 2000 was the premium line's name, and it was good stuff, nicely made and painted, and developed a fine reputation. Some time later Walthers bought the Proto2000 line, and perhaps all of Lifelike in the bargain. I don't remember exactly. The locomotive marked Lifelike was made before the Walther's buyout.
As to your derailing problem. Since one locomotive makes it thru OK and the other doesn't, that hints a locomotive problem. Since the derailments occur at track joints, that hints at track problems. It's probably a bit of both.
For the track. Go over the track carefully with track gauges looking for out of gauge spots expecially right over the rail joiners where you have to remove a few ties to let the rail joiners fit in. Feel the track joint with your fingers, it should be nearly as smooth as just plain rail. Inspect the rail joiners, are they bent out of shape and loose? Or has the rail flange failed to enter the joiner and is lurking clean on top of the rail joiner ? Look for kinks at the track joint, and repair any detected.
For the rolling stock. Check wheel gauge carefully. Clean all the wheels. Check for free swing of the trucks. Check for truck side frames touching the rail, dragging equipment and/or low flying coupler glad hands. Check that the metal axle bearings are all properly seated in the power truck frames. Adding weight is always good for locomotives, more is better. For cars, I stick with the NMRA recommended weight (1/2 oz plus 1/2 oz for every inch of car length). Most rolling stock comes from the factory a little bit light.
David Starr www.newsnorthwoods.blogspot.com
It's not that one doesn't work, but more likely that it's just dumb luck the other one does work. Slight differences in manufacturing tolerances could limit the rotational travel of one truck, or give one truck more flexibility.
Watch very closely as you run the engines over the bad spot. My guess is, you'll see the front wheel on the outside of the curve climb over the rail a bit before the joint in question. Look closely at the curve and the joint. You may notice a small kink in the track work, either horizontal or vertical, or the curve radius may be not quite as large as you think it is.
What radius are you using for the helix? These engines can be kind of fussy on tight curves anyway. 18 inch curves are marginal at best for longer engines. Get a Ribbon-Rail gauge for the track curviture you are trying to achieve and check every inch of your track. This will help you find kinks, too.
Don't close this up and make trackwork impossible for a long time. I've had spots on my layout that were fine for years until I added a new steam engine or a long passenger car to my roster. Suddenly, I had track work to do.
It takes an iron man to play with a toy iron horse.
Welcome to the Forum.
I don't have a helix but I do have a 180-degree (or so) curve under a yard and hills area that I cannot access. I did not have an option not to cover it (mainly with upper area plywood) so I test ran it with everything I could throw at it quite a lot before covering it and proceeding with what went atop. I would try to beg or borrow additional locos to test, plus rolling stock. In my case, my most finicky loco is a BLI 4-8-2 Mountain, for instance. Even if you find the poor loco can be adjusted to work (with or without track adjustments) I would caution against permanently covering it until tested with more than two locos.
Paul
Modeling HO with a transition era UP bent
If you can rebuild your helix, I strongly suggest making it out of Kato Unitrack and running electrical feeders to each track section.
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The only helix I have ever seen that ran flawlessly was made this way. Kato makes a large variety of radius sizes, and something should work. They are manufactured well, so you will not have kinks or bad spots in the track. The one I saw did not fasten the track, but instead used wooden guides glued to the helix base to hold the track in position, but never put it under an stress.
A helix is difficult to repair, and I honestly believe that Kato track is the best solution.
-Kevin
Living the dream.
Thanks for all your advice. The loco that does make it through the tough points is slightly heavier so that may have something to do with why it makes it and the other doesn't. I will, ugh, be rebuilding this track section. I am limited by space so the piece of track in question is an 18 inch radius. I have a 4-6-4 that handles it fine.
If I can throw out another question, does anyone have experience running a 2-8-0 or even a 2-8-2 on 18 inch radius? BLI indicates their 2-8-0 will run on an 18 radius. Thoughts?
Hey Liladdy!
Welcome to the forums!
These may be stupid questions, but have you checked the wheel gauges on all axles of the offending locomotive? Do the trucks pivot freely both from side to side and for and aft? A member of our club recently had a problem with a derailing locomotive. He discovered that a screw had fallen down on top of one of the trucks and was interfering with free movement.
One recent suggestion on the forums was to take a video of the locomotive as it passes over the joint. By playing the video back in slow motion or freeze frame you will be able to see exactly where the wheel(s) are leaving the track.
Another suggestion, although this may be coming a bit late, is to offset the rail joints by a few inches to reduce the possibility of introducing a kink at the joints.
In any case, it goes without saying that the helices tracks must work flawlessly before you cover them up. Don't be satisfied if you can get your P2K diesel to cooperate. Test them with everything you got. The best tests will be made with long steamers or six axle diesels.
Good luck!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
SeeYou190I honestly believe that Kato track is the best solution.
Kevin:
I'm sure Kato Unitrack would work quite nicely, but the additional thickness of the roadbed could require that the grade be increased. If a person was working with minimal radii the least thickness that can be achieved in all the components becomes a major factor.
I discovered that the offending derailer was a Life Like and old reliable was a Limited Edition because I turned them over to check the wheel guage. They seemed fine and seemed to have the same amount of side to side play in the trucks and the entire wheel sets seemed to move the same. One of the other responders said if I look close I would see the forward wheel on the outside of the curve jump the rail. I can't see the outside rail as it is against a wall but the inside followed what he described.
I had read about offsetting the rail joints but I am wondering if part of my kink problem is cutting off too many ties to make the connection with the track joiners. It looks like the outside rail is pulled in at the joint becuase there aren't the ties there to keep them at the proper gauge. I am soldering the joints. I've decided at least for my track laying skills the best thing on the tight curves is go to sectional track. It will be hidden so I don't have to worry about the look of the ties at the joints. The two locos I have been comparing are 6 axle diesels.
SeeYou190 If you can rebuild your helix, I strongly suggest making it out of Kato Unitrack and running electrical feeders to each track section. . The only helix I have ever seen that ran flawlessly was made this way. Kato makes a large variety of radius sizes, and something should work. They are manufactured well, so you will not have kinks or bad spots in the track. The one I saw did not fasten the track, but instead used wooden guides glued to the helix base to hold the track in position, but never put it under an stress. . A helix is difficult to repair, and I honestly believe that Kato track is the best solution. . -Kevin .
As a counter point, I have seen many helices (pl. of Helix?) made with flex track. All have worked flawlessly. It is all in the construction technique. The extra thickness will require higher overhead clearance if you have to reach in to extract a piece of rolling stock for whatever reason (say if a coupler box got ripped out or you lost a screw out of a truck <--saw that happen with an Atlas RTR car).
Using Unitrack also causes you to be limited in the radius you can use in the helix. If I were building a helix, the radius would be probably 36 or greater, because I would not want the ruling grade on my layout to be in a hidden track. Curvature adds to the effective grade.
I also have an SD7 and a SD9. I would check the guage on the wheelsets with an NMRA guage. One or both of them may be slightly out/your solder might be interfering. I seem to remember having to adjust the wheelsets on my P2k (Blue Box) SD 9 (it was less slightly less than allowed tollerance). The SD7 might have also needed adjustment.