Turnout Question

[psmithhamilton]

Building my first layout and I am running and Intermountain FP9 A&B MU pulling heavy weight passenger coaches with 6 wheel bogies. I am using #4 turnouts back to back to move the train from one track to the the parallel line and the coaches are derailing in the turnout Help what am I doing wrong
Thanks

 

[Selector]

If I understand your description, you have the dreaded S curve. Your couplers are jerking the cars out of the rails when they can't deflect in azimuth any further, Two cures, get longer turnouts, I'd go for #6, or get longer coupler shanks. Much longer.

 

[Dortoh1]

Depending on what brand passenger cars your running a swinging style coupler box like Walthers uses on their streamlined cars definitely helps, but asking them to negotiate #4's back to back asking a lot.

 

[psmithhamilton]

Sorry I should have been specific about the cars, they are Branchline Blueprint cars. Also I am using Atlas code 83 track.

 

[Trucula]

#4 switches are bad on a mainline..other than a simple siding using small engines and rolling stock you want to stay away from #4. While they are fine in a slow moving yard its too much of a change on a faster mainline.
And back to back 4s will make a dreaded "S" turn will case major issues. Look into a double cross-over for your application. These will be #6s or better.

 

[TomR]

I've been playing with my switches (turnouts) this past weekend, and I've found the alignment of tracks into the turnout is much more problematic than the actual turnout type.

I built a little alignment gauge and even my tightest turnoutouts (unlabeled) never get worse than an 18 inch radius curve at the worse spots.

What I did have trouble with are a few cars that have the wheels too close together and, if the diverging track turns out too close to the switch, three wheel trucks with long couplers get offset too much. What I did was cut the angle closer to the exit rail by coming out straight for a few inches and then doing whatever.

I can run things through my small turnouts just fine now, even at high speed. Of course the #6 Atlas look safer and don't push the cars offset so much, but even all my tight stuff was not as bad as a 18" r curve when I measured things.

I also had to do a little shaping of edges and blending here and there.

Tom

 

[RexHea]

I do not know if the newer Branchline heavys are better than the old, but the old (as I have) are terrible with smaller radii: under 24". Many have had to remove the center axles just to negotiate the curves. I finally replaced my trucks/axles with 3d party equipment and they run and hug the rails much better. I would definitely change out the #4's for #6's and see if it takes care of your problem first.