Minimum straight section between Opposing O27 curved track sections?

@Mannyrock posted:

Hey Guys,

Is there any rule that tells me what the shortest length can be, and still have O27 rolling stock stay on the tracks? 

Mannyrock

The safest will be 1.5x the length of your longest car. Shortest, the actual length of your longest car. What you don't want is a truck on one end of a car turned in one direction, while the truck on the other end of the car is turned the opposite direction. That is a recipe for a derailment.

This is not 027 specific. I have plans for an S Curve offset on our modular layout. Curve diameters on that layout are 072/081. Our longest cars are typically 21" passenger cars. So, the MINIMUM is 21". But if we can make it work with 32", all the better.

That should work for a Scout engine. JohnA 

If you are running O27-sized trains, you would probably be okay with no straight track at all between the opposing curves if so desired.  You might want to throttle back a little bit when going through these curves.

OTOH, your trains would definitely look better (and maybe even perform a little better) if the second straight piece of track were at least about as long as your longest piece of rolling stock.

With that in mind, 5" would be better than nothing.  A full standard length straight section (8 7/8" or so) would be better yet, if you have the room for it.  Plus, you wouldn't have to cut it.

That straight in a S curve being as long as your longest car is correct for HO and N but with Lionel big flanges on the wheels and ability to go on small radius curves I'll bet your 5" straight will be fine. You might want to test it 1st before getting too committed.

That 1101 2-4-2 has the best motor of the 2-4-2 engines and is a nice engine.

Truck mounted couplers-no rule.  Body mounted couplers-use above rules.

Excellent answers all!  Thanks,

I am trying to expand somewhat the inner 8 loop inside of the fixed large oval loop, and there is not much room for doing that.  So, that is why I can't use a plain 9 inch straight piece as the straight between the curves.   I'll try 5 inches to start.

I will only use O27 rolling stock, so I think that will help the situation.

Regards,

Mannyrock

Mannyrock,

Just FYI, you can buy O27 height/gauge track with wider radius of O42, O54 and (very hard to find) O72. Smoother running than straights between O27 radius curves.

That said, your Scout set will run and look just fine with O27 radius curves. If you want to add straights in between, their length  will depend on he space you have.

FWIW,  I tested that black gondola on this curve and it worked fine: 

You'll find that O27 is quite forgiving.   

Mitch