Lionel Santa Fe Valley Flyer 2-10-10-2

Yes the latest 2-10-10-2 is rated at o72 minimum curve.

Brad

@B rad posted:

Yes the latest 2-10-10-2 is rated at o72 minimum curve.

Brad

Unfortunately manufacturers don't provide a 'trackside minimum' curve.  You know, the 'clean sweep zone' the overhanging boiler will claim.  Articulated locomotives on sharp curves are quite demanding in that regard.

For an engine of this size/swing you'll probably need an O80 (or better) clearance for thingies, accessories, and structures...or other trains...along the outside of an O72 curve.

It would be nice if manufacturers provided this overhang-at-the-minimum-operating-radius info.  At the price for these beasts, it can be rather disappointing to discover any/all trackside constraints to that first celebratory run.

Alternatively, some enterprising forumite might create a reference table to be embedded/updated in the forum...somewhere...to provide this simple piece of data for the unknowing and unwitting and for all past/present manufacturers/relevant models.

Just a thought.

@dkdkrd posted:

Unfortunately manufacturers don't provide a 'trackside minimum' curve.  You know, the 'clean sweep zone' the overhanging boiler will claim.  Articulated locomotives on sharp curves are quite demanding in that regard.

For an engine of this size/swing you'll probably need an O90 (or better clearance) for thingies, accessories, and structures...or other trains...along the outside of an O72 curve.

It would be nice if manufacturers provided this overhang-at-the-minimum-operating-radius info.  At the price for these beasts, it can be rather disappointing to discover any/all trackside constraints to that first celebratory run.

Alternatively, some enterprising forumite might create a reference table to be embedded/updated in the forum...somewhere...to provide this simple piece of data for the unknowing and unwitting and for all past/present manufacturers/relevant models.

Just a thought.

Having done a fair bit of practical research on this for building corner modules, the Kings of overhang are the C&O M1 turbine and a DM&IR 2-8-8-4, both of which hang out a little over 3". So its safe to say that if you have 4" of clearance track side, you are good to go.  Length of the locomotive isnt as much a factor as how much of the locomotive sticks out in front of the pivot point for the front truck.

You run into issues and need to take extra caution if you have parallel tracks with a "tight" S curve. That is to say, a pair of O72s back to back in opposite directions of curvature.  Then you have an issue where a collision of boiler front to boiler front is possible, and also the possibility of the front end of a locomotive hitting the center of a long car that underhangs the corner.  

It is very situational, but a lot of these problems are eliminated with proper layout planning. Not using back to back S curves and replacing O-XX switches with numbered switches that diverge on a straight tangent, especially for crossovers between tracks, will alleviate a lot of headaches when trying to run big things. If you have room for bigger curves, 81, 90, 99.... 128 it helps, but they dont fit everywhere.

@B rad posted:

Yes the latest 2-10-10-2 is rated at o72 minimum curve.

Brad

Brad,

Thanks very much for the reply.

@Boilermaker1 posted:

Having done a fair bit of practical research on this for building corner modules, the Kings of overhang are the C&O M1 turbine and a DM&IR 2-8-8-4, both of which hang out a little over 3". So its safe to say that if you have 4" of clearance track side, you are good to go.  Length of the locomotive isnt as much a factor as how much of the locomotive sticks out in front of the pivot point for the front truck.

You run into issues and need to take extra caution if you have parallel tracks with a "tight" S curve. That is to say, a pair of O72s back to back in opposite directions of curvature.  Then you have an issue where a collision of boiler front to boiler front is possible, and also the possibility of the front end of a locomotive hitting the center of a long car that underhangs the corner.  

It is very situational, but a lot of these problems are eliminated with proper layout planning. Not using back to back S curves and replacing O-XX switches with numbered switches that diverge on a straight tangent, especially for crossovers between tracks, will alleviate a lot of headaches when trying to run big things. If you have room for bigger curves, 81, 90, 99.... 128 it helps, but they dont fit everywhere.

I certainly do appreciate all the insight.

I'm fairly new at this but having a lot of fun with it.

No doubt about it, it's a lot of Homework.

Thanks again,

Tim

@dkdkrd posted:

Unfortunately manufacturers don't provide a 'trackside minimum' curve.  You know, the 'clean sweep zone' the overhanging boiler will claim.  Articulated locomotives on sharp curves are quite demanding in that regard.

For an engine of this size/swing you'll probably need an O90 (or better clearance) for thingies, accessories, and structures...or other trains...along the outside of an O72 curve.

It would be nice if manufacturers provided this overhang-at-the-minimum-operating-radius info.  At the price for these beasts, it can be rather disappointing to discover any/all trackside constraints to that first celebratory run.

Alternatively, some enterprising forumite might create a reference table to be embedded/updated in the forum...somewhere...to provide this simple piece of data for the unknowing and unwitting and for all past/present manufacturers/relevant models.

Just a thought.

@dkdkrd posted:

Unfortunately manufacturers don't provide a 'trackside minimum' curve.  You know, the 'clean sweep zone' the overhanging boiler will claim.  Articulated locomotives on sharp curves are quite demanding in that regard.

For an engine of this size/swing you'll probably need an O90 (or better clearance) for thingies, accessories, and structures...or other trains...along the outside of an O72 curve.

It would be nice if manufacturers provided this overhang-at-the-minimum-operating-radius info.  At the price for these beasts, it can be rather disappointing to discover any/all trackside constraints to that first celebratory run.

Alternatively, some enterprising forumite might create a reference table to be embedded/updated in the forum...somewhere...to provide this simple piece of data for the unknowing and unwitting and for all past/present manufacturers/relevant models.

Just a thought.

@66 Plaster posted:

I've recently bought the Santa Fe Valley Flyer 2-10-10-2 Engine with the Tender. Will O-72 track be ok for this Engine?

Length with Tender is 31"

Thanks

Overhang is ugly.  But will go through.  FYI, the overhang is wider than Visionline Bigboy.  Had to move a 1 item.  Barely cleared BB.

Yanno, @dkdkrd has a point. A trackside minimum would be a helpful and easy thing for manufacturers to provide. Just need a rule of thumb; like a ruler is laid in the middle of the arc of the minimum radius and the measurement is taken from the overhang on that ruler. It could be measured when the pilot models come in.

I guess if they did that they would have to give the overhang dimensions for every track radius to appease everybody's situation. Or are you suggesting they could provide the maximum overhang for that particular locomotives minimum radius?

I guess that would be helpful to some and simple enough to provide the customer.

Brad

I would be looking for maximum overhang. I define that as the maximum overhang anywhere on the locomotive/car on the designated minimum curve. So if my engine has a minimum curve of 0-42, I expect that's where the maximum overhang would occur. Depending on the pivot points, it might be the front or rear of the engine. That's what I would just put a ruler along the middle of the minimum curve and measure as the piece rolls through.

I'm just thinking out loud. I have never actually done this myself. I'm trying to picture a locomotive going through. You could also put a rule on the inside for the maximum overhang there too.

@Boilermaker1 posted:

Having done a fair bit of practical research on this for building corner modules, the Kings of overhang are the C&O M1 turbine and a DM&IR 2-8-8-4, both of which hang out a little over 3". So its safe to say that if you have 4" of clearance track side, you are good to go.  Length of the locomotive isnt as much a factor as how much of the locomotive sticks out in front of the pivot point for the front truck.

I can say a scale Big Boy has more overhang than a scale DM&IR Yellowstone. I own a MTH Premier DM&IR Yellowstone and it goes around the 072 curves on my layout without hitting anything. A scale Big Boy will not make it around my layout without hitting anything, it overhangs more.