Calculating overhang on MTH Premier articulated locomotives

In my opinion, the two worst overhangs occur on the SP AC12 Cab Forward and the UP Big Boy. I have a minimum of 2.5 inches clearance on both sides of curve tracks, and on the first 10 inches of tangent track leading into / out of curves on my railroad.

Thanks for your reply Bobby!!  

I had bought a Premier MTH Challenger but the boiler over could not negotiate the tunnel portal wall on O72+ curve.  I had to sell the train.  I would like to run other Premier articulated engines but am very apprehensive to purchase another.  I may have to stick to Imperial models on the articulated locos.  My Premier Q2 4-4-6-4 can negotiate the curve fine.  I figure that most fixed wheel steam engines will fit if the Q2 fits!!  I was hoping there was a way to determine the overhang prior to purchasing a Premier articulated model without going to the dealer to measure.

You would have to know width and the distance from rearmost driver axle to rear of cab/from frontmost driver axle to front of loco at widest point.  

I'm not sure there is a formula for 3-rail trains.  Too many design compromises to make a large engine work on tight curves. 

As far as the manufacturer listing the overhang of their engines in the users manual, what curve would you have them use?  Just list the overhang for the minimum curve listed for that engine?  Or for the minimum curve and all the curve sizes they manufacture larger than the minimum curve?  This stuff adds some cost which could be a factor.

There is always the possibility the manufacturer may not want to list this because a lot depends on the track laying ability of the hobbyist.  I've visited layouts that had pretty good kinks between curve sections to make the track fit the area, which would negate any overhang measurement.

It might be fun to have a standing topic on this issue;  when someone buys a new engine they measure the overhang on the curves they use and post it.  After a while, it would be a pretty good database.

HI Ron...I think a running topic on this would be great. Just to be able to get an approximation of the overhang would help. I agree that track layout would certainly factor into how accurate measures would be.

I thought getting an over hang measurement for the minimum curve of the engine (most often O72) could be very helpful when designing a layout in which someone wants to run these large engines. 

I appreciate your comments!!

-Tim

This engine wreaked havoc on my scenery. The overhang of the cab is large!

Don't own any though from watching many in operation it seems the UP steamers, Big Boy's and Challengers, have the most issues with excessive front overhang on layouts.

I had ask this question to MTH a year ago. Sorry they never got back to you as they did personally call me with a measurement. At that time I was told a big boy had an overhang  of 3 and a half inches. Now my original question was how much does an engine overhang so I can place another track next to the existing track. Interestingly enough i FAILED to ask what the size curve as mentioned here is this discussion. Yes the curve is definitely going to make a difference. I would think the answer reflected the minimum curve that was listed for the Big Boy. Hope this helps. Regina at MTH may remember as she was the one whom I talked with. Please remember that it took over a week for her to call back as they had to actually make the measurement. Again that was in 2015 at the end of the year.

CurtisH posted:

I had ask this question to MTH a year ago. Sorry they never got back to you as they did personally call me with a measurement. At that time I was told a big boy had an overhang  of 3 and a half inches. Now my original question was how much does an engine overhang so I can place another track next to the existing track. Interestingly enough i FAILED to ask what the size curve as mentioned here is this discussion. Yes the curve is definitely going to make a difference. I would think the answer reflected the minimum curve that was listed for the Big Boy. Hope this helps. Regina at MTH may remember as she was the one whom I talked with. Please remember that it took over a week for her to call back as they had to actually make the measurement. Again that was in 2015 at the end of the year

Thank you CurtisH!!

I had contacted MTH 6+ months and no one has gotten back to me.  I appreciate the BigBoy over hang measurement, I can use that as a starting point.  Thank you for your reply.

-Tim

Call main office in Columbia and ask for Regina. What a wonderful person to work with and I can almost 100% quarantine she will get back to you. I ask my wife a few minutes ago how long it took for them to contact me back via phone and she said it took a couple months. So sorry for the mistake in time. getting old means things speed up.  LOL

CurtisH posted:

Call main office in Columbia and ask for Regina. What a wonderful person to work with and I can almost 100% quarantine she will get back to you. I ask my wife a few minutes ago how long it took for them to contact me back via phone and she said it took a couple months. So sorry for the mistake in time. getting old means things speed up.  LOL

Thank you. I will give her call this week!!  I appreciate your help. 

-Tim

I can't remember which magazine it was in the past 2 yrs but there was an article on this.  Once the max distance of the boiler swing was known a tool was made. If I remember correctly it was basically a truck from a train car with a small flat piece of wood with a hole drilled in it.  In this hole was a pencil to mark the top of the layout.  I'm google searching like crazy for it but maybe I can find which magazine it's in here at home. 

Keep in mind as well that if you have 2 curved sections running parallel to take into account a long passenger car on the outside track passing an articulated locomotive on the inside track.

Sparky74 posted:

I can't remember which magazine it was in the past 2 yrs but there was an article on this.  Once the max distance of the boiler swing was known a tool was made. If I remember correctly it was basically a truck from a train car with a small flat piece of wood with a hole drilled in it.  In this hole was a pencil to mark the top of the layout.  I'm google searching like crazy for it but maybe I can find which magazine it's in here at home. 

Keep in mind as well that if you have 2 curved sections running parallel to take into account a long passenger car on the outside track passing an articulated locomotive on the inside track.

A tool like that would be perfect. Please let me know if you find the article. Thank you!!

-Tim

I have a Big Boy, Class A, Allegheny, Cab Forward, Challenger, etc. and my double track is 096 / 088.  Spacing between the center rails is minimum 4-1/4" on the curves.  One end of a curve enters a long trestle and I needed 6" straight prior to entering the bridge.   Trust me, you need a lot of room  on curves for those locomotives.  O72 would be greater distance.

bruce