I would like to add a SD-40 to my layout, but the guy at the hobby shop said it wouldn’t run on 18 inch radius turns. I have a GP 35 & 38 and have had zero derailments. He said if it didn’t derail that the first car would derail? Any thoughts?
Thanks
Chris
it’s because of the overhang of the locomotive on the track. It will pu***he first car’s coupler too far off the track centerline, and force the car off the track.
The SD-40 is a six-axle locomotive. Your geeps have four axles. You’ll need no less than 22" radius to run those big boys.
Thanks guys, unfortunatly thats what I had thought, I was just hoping that it was more of an “idealy you need 22, but it will work with 18” kind of thing?
Thanks
Chris
Not entirely true, glcole6. You could run an SD7 or SD9. They are six axle units, but are much shorter than a SD40, and would work on 18" radius. The SD40 will run on 18" curves by itself, but will pu***he coupler on the first car quite a bit to the side. If the coupler has too little swing, the car will be forced off the track. On the other hand, if the coupler has a lot of swing to it, the you might be ok (but only with cars that have a lot of coupler swing).
Now, you probably could use one full section of 22" radius curve as an “easement”, if you did this for each and every time you have an 18" curve then you might be OK. The wider curve would allow some distance for the car behind the engine to start to “follow the leader”, and when it gets to the 18" section, it won’t be so abrupt a change, and the angle between the engine and car won’t be so bad. As a result, the coupler swing won’t be as much (well, technically it would be, but the differential between the engine and car would be less), and you should be able to run it.
I plan on using all 22" curve on my next layout, but if I end up having to use any 18", I will definately use the 22" “easement” method. Since I model 1957, I primarily run 4 axle power, along with 40’ cars (50’ maximum), and smaller steam power, so any 18" curves I may need to use won’t be as much of a problem as those of us who model more modern eras.
Brad
I have used Athearn SD40-2’s on 18 inch curves. I’ve also used BB AC4400’s on them as well.
They did not like going backwards through them though.
I didn’t have a problem with cars derailing either.
Try it, see if it works, if not, go with 22" curves as they are better to use
Gordon
I can run Kato SD40-2s all day on 18" turns, no problem. If you have a coupler problem use an extended shank Kadee. That is what I did for a long time until the “whiskers” came out. Now I am using a #148. I trimmed the Kadee #5 box to allow some extra side-to-side movement. Works great.
Here is a link to the BIG discussion we had a while back:http://www.trains.com/community/forum/topic.asp?page=-1&TOPIC_ID=59938&REPLY_ID=672620#672620
Jim
BLI locos SD40-2 can run in 18" inch radius curved track and together with railways cars without any problem.It`s all has to do about well laid track on the bench,that make sure noproblem traintraffic!
agge