In my layout I have three loops in a U shape, however my outer loop is 22" radius and the other two are 18" radius. I am considering in buying some big six axle locomotives like an Athearn Dash 9’s and/or AC4400 and running them in my outer loop, however due to my location of my engine yard and freight yard I need to pass thru the 18" radius loops before I can get to the outer 22". Can these locos handle a little bit of 18" radius curves.
Those locos were not really intended for small radius curves. It’s kinda like when you
see the “no trucks” signs in a residental area. Too big for the space. I would try to
stick with small deisel and steam power. Or build a layout with wider radius curves.
Dave
i ono about the athearn dash 9s, but on my layout we have a mix of 22" and 18" and we have some athearn C-C U-boats, and an F-45. those are fine on the 22". they can some times do ok on the 18" (as in not derailing) but if the slightest thing is wrong wiht the track or the wheels are a lil outa gaduge then its off the rails for them. so yeah, if your were just gonna opperate them on the out side that would work id say, but the 18"s are really pushing it. just my oppinion
A “little bit”? Is that like being a “little bit pregnant”?
Dash-9’s seem like they would be a little big to handle such curves. If you want to run big iron, use big curves is all I can say…if you want tight radius curves, there are plenty of smaller engines that can handle them just fine, and plenty of prototypes, even today, where you can see said engines in business.
As bad as it may look to use these trains on 18" radius curves, mechanically they should be just fine. 18" is the minimum standard for 90% of all HO trains made.
I fully agree with Big Boy…90% of our locomotives will go around a 18" curve…You see they was built to do just that.They may not look pretty doing it nor do I recommend 6 axle units on 18" curves…
I can speak from experience but an athearn GE dash -8, GE u33c, EMD SD-50 or an AC4400 will not work on an 18" radius…my last layout had 15" and 18" radius and the above locomotives went into a box for years until i built my new layout after I watched them go off the track at each bend …my new layout has nothing less than 26" radius so there is no doubt the engines will run…I missed those loco’s for years!..Chuck[:D]
locomotive3 is right. I had a problem on a club layout with the lead loco pulling the trailing unit off the track. The couplers did not have enough travel and would pull the loco or a long following (anything over 50’ ) car off the track.
Kadee couplers or horn hooks? Coupler swing issues are a function of car length only, not wheel base or wheel arrangement. You may need to modify the coupler pocket to allow for the tighter curves.
I can say that their Dash 9, AC4400, SD40-2 and SD40T-2 will handle 18in radius - I have run them on Hornby 3rd radius curves which are about 18in and they were ok, though they would behave better on more gentle curves - I only used this circuit for testing purposes. I did find that replacing the metal strip across the top of the motor (that carries power from the trucks to the motor) with fine, flexible wire helps with both trackholding and reliable current collection - it seems to give the trucks more freedom to move. Hope this helps!
KD makes over 40 different couplers and conversion kits/brackets for many-many different applications that also allow for greater coupler lateral extended swing and permits the negotiation of 18" radius curves such as the 453/454 close coupling swing brackets.