I've ran a Athearn SD45-2 through 15"-24" curves with no issues,ran into a few issues with larger rolling stock on tight curves but that was an obvious issue.Seems to me that the OP has some out of wack track either a rail is bent or there may be even a small nick in the track causing a issue (had both happen to me on my old "L" shape layout.I'd check the track first and see if there are any issues like i've mentioned or as the others have mentioned,then if it isn't the track go to the engine and go from there.
carl425 Additionally, if typical radius requirements for equipment have changed since Armstrong, they have gone down, not up. I'm not aware of any widely available current production models that require broader curves than a big 4-8-4 and a string of 85-foot passenger cars from Armstrong's day.
Additionally, if typical radius requirements for equipment have changed since Armstrong, they have gone down, not up. I'm not aware of any widely available current production models that require broader curves than a big 4-8-4 and a string of 85-foot passenger cars from Armstrong's day.
That may be true from a mechanical standpoint, as manufacturers did whatever it takes to get equipment to run around 18" radius curves - from strange articulations to radical removal of parts (in the "toy train" class - like Tyco removing the 'troublesome' front and rear trucks from the Mike and making it an 0-8-0) but from an appearance standpoint - in Armstrong's day, sure there were 85' passenger cars. Still are. But you could choose to run a freight-only railroad where the most common engine of the day was a small to mid size Consolidation or Mike, or first gen diesels and only a few special freight cars were longer than 40 ft. Modern trains - not only are the locos bigger than the first gen ones, but nearly every car in the train is 50' or longer.
That notwithstanding, any Athearn diesel should negotiate a 22" radius curve. There's either a defect in the loco, or a defect in the OP's tracklaying. Even my 4-8-4 handled 22" radius curves - just had to put the tender in the furthest drawbar hole and keep the speed down. Once you hit 28" radius and up, you can put it in the closest hole and also run at ludicrous speed, assuming the track is properly laid.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
riogrande5761* crickets * what happened to the original poster? * chirp chirp * Title of the topic is misleading because 22 inch radius is "Wide radius" NOT! Any thing under 24 inches is a sharp or tight radius by most standards including John Armstrong and he is "old school" too, and tended to be conservative on curves. He called 18 inch sharp, 24 inch medium/conventional, and 30 inch wide/broad in his book Track Planning for Realistic Operation.
Maybe he was put off by the fact that the very first reply to his query was correcting him on a fact that doesn't matter. Athearn says that this locomotive is supposed to run on a 22" radius and his doesn't. What does it matter that he thinks 22"-24" is "wide"?
riogrande5761By modern or todays standards
There is no "standard" for radius. There is only a recommended practice and it states very clearly "Use of the largest radius curves, properly eased, consistent with the design limitations of the individual layout, is strongly recommended for best operation".
The only thing radius related that's gone "up" since Armstrong wrote his books is the number of "radius snobs".
And btw, the RP for an HO scale SD45 would be 32" radius. We all know that anything from Athearn will operate fine on way less than that.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
The way the OP phrased his problem and question was a bit hard to follow, and yes the OP seems to have withdrawn into his shell (amazing how often that seems to happen). But a couple of points. I am most familiar with the "old" Athearn SD45 and SDP40 models and they were intended or designed to run on 18" radius, while looking absurd doing so.
But there were issues with selected models, perhaps due to torque or mechanical binding with that silly old "power strip" thing that carried the current to the motor and lights, or other thing about the truck itself that would lift up a wheelset (it happened with dummies too, which would rule out torque). They could and did derail on 18" and even 22" radius curves particularly where the curve met the tangent. They could also derail on #4 and snap switches. Since not all of them did, the issue was presumably a mechanical one with the locomotive. Indeed some of them could run on 15" radius although Athearn did not promise that.
I did not grasp what the OP was saying out 22" and 24" radius sectional track, but I don't agree with those who say the two should not be mixed; if 22" is broad enough by itself there is no harm from putting in some 24" or larger. Indeed sticking in 22" radius pieces at the extreme ends of an 18" radius curve was a time honored way to approximate the effect of an easement curve. The greatest challenge as John Armstrong demonstrated is where the tangent meets the fixed radius curve and anything that can be done to lessen the challenge helps. What surely CAN and WOULD cause problems however is if you mix various radiuses (?) of sectional track and still expect the perfect fixed geometry of sectional track to remain true. That is where guys are tempted to force fit the track, creating a kink which can be the equivalent of an astoundingly sharp radius. It is extraordinarily easy to create such a kink if you have flex track meeting sectional curved track -- and it can look perfect!
Indeed I suspect a kink where two pieces of sectional track meet might be the OP's real problem assuming the locomotive is OK. I have seen such kinks on some very good layouts.
Dave Nelson
* crickets * what happened to the original poster? * chirp chirp *
Title of the topic is misleading because 22 inch radius is "Wide radius" not. Any thing under 24 inches is a sharp or tight radius by most standards including John Armstrong and he is "old school" too, and tended to be conservative on curves. He called 18 inch sharp, 24 inch medium/conventional, and 30 inch wide/broad in his book Track Planning for Realistic Operation.
By modern or todays standards I think we would call even 24 inches sharp and 30 inches conventional and 36 and above wide/broad.
Ok, now that thats out of the way, as others have noted, there may be something in the chassis that is obstructing the swing of the trucks, or possibly the axles are not freely floating in their bearings. Many 6-axles loco's such as Athearn SD45's and SD40-2's are manufactured to handle sharp modular track curves such as 18 and 22 inches which are typical of 4x8 layouts.
Rio Grande. The Action Road - Focus 1977-1983
kasskaboose I have a radius of 22-24" and my new Ath SD45 jumps the track going around the curve. Why is this happening and what to do to prevent that? I checked the track and is aligned using the track gauge. I've tried different sectional track but get the same result.
I have a radius of 22-24" and my new Ath SD45 jumps the track going around the curve. Why is this happening and what to do to prevent that? I checked the track and is aligned using the track gauge. I've tried different sectional track but get the same result.
Alton Junction
I can think of no reason why a proper curve of that radius should cause you grief unless your trucks are not pivoting fully. Your wheels pass through a turnout or two, so your axle gauges are fine.
If the derailment is toward the outside of the curve, you have a dip in the outer rail somewhere just prior to the actual place where the derailment becomes evident. It gets worse if you have super-elevation, whether by design or by accident.
Tia,
You say You have a radius of 22-24'' and use sectional track. Is that in the same curve respectively. If it is...that would be the first place to look, for kinks. Not a good idea to mix radius sectional track in a curve...always results in problem's...if that is what You are doing. Could You be more specific, as to what You mean by that?
Also using a mirror or piece of glass is a good idea, but also try to slide a piece of paper under the trucks and wheels...If You can slide under with the paper...that is where You're problem will lie, especially with sectional track, where it is not perfectly level in a curve....no dips... or high spots.
Try to be a little more methodical in Your tests.
Good Luck!
Frank
Have you checked that the axles/wheels on the loco trucks are spaced within spec?
Modeling an HO gauge freelance version of the Union Pacific Oregon Short Line and the Utah Railway around 1957 in a world where Pirates from the Great Salt Lake founded Ogden, UT.
- Photo album of layout construction -
BroadwayLion REMEMBER. The initial derailment may have occured elsewhere on the layout and only became obvious in the curve. ROAR
REMEMBER. The initial derailment may have occured elsewhere on the layout and only became obvious in the curve.
ROAR
REMEMBER. The initial derailment may have occured elsewhere on the layout and only became obvious in the curve. Lion has several places like that.
And it may well be the equipment rather than the track. Check that all wheels are free wheeling and in proper gauge.
Blaming the poor track, indeed! The track inspector wants to have words with you!
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Spot checking Athearn six axle locos at MB Klein all had 18" minimum and 22" recommended. They didn't have the SD45 listed, but everything else would run on the op's layout. I would look to see if the track is level side to side, it doesn't take much.
Hi,
Well, the previous posts pretty much said it all. 22-24 inch radius is not considered wide, and your loco may not be able to handle it. Also, there may be kinks or some out of gauge sections. Or, there may be vertical differences as well. Lastly, the loco wheels may be a bit out of gauge, but IMO that is unlikely.
Easy test........ try smaller locos on that section. If they go thru w/o a hitch, then your original loco is very likely just too big.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
In addition to the above suggestions, place the locomotive on a "surface plate" or flat piece of glass or mirror.
Observe each wheel and be sure it is touching the glass. Then try to rock the truck like a "teeter-totter" to see if the middle axle is lower than the one ahead or behind it. I have had a few six-axle locomotives where the middle axle was not seated into the truck frame due to plastic flash and it would cause derailments due to not enough weight on the lead axle.
Use a skewer to gently prod the wheels up off the glass to see if one or more might be causing the other wheels to lift off the rails. Equalization, or the ability for the wheels to "float" is important to keep even, downward pressure on all wheels.
Good Luck, Ed
kasskabooseI checked the track and is aligned using the track gauge.
Check all the joints to make sure the sectional track has lined up and is in the joiners.
Does the engine derail at the same spot every time?
Does the engine derail the if you reverse the direction its facing?
Does the engine derail the same end regardless of which way its facing or does it always derail the leading truck? Does it derail the trailing truck?
With the power off, put a straight edge along the rails and see if there are any dips or sags or twists in the track.
Take the shell off the locomotive and watch it go through the curve to see if the truck is binding on anything (wire catching on the tower, brake cylinder hitting a step, etc).
Dave H. Painted side goes up. My website : wnbranch.com
I have a radius of 22-24" and my new Ath SD45 jumps the track going around the curve. Why is this happening and what to do to prevent that? I checked the track and is aligned using the track gauge. I've tried different sectional track but get the same result. This issue is quite annoying frustrating.
Any suggestions are most welcome!
TIA!