Safe operational speed

[Anonymous]

Hello All,
I've been reading this forum for the last few weeks and have really enjoyed the topics covered and all the good advice given. I have an operational question. I'm in the process of constructing a layout and am not clear on what is considered a safe operational speed around turns. I've been getting derailments around certain curves in my layout at what I thought was not too fast a speed. Is there a rule of thumb? Thanks for your help!

[mls1621]

The best speed is whatever looks good for the scale you're modelling.

Some things to consider are the length of the train and is your rolling stock properly weighted.

You might check the gauge of the track in the curves where the derailments are occurring. If the curve has a small radius a six axle locomotive may bind through the curve and climb the rail.

I hope this is helpful.

[Jacktal]

There are a few reasons why trains may occasionally derail and speed may be one for sure.I have a rather limited experience so far but I have discovered a few things.You may have faulty trackwork(out of gauge,too sharp or irregular curves,inclined towards outside,bumpy joints,etc) so I'd check this first.Turnouts and crossings can also create derailments if not properly installed,specially the cheaper ones.

You may also have some fo your rolling stock with wheels out of gauge also,or binding truck swivels.Are your rolling stocks properly weighed?You could also take care to install the heavier equipment closer to the loco,so that heavy pulls light,and so on.

Speed could be the reason but then I'd believe that you operate your trains beyond what could be called "scale" speed,that is if everything else is right.There's a very good article called "Banish derailments" on Model Railroader Magazine's website,that you can find just by clicking MR on top of this page,very well done and instructive.

[Anonymous]

Rule of thumb - no more than double the turnout number or curve radius (in scale miles per hour). So if you are going through a #6 turnout - no faster than 12 scale mph. If you are going around a curve with radius 22" - no more than 44 scale mph.

Simpler rule of thumb - you can never go too slow. The most common "error" (if you can call it that) in operations is probably running too fast. Many locos are geared/powered in such a way that they easily exceed the top speed of their prototype counterparts. Just look at some of the reviews in MR - top speeds of some locos reach 200-300 mph!

Andrew

[Anonymous]

Just to add to Jacktal's excellent note - the article on MR can be found by clicking on the Model Railroader at the top of the page, which will take you to the home page for MR. Scroll down to the bottom of the page and you'll see a link to How-To articles. The "Banish Derailments is near the bottom of the list of articles.

I agree with Jacktal that Jim Hediger has written a very good article. It's informative without being excessively technical. After all, it was written with the beginning modeler in mind. However, that doesn't prevent it from being useful to the intermediate or expert modeler.

[Roadtrp]

I think if you are having problems with derailing on curves your track probably needs some work.

I have crummy cheap locos pulling crummy cheap rolling stock so God knows if anyone should have derailing problems it's me. [;)]

Yet I have no problem running my passenger train (4 cars) around my 11-1/4 inch radius curves (N scale) at a prototypical top speed of 90-100 scale mph.

I also have no problem running my freight train (9 cars) around the curves at a prototypical top speed of 60 mph.

I spent hours and hours up front (sometimes very frustrating hours) getting my track to where nothing ever derailed at anywhere near reasonable speeds. The payoff has been that I can run my crappy cheap equipment at any darned speed I want. [:D][:D]

[cwclark]

I would agree that your track needs work...I wouldn't run anything under an 18" radius but the more radius the better...my layout has nothing less than 24" and i really prefer at least a 32" -36" if i have the room...most GP's can handle anything over 15" radius but if you run SD's or some of those really long steamers derailment can be a problem...also..is the track level in the curves and is the gauge spacing accurate?...level track is a must and better yet putting about an 8 degree incline into the outside rail in a curved uphill track is better....well...that's what i do.... [:D]

[CP5415]

My layout once sported 18" radius curves on several key corners. Not once, did any of my 6 axle Athearns de-rail even with the throttle maxed out & a train behind it. This includes an 270 degree, 18" curve in a tunnel that transitioned to a small 18"curve, curving the opposite way shortly afterwards.
All my track work has been Kid tested. I've allowed my 2 year old at the controls while I nervously looked on ( but extremely close by ) & I never had a de-railment caused by track.
All of my de-railments were caused by the rolling stock & usually the trucks were too tight on the body.

Check your track work, this is probably the cause.
Read the article the others have mentioned & hopefully it will help.

Gordon

[Anonymous]

Thanks everyone for your advice!! The track was the culprit. I did some tweaking and already have much better perfomance on running the trains.

[AntonioFP45]

For those of you that operate "Prototype Style".

Whether you operate yourself or with friends do you have specific scale "Speed Limits" on your: Main Lines, Branches, Spurs, City Limits, etc?

On the layout I'm planning, the permissible speeds for trains:
On sidings and the yard; restricted to 15 scale mph.
On the 2 track manline: Passenger trains 80 mph max; Freight 60 mph max.
In locomotive service shop area, 5 mph.

I was just curious if some of you operated along similar lines. [;)][8D]
I'm not going to be an operational Nazi about it, but this will be the "verbal rules" for visitors to keep operations looking realistic. Even the prototype FP7s, which could take off quickly, still took over a minute to hit 60 mph!

Thanks Amigos! Peace out![:D][:)][^]

[Roadtrp]

Yes, I limit my passenger trains to about 75-85 mph and my freights to 60mph. I used to operate my passenger train at close to the 105 mph top speed of the F40PH loco, but then decided there probably wasn't any track in the Midwest that could support that speed.

[AntonioFP45]

Rdrtp,

Sounds pretty realistic. [C):-)][tup]

Regarding the Prototype. According to stories from engineers that I've read, some Santa Fe "hot shot" trains pulled by high geared FP45s did hit 90 mph on Class 5 track in the 1980s.[:0][;)][:D] I read that this would happen in low population mountain/desert areas.

Would be really neat if this has been captured on video!! I'd buy it! [:p][:D]

Have to admit though that these speeds wouldn't look too realistic on a relatively short HO scale layout.

[BR60103]

Here's a technique for checking whether thetrack or the rolling stock is a problem.
Every time there is a derailment, the location and the vehicle are marked (non-permanently!), the vehicle being marked at the end that derails. After a suitable time, check where all the markers are. If a piece of track is accumulating them, there is probably a problem there, especially if it's different cars each time. Same with a car that derails all over the place.
If it's the same car and the same location, you have more than one problem.