Derailment testing procedure?

[Anonymous]

When I was in my teens, my method for checking my mainline for potential derailments and smoothness of my tracklaying ability... was to crank up the power pack and run a 5 car train at full speed until it derailed. Obviously... this wasn't the correct way to check for possible derailment points.... is there a procedure for checking for potential derailment points in your track before everything gets too far along to relay track? Obviously check everything with an NMRA gauge, but what about actually running the trains? And how do you decide exactly what your speed limits on your track should be? Around here, we don't have any passenger trains on mainline track, and I have a map that includes the local speed limits, so I was going to go with that, 50 mph in low density residential, 40 in heavy residential or inside city limits, 35 if local switching, and 20 on deverging routes, industrial and interchange tracks.

[mondotrains]

Hi,
Actually, I kind of do what you mentioned you used to do. After I build a car, I put it in a train and run it very fast, both forward and reverse. If it derails, I know I've probably tightened the bolster screw too much or haven't weighted the car properly. If it doesn't derail at "full speed ahead", either forward or reverse, then the car is okay.

As far as the track.....if multiple cars derail in a particular section of track, then I know it's the track and not the cars.
I look for misaligned joints and fix them or check the track width with a gauge for out-of-gauge areas.

Hope this helps.
Mondo

[selector]

My test is to pull, then push, mixed trains, all pax, and all freight at varying speeds, placing all the cars in various orders. Odds are you'll get at least one derailment due to the quantum physics and statistical probability. But, if two or three passes the same way with the same set-up results in two consecutive derailments, I know for sure that I have a problem with the track at that spot.

[cwclark]

use an NMRA gauge and check everything on the track before proceeding with a train...the NMRA gauge has many functions to check the track, turnouts, coupler height, train width, (it's wide enough so that you can check the clearance between a train and a new section of a mountain or a track next to another track so you won't hit it with the train in case it's built too close to the track) and wheel flange gauge....chuck

[Anonymous]

An NMRA gauge is on my 'to buy before I lay track' list, so I'm definitely going to check every single piece of track as I lay it, and every car and loco before it even hits the layout. But I'm actually very glad (and surprised!) to hear that I'm not the only one that's used the 'run it as fast as you can' procedure! Thanks for the tips guys!

[rrinker]

I do the same thing, only without a loco. Push and pull a short train of various size cars (I only run up to 50' cars, but couple a 50' next to a short USRA 2-bay 34' hopper and you have a good mismatch) at LUDICROUS SPEED through the trackwork - if it doesn;t derail, it's good. I also try with some 80 and 85' passenger cars - with body mounted couplers and diaphragms. If THOSE can make it through crossovers at crazy speed pushign and pulling, there can;t be anything wrong witht he trackwork. ANd then there's always the long wheelbase loco test, biggest thing we have is a BLI M1A. Another good check is the long wheelbase trucks on the Atlas Trainmaster.
I work carefully, but certainly not with micrometer precision, and NOTHING derails. I've even set up for testing purposes some of those absolute DO NOTS, like having a siding drop from roadbed to tabletop level with no transition grade, and run long wheelbase equipment through with nary a problem.
Of course, I've probably jinxed myself now, so while those multple crossovers will continue to work flawlessly, I'll start getting odd derailments on a perfectly straight piece of track with no joints anywhere near it.

--Randy

[Anonymous]

In addition to the above suggestions...

Take a long frame light weight locomotive and pile a ton of cars behind it and have it run around the track. The front truck will tend to lift off the track (pop a wheelie). If the track is smooth and true it won't derail.

You can also buy a special "track inspection car" that is simply a piece of plexiglass with a couple of trucks attached "too tightly" that can be used to help sniff out problem areas on your track.

Well-adjusted cars and locomotives can handle quite a bit, it's the "problem cars" that can suffer with imperfect trackwork.

Mark in Utah

[Adelie]

I keep two trucks handy, one freight, one passenger. I'll run those around by hand (starting them at Warp 2, Mr. Scott), first one direction, then the other, for a couple of passes and look for any jumping around or signs of trouble. If that works out okay, then I couple an Atlas ore car (N-scale), without the weight to the passenger truck. Same drill. Then try various trains from a string of ore cars (with the weights), then a string of longer cars, then the passenger train. If all that works, I declare victory and move on. When running the strings of cars, I do it slow first, then normal speed, then open throttle. I'm generally looking for any wobble as the string of cars runs along (helps to have the strings be the same height of car, like box cars, reefers, etc. Tends to make the wobble more visible).

Yep, it's probably overkill. I've had to fix a couple of joints from time to time, I've even pulled up and relaid a section or two, but I don't have any consistent problems once I move on.

[BR60103]

It won't help at this stage, but I read of a club where every time something derails they put a marker on the track and on the end of the car that derails. When something acquires 3 or 5 markers, it is taken out and inspected. This helps decide whether to blame track or cars.

[Anonymous]

A guy in my club has an MRC loco he buit that must wobble 20 degrees side to side.[(-D]. Anyway, whenever he lays track, he runs it back and forth and if that engine can make it, anything can.