Derailments

[PhilP]

Just beware that in your efforts to get a level section before the curve, you do not increase the gradient too much..
I personally think that gradients do not really 'scale' well, with the other limitations of our stock and track geometry. Less is better, but we are often constrained by the prevailing conditions.

PhilP

 

[JimmyB]

Thanks Jimmy and Rhinochugger
It will be difficult to relay the track to make the turn fully flat with a lead in but I think allowing a lean as Jimmy suggests could be a solution, we give it a try.
Robin

I have most of my gradients with curves, it can work, but may take some "fettling"

 

[Ralphmp]

Typical string line derailment

The wagons act just like a piece of string pulled (in a chord) across the curve.

From the video it looks like the cars that derailed were lighter than those in front / behind. This would presumably mean the force being exerted on them to “pull” the remainder of the wagons was greater then the downward “force” generated by the weight, or lack of weight, of the wagons that derailed, resulting in them string lining. (Apologies for not using correct terminology). If so, then the culprit here is presumably a badly formed train, and the problem could be avoided by having the lighter wagons at the rear?

 

[dunnyrail]

From the video it looks like the cars that derailed were lighter than those in front / behind. This would presumably mean the force being exerted on them to “pull” the remainder of the wagons was greater then the downward “force” generated by the weight, or lack of weight, of the wagons that derailed, resulting in them string lining. (Apologies for not using correct terminology). If so, then the culprit here is presumably a badly formed train, and the problem could be avoided by having the lighter wagons at the rear?

I am also pretty sure those Ribs had body mounted couplings, on light vehicles that would not help. But tricky to see how they and they alone could have bogie mounted couplings, perhaps that is a start of build decision with Kd’s.

 

[Greg Elmassian]

having the outer rail higher is called superelevation.... almost always not a good idea on our models, as it HELPS stringlining, since you are already tipping cars inwards..

make the cross level (across the rails) dead flat everywhere.

Greg

 

[Monifieth Stuart]

Ok so I ordered 2 sets of Bachmann wheels but unfortunately did not pay attention to advice above and got 24.5mm wheels instead of 31mm so they will go back in post. Now I find that I cannot find bigger size on Ebay unless they come from USA. I can actually buy 10 sets for about £200 plus £38 p&p which is most economical way ...dare I?

 

[maxi-model]

Ok so I ordered 2 sets of Bachmanns wheel but unfortunately did not pay attention to advice above and got 24.5mm wheels instead of 31mm so they will go back in post. Now I find that I cannot find bigger size on Ebay unless they come from USA. I can actually but 10 sets for about £200 plus £38 p&p which is most economical ay ...dare I?

Any good ? https://www.grsuk.com/shop/Wheels-black-45mm-gauge-Steel-305mm-3mm-Axle-45mm-M13286 Closer to home. Other shops available in the UK. Max

 

[Monifieth Stuart]

Any good ? https://www.grsuk.com/shop/Wheels-black-45mm-gauge-Steel-305mm-3mm-Axle-45mm-M13286 Closer to home. Other shops available in the UK. Max

Thanks. I actually ordered last two Bachmann sets from amazon for £54 (£7 per axle) which is slightly cheaper but still looking for cheaper source if they work. Stuart

 

[KeithT]

A couple of points I don’t think have been covered previously, have you checked the bogie pivots? If the bogie upper surface is well worn it can allow the body to rock sufficient to cause a derail.Second, I recall some early LGB rolling stock, not sure about later, having a couple of screws on the underside of the bogies to adjust the vertical alignment and possibly the ‘twist’ in the bogie frame.

 

[Greg Elmassian]

OP said he would check this in post #33.
I think your second suggestion is called equalization, for trucks that are not sprung, a loose connection between the sideframes and the bolster to allow all 4 wheels on a 2 axle truck to contact the rails, a good suggestion.

 

[Gavin Sowry]

got 24.5mm wheels instead of 31mm so they will go back in post.

No, put them in your stock of 'spare' parts, they will come in handy when you see the light and start adapting rollingstock into other forms..... how do I know this?

 

[Paul M]

. how do I know this?

Don't know. Go on give us a clue

 

[OLD FELLA]

Metal wheels are far better, if you can afford to change all of your stock. They behave much better, and they add more weight where you need it.

LGB 4-w stock tends to have swivelling axle trucks (which I hate but are necessary for R1 & R2) but which may not always straighten up in between curves - s- it might be worth checking whether these are swivelling freely.

I suppose the other question is whether there is some obstruction adjacent to the track which is catching something.

LGB's deep flanges tend to stay on the track fairly well, as they are designed to keep the rolling stock on the rails through the tighter curves (R1 & R2 again).

The best solutioneering with derailments is to get the Mk1 eyeball down to track level at the offending point and watch what happens - it may take a few attempts (in my case it would take a few attempts at bending down as well ).

Your last comment struck a cord with me -- being over 6foot tall -- so when wishing for an eye-ball view -- use a small mirror -- and depending on your eyesight you need not stoop so low!!!

 

[Gavin Sowry]

Don't know. Go on give us a clue

Joking aside, when I was starting out, I bought some LGB tippler wagons. Not liking the idea of plastic wheels, I also got some metal wheels. It was only when I got home, that I realised they were the small ones.... and I wasn't going to go back 400 miles to swap them. TWENTY years later, I got into 7/8ths (as discussed on here), and decided to 7/8ths the tipplers.... just happened to have some suitable wheels on hand.

 

[stevedenver]

from post 33, derailments at the bottom of a grade into a 90degree curve, sounds like ‘buff’ (the opposite of drag) the opposite of stringlining, ie the weight of the train causes it to push against the loco and a presumably lighter car(s) outward on the curve, if I understand it. I assume trains are flipping to the outside of the curve???

also, buff can cause the coupler loops to climb over one another, lifting an axel/the wheels. This can happen running slowly, or be exacerbated by deceleration of the loco .

cure: shorter train, or, less grade, or, no curve until train more or less level, or slightly slower loco at back of train (this may present other problems,however)

back when new to lgb, and having ‘clever’ ideas
i used to run a heavy, top heavy bar train to the patio, slight grades, curves too.
Initially double headed, i found using a pusher instead spread forces more evenly and eliminated toppling due to stringlining. Take away…besides the pusher aspect, bar trains are stoopid…lol.


A remote possibility,
but it does happen
check the track gauge, ie distance between rails.

sometimes the plastic spikes on the ties break.
if enough break the gauge can change, rails can roll inward or outward, especially when a train passes.

 

[Melbournesparks]

from post 33, derailments at the bottom of a grade into a 90degree curve, sounds like ‘buff’ (the opposite of drag) the opposite of stringlining, ie the weight of the train causes it to push against the loco and a presumably lighter car(s) outward on the curve, if I understand it. I assume trains are flipping to the outside of the curve???

also, buff can cause the coupler loops to climb over one another, lifting an axel/the wheels. This can happen running slowly, or be exacerbated by deceleration of the loco .

cure: shorter train, or, less grade, or, no curve until train more or less level, or slightly slower loco at back of train (this may present other problems,however)

It's a good point, the importance of couplings to good train running is often ignored. Some of the common large scale coupling types work poorly in compression, especially for couplings mounted directly to the bogies where the compressive forces will try to turn the bogies away from straight and has to be resisted by the flanges against the rail.

Having steep gradients and tight curves as well I've had problems in the past with LGB bogie mounted couplings, all rollingstock has been retrofitted with body mounted autos. Recently I've been changing over to a new pattern of automatic coupling with vertical alignment notches which lock securely together in compression and make sure the train forces are transmitted to the next car in as straight a line as possible.

 

[stevedenver]

Wow that looks almost prototypical.

 

[Greg Elmassian]