Tail-end (new) wagon problem

[Rhinochugger]

One mistake I made initially was using stubby off-cuts of track to bodge the correct alignment geometry on curves. These end up distorting and ultimately coming apart as the joiners alone have too much give where the track's not bolted down.

Ah, my track is only fixed in a few places - every ten foot or so , and only on the crucial bridge approaches where it sits in ballast.

That length of track in front of the fruit cage has only 3 or 4 fixings in the whole length.

 

[Chris Vernell]

Gotta be careful here, or we'll be posting pictures of my track's worse than yours

I am happy to concede your supremacy

 

[Northsider]

Sorry to bombard you with suggestions (but you did ask...), but also check to see if your track is level from side to side. Track that is rising or falling  and going round a corner will be difficult for rolling stock to negotiate. Some pieces will manage it and others won't, seemingly with no explanation. Although our railways are built to scale, the forces involved are full-sized, and this can cause problems...

Without wanting to be rude, I think the problem lies in your track; or more precisely, when I have had similar difficulties, they have almost always been due to the track, not the wagon.

 

[korm kormsen]

my track ... with mainly R1 curves and sharp changes in gradient

i dare to say, you need much more derailments. - for observing.

* at which place
* which bogie of which wagon
* derailing to the left or to the right
* on a sideways inclined track
* on an upwards gradient, or downwards
* on a curve, or on a straight
* where curve becomes straight
* where straight becomes curve

finally, when you really know exactly, what happens, it will be easy to find the adequate remedy.

from what you told us until now, i would be tempted to bet that it is either a too steep change of gradient, or a change between curve and straight.
the former could need a longer change of grade (under 2° per 15cm/½ft. track-pieces), or a loosening between bogie and wagon.
the latter could need some more weight in the wagon, or guard-rails on the side opposite of the derailings.

like this:

 

[Paul M]

Yes, the wagon weighs 1.16kg and has a (relatively) long wheelbase so maybe the bogies move about a bit more than say the long RhB passenger coaches (with which I've had no trouble). Maybe I'll try some weight in the hopper or some lead under the chassis. The bogie pivot to pivot distance on the wagon is 310 mm whereas on the passenger coach (LGB 30510) its 428 mm. The weight of the coach is 2.28 kg so the wagon is pretty much half the weight but roughly two thirds the wheelbase of the coach. I have tried turning the wagon around and the problem seems to lie mainly with whichever bogie is at the rear. I've only got the one hopper wagon so nothing with which to compare. I get the feeling it's a weight distribution thing as most of the structure sits in the middle of the wagon. With any other vehicle hooked on the back the problem disappears. The photo show that the wagon's coupling 'arm' (top) is only slightly shorter than that of the passenger coach (bottom).

Lookat the picture, the left hand wheels look a bit out compared to the right hand axle, it could just be the way the axles are lying, but if the wheels are out of alignment with each other, you will get problems

 

[dunnyrail]

Oh another thought, on many LGB bogies one of the side-frames is allowed to flex with a loose screw one side. I wonder have you checked that and could that flex not be working?

 

[HobbitFertang]

Hi folks, thanks for the in depth tips. I will follow up on them all. Korm, you're correct in singling out the changes of gradient and the curves. These are pretty much where the issue lies . . plus the point about random off-cuts of track that I mentioned earlier. The guard rail method appeals. How do you fix them to the track? The wagon's bogies were pretty slack out of the box (bags of relative movement). I don't think they need slackening further. I'll try the added weight idea too.

 

[korm kormsen]

The guard rail method appeals. How do you fix them to the track?

well, after bending the rail to fit with the track, i mark the rail-foot, file out the places, where the plastic rail-fasteners are and glue them down with the standard "UHU" (that has a good grip, but can be loosened, if the guardrail was positioned subobtimal. (in one place i used two part epoxy - ripping that up again did cost some of the sleepers)
the guardrail has to be so near the rail, that on the other side the flanges can get up on the rail, but not get over it.