Derailments

[Airbuspilot]

I am posting here but it is also relevant to freight wagons.

I came into this garden railway project after most of the rolling stock had already been purchased. We have a high proportion of second hand Locos, passenger coaches and freight wagons. Some train combinations can be run without a problem but we have a regular derailment problem with some coaches and wagons.

The freight wagons were problematic but in most cases they had badly worn plastic wheels, they have now been replaced by metal wheels and run well. However we still have occasional derailments and uncoupling's.

For some reason some passenger coaches derail and often flip, usually in the same part of the track and usually a curve. As far as I can see the track is flat, level and unobstructed and i can see no reason why this should happen.

The minimum radius curve is a 3.

As items have been purchased from multiple sources there is no single frame of reference. I have found that, for both Locos and rolling stock, some have a coupling at both ends and some only one end. Is there any logic to this?

Is it possible that during a turn on a radius 3 curve a double coupling could lock at both ends and flip a coach?

Do metal wheels wear to a point that could cause an issue? I don't see significant wear on the problem coaches.

On my own N scale layout I use a tiny amount of pritt stick on the couplings to stop them uncoupling, not something which would work on G scale. Is there some way of preventing unwanted uncoupling with these coaches and wagons.

Robin

 

[JimmyB]

What type of coupling are you using, from your comments it would seem to be hook and loop. If that is correct then your question about single and double coupling makes sense. LGB mainly supply a single hook fitted, though often supply a second hook, though on some older stock it is not possible (without modification) to add a second hook. It would seam the reason for single hooks is the ease to uncouple, but as you have found it can be too easy, personally I double hook.
Other questions include, are the coupling body or bogie mounted, bogie mounted are less likely to lock.
Speed is also another factor in derailment.
I have found generally that the issue with derailment is the track rather than the rolling stock, however, do check the back to back (40mm). Also what track are you using, I know you have checked it, but is the common area of derailment flat and level, with the curve, or is there a gradient, if there is a whole new ball game.
Some bits for you to ponder, sorry about the rambling, but just getting my thoughts down in a bid to help.

 

[maxi-model]

Some pictures of the problematic stock would help, at the coupling ends. Also some pictures of your line in the areas causing repeated issues. For example, do you have any reverse curves, aka S bends ? A lot of derailment issues can be caused by couplings travelling far beyond the centreline of the track resulting in the wheels being dragged off the track or a vehicle being pulled over. Max

 

[Rhinochugger]

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 ).

 

[PhilP]

Check your axles are free-running (spin) a spot of oil may help.
Check back-to-back.
Check pivoting axles (and bogies) turn freely. - Also check there is some freedom of movement, to allow for undulations. As little as a quarter-turn of a pivot screw, can make a difference.
On curves, and especially points, check cross-level and for twist. - This can be made worse by temperature changes.

Finally, a little extra weight (though usually metal wheels is enough) might help with lightweight stock.

PhilP

 

[Melbournesparks]

Agree that some pictures of the rollingstock and track might be worth 1000 words in this case. Just based on my own experience though, passenger stock tends to be longer than goods wagons, so lateral twist of the track can be much more of a problem. Something to check is that the bogies have a small amount of side to side movement to allow them to follow twists in the track, but not too much or the car body will roll inwards on the curve. Lateral twist can be hard to see from above, putting a camera on a wagon and taking a driver's eye video can often be the easiest way to see it. Vertical curves should also be as gentle as possible, again something that is easier to identify at rail level.

 

[Rhinochugger]

I usually add my rider at this point - that I am an expert in badly laid track, and that I run a lot of stock with far finer flange profiles than LGB

The only derailment I had on Sunday was when the brake gear fell off the bogie from a Bachmann Fn3 box car

 

[dunnyrail]

My way of doing things is to have all rolling stock double hooked but no hooks on locomotives. Locomotive loops are dropped down by placing 20-30 though plasticard in the slot where the coupling is secured. All stock is lubed with LGB 50019 into the axle bearings every 2-3 years. Boigie rubbing areas are also similarly lubed but less often, a give away that this has never been done is a showing of white powder, this being a sign of wear on those bearings. All couplings are LGB hook and loop even to the extent that I swop out Bachmann ones for LGB. Derailments virtually non existent on my line generally being related to operator error with wrongly set points.

 

[PhilP]

One thing I did not mention:
The LGB hook and loop couplings are 'better' than other brands..
However, if stock has been box-stored for some considerable length of time, the hooks can be displaced, or the springs have a 'memory' of how they have been in storage.

Also worth using the Mk.1 eyeball, at track-level, to check coupling heights match, and you do not have drooping couplings..

PhilP

 

[dunnyrail]

One thing I did not mention:
The LGB hook and loop couplings are 'better' than other brands..
However, if stock has been box-stored for some considerable length of time, the hooks can be displaced, or the springs have a 'memory' of how they have been in storage.

Also worth using the Mk.1 eyeball, at track-level, to check coupling heights match, and you do not have drooping couplings..

PhilP

Good point Phil, the springs can be turned upside down to get a new lease of life ensuring the hooks are correct again. Though the molding of the spring would appear to preclude this it does work just fine. A bent left or right spring is generally bendable back to shape but if that fails sorry new ones required. Supplied in packs as seen below, other suppliers available
.

LGB Coupler Springs 16 Pieces (L64409) | Garden Railway Specialists Tel:01844 345158

www.grsuk.com

 

[Airbuspilot]

Good point Phil, the springs can be turned upside down to get a new lease of life ensuring the hooks are correct again. Though the molding of the spring would appear to preclude this it does work just fine. A bent left or right spring is generally bendable back to shape but if that fails sorry new ones required. Supplied in packs as seen below, other suppliers available
.

LGB Coupler Springs 16 Pieces (L64409) | Garden Railway Specialists Tel:01844 345158

www.grsuk.com

Gents, I have just come home and found multiple answers. Give me some time to read through and I will respond.
There really is a great community on this site.
Thanks
Robin

 

[Paradise]

The geometry on sharp S bends pushes the limits of the couplings. This could be your problem. Straighten out your S bends might help matters.

 

[Greg Elmassian]

From reading your first post, you say that the cars derail and the flip and become uncoupled.

I would first try to see if you have derailments or uncoupling as the first thing that happens.
(from reading your post, it seems to me you have a derailment)

Now as you intimated, do you have long cars that are forced to derail by couplers or some other force not LETTING them traverse the curve

Or do you have long cars that derail because there is some binding that won't let the trucks track the curve
(probably not, you checked)

Or do you run trains that are "stringlining", where the drag is so great that it literally pulls a car off the inside of the curve.
This one is easy to see, because it will be a car near the front of the train that is subject to the most stress, with the "tail" of the train pulling on it and the locos too.
This is clear since the train will try to go to the inside of the curve, just like laying a string down on the ground in a curve and pulling the ends.

Stringlining can be caused by excessive rolling friction, interference with the pivoting of trucks, poor wheel gauge, locked couplers, etc.

S bends are another issue, where the problem is compounded by sharp angles between cars exacerbating the issue.

Greg

 

[Monifieth Stuart]

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 ).

I have seen recommendations before about changing to metal wheels. At about £25 a set for LGB this is quite a big outlay. Is there a cheaper/ better source?

 

[Neil Robinson]

I have seen recommendations before about changing to metal wheels. At about £25 a set for LGB this is quite a big outlay. Is there a cheaper/ better source?

This source is a bit cheaper at £.32.95 for four axles but not genuine LGB.

2 PAIRS G SCALE 45mm GAUGE METAL 30mm TRUCK WHEELS / AXLES GARDEN RAILWAY TRAIN | eBay

G SCALE RAILWAY CARRIAGE/TRUCK. 2 PAIRS, 4 AXLES, AS SHOWN. FITTED ON AXLES. Fits NQD and Piko and many others! COMPLETE AS SHOWN. FULLY INSULATED.

www.ebay.co.uk

 

[JimmyB]

I have seen recommendations before about changing to metal wheels. At about £25 a set for LGB this is quite a big outlay. Is there a cheaper/ better source?

Bachmann

Bachmann Europe plc - 31.0mm Standard Metal Wheel Set (4/Card)

www.bachmann.co.uk

 

[Neil Robinson]

Bachmann

Bachmann Europe plc - 31.0mm Standard Metal Wheel Set (4/Card)

www.bachmann.co.uk

I suggest you go for those Bachmann wheels before they sell out. I've used them successfully myself. Sadly I don't think either non LGB sources do spoked wheels.

 

[Paradise]

I suggest you go for those Bachmann wheels before they sell out. I've used them successfully myself. Sadly I don't think either non LGB sources do spoked wheels.

Liliput-Bachmann make a metal spoke wheels in packs of 4. I'm not sure of a good source though.
The Chinese wheels which are are the same as what Al Kramer sells are heavy, machined and more truer than a wonky Bachmann sintered (pressed) wheel but only about 29mm tread diameter so your existing stock's couplings may have issues having wheels a little larger in diameter.

 

[Paradise]

.

 

[dunnyrail]

I have seen recommendations before about changing to metal wheels. At about £25 a set for LGB this is quite a big outlay. Is there a cheaper/ better source?

I forgot to mention in post #8 that all of my stock is fitted with metal wheels. I lucked out at a show and got a bag of LGB metal wheels, but I have also extensively used the much cheeper Bachman ones. Whilst the quality is not quite so good, no spokes accepting a bit of occasional wobble on some they do run very well and reliably.