The strange anomalies of locomotives and track!

[petercharlesfagg]

Friends,

I have been working long hours trying to get things up and running for a visit by relatives who have contributed the layout over the months with rolling stock or sundries.

To that end I have managed to electrify 90% of the track (ran out of joiners!) and have tried running all my locomotives.

This is what I experienced:-
Dapol Class 66, runs beautifully when warm otherwise it stutters!

GF Class 37 after having an overhaul by Bob Lines runs well but not wonderfully but for some reason will slow down on a curved section in one direction but not when running in the opposite direction!

I have (3) Fleischmann Loco's 7033, 7035 and 7094, they all run beautifully over all the points and track with no hesitation but all do a little dance on the short crossing and uncouple from everything!

There are (2) Bachmann "Bee line" loco's, I forget the numbers, one will not go in one direction but is fine in the reverse, the other will run through a long crossing beautifully one way but takes off on a separate track in the reverse direction!

My Dapol "William Shakespeare" with its tender drive through a cardan shaft is wonderful until it navigates just one point and the bogie goes up the wrong track!  Every other point on the layout is fine!  Tender first and it jumps off across the long crossing!

I have (1) Walthers diesel loco, "Norfolk Line", and it goes everywhere no problems whatsoever!

Finally there is the Class 101 that I converted with the Tomix chassis, looks a bit odd but who cares!  It zips around like it's on holiday and is absolutely fantastic until it stops i.e. when I forget to change a point and then it needs a prompt to get it going again!

I find this most frustrating but is it anything unusual?

Regards, Peter.

[scottmitchell74]

Thanks for sharing!

I don't know if it's unusual. I think many of us have these weird problems. My track isn't perfect, but I have a couple Life-Like E8s, two LL SW8/1200s, an LL GP18, an Atlas H15-44, an Atlas GP30, Graham Farish DP1, 25/3 and Class 50 and they all run around my layout like nothing in the world is wrong. However, I can't get beautiful and vaunted Kato machines to navigate my track decently at all. Sometimes they'll go OK, but then they'll speed up or slow down in weird spots, or start to get all herky-jerky. The same can be said with my Union Mills locos. They are more finicky on my track. I wonder if the finer the machine, the less forgiving they are?

These observations I'm taking as lessons and will be much, much more meticulous with track laying on my up and coming layout.

[Newportnobby]

Hi Peter,

First dumb question I have to ask is 'Did you clean your track before attempting to run everything?'
Have you checked every fishplate joint to ensure they are seated correctly and not perhaps slipped under a rail instead of over it? This will cause 'steps' in the track level and may cause uncoupling/derailment.
Lastly, some locos can be quite perverse even on clean level track. I have more than one which will derail at first on a circuit but then will proceed to run perfectly once rerailed
I'm afraid I can't comment on individual locos as (a) I haven't even heard of some of yours and (b) I guess we all have certain quirky ones

[zwilnik]

The Class 37 could be a couple of possible issues but one likely cause of issues going round corners in one direction is that the pickups on the bogies may be more loose on one side, so that when the engine goes around the corner, the sideways force on the bogie/wheels is lifting the contacts off the wheels and reducing power.

Another possibility is that the wheels or track are simply dirtier on that side and whereas they contact ok when the bottom and side of the wheel are contact with the top and inside of the rail, losing the side contact on the inside of the curve is reducing the power available due to the bottom of the wheel or top of the rail being dirtier. The possibility here is that the back to backs of the wheels are off, but as it's been to BR lines I'd say that's less likely.

[petercharlesfagg]

Hi Peter,

First dumb question I have to ask is 'Did you clean your track before attempting to run everything?'
Have you checked every fishplate joint to ensure they are seated correctly and not perhaps slipped under a rail instead of over it? This will cause 'steps' in the track level and may cause uncoupling/derailment.
Lastly, some locos can be quite perverse even on clean level track. I have more than one which will derail at first on a circuit but then will proceed to run perfectly once rerailed
I'm afraid I can't comment on individual locos as (a) I haven't even heard of some of yours and (b) I guess we all have certain quirky ones

Not a dumb question at all!  The answer is Yes, I am using the Woodland Scenics track cleaning kit with all the pads etc. and IPA on the final pads.

The track joints are all soldered and I have double checked that the joiners were correctly installed before soldering.

Thanks for the thoughts, anyone starting will find a reminder useful!

Regards, Peter.

[petercharlesfagg]

The Class 37 could be a couple of possible issues but one likely cause of issues going round corners in one direction is that the pickups on the bogies may be more loose on one side, so that when the engine goes around the corner, the sideways force on the bogie/wheels is lifting the contacts off the wheels and reducing power.

Another possibility is that the wheels or track are simply dirtier on that side and whereas they contact ok when the bottom and side of the wheel are contact with the top and inside of the rail, losing the side contact on the inside of the curve is reducing the power available due to the bottom of the wheel or top of the rail being dirtier. The possibility here is that the back to backs of the wheels are off, but as it's been to BR lines I'd say that's less likely.

Thankyou, I have checked the pickups and the transfer strips above the bogies and wherever you move the bogies relevant to the bodywork it all stays in contact.  I feel sure that Bob would have check run the loco before returning it to me!

Regards, Peter.

[EtchedPixels]

Dapol Class 66, runs beautifully when warm otherwise it stutters!

Possibly transit grease. Which version of the model is it ?

GF Class 37 after having an overhaul by Bob Lines runs well but not wonderfully but for some reason will slow down on a curved section in one direction but not when running in the opposite direction!

Could be a slight lack of lubricant or slight tightness on one bogie. Common with the Poole built models. If it's been overhauled and any gears changed it may just need to run in a bit. The important test is to run it very slowly around the curve and if it stalls apply more power. If it then continues to move its probably not a pickup problem but mechanical tightness. If it needs poking each time it happens maybe its power pickup

If it is mechanical it's often as trivial as a quarter turn loosening on a couple of screws.

I have (3) Fleischmann Loco's 7033, 7035 and 7094, they all run beautifully over all the points and track with no hesitation but all do a little dance on the short crossing and uncouple from everything!

Only on the crossing ?

There are (2) Bachmann "Bee line" loco's, I forget the numbers, one will not go in one direction but is fine in the reverse, the other will run through a long crossing beautifully one way but takes off on a separate track in the reverse direction!

Older Bachmann also suffers split gears, running one way jamming the other is common. If it runs one way and shorts the other then its more likely a lighting fault. Wrong track see below (but its perhaps easier to check and fix on the Bachmann)

My Dapol "William Shakespeare" with its tender drive through a cardan shaft is wonderful until it navigates just one point and the bogie goes up the wrong track!  Every other point on the layout is fine!  Tender first and it jumps off across the long crossing!

Long crossings are the biggest test of accurate gauging of wheels and levelness of track. If a bogie goes down the wrong track then a couple of things can happen (and its mobile phone and slow motion time to see which). The first possibility is that the gauging is sufficiently out that the check rail fails to stop the wheel wandering onto the wrong side of the frog. It should be physically impossible for the wheel to pass the wrong side of the frog with the other wheel of the pair engaged in the check rail.

The second is that the bogie is simply lifting up off the rails, that may indicate a lack of weight on the bogie, twists or bowing in the track, or some combination. A few models are particularly bad on the weight issue but not afaik the Britannia.

I have (1) Walthers diesel loco, "Norfolk Line", and it goes everywhere no problems whatsoever!

Short bogies with a lot of freedom to move on a heavy chassis will take all sorts of truely horrible track. American railroads use short bogies for the same reason - their trackwork is often dreadful.

Finally there is the Class 101 that I converted with the Tomix chassis, looks a bit odd but who cares!  It zips around like it's on holiday and is absolutely fantastic until it stops i.e. when I forget to change a point and then it needs a prompt to get it going again!

Does it stop because its not picking up power or because its sticking (ie drawing power). Did you add weight to it when you did the conversion ?

I find this most frustrating but is it anything unusual?

Initially no. Its one reason running a layout a fair bit before adding ballast is a good idea. Most of these problems can be fixed by being methodical and understanding that the track/wheel interface is a collection of quite precise properties and that combinations of out of tolerance bits tend to cause the derailments so show up the problem areas.

As you hunt them down not only do you fix the worst cases but you find the rest of the stock runs more reliably too.

Alan

[zwilnik]

Is the track ballasted btw? If so there's a chance you've got a tiny bit of ballast between the rail and guide rail in the points that's causing engines with different depth wheel flanges to jump a little. If not ballasted, possibly grit.

[Newportnobby]

I find this most frustrating but is it anything unusual?

Initially no. Its one reason running a layout a fair bit before adding ballast is a good idea. Most of these problems can be fixed by being methodical and understanding that the track/wheel interface is a collection of quite precise properties and that combinations of out of tolerance bits tend to cause the derailments so show up the problem areas.

As you hunt them down not only do you fix the worst cases but you find the rest of the stock runs more reliably too.

Alan

Thanks Alan. Another excuse reason for me playing testing trains goes into the memory bank (I wonder what's fallen out to make room )

[Bealman]

I shall ignore that above post because, although it's an open invitation to provide a smart answer, it is addressed to EP. 

Peter, having gone through all of the above, they are all sensible and helpful responses to your original query, but there is almost no getting around Murphy's. Some things just happen, well, because they do. As the above folk (airlines, and NASA also) promote, you can only go through a procedure of testing and troubleshooting until things operate to your satisfaction.

Example: when I first gave my Christmas gift from my daughters a run (by the way, did I tell you it was a Blue Pullman?  ), it ran perfectly up and down the branch on my layout from the terminus to the mainline (a not inconsiderable distance which involves a gradient and a very tight curve) several times without a hitch.

As soon as I invited one of the girls in to have a look at their hard earned cash performing like a champ, multiple derailments (not just the odd carriage but most of the train). Much grunting and  from yours truly - keep trying, stoic look on face.... same deal. Looked like a blue concertina on the hillside.

That was just shortly after Christmas. Gave it a run a couple of weeks ago.... no problems.

In summary, I think that the advice already given is sound.... like any mechanical operation, you try to test and make all possible troublespots as minimal as possible - but at the same time you can betcha there'll be a gremlin hiding somewhere!

George

[petercharlesfagg]

Example: when I first gave my Christmas gift from my daughters a run (by the way, did I tell you it was a Blue Pullman?  ), it ran perfectly up and down the branch on my layout from the terminus to the mainline (a not inconsiderable distance which involves a gradient and a very tight curve) several times without a hitch.

As soon as I invited one of the girls in to have a look at their hard earned cash performing like a champ, multiple derailments (not just the odd carriage but most of the train). Much grunting and  from yours truly - keep trying, stoic look on face.... same deal. Looked like a blue concertina on the hillside.
George

Yes, Sod's law strikes again!

I had thought that this might be the case but the sheer frustration of trying to get just ONE locomotive to run a full circuit without problems was defeating me, BTW, I have swept up the hair and shelved the idea of showing it running!

If they demand to see it I can push the things around!

Regards, Peter.

[petercharlesfagg]

Is the track ballasted btw? If so there's a chance you've got a tiny bit of ballast between the rail and guide rail in the points that's causing engines with different depth wheel flanges to jump a little. If not ballasted, possibly grit.

Thankyou for the reply, none of the track is ballasted as yet, I was attempting to get everything running BEFORE I tackle the ballast, at least I would know that it was operational!

It is just that relatives who have chipped in or given me items, MIGHT, want to see them in situ?

Regards, Peter.

[petercharlesfagg]

Lots of words and useful ideas!

Alan, Thankyou for a VERY comprehensive reply!

I have copied it to Word and will answer each section in turn when I have analysed and sorted more information relevant to your answers!

Regards, Peter.

[Bealman]

If they demand to see it I can push the things around!

Regards, Peter.

British N Gauge owes a lot of it's beginnings to Lone Star die-cast push-along metal locomotives and track. I owned heaps!

So don't worry if you have to push stuff, Peter.... as you probably know, the older we get, the more we have to push stuff uphill 

[petercharlesfagg]

So don't worry if you have to push stuff, Peter.... as you probably know, the older we get, the more we have to push stuff uphill

Its not the pushing that gets me its the getting up the hill on my own!