Hornby TTS class 47 derailing

[125_driver]

I have a problem with 2 separate TTS 47s. Both seem to derail , but only when hauling stock and only when the driven bogie is trailing (ie next to the stock). 

It is not an issue light engine or if the driven bogie is leading. The problem is inflicting 2 locos which leads me to think it's some sort of design fault which may be correctable as I have a couple more Hornby 47 tts which run normally.

 

Anyone else experienced this or know a possible fix??

[Graham108]

53 minutes ago, 125_driver said:

I have a problem with 2 separate TTS 47s. Both seem to derail , but only when hauling stock and only when the driven bogie is trailing (ie next to the stock). 

It is not an issue light engine or if the driven bogie is leading. The problem is inflicting 2 locos which leads me to think it's some sort of design fault which may be correctable as I have a couple more Hornby 47 tts which run normally.

 

Anyone else experienced this or know a possible fix??

You don't say where the derailment takes place - on the straight, curves or through points.

 

I have problems with older locos having the large couplings, when pulling modern wagons with the smaller couplings - there's not enough 'swing' on the loco bogie on curves so either the loco or the first wagon derails.

[Guest Half-full]

1 hour ago, 125_driver said:

I have a problem with 2 separate TTS 47s. Both seem to derail , but only when hauling stock and only when the driven bogie is trailing (ie next to the stock). 

It is not an issue light engine or if the driven bogie is leading. The problem is inflicting 2 locos which leads me to think it's some sort of design fault which may be correctable as I have a couple more Hornby 47 tts which run normally.

 

Anyone else experienced this or know a possible fix??

Check the back to backs on the wheelsets, the weight of the stock can lift the bogies ever so slightly, but enough to take any pressure off the axles, which can let them wander and strike the blades of points if the B2B's are out.  

 

A little bit of extra weight over the centre of the chassis can help this too

[125_driver]

Just to clarify it is always on curves. I shall look at the suggestions you have made and will report back, thanks. 

[Hroth]

Something I experienced with the first TTS class 47 was that the loco would go round a curve with one end leading, and derail if the other end led.  It seemed that the motor bogie was fouling part of the chassis/bodyshell in one direction and not turning sufficiently.  Pop the body off and run it around curves in both directions, see if there's any fouling.