[dwb]

I was having a short running session for the first time in a few months. The temperatures in the loft have abated and as the evenings draw in, it's time to get back to some modelling once more. ESU might even manage to deliver their new ECoS to the shops which would be a great incentive to get moving too.

So I was only running two trains. One of these started to derail persistently when run at speed over a Peco code 100 medium radius crossing. It consisted of a Bachmann V2 coupled to a Bachmann Thompson coupled to a Hornby Pullman coupled to a Bachmann Mk1. The leading bogie of the Mk1 would consistently go astray over the crossing.

At first sight, nothing was obviously wrong but after a few "reruns" I came to this conclusion:-

About 3 feet before the crossing, the V2 stuttered due to poor electical contact. The shock of this stutter was communicated back down the train to the coupling between the Pullman and the Mk1. Both of these bogies have the elongating mechanism that allows these coaches to negotiate small radius set track curves. There appears to be enough "play" in these elongating mechanisms that the coupling on the Mk1 rides up onto the coupling of the Pullman. The front wheels of the Mk1's leading bogie are now suspended in the air at an angle to the track. They will now derail at the next obstruction in the four foot which is of course the crossing. Et voila - my own derailment disaster.

Fortunately The Northumbrian was not in the vicinity when the first derailment occurred.

So the moral of this story is - keep your track clean and loco wheels clean.

David

 

[5696Arethusa]

Or as an added precaution use the new Hornby couplings or similar. I got my first Bachmann Mk1s at the weekend, with my trackwork being laid around 15 years ago and mostly being Hornby I've stayed away from the latest generation rolling stock but with the construction of my brothers exhibition layout well underway we need to get some better quality rolling stock. Any way I got them out today and thought I'd try these new couplings, they're a bit tight for the mk1s but they have allowed me to run my Hornby 50 with some stock without it dragging the lead coach of the line. In the rake I used the Bachmann supplied vacuum pipes to couple the coaches, beautiful close coupling and no slack between the coaches, I'm totally sold on these new couplings now all I need to do is fit NEM pockets to all the locos not fitted, any recommendations as to which is the best way to do this?
Arethusa

 

[dwb]

Interesting comment. In the long term I plan to change to Kadees for the ends of coaching rakes. Sounds like changing to permanent couplings within the rakes would be a good move.

What is your minimum radius? My smallest is about 2 feet.

David

 

[5696Arethusa]

I really tried to keep away from 1st radius but with the space constraints I have I was unable completely avoid them, I have 22.5 degrees on one part a 45 degrees on another, the coaches go round as do all the new locos I have that say they're not suitable for 1st radius, though I'd try to avoid them in longer runs as I think the reason I get away with it is because they are only for such short lengths.
Incidently the only locos that do have a problem and really don't like 1st radius are my Mainline and Bachmann LMS 4-6-0s and Lord Nelson class, the rear wheels foul the cylinder block and lift the front wheel of the rails.
Arethusa

 

[dwb]

Thanks for the info. I will definitely try the Bachmann close couplers as you have suggested. I just to need to buy some more eastern region blood and custard Mk1s.

David

 

[5696Arethusa]

The Mk1s I have are the latest 39-xxx versions I don't know if the older ones have the close coupling system just thought I'd add that as I just got off the phone with my brother and was explaining what I'd done. Now if I can get some more of these vac pipe couplings I may give the latest Hornby Gresleys a go.
Arethusa

 

[neil_s_wood]

I have some Branchline American coaches which I built from kits and they derail at every available opportunity. The problem seems to be that the couplers, Kadees, are fastened to the body rather than the bogie as with Hornby and Bachmann coaches. Because they are quite long they really need a very wide radius to go round. I currently have them going round a 90 cm radius and it seems that is still not enough. Any suggestions?