co-co derailing

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co-co derailing

Postby 4472 » Tue Nov 26, 2019 4:25 pm

On my outer loop I have some flexitrack with a join on a bend. I cannot change the track. I have a class 60 diesel that when it goes over the join one set of wheels on each bogie derail. It is the only diesel I have and all my steam locos traverse the join ok. By eye I can see that the join is not a completely smooth curve. Would I have a better chance of not derailing is I used a bo-bo diesel.
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Re: co-co derailing

Postby Bigmet » Tue Nov 26, 2019 11:07 pm

I would aim to reprofile the curve at the joint, so the curve is smooth and continuous. It will find the more track sensitive locos and vehicles to derail if left uncorrected.

You may be able to get the class 60 to work, check that the bogies are free to pivot sufficiently and are also able to rock a little.

Probably a BoBo will be less sensitive to this track joint, but this is not guaranteed.

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Re: co-co derailing

Postby Bufferstop » Tue Nov 26, 2019 11:30 pm

You say you cannot change the track, I presume it's stuck down and ballasted. There is a way to do it which will move the joint. You'll need a Dremel or similar with a cutting disc as track cutters won't give a clean enough end. Cut the outer rail 100mm or so from the other end to the bad joint, take out that bit of rail, and slide the rail along to close up the gap, moving the joint along away from the join in the sleeper bases, you may have to remove one or two of the rail fixings around the area of the joint. Transfer the cut piece to the other end of the two sections of track. If you remove all of the outside fixings of the rail in the gap you can fit it into place with fishplates slid onto the rail then push them outwards to fix it in place. Use some Peco track pins to replace the cut of fixings, snip them off just above the bottom flange of the rail and crimp them over using a pair of pliers. Repeat the operation for the other rail only moving it in the opposite direction.
If you look at a joint in flexi track and say it'll do, it won't, it will come back and bite you when you think you've got away with it. How do you think I know how to repair one :oops:

PS A roller track gauge is useful for jobs like this, two of them are even better.
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Re: co-co derailing

Postby DonB » Thu Nov 28, 2019 1:21 am

Is your Class 60 a Lima one?

I had a similar problem a while back with one of mine (strangely, my other 60s were OK); turns out there was a very pronounced moulding 'gate' and seam on each end of the bogie that was interfering with bogie swing.

A little treatment with a modelling knife, file, and P1000 and it works fine now. As a result, I now check and rectify where required, every Lima diesel that I buy.

But, as others have said, check your track too.



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Re: co-co derailing

Postby Forfarian » Thu Nov 28, 2019 7:59 am

I had this problem of a join in the middle of a curve, I'm afraid for smooth running you will have to bite the bullet and replace that section of track to eliminate the join as i did! A mtr of flexi can normally solve the problem. :D
The other option is to push the track into the correct radius, hold it in position and solder the join, its a temporary measure, but it does work.
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Re: co-co derailing

Postby SRman » Thu Nov 28, 2019 10:39 am

When joining two lengths of flexi-track on a curve, I always tweak the rail ends with a pair of pliers to put a permanent bend just in the rail ends to smooth the transition from one piece to the next. You might still be able to do this even with the track fixed down.

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Re: co-co derailing

Postby 4472 » Thu Nov 28, 2019 10:24 pm

Thanks for the replies. I am not able to relay the track, so as all the other rolling stock navigates the bend with no problem I think I will retire the diesel and stick with steam locos and a couple of dmu/emu's. Bit of a cop-out but heyho !!
Great grandson of Peter Benjamin Spicer (LNWR retired)

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