Rogue coaches!

petercharlesfagg · May 01, 2013, 07:27:20 PM

Friends,
As you are aware I have been overhauling (

early Pullman coaches.

I have washed them, fitted new bogies and new wheels, repaired the cracks and repainted.

Running them reveals that one coach has a mind of it's own!

No matter where it is placed in the rake it derails or causes the one behind to jump the tracks. It makes no difference if it is straight, curved or points or crossings, it causes havoc!

I have checked the bogies against a straight edge, removed and replaced the new wheels with other new wheels and generally given this coach the 3rd. degree!

Is this an unusual phenomena or am I just unlucky?

Regards, Peter.

H · May 01, 2013, 07:47:55 PM

It's not usual.

There will be a reason for it's errant behaviour - but you just haven't yet found and erradicated it.

H.

scotsoft · May 01, 2013, 07:58:59 PM

Have you checked the gaps between the wheels Peter?
You would need a back to back gauge for this.

cheers John.

petercharlesfagg · May 02, 2013, 08:30:46 AM

Quote from: scotsoft on May 01, 2013, 07:58:59 PM
Have you checked the gaps between the wheels Peter?
You would need a back to back gauge for this.

cheers John.

John, no I haven't checked but then I thought that I shouldn't need to because they were all new from our friend Bob Russell.

I did try putting another set into the bogies but it made no difference and the bogies and coach that they came out from runs sweetly.

I have tried a straight edge against the main body and it has an ever so slight twist.

I tried it on its own without locomotive or other stock it runs perfectly! Which sets me thinking that it must be one or all of the others that upset its running!

If I cannot find the cause I will leave the train at 7 coaches, 1 GUV and hope for the best.

Regards, Peter.

Belated · May 02, 2013, 10:18:27 AM

Hi Peter,

I've had a few problems of that sort, lol. Usually blamed my track-laying until it was exonerated because nothing else misbehaved at the same point.

Sounds like you've checked most things; changing wheels sets should eliminate back to back of wheels, wheels not square on axles (I've had this); did you say you'd changed the bogies or only the wheels? Worn sockets or misaligned sockets for pin-point axles can cause derailments.

The other possiblilty is the couplings. If the coupling makes the coach ride 'up', this is hard to spot and not always easy to cure.

You mentioned a slight twist against a straight edge for the body - trying the old trick of running the coach across a sheet of glass and see if it runs true. A twisted chassis will give problems.

Best of luck, let us know what you find, I'm sure others will know more than me.

John

petercharlesfagg · May 02, 2013, 10:34:45 AM

Quote from: Only Me on May 02, 2013, 08:34:09 AM
Hi Peter,

Could it be that said coach has a weight in it somewhere added by a previous owner which is unbalancing it ?

I ask because I have a few coaches I have weighted myself and found that strange things occur if the weight is not central..

Paul

Paul, Thankyou for the thought, as I stated earlier I have completely disassembled the coaches and washed them so any weighting would have been seen.

There was none.

Cannot weight them now since I have glued the roofs in place, didn't think it was necessary!

Anyway, I could place Blu-tack underneath, could try that!!!

regards, Peter.

petercharlesfagg · May 02, 2013, 10:39:32 AM

Quote from: Belated on May 02, 2013, 10:18:27 AM
Sounds like you've checked most things; changing wheels sets should eliminate back to back of wheels, wheels not square on axles (I've had this); did you say you'd changed the bogies or only the wheels? Worn sockets or misaligned sockets for pin-point axles can cause derailments.

The other possiblilty is the couplings. If the coupling makes the coach ride 'up', this is hard to spot and not always easy to cure.

You mentioned a slight twist against a straight edge for the body - trying the old trick of running the coach across a sheet of glass and see if it runs true. A twisted chassis will give problems.

Best of luck, let us know what you find, I'm sure others will know more than me.

John

John, thankyou for a very comprehensive reply.

New bogies, new wheels (Metal).

Couplings is something that hadn't crossed my mind, I do have a height gauge but it is the wearing of magnifying lenses and getting close enough gives me a literal pain in the neck!

Tried the sheet of glass, ran true and nearly straight BUT broke the sheet of glass, dropped it!

Photographs WILL follow!

regards, Peter.

silly moo · May 02, 2013, 04:50:50 PM

I have a rake of older GF Pullmans and also experienced derailing until I added weight to the bottom centre of each coach. There's a box dead centre of the undercarriage framework (no idea what it is or what it's called, possibly it's a battery?) but it's a handy place for adding weight as you want the weight to be as low down as possible. I used small pieces of lead but you could experiment with Blu tack.

Regards

Veronica.

H · May 02, 2013, 05:48:02 PM

Changing wheelsets won't necessarily eliminate any B-t-B issues. They can be wrong from new. Always check and correctly set them when installing as new and when servicing stock.

Check for concentricity.

Check there is no wobble on the axle.

Check the treads and flanges for damage or any lumps.

Check the axles aren't bent.

Check the axle end pin points seat properly in the bogies.

Check the bogies are square and flat.

Check they rotate freely and don't foul anything on the pivot point.

etc.

Get you eye down to where they derail and wacth carefuly as they pass slowly by. Check everything until you find the problem.

H.

petercharlesfagg · May 06, 2013, 07:31:52 PM

My sincere thanks to everyone who has contributed.

Having experimented I find that the addition of just a little extra weight makes all the difference! (Qty. unknown unless a bit of Blue tack with embedded fishing weights is acceptable)
Made the coach look as if it had mumps!!!

Anyway, reasonable success, I am just waiting for the sticky backed lead strip to arrive.

Regards, Peter.

EddieA · May 06, 2013, 08:23:20 PM

Hi

Is it possible to slightly loosen off the pivots holding the bogies to the chassis'?

If the chassis is a bit twisted the free play might solve your problems.

Regards
Eddie

petercharlesfagg · May 07, 2013, 06:33:35 AM

Quote from: EddieA on May 06, 2013, 08:23:20 PM
Hi

Is it possible to slightly loosen off the pivots holding the bogies to the chassis'?

If the chassis is a bit twisted the free play might solve your problems.

Regards
Eddie

Eddie,
Thankyou for the thought, it was one of the things I did right at the beginning thinking that the new bogies might be a little tight on their pivots!

Regards, Peter.