[Guest]

Having coaches of various makes ie: TT? Lima & Hornby. Has anyone any ideas on how to avoid this condition.
Anything smaller than the largest curves and they buffer lock and derail. I know it would not look correct, but are longer couplings available and if so from where? They are the flat pressed metal type , not the 'pocket'

 

[pedromorgan]

I think you are having another problem here and you are confusing it with buffer lock. you should only get buffer lock on very tight curves and not at all with the pressed steel couplings that you are using.
With the pressed steel couplings the coaches are always kept sloghtly apart and should never come close enough to touch let alone buffer lock.

Check the height of the couplings. it may well be the case that one is actually riding over the top of the other one. to solve this, pick one coach and bend all the others to match.

Buffer lock is normally a problem for finescale modellers with screw or 3 link couplings.

Hope this helps

Peter