Derailment When Decoupling Fsa/fta Flats

Hi All,

I have created a scenario - Rugby Freight for the WCML South route which I published a couple of years ago. I've been trying to update this recently, and one of the updates is to decouple half the consist at Wembley yard before proceeding to Willesden. Unfortunately when I attempt to decouple the consist immediately derails. The error message says AI derailment even though its the player consist.

I've noticed other threads that discuss derailment when coupling, so I wondered if its an issue with the length of the flats in the config.

I've tried decoupling at the very start of the published scenario with the same results. Can anyone provide any guidance please that suggests why this is happening?

Thanks.

 

Are you uncoupling at a FSA to FSA connection?

 

Does the Scenario use these wagons or did you change them for the scenario?

 

Thanks for the replies, and apologies for the late response.

Gary Padley, the derailmant happens wherever I decouple.
749006 I included them when I created the scenario from scratch.

 

Maybe you did not place the wagons correctly?
Did you place the wagons from scratch or use TSTools or Locoswap to change them?

They should be FSA-FSA-FTA-FTA with the higher buffers of the FTA at the outer ends of each set.
Under normal circumstances you don't uncouple the FSA wagons as the buffers are too low

 

Thanks. Yeah I made sure they were coupled correctly. I will check my consist but it derails no matter where I decouple.

 

FSAs are the outer wagons Peter, the FTAs being the lower buffered type. Usually it's FSA-FTA (up to 4)-FSA as a semi=permanent "set" but there are mutterings that 5 or 6 FTAs have been seen as the "sandwich filler"

 

Welcome back Gary

 

A bad bit of typing on my part - as you say the FSA are at the outer ends and the FTA are the middle wagons