Loading truck trailers on to trains

[boleyd]

I have tried two assets to load trucks to trains but no go.
I have a yellow straddle crane with inputs for the train and two for tracks I guess it is supposed to ride on. There is another an that may be for a truck/road. Is there any explanation and suggestions on how to use this?

 

[cascaderailroad]

The railcars must have the trailers kuid in the config file as one of the possible loads