Unchecked assignment for 'java.util.ArrayList'

You want new ArrayList<>(); so that you use the right generic type. At the moment you're using the raw type on the right hand side of =. So you want:

private ArrayList<LocoList> myLocations = new ArrayList<>();

Or just be explicit:

private ArrayList<LocoList> myLocations = new ArrayList<LocoList>();

(You might also consider making the type of the variable List<LocoList> instead of ArrayList<LocoList>, unless you're using ArrayList-specific members. I'd also ditch the "my" prefix, personally.)