A rail vehicle in Train Sim World always consists of at least two Blueprint inheriting from the RailVehicle (also referred to as 'Rail Vehicle Model' or RVM for short) and RailVehicleView (RVV for short) class each.
The terms 'model' and 'view' might ring a bell or two for programmers who worked with the model-view-controller 'MVC' design pattern before. In TSW though the controller's tasks are also taken care of by the model.
The RVM actor of a rail vehicle is never destroyed while playing on a route and is constructed while loading a route, even when currently stored in the vault. It hosts the SimuGraph simulation component, service components, VHID model compoents, and in general stores data that should persist even when RVVs are destroyed.
The RVV actor handles both the visuals and the interactions with the 3D world of a rail vehicle.
The RVV is also fully destroyed when at a sufficient distance from the player camera or when the train is in the vault.
Optionally so called AdditionalViewActorAssets can be defined in the RailVehicleDefinition data asset which are spawned and destroyed alongside the usual RVV.
A common use case for these is for handling audio in a seperate 'Rail Vehicle Audio' (RVA) actor.