OK, when making a hornsound for trainz, a file will consist of these parts:
1. horn =the complete hornsound clip
2. horn_loop = this will be the edited part of the horn that will replay when the horn key is held
3. horn_ start =this will be the part of the horn before the looped section, this will typically be the beginning of the horn, and will not loop in the game
4. idle =this is the bell sound file, and will loop in the game
<all the files above are wav. files, and when put into the folder of the hornsound asset in TRAINZ, should use those exact names>
to open the folder for your hornsound asset in TRAINZ, right click on the asset, and select the "edit in explorer" option under edit. this will open the assets file, and allow you to add content