This collection is called the "Train Collection" in the game, which makes two collections with the same name. The word "Upgrades" is added here to distinguish the two.
The Train Upgrades Collection is a Collection in CityVille that contains items which can be acquired by clicking on your Friends' wall post that asks for help with the stops, when they send Trains. Turning in this collection rewards you with the Golden Grain Elevator The collection becomes available once you have upgraded your station during the 
Upgrade Your Train goal.
There is a chance of acquiring these collectibles by putting them on your wishlist and either opening a Mystery Gift or clicking a neighbor's train wall post.
| Collectibles | Trade in Reward | ||||
|
|
|
|
|
|
| Golden Ticket | Train Door | Railway Spike | Conductor Whistle | Train Seat | Golden Grain Elevator |