Board Thread:Questions and Answers/@comment-99.126.74.115-20150810203444/@comment-26518423-20150819025536

Yes, the special/vintage often cost gems, but they are not essential to completing any task. You'll also note that when you purchase a large loco, a set is often available w/o spending additional gems.

It will take longer to complete a task w/o spending gems, but every challenge and contract has a way of being completed, either with coins or collecting items from previous contracts. That sets this game apart from so many on Facebook.