Problem at the yellow mine digger

[Thomas]

hmm... k - i'm not near as far along with this puzzle as i thought - didn't know i needed gas for it, so i'm kindof sad i read that spoiler. I've been stuck looking for the key for over an hour, and wouldn't mind a spoiler to tell me where to find the key. spoil carefully please!

Where you find a crane you might find key. Symbol might show you locations.

Was that careful enough?