Within minutes, they had their equipment packed. They were off!

Combined sentence: Within minutes, they had their equipment packed and were off!
Does the combined sentence use a compound subject, compound verb, or
compound object?

3 answers

Please see my answer below.
It's a compound sentence, so has two subjects and two verbs. As written, the subject of the second clause is implied, but is "they". This sentence or sentences has/have no direct object. There is, however, a misplaced modifier.
Sorry, that is not all correct. "equipment" is the direct object of the verb "packed".