The crew was used to it. They’d been on shakedown cruises before, and they knew that on an interstellar vessel the word “shakedown” can have a very literal meaning. The beat note wasn’t dangerous, but it wasn’t pleasant, either.
Within five minutes everybody aboard had the galloping collywobbles and the twittering jitters.
Mike and his power crew all knew what to do. They took their stations and started to work. They had barely started when Captain Quill’s voice came over the intercom.
“Power Section, this is the bridge. How long before we stop this beat note?”
“No way of telling, sir,” said Mike, without taking his eyes off the meter bank. “Check A-77,” he muttered in an aside to Multhaus.
“Can you give me a prognosis?” persisted Quill.
Mike frowned. This wasn’t like Black Bart. He knew what the prognosis was as well as Mike did. “Actually, sir, there’s no way of knowing. The old Gainsway shook like this for eight days before they spotted the tubes that were causing a four-cycle beat.”
“Why can’t we spot it right off?” Quill asked.
Mike got it then. Fitzhugh was listening in. Quill wanted Mike the Angel to substantiate his own statements to the roboticist.
“There are sixteen generator tubes in the hull—two at each end of the four diagonals of an imaginary cube surrounding the ship. At least two of them are out of phase; that means that every one of them may have to be balanced against every other one, and that would make a hundred and twenty checks. It will take ten minutes if we hit it lucky and find the bad tubes in the first two tries, and about twenty hours if we hit on the last try.